Short-term Symptom Aggravation after Cubital Tunnel Decompression: Clinical Features and Mechanistic Insights from a Retrospective Cohort Study

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The underlying mechanisms remain poorly understood. Methods We retrospectively analyzed 127 patients who underwent anterior ulnar nerve transposition without corticosteroids. Clinical scores (VAS, PRUNE, two-point discrimination) and electrophysiological parameters (CMAP, SNCV, MNCV) were assessed preoperatively, at 2 weeks, and at 6 months. Early worsening was defined as deterioration in any clinical indicator at 2 weeks. Results At 6 months, most patients improved significantly. However, 26.8% showed early worsening at 2 weeks, with elevated PRUNE scores, reduced sensory discrimination, and declines in CMAP, SNCV, and MNCV (all p < 0.001). These changes resolved spontaneously without surgical failure. Likely contributors include inflammatory edema, mechanical stress, transient ischemia, and central sensitization. Conclusions Early postoperative worsening affects over one-quarter of CuTS patients but is typically self-limiting. Awareness of this pattern can prevent misdiagnosis, reduce unnecessary interventions, and improve patient counseling. Future research should identify predictive markers and develop mitigation strategies. Cubital tunnel syndrome ulnar nerve early symptom worsening decompression surgery nerve conduction postoperative recovery Figures Figure 1 Figure 2 Figure 3 Introduction Cubital tunnel syndrome (CuTS) is the second most prevalent peripheral nerve compression disorder of the upper extremity, primarily resulting from chronic compression of the ulnar nerve at the elbow 1 – 3 . Clinically, it manifests as numbness, pain, and impaired hand function. Surgical decompression or anterior transposition of the ulnar nerve is widely regarded as an effective treatment, offering substantial symptom relief and functional improvement in most patients 4 , 5 . However, clinical experience has shown that a subset of patients may develop transient recurrence or worsening of symptoms in the early postoperative period, typically within the first two weeks following surgery 6 , 7 . These aggravations are characterized by intensified numbness, increased pain, diminished two-point discrimination, and temporary deterioration in electrophysiological parameters as assessed by electromyography (EMG) 8 .Notably, such symptom flare-ups usually occur in the absence of overt surgical complications such as infection or direct nerve injury. Fortunately, they tend to resolve spontaneously, with reported incidence ranging from 15–30% in previous studies on peripheral nerve decompression 9 , 10 . Similar short-term exacerbations have also been reported following decompression for other entrapment neuropathies.Ejiri observed temporary worsening of nerve conduction and clinical symptoms after carpal tunnel release, suggesting intraoperative nerve manipulation as a contributing factor 11 .Likewise, Ido reported early symptom aggravation and electrophysiological decline after ulnar nerve anterior transposition, attributing it to mechanical stress and positional adaptation of the nerve 12 , 13 . Although increasing attention has been paid to this phenomenon, its underlying mechanisms remain poorly understood. Proposed explanations include postoperative neural edema and inflammatory responses, mechanical stress related to nerve transposition, postoperative hyperexcitability and central disinhibition, and microvascular ischemia 14 , 15 .However, these remain hypothetical, and robust clinical evidence is lacking.Moreover, no unified explanatory framework currently exists to connect these diverse mechanisms with observed clinical trajectories, limiting opportunities for perioperative intervention. Given the potential impact of early postoperative symptom aggravation on patient perception and satisfaction,it is essential to clarify its clinical characteristics and explore underlying mechanisms.A mechanistic understanding of this phenomenon could inform predictive risk models, improve perioperative counseling, and support the development of targeted strategies to mitigate early symptom flare-ups.Repeated clinical observations of transient symptom rebound following CuTS decompression—despite successful surgical release—highlighted a poorly understood but potentially meaningful postoperative pattern. Motivated by this real-world phenomenon, we conducted a clinically driven investigation to define its short-term clinical and electrophysiological characteristics and explore plausible underlying mechanisms. The aim is to generate actionable insights that may inform preoperative counseling, early postoperative monitoring, and recovery pathway optimization. Methods This retrospective cohort study was conducted at the First Affiliated Hospital of Anhui Medical University between August 2018 and August 2024. All procedures adhered to institutional ethical guidelines and received approval from the hospital’s ethics committee. Clinical data, surgical records, and follow-up information were retrieved from the hospital’s electronic medical record (EMR) system. Patient Selection A total of 182 patients diagnosed with cubital tunnel syndrome (CuTS) were initially screened for eligibility.55 patients who received intraoperative corticosteroid injections were excluded to eliminate pharmacological confounding.The final study population included 127 patients who underwent standardized anterior ulnar nerve transposition without steroid use and completed scheduled follow-up assessments. Inclusion and Exclusion Criteria Inclusion criteria were as follows: patients aged 18 to 75 years with a diagnosis of CuTS and clinical indications for surgery; symptoms persisting for more than 3 months despite conservative treatment; no previous history of ulnar nerve surgery; no systemic corticosteroid use within 3 months prior to surgery; and complete clinical and electrophysiological data available at all designated time points. Patients were excluded if they presented with significant elbow joint deformities, systemic neurologic conditions, contraindications to surgery or electrical stimulation testing, pregnancy or lactation, presence of a pacemaker, or incomplete postoperative follow-up. Surgical Procedure All procedures were performed under general anesthesia or brachial plexus nerve block. Patients were placed in the supine position with the affected limb externally rotated and abducted on an arm table. A pneumatic tourniquet was applied to the proximal upper arm to establish a bloodless field. After confirming adequate anesthesia, a 10 cm curvilinear incision was made along the medial aspect of the elbow, centered over the ulnar nerve and positioned posterior to the medial epicondyle(Fig. 1 a). Subcutaneous tissues were dissected to expose the deep fascia and Osborne’s ligament. The ligament was incised longitudinally along its ulnar edge and reflected anteriorly(Fig. 1 b). The ulnar nerve was then carefully identified and isolated under loupe magnification. Complete decompression was performed using microsurgical instruments, extending from approximately 8 cm proximal to 6 cm distal to the medial epicondyle. All potential entrapment sites were released, including the arcade of Struthers, Osborne’s fascia, the intermuscular septum, and fascial bands within the flexor carpi ulnaris (FCU)(Fig. 1 c). The epineurium and intraneural blood supply were preserved throughout the procedure. The medial antebrachial cutaneous nerve and adjacent vasculature were identified and protected. After decompression, the ulnar nerve was transposed anteriorly to a subfascial position anterior to the medial epicondyle(Fig. 1 d). A 3 × 3 cm fascial flap was harvested from the flexor–pronator fascia and sutured loosely over the transposed nerve to ensure a tension-free position and prevent posterior subluxation(Fig. 1 e) 16 , 17 . Elbow flexion and extension were passively performed intraoperatively to confirm smooth nerve gliding. After hemostasis and irrigation, a drainage strip was placed. The wound was closed in layers using absorbable sutures for deep tissues and interrupted non-absorbable sutures for the skin. The elbow was immobilized in a posterior plaster splint at approximately 60° of flexion(Fig. 1 f). Postoperative Management All patients were immobilized in a plaster splint for early postoperative protection. Wound dressings were changed regularly, and sutures were removed on postoperative day 12. Patients were followed up at 2 weeks and at 6 months after surgery. Clinical and electrophysiological evaluations were performed at each time point to assess ulnar nerve function and symptom progression. Outcome Measures Clinical assessments were conducted at three key time points: preoperatively, 2 weeks postoperatively, and 6 months postoperatively. Pain severity was evaluated using the Visual Analog Scale (VAS), with scores ranging from 0 (no pain) to 10 (worst possible pain). The Patient-Rated Ulnar Nerve Evaluation (PRUNE) was used to measure subjective symptoms such as tingling, numbness, hand weakness, and activity limitations, with higher scores indicating more severe impairment. Sensory function was assessed using two-point discrimination testing in the ulnar nerve distribution area. Electrophysiological function was evaluated using surface electromyography (EMG). The parameters measured included compound muscle action potential (CMAP), sensory nerve conduction velocity (SNCV), and motor nerve conduction velocity (MNCV). For patients who reported early postoperative symptom aggravation, additional EMG testing was performed during the early recovery period to monitor neural function and confirm transient decline. Definition of Early Symptom Aggravation Early symptom aggravation was defined as any measurable deterioration in clinical or electrophysiological indicators at the 2-week postoperative follow-up compared to baseline. Specifically, patients were classified into the early aggravation subgroup if they exhibited an increased PRUNE score, worsened two-point discrimination threshold, or sustained/increased VAS score at 2 weeks relative to their preoperative status. This subgroup classification was used for comparative analysis. Statistical Analysis All statistical analyses were conducted using Python version 3.9.7. Continuous variables were expressed as means with standard deviations. Normality of data distribution was assessed using the Shapiro–Wilk test. For variables with normal distribution, paired-sample z-tests were applied to evaluate differences between preoperative and postoperative measurements. For non-normally distributed variables or small sample sizes, the Wilcoxon signed-rank test was used. Statistical significance was defined as a two-sided p-value less than 0.05. Analytical comparisons were performed in two phases: first, evaluating preoperative versus 6-month outcomes for the overall cohort; second, analyzing short-term changes at 2 weeks in the subgroup with early symptom aggravation. Result A total of 127 patients who met the inclusion criteria were included in the final analysis. The mean age of the cohort was 52.86 ± 13.78 years, with a mean disease duration of 1.83 ± 2.85 years and a mean body mass index (BMI) of 23.87 ± 3.17 kg/m². Among them, 26.77% had left-sided involvement, 67.71% had right-sided involvement, and 5.51% presented with bilateral symptoms. Based on McGowan grading, 18.11% were classified as grade I, 26.77% as grade II, and 55.11% as grade III (Table 1 ). Table 1 Baseline Characteristics of Patients with Cubital Tunnel Syndrome Group Age(year)( \(\:\stackrel{-}{x}\pm\:s\) ) Course of disease(year)( \(\:\stackrel{-}{x}\pm\:s\) ) BMI(kg/m²)( \(\:\stackrel{-}{x}\pm\:s\) ) Left or right hand (%) McGowan (%) left right both Ⅰ Ⅱ Ⅲ All Patiences 52.86 ± 13.78 1.83 ± 2.85 23.87 ± 3.17 26.77 67.71 5.51 18.11 26.77 55.11 Aggravation Group 56.42 ± 12.14 4.03 ± 3.92 24.00 ± 3.18 26.47 67.64 5.88 0 23.52 76.47 At the six-month follow-up, patients demonstrated statistically significant improvement in both clinical and electrophysiological outcomes. CMAP increased from 1.79 ± 0.38 mV preoperatively to 5.70 ± 0.76 mV (p = 0.0006), SNCV improved from 32.49 ± 6.41 m/s to 48.04 ± 5.22 m/s (p = 0.0004), and MNCV rose from 32.92 ± 6.32 m/s to 48.20 ± 4.74 m/s (p = 0.0003). Correspondingly, VAS scores decreased from 4.61 ± 1.01 to 2.22 ± 1.16 (p = 0.0005), PRUNE scores dropped from 50.91 ± 10.04 to 30.08 ± 6.82 (p = 0.0006), and two-point discrimination improved from 8.87 ± 1.89 mm to 5.80 ± 1.89 mm (p = 0.0032) (Table 2 ; Fig. 3 ). Table 2 Comparison of Electrophysiological and Clinical Outcomes Before and Six Months After Surgery in All Patients( \(\:\stackrel{-}{x}\pm\:s\) )༈α=0.05༉ CMAP(mV) SNCV(m/s) MNCV(m/s) VAS PRUNE Two-Point Discrimination(mm) Pre-op 1.79 ± 0.38 32.49 ± 6.41 32.92 ± 6.32 4.61 ± 1.01 50.91 ± 10.04 8.87 ± 1.89 post-op(6M) 5.70 ± 0.76 48.04 ± 5.22 48.20 ± 4.74 2.22 ± 1.16 30.08 ± 6.82 5.80 ± 1.89 Z value −48.75 −20.06 −20.61 16.50 18.30 12.24 p value 0.0006 0.0004 0.0003 0.0005 0.0006 0.0032 Pre-op: Preoperative;Post-op(6M)༚Postoperative(6 month);VAS༚Visual Analog Scale༛PRUNE༚Patient-Rated Ulnar Nerve Evaluation༛CMAP༚Compound Muscle Action Potential༛ SNCV ༚Sensory Nerve Conduction Velocity༛MNCV༚Motor Nerve Conduction Velocity༛ In the short-term postoperative assessment at 2 weeks, modest improvements were noted in most clinical indicators. VAS scores decreased slightly to 3.89 ± 1.10 (p = 0.038), PRUNE scores decreased to 46.86 ± 10.35 (p = 0.0027), and two-point discrimination improved marginally to 8.33 ± 2.24 mm (p = 0.047). However, these early results exhibited a wider standard deviation, indicating substantial inter-individual variability in early recovery trajectories (Table 3 ; Fig. 2 ). Table 3 Comparison of Preoperative and Short-Term VAS, PRUNE Scores, and Two-Point Discrimination in All Patients()༈α=0.05༉ VAS PRUNE Two-Point Discrimination(mm) pre-op 4.61 ± 1.01 50.91 ± 10.04 8.87 ± 1.89 post-op(6M) 3.89 ± 1.10 46.86 ± 10.35 8.33 ± 2.24 Z value 5.10 2.99 1.97 p value 0.038 0.0027 0.047 Pre-op: Preoperative;Post-op(6M)༚Postoperative(6 month);VAS༚Visual Analog Scale༛PRUNE༚Patient-Rated Ulnar Nerve Evaluation༛ Due to this variability, patients were stratified post hoc based on early postoperative symptom trajectory. A subset of 34 patients (26.8%) who demonstrated clinical deterioration at 2 weeks postoperatively was classified into the symptom aggravation group. Baseline characteristics of this subgroup included a longer disease duration (4.03 ± 3.92 years) and a higher prevalence of McGowan grade III (76.47%), suggestive of more advanced disease at presentation (Table 1 ). In the symptom aggravation subgroup, clinical scores demonstrated a paradoxical deterioration during the early postoperative phase. PRUNE scores increased from 51.96 ± 9.80 to 53.66 ± 9.27 (p = 0.0003), indicating a perceived worsening of symptoms. Two-point discrimination worsened from 9.69 ± 1.07 mm to 10.75 ± 1.27 mm (p = 0.0002), suggesting reduced sensory acuity. VAS scores, however, showed only a modest decline from 4.57 ± 1.00 to 4.21 ± 1.21 (p = 0.0186), indicating that subjective pain perception remained relatively stable during this early interval (Table 4 ). Table 4 Comparison of Preoperative and Short-Term VAS, PRUNE, and Two-Point Discrimination in Patients with Symptom Aggravation()༈α=0.05༉ VAS PRUNE Two-Point Discrimination(mm) pre 4.57 ± 1.00 51.96 ± 9.80 9.69 ± 1.07 post(short-term) 4.21 ± 1.21 53.66 ± 9.27 10.75 ± 1.27 S-W-p 0.0073/0.0588 0.4635/0.5421 0.0002/0.0033 SRT-p 0.0186 0.0003 0.0002 Pre-op: Preoperative;Post-op(short-term)༚Postoperative(short-term);VAS༚Visual Analog Scale༛PRUNE༚Patient-Rated Ulnar Nerve Evaluation༛ Electrophysiological testing in the same subgroup revealed statistically significant declines across all recorded parameters. CMAP decreased from 1.77 ± 0.38 mV preoperatively to 1.29 ± 0.28 mV (p = 0.0002), SNCV dropped from 33.08 ± 6.18 m/s to 29.58 ± 5.55 m/s (p = 0.0002), and MNCV fell from 32.83 ± 5.56 m/s to 26.41 ± 4.62 m/s (p = 0.0002). These results reflect a measurable yet transient impairment in nerve conduction during the early postoperative recovery window (Table 5 ). Table 5 Comparison of Preoperative and Short-Term CMAP, SNCV, and MNCV in Patients with Symptom Aggravation()༈α=0.05༉ CAMP SNCV MNCV pre 1.77 ± 0.38 33.08 ± 6.18 32.83 ± 5.56 post(short-term) 1.29 ± 0.28 29.58 ± 5.55 26.41 ± 4.62 S-W-p 0.3893/0.1168 0.2901/0.3673 0.5611/0.6112 SRT-p 0.0002 0.0002 0.0002 Pre-op: Preoperative;Post-op(short-term)༚Postoperative(short-term);CMAP༚Compound Muscle Action Potential༛ SNCV ༚Sensory Nerve Conduction Velocity༛MNCV༚Motor Nerve Conduction Velocity༛ Taken together, these findings confirm the presence of a distinct early symptom aggravation pattern affecting approximately one-quarter of patients. This subgroup displayed both subjective and objective deterioration in the absence of structural failure or surgical complication, with indicators subsequently improving over time as part of a reversible recovery phase. Discussion This study confirms the presence of a reproducible pattern of early postoperative worsening in approximately one-quarter of patients undergoing anterior ulnar nerve transposition for cubital tunnel syndrome. Although the majority of patients demonstrated progressive improvement in both clinical and electrophysiological indicators, a subset exhibited transient aggravation of symptoms within the first two weeks after surgery 18 .This phenomenon manifested as increased subjective burden—reflected by higher PRUNE scores and worsened two-point discrimination—as well as measurable reductions in CMAP, SNCV, and MNCV 19 . Importantly, these deteriorations resolved spontaneously over time, with no indication of structural failure or need for revision, underscoring the reversible nature of this recovery phase 20 . Similar patterns of early symptom exacerbation have been described in previous studies of peripheral nerve decompression 20 .Ejiri observed transient declines in nerve conduction and sensory symptoms following carpal tunnel release, which were attributed to intraoperative nerve manipulation and postoperative edema 11 . Ido reported short-term worsening in both symptoms and electrophysiology after anterior ulnar nerve transposition, proposing that repositioning stress and biomechanical adaptation were key contributors 12 .These findings collectively support the interpretation that early postoperative deterioration is not an anomaly or surgical error, but rather a physiological response to intervention. Several mechanisms may account for this transient worsening. One prominent factor is postoperative inflammatory edema 21 . Surgical handling of the nerve often initiates an inflammatory cascade, leading to the release of cytokines such as IL-1β and TNF-α 22 , 23 . These mediators promote perineural and intraneural swelling, which can temporarily increase endoneurial pressure and disrupt axonal conduction, particularly in sensory fibers 24 , 25 . Experimental studies by Olmarker and others have demonstrated that such inflammation-induced swelling impairs nerve signal transmission, resulting in symptoms of numbness and paresthesia 21 .Furthermore, local inflammation may sensitize nociceptors, amplifying pain perception beyond the level of structural impairment 26 .This dual influence of mechanical compression and neurochemical sensitization provides a plausible explanation for the early subjective symptom flare-ups observed in our patients. Another important contributor is mechanical stress and biomechanical adaptation following nerve transposition. Releasing a chronically compressed nerve and relocating it to a new anatomical bed imposes novel tension forces and glide path requirements 27 .As noted by Couch and Dowdle, this sudden change in biomechanical environment may induce transient neurapraxia until the nerve adapts to its new trajectory 28 29 . Foran demonstrated that altered tension along the nerve could reduce intraneural blood flow and delay signal propagation 30 . In our cohort, the early worsening of CMAP and conduction velocities likely reflects these temporary disruptions in mechanical homeostasis. Fortunately, as the nerve acclimates and stabilizes, these metrics tend to recover in parallel with symptom resolution. Transient ischemia is another plausible mechanism. Peripheral nerves are sensitive to even brief periods of blood flow interruption, and several perioperative factors—including tourniquet use, tissue retraction, and postoperative swelling—may compromise perfusion 31 , 32 . Seidel's intraoperative studies found that short-duration ischemia could significantly slow nerve conduction 31 . Nitz further observed that brief ischemic episodes may result in sensory deficits that resolve after reperfusion 33 . Although care was taken to preserve epineural vessels in our surgical protocol, minor disruptions in microvascular supply may have contributed to the early electrophysiological decline seen in the symptom-worsening group. Lastly, central sensitization and disinhibition may amplify postoperative discomfort. Surgical trauma to a peripheral nerve not only affects local conduction but also alters central processing of sensory input 34 . Carlton and Kim described how nerve injury increases dorsal horn excitability and reduces descending inhibitory control, leading to heightened pain perception 35 . This central sensitization may explain why VAS scores remained relatively unchanged in our early worsening group, despite objective declines in nerve function 36 37 .In such cases, symptoms are driven more by central amplification than peripheral dysfunction, reinforcing the need for clinician awareness of non-structural contributors to early symptom burden. Taken together, these findings indicate that early postoperative worsening is a multifactorial phenomenon driven by inflammatory, mechanical, ischemic, and central neural factors. It should not be misinterpreted as surgical failure. Recognition of this transient response pattern can help prevent unnecessary interventions, reduce patient anxiety, and support realistic postoperative counseling.Clinicians should reassure patients that early deterioration is often self-limiting and does not predict long-term outcomes. This study has several limitations. First, its retrospective design inherently limits causal inference and may be subject to selection or information bias. Although standardized assessments were used, the interpretation of symptom worsening remains partly subjective, especially regarding PROMs like PRUNE and VAS, which are influenced by psychological and contextual factors. Second, we did not include advanced imaging or biomarker data that could directly validate the proposed mechanisms such as inflammatory edema, ischemia, or central sensitization. Third, while the electrophysiological assessments were objective, their timing may not fully capture the dynamic fluctuations in nerve function during the acute postoperative phase. Lastly, our cohort was derived from a single center, which may limit the generalizability of findings. Prospective, multicenter studies with real-time physiological monitoring are needed to validate and extend these results. From a translational perspective, these insights may guide the development of perioperative strategies aimed at minimizing transient dysfunction.Such approaches may include anti-inflammatory interventions, tension-reducing techniques during transposition, enhanced nerve protection during surgery, and targeted patient education. Future research should focus on prospective validation of these mechanisms using imaging, inflammatory biomarkers, and dynamic nerve tension assessments. Ultimately, integrating biological understanding with clinical observation may help personalize recovery pathways and improve the quality of care in peripheral nerve surgery. Conclusion Early postoperative worsening is a transient yet clinically relevant phenomenon affecting approximately one-fourth of patients after anterior ulnar nerve transposition for cubital tunnel syndrome. It is characterized by short-term symptom aggravation and electrophysiological decline, which typically resolve without structural failure or long-term impairment. This response appears to result from a combination of inflammatory edema, mechanical stress, transient ischemia, and central sensitization. Recognizing this reversible trajectory can prevent unnecessary interventions, guide patient reassurance, and improve postoperative management. Future studies should focus on validating underlying mechanisms and identifying predictive markers to optimize personalized recovery strategies. Abbreviations BMI Body Mass Index CMAP Compound Muscle Action Potential CuTS Cubital Tunnel Syndrome EMG Electromyography FCU Flexor Carpi Ulnaris MNCV Motor Nerve Conduction Velocity PRUNE Patient-Rated Ulnar Nerve Evaluation SNCV Sensory Nerve Conduction Velocity VAS Visual Analog Scale Declarations Ethical Publication Statement We confirm that we have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. Data Availability Statement The data that support the findings of this study are available from the corresponding author upon reasonable request. Access to the data is subject to approval by the Ethics Committee of the First Affiliated Hospital of Anhui Medical University to ensure compliance with patient confidentiality and institutional regulations. Disclosure of Conflicts of Interest None of the authors has any conflict of interest to disclose. Funding This study did not receive any specific funding from public, commercial, or not-for-profit agencies. Ethics Approval and Consent to Participate This study was approved by the Institutional Review Board of the First Affiliated Hospital of Anhui Medical University (Approval No. PJ2024-12-17). Written informed consent for participation and data analysis was obtained from all patients involved in the study. Consent for Publication Not applicable. Permissions for Reproduced Material No previously published material was reproduced in this manuscript. Clinical Trial Registration This study was a retrospective cohort study and was not registered in a clinical trial registry. References Izadpanah A, Gibbs C, Spinner RJ, Kakar S (2021) Comparison of In Situ Versus Subcutaneous Versus Submuscular Transpositions in the Management of McGowan Stage III Cubital Tunnel Syndrome. Hand (New York, N.Y.) 16, 45–49. 10.1177/1558944719831387 Pagnotta A, Formica VM, Marcovici LL, Molayem I, Taglieri E (2021) A novel local adipofascial flap for the management of recalcitrant ulnar tunnel syndrome. Hand Surg rehabilitation 40:377–381. 10.1016/j.hansur.2021.03.010 Power HA, Peters BR, Patterson JMM, Padovano WM, Mackinnon SE (2022) Classifying the Severity of Cubital Tunnel Syndrome: A Preoperative Grading System Incorporating Electrodiagnostic Parameters. Plast Reconstr Surg 150:115e–126e. 10.1097/prs.0000000000009255 Chen HW et al (2014) Clinical efficacy of simple decompression versus anterior transposition of the ulnar nerve for the treatment of cubital tunnel syndrome: A meta-analysis. Clin Neurol Neurosurg 126:150–155. 10.1016/j.clineuro.2014.08.005 Dong YM, Han JW, Xu YL (2010) [Cubital tunnel syndrome caused by osteoarthritis of elbow joint with cyst: a case report]. Zhongguo gu shang = China J Orthop Traumatol 23:611–612 Davidge KM, Ebersole GC, Mackinnon SE (2019) Pain and Function Following Revision Cubital Tunnel Surgery. Hand (New York N Y) 14:172–178. 10.1177/1558944717743593 Nakashian MN, Ireland D, Kane PM (2020) Cubital Tunnel Syndrome: Current Concepts. Curr Rev Musculoskelet Med 13:520–524. 10.1007/s12178-020-09650-y Cross D, Matullo KS (2014) Concomitant endoscopic carpal and cubital tunnel release: safety and efficacy. Hand (New York N Y) 9:43–47. 10.1007/s11552-013-9552-3 Yian EH et al (2015) Incidence of symptomatic compressive peripheral neuropathy after shoulder replacement. Hand (New York N Y) 10:243–247. 10.1007/s11552-014-9701-3 Thomson SE et al (2022) Bioengineered nerve conduits and wraps for peripheral nerve repair of the upper limb. The Cochrane database of systematic reviews 12, Cd012574. 10.1002/14651858.CD012574.pub2 Ejiri S et al (2012) Short-term results of endoscopic (Okutsu method) versus palmar incision open carpal tunnel release: a prospective randomized controlled trial. Fukushima J Med Sci 58:49–59. 10.5387/fms.58.49 Ido Y et al (2016) Postoperative improvement in DASH score, clinical findings, and nerve conduction velocity in patients with cubital tunnel syndrome. Sci Rep 6:27497. 10.1038/srep27497 Lawand JJ, Saab D, Luan A, Curtin C, Hagert E (2025) Return to play and outcomes of surgically treated upper limb nerve entrapment in athletes: a systematic review. Int Orthop. 10.1007/s00264-025-06473-9 Burahee AS, Sanders AD, Shirley C, Power DM (2021) Cubital tunnel syndrome. EFORT open reviews 6:743–750. 10.1302/2058-5241.6.200129 Osborne NR, Anastakis DJ, Davis KD (2018) Peripheral nerve injuries, pain, and neuroplasticity. J hand therapy: official J Am Soc Hand Therapists 31:184–194. 10.1016/j.jht.2018.01.011 Chang WK, Li YP, Zhang DF, Liang BS (2017) The cubital tunnel syndrome caused by the intraneural or extraneural ganglion cysts: Case report and review of the literature. J Plast Reconstr aesthetic surgery: JPRAS 70:1404–1408. 10.1016/j.bjps.2017.05.006 Danoff JR, Lombardi JM, Rosenwasser MP (2014) Use of a pedicled adipose flap as a sling for anterior subcutaneous transposition of the ulnar nerve. J Hand Surg 39:552–555. 10.1016/j.jhsa.2013.12.005 Shi Q, MacDermid JC, Santaguida PL, Kyu HH (2011) Predictors of surgical outcomes following anterior transposition of ulnar nerve for cubital tunnel syndrome: a systematic review. The Journal of hand surgery 36, 1996–2001.e1991-1996. 10.1016/j.jhsa.2011.09.024 Hu T et al (2025) Improving Short-term Outcomes of Cubital Tunnel Syndrome Decompression with Intraoperative Dexamethasone. World Neurosurg 123885. 10.1016/j.wneu.2025.123885 Meiling JB, Schappell JB, Twohey EE, Prokop LJ, Cushman DM (2023) Preoperative electrodiagnostic studies and postoperative outcomes for ulnar mononeuropathy at the elbow: A systematic review. PM R: J injury function rehabilitation 15:1326–1334. 10.1002/pmrj.12952 Olmarker K, Rydevik B (2001) Selective inhibition of tumor necrosis factor-alpha prevents nucleus pulposus-induced thrombus formation, intraneural edema, and reduction of nerve conduction velocity: possible implications for future pharmacologic treatment strategies of sciatica. Spine 26:863–869. 10.1097/00007632-200104150-00007 Shamji MF et al (2009) Gait abnormalities and inflammatory cytokines in an autologous nucleus pulposus model of radiculopathy. Spine 34:648–654. 10.1097/BRS.0b013e318197f013 Vardeh D, Mannion RJ, Woolf CJ (2016) Toward a Mechanism-Based Approach to Pain Diagnosis. J pain 17:T50–69. 10.1016/j.jpain.2016.03.001 Rhee JM, Schaufele M, Abdu WA (2006) Radiculopathy and the herniated lumbar disc. Controversies regarding pathophysiology and management. J bone joint Surg Am 88:2070–2080. 10.2106/00004623-200609000-00023 Stafford MA, Peng P, Hill DA (2007) Sciatica: a review of history, epidemiology, pathogenesis, and the role of epidural steroid injection in management. Br J Anaesth 99:461–473. 10.1093/bja/aem238 Xie W et al (2016) Localized Sympathectomy Reduces Mechanical Hypersensitivity by Restoring Normal Immune Homeostasis in Rat Models of Inflammatory Pain. J neuroscience: official J Soc Neurosci 36:8712–8725. 10.1523/jneurosci.4118-15.2016 Manvell JJ, Manvell N, Snodgrass SJ, Reid SA (2015) Improving the radial nerve neurodynamic test: An observation of tension of the radial, median and ulnar nerves during upper limb positioning. Man Therap 20:790–796. 10.1016/j.math.2015.03.007 Couch B et al (2024) A systematic review of steroid use in peripheral nerve pathologies and treatment. Front Neurol 15:1434429. 10.3389/fneur.2024.1434429 Dowdle SB, Chalmers PN (2020) Management of the Ulnar Nerve in Throwing Athletes. Curr Rev Musculoskelet Med 13:449–456. 10.1007/s12178-020-09639-7 Foran I et al (2016) Regional Ulnar Nerve Strain Following Decompression and Anterior Subcutaneous Transposition in Patients With Cubital Tunnel Syndrome. J Hand Surg 41:e343–e350. 10.1016/j.jhsa.2016.07.095 Seidel GK et al (2025) Electrodiagnostic Assessment of Peri-Procedural Iatrogenic Peripheral Nerve Injuries and Rehabilitation. Muscle Nerve 71:747–767. 10.1002/mus.28364 Nitz AJ, Dobner JJ, Matulionis DH (1986) Pneumatic tourniquet application and nerve integrity: motor function and electrophysiology. Exp Neurol 94:264–279. 10.1016/0014-4886(86)90101-9 Nitz AJ, Dobner JJ (1989) Upper extremity tourniquet effects in carpal tunnel release. J Hand Surg 14:499–504. 10.1016/s0363-5023(89)80011-5 Carlton A, Khalid SI (2018) Surgical Approaches and Their Outcomes in the Treatment of Cubital Tunnel Syndrome. Front Surg 5. 10.3389/fsurg.2018.00048 Kang J et al (2020) Regional Hyperexcitability and Chronic Neuropathic Pain Following Spinal Cord Injury. Cell Mol Neurobiol 40:861–878. 10.1007/s10571-020-00785-7 Hulsebosch CE, Hains BC, Crown ED, Carlton SM (2009) Mechanisms of chronic central neuropathic pain after spinal cord injury. Brain Res Rev 60:202–213. 10.1016/j.brainresrev.2008.12.010 Tran EL, Crawford LK, Revisiting PNS (2020) Plasticity: How Uninjured Sensory Afferents Promote Neuropathic Pain. Front Cell Neurosci 14. 10.3389/fncel.2020.612982 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 10 Jan, 2026 Read the published version in Neurosurgical Review → Version 1 posted Editorial decision: Revision requested 01 Sep, 2025 Reviews received at journal 15 Aug, 2025 Reviews received at journal 15 Aug, 2025 Reviews received at journal 08 Aug, 2025 Reviewers agreed at journal 06 Aug, 2025 Reviewers agreed at journal 04 Aug, 2025 Reviewers agreed at journal 04 Aug, 2025 Reviewers invited by journal 02 Aug, 2025 Editor assigned by journal 02 Aug, 2025 Submission checks completed at journal 22 Jun, 2025 First submitted to journal 22 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6949952","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":496757660,"identity":"d83dde01-b7a1-4986-aeb4-2dc6277754c3","order_by":0,"name":"Tianyou Hu","email":"","orcid":"","institution":"The First Affiliated Hospital of Anhui Medical University","correspondingAuthor":false,"prefix":"","firstName":"Tianyou","middleName":"","lastName":"Hu","suffix":""},{"id":496757661,"identity":"783aeb91-9362-4cf9-bc14-9c801d03aedc","order_by":1,"name":"Yujie Bian","email":"","orcid":"","institution":"The First Affiliated Hospital of Anhui Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yujie","middleName":"","lastName":"Bian","suffix":""},{"id":496757662,"identity":"c58edef0-6a59-4e6f-ad1b-aab9e7bb68bd","order_by":2,"name":"Tao Zhou","email":"","orcid":"","institution":"The First Affiliated Hospital of Anhui Medical University","correspondingAuthor":false,"prefix":"","firstName":"Tao","middleName":"","lastName":"Zhou","suffix":""},{"id":496757663,"identity":"56f2058a-c9ef-4985-8e63-054a8ca0591e","order_by":3,"name":"Qiankun Wang","email":"","orcid":"","institution":"The First Affiliated Hospital of Anhui Medical University","correspondingAuthor":false,"prefix":"","firstName":"Qiankun","middleName":"","lastName":"Wang","suffix":""},{"id":496757664,"identity":"b7974eff-f59e-433d-b060-0c75918404b6","order_by":4,"name":"Liang He","email":"","orcid":"","institution":"The First Affiliated Hospital of Anhui Medical University","correspondingAuthor":false,"prefix":"","firstName":"Liang","middleName":"","lastName":"He","suffix":""},{"id":496757665,"identity":"0c9bd041-c40d-47d2-bad6-8ad76466731a","order_by":5,"name":"Jun Huang","email":"","orcid":"","institution":"The First Affiliated Hospital of Anhui Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jun","middleName":"","lastName":"Huang","suffix":""},{"id":496757666,"identity":"41920b26-79e7-42ba-a96d-ea114e240282","order_by":6,"name":"Hongxiang Zhou","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYDACCQYGZgYGGzl+9uYDBz78IF5LmrFkz7HEgzN7iNdyOHHDjRzjwxxsROiQn918TLqwDWTLmQ+HGXgY5PnFDuDXwjjnWJr0jDMgv/RuOFxgwWA4c3YCfi3MEjlm0jwVIFvObjg8g4chweA2AS1sYC0GYL88OMzDRoQWHogtYC0MxGmRkEhLtuY5Aw5kA2AgSxD2i/yM5IO3edvAUfn4w4cfNvL80gS0YNhKmvJRMApGwSgYBdgBACRXRCdL8OyCAAAAAElFTkSuQmCC","orcid":"","institution":"The First Affiliated Hospital of Anhui Medical University","correspondingAuthor":true,"prefix":"","firstName":"Hongxiang","middleName":"","lastName":"Zhou","suffix":""}],"badges":[],"createdAt":"2025-06-22 14:08:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6949952/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6949952/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10143-025-03927-x","type":"published","date":"2026-01-10T15:57:55+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":88756505,"identity":"7c09cf4c-82fe-4b2a-80ab-aad640dcaedf","added_by":"auto","created_at":"2025-08-11 07:20:27","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":96339,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative intraoperative steps of anterior subfascial transposition of the ulnar nerve for cubital tunnel syndrome.(a) A 10 cm curvilinear skin incision along the medial elbow, posterior to the medial epicondyle.(b) Exposure and longitudinal division of Osborne’s ligament along its ulnar margin.(c) Microsurgical decompression of potential entrapment sites, including the arcade of Struthers, intermuscular septum, Osborne’s fascia, and deep fascia bands within the flexor carpi ulnaris, with protection of the medial antebrachial cutaneous nerve.(d) Anterior transposition of the ulnar nerve to a subfascial position anterior to the medial epicondyle.(e) Loose suturing of a 3 × 3 cm fascial flap over the transposed nerve to ensure tension-free coverage and prevent posterior subluxation.(f) Postoperative immobilization using a posterior plaster splint at 60° elbow flexion.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6949952/v1/6bb8e2f9dcc7b018ca0e34ee.jpg"},{"id":88755406,"identity":"53ba795f-d4e8-4aac-a9bd-5be1f91c030f","added_by":"auto","created_at":"2025-08-11 07:12:27","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":111300,"visible":true,"origin":"","legend":"\u003cp\u003eLine graph illustrating longitudinal changes in PRUNE, VAS, and two-point discrimination scores from preoperative baseline to approximately 2 weeks and 6 months postoperatively. The trajectories reflect both early postoperative fluctuations and subsequent functional recovery.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6949952/v1/90c594c66ca3e92651104711.jpg"},{"id":88755405,"identity":"a8558686-4a7a-40bd-b0cc-0e4f1f153941","added_by":"auto","created_at":"2025-08-11 07:12:27","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":106067,"visible":true,"origin":"","legend":"\u003cp\u003eLine graph showing mean electrophysiological values before surgery and at 6-month follow-up. Improvements in CMAP, SNCV, and MNCV values confirm objective neural recovery after decompression.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6949952/v1/40407a15bbaf802e4c7c4d61.jpg"},{"id":100069248,"identity":"72a7815e-044d-4f3b-879d-3ff785e6e064","added_by":"auto","created_at":"2026-01-12 16:11:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1055743,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6949952/v1/f28744ba-80fa-4685-922f-7c9931f4dad8.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Short-term Symptom Aggravation after Cubital Tunnel Decompression: Clinical Features and Mechanistic Insights from a Retrospective Cohort Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCubital tunnel syndrome (CuTS) is the second most prevalent peripheral nerve compression disorder of the upper extremity, primarily resulting from chronic compression of the ulnar nerve at the elbow\u003csup\u003e\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. Clinically, it manifests as numbness, pain, and impaired hand function. Surgical decompression or anterior transposition of the ulnar nerve is widely regarded as an effective treatment, offering substantial symptom relief and functional improvement in most patients\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eHowever, clinical experience has shown that a subset of patients may develop transient recurrence or worsening of symptoms in the early postoperative period, typically within the first two weeks following surgery\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. These aggravations are characterized by intensified numbness, increased pain, diminished two-point discrimination, and temporary deterioration in electrophysiological parameters as assessed by electromyography (EMG) \u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e.Notably, such symptom flare-ups usually occur in the absence of overt surgical complications such as infection or direct nerve injury. Fortunately, they tend to resolve spontaneously, with reported incidence ranging from 15\u0026ndash;30% in previous studies on peripheral nerve decompression\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eSimilar short-term exacerbations have also been reported following decompression for other entrapment neuropathies.Ejiri observed temporary worsening of nerve conduction and clinical symptoms after carpal tunnel release, suggesting intraoperative nerve manipulation as a contributing factor\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e.Likewise, Ido reported early symptom aggravation and electrophysiological decline after ulnar nerve anterior transposition, attributing it to mechanical stress and positional adaptation of the nerve\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eAlthough increasing attention has been paid to this phenomenon, its underlying mechanisms remain poorly understood. Proposed explanations include postoperative neural edema and inflammatory responses, mechanical stress related to nerve transposition, postoperative hyperexcitability and central disinhibition, and microvascular ischemia\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e.However, these remain hypothetical, and robust clinical evidence is lacking.Moreover, no unified explanatory framework currently exists to connect these diverse mechanisms with observed clinical trajectories, limiting opportunities for perioperative intervention.\u003c/p\u003e\u003cp\u003eGiven the potential impact of early postoperative symptom aggravation on patient perception and satisfaction,it is essential to clarify its clinical characteristics and explore underlying mechanisms.A mechanistic understanding of this phenomenon could inform predictive risk models, improve perioperative counseling, and support the development of targeted strategies to mitigate early symptom flare-ups.Repeated clinical observations of transient symptom rebound following CuTS decompression\u0026mdash;despite successful surgical release\u0026mdash;highlighted a poorly understood but potentially meaningful postoperative pattern. Motivated by this real-world phenomenon, we conducted a clinically driven investigation to define its short-term clinical and electrophysiological characteristics and explore plausible underlying mechanisms.\u003c/p\u003e\u003cp\u003eThe aim is to generate actionable insights that may inform preoperative counseling, early postoperative monitoring, and recovery pathway optimization.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eThis retrospective cohort study was conducted at the First Affiliated Hospital of Anhui Medical University between August 2018 and August 2024. All procedures adhered to institutional ethical guidelines and received approval from the hospital\u0026rsquo;s ethics committee. Clinical data, surgical records, and follow-up information were retrieved from the hospital\u0026rsquo;s electronic medical record (EMR) system.\u003c/p\u003e\u003cp\u003ePatient Selection\u003c/p\u003e\u003cp\u003eA total of 182 patients diagnosed with cubital tunnel syndrome (CuTS) were initially screened for eligibility.55 patients who received intraoperative corticosteroid injections were excluded to eliminate pharmacological confounding.The final study population included 127 patients who underwent standardized anterior ulnar nerve transposition without steroid use and completed scheduled follow-up assessments.\u003c/p\u003e\u003cp\u003eInclusion and Exclusion Criteria\u003c/p\u003e\u003cp\u003eInclusion criteria were as follows: patients aged 18 to 75 years with a diagnosis of CuTS and clinical indications for surgery; symptoms persisting for more than 3 months despite conservative treatment; no previous history of ulnar nerve surgery; no systemic corticosteroid use within 3 months prior to surgery; and complete clinical and electrophysiological data available at all designated time points. Patients were excluded if they presented with significant elbow joint deformities, systemic neurologic conditions, contraindications to surgery or electrical stimulation testing, pregnancy or lactation, presence of a pacemaker, or incomplete postoperative follow-up.\u003c/p\u003e\u003cp\u003eSurgical Procedure\u003c/p\u003e\u003cp\u003eAll procedures were performed under general anesthesia or brachial plexus nerve block. Patients were placed in the supine position with the affected limb externally rotated and abducted on an arm table. A pneumatic tourniquet was applied to the proximal upper arm to establish a bloodless field.\u003c/p\u003e\u003cp\u003eAfter confirming adequate anesthesia, a 10 cm curvilinear incision was made along the medial aspect of the elbow, centered over the ulnar nerve and positioned posterior to the medial epicondyle(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). Subcutaneous tissues were dissected to expose the deep fascia and Osborne\u0026rsquo;s ligament. The ligament was incised longitudinally along its ulnar edge and reflected anteriorly(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe ulnar nerve was then carefully identified and isolated under loupe magnification. Complete decompression was performed using microsurgical instruments, extending from approximately 8 cm proximal to 6 cm distal to the medial epicondyle. All potential entrapment sites were released, including the arcade of Struthers, Osborne\u0026rsquo;s fascia, the intermuscular septum, and fascial bands within the flexor carpi ulnaris (FCU)(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec).\u003c/p\u003e\u003cp\u003eThe epineurium and intraneural blood supply were preserved throughout the procedure. The medial antebrachial cutaneous nerve and adjacent vasculature were identified and protected. After decompression, the ulnar nerve was transposed anteriorly to a subfascial position anterior to the medial epicondyle(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed). A 3 \u0026times; 3 cm fascial flap was harvested from the flexor\u0026ndash;pronator fascia and sutured loosely over the transposed nerve to ensure a tension-free position and prevent posterior subluxation(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee) \u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eElbow flexion and extension were passively performed intraoperatively to confirm smooth nerve gliding. After hemostasis and irrigation, a drainage strip was placed. The wound was closed in layers using absorbable sutures for deep tissues and interrupted non-absorbable sutures for the skin. The elbow was immobilized in a posterior plaster splint at approximately 60\u0026deg; of flexion(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ef).\u003c/p\u003e\u003cp\u003ePostoperative Management\u003c/p\u003e\u003cp\u003eAll patients were immobilized in a plaster splint for early postoperative protection. Wound dressings were changed regularly, and sutures were removed on postoperative day 12. Patients were followed up at 2 weeks and at 6 months after surgery. Clinical and electrophysiological evaluations were performed at each time point to assess ulnar nerve function and symptom progression.\u003c/p\u003e\u003cp\u003eOutcome Measures\u003c/p\u003e\u003cp\u003eClinical assessments were conducted at three key time points: preoperatively, 2 weeks postoperatively, and 6 months postoperatively. Pain severity was evaluated using the Visual Analog Scale (VAS), with scores ranging from 0 (no pain) to 10 (worst possible pain). The Patient-Rated Ulnar Nerve Evaluation (PRUNE) was used to measure subjective symptoms such as tingling, numbness, hand weakness, and activity limitations, with higher scores indicating more severe impairment. Sensory function was assessed using two-point discrimination testing in the ulnar nerve distribution area.\u003c/p\u003e\u003cp\u003eElectrophysiological function was evaluated using surface electromyography (EMG). The parameters measured included compound muscle action potential (CMAP), sensory nerve conduction velocity (SNCV), and motor nerve conduction velocity (MNCV). For patients who reported early postoperative symptom aggravation, additional EMG testing was performed during the early recovery period to monitor neural function and confirm transient decline.\u003c/p\u003e\u003cp\u003eDefinition of Early Symptom Aggravation\u003c/p\u003e\u003cp\u003eEarly symptom aggravation was defined as any measurable deterioration in clinical or electrophysiological indicators at the 2-week postoperative follow-up compared to baseline. Specifically, patients were classified into the early aggravation subgroup if they exhibited an increased PRUNE score, worsened two-point discrimination threshold, or sustained/increased VAS score at 2 weeks relative to their preoperative status. This subgroup classification was used for comparative analysis.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eAll statistical analyses were conducted using Python version 3.9.7. Continuous variables were expressed as means with standard deviations. Normality of data distribution was assessed using the Shapiro\u0026ndash;Wilk test. For variables with normal distribution, paired-sample z-tests were applied to evaluate differences between preoperative and postoperative measurements. For non-normally distributed variables or small sample sizes, the Wilcoxon signed-rank test was used. Statistical significance was defined as a two-sided p-value less than 0.05. Analytical comparisons were performed in two phases: first, evaluating preoperative versus 6-month outcomes for the overall cohort; second, analyzing short-term changes at 2 weeks in the subgroup with early symptom aggravation.\u003c/p\u003e\u003c/div\u003e"},{"header":"Result","content":"\u003cp\u003eA total of 127 patients who met the inclusion criteria were included in the final analysis. The mean age of the cohort was 52.86\u0026thinsp;\u0026plusmn;\u0026thinsp;13.78 years, with a mean disease duration of 1.83\u0026thinsp;\u0026plusmn;\u0026thinsp;2.85 years and a mean body mass index (BMI) of 23.87\u0026thinsp;\u0026plusmn;\u0026thinsp;3.17 kg/m\u0026sup2;. Among them, 26.77% had left-sided involvement, 67.71% had right-sided involvement, and 5.51% presented with bilateral symptoms. Based on McGowan grading, 18.11% were classified as grade I, 26.77% as grade II, and 55.11% as grade III (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline Characteristics of Patients with Cubital Tunnel Syndrome\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"10\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eGroup\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eAge(year)(\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\stackrel{-}{x}\\pm\\:s\\)\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eCourse of disease(year)(\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\stackrel{-}{x}\\pm\\:s\\)\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eBMI(kg/m\u0026sup2;)(\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\stackrel{-}{x}\\pm\\:s\\)\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e\u003cp\u003eLeft or right hand (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c10\" namest=\"c8\"\u003e\u003cp\u003eMcGowan (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eleft\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eright\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eboth\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eⅠ\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eⅡ\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e\u003cp\u003eⅢ\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAll Patiences\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e52.86\u0026thinsp;\u0026plusmn;\u0026thinsp;13.78\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e1.83\u0026thinsp;\u0026plusmn;\u0026thinsp;2.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e23.87\u0026thinsp;\u0026plusmn;\u0026thinsp;3.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e26.77\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e67.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e5.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e18.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e26.77\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e55.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAggravation Group\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e56.42\u0026thinsp;\u0026plusmn;\u0026thinsp;12.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e4.03\u0026thinsp;\u0026plusmn;\u0026thinsp;3.92\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e24.00\u0026thinsp;\u0026plusmn;\u0026thinsp;3.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e26.47\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e67.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e5.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e23.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e76.47\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAt the six-month follow-up, patients demonstrated statistically significant improvement in both clinical and electrophysiological outcomes. CMAP increased from 1.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38 mV preoperatively to 5.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76 mV (p\u0026thinsp;=\u0026thinsp;0.0006), SNCV improved from 32.49\u0026thinsp;\u0026plusmn;\u0026thinsp;6.41 m/s to 48.04\u0026thinsp;\u0026plusmn;\u0026thinsp;5.22 m/s (p\u0026thinsp;=\u0026thinsp;0.0004), and MNCV rose from 32.92\u0026thinsp;\u0026plusmn;\u0026thinsp;6.32 m/s to 48.20\u0026thinsp;\u0026plusmn;\u0026thinsp;4.74 m/s (p\u0026thinsp;=\u0026thinsp;0.0003). Correspondingly, VAS scores decreased from 4.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01 to 2.22\u0026thinsp;\u0026plusmn;\u0026thinsp;1.16 (p\u0026thinsp;=\u0026thinsp;0.0005), PRUNE scores dropped from 50.91\u0026thinsp;\u0026plusmn;\u0026thinsp;10.04 to 30.08\u0026thinsp;\u0026plusmn;\u0026thinsp;6.82 (p\u0026thinsp;=\u0026thinsp;0.0006), and two-point discrimination improved from 8.87\u0026thinsp;\u0026plusmn;\u0026thinsp;1.89 mm to 5.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.89 mm (p\u0026thinsp;=\u0026thinsp;0.0032) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e; Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e\u003cp\u003eComparison of Electrophysiological and Clinical Outcomes Before and Six Months After Surgery in All Patients(\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\stackrel{-}{x}\\pm\\:s\\)\u003c/span\u003e\u003c/span\u003e)༈α=0.05༉\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCMAP(mV)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSNCV(m/s)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMNCV(m/s)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVAS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePRUNE\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eTwo-Point Discrimination(mm)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre-op\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32.49\u0026thinsp;\u0026plusmn;\u0026thinsp;6.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e32.92\u0026thinsp;\u0026plusmn;\u0026thinsp;6.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e50.91\u0026thinsp;\u0026plusmn;\u0026thinsp;10.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e8.87\u0026thinsp;\u0026plusmn;\u0026thinsp;1.89\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epost-op(6M)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e48.04\u0026thinsp;\u0026plusmn;\u0026thinsp;5.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e48.20\u0026thinsp;\u0026plusmn;\u0026thinsp;4.74\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.22\u0026thinsp;\u0026plusmn;\u0026thinsp;1.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e30.08\u0026thinsp;\u0026plusmn;\u0026thinsp;6.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e5.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.89\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eZ value\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u0026minus;48.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026minus;20.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026minus;20.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e16.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e18.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e12.24\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.0006\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.0004\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.0003\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.0005\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.0006\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.0032\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003ePre-op: Preoperative;Post-op(6M)༚Postoperative(6 month);VAS༚Visual Analog Scale༛PRUNE༚Patient-Rated Ulnar Nerve Evaluation༛CMAP༚Compound Muscle Action Potential༛ SNCV ༚Sensory Nerve Conduction Velocity༛MNCV༚Motor Nerve Conduction Velocity༛\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eIn the short-term postoperative assessment at 2 weeks, modest improvements were noted in most clinical indicators. VAS scores decreased slightly to 3.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.10 (p\u0026thinsp;=\u0026thinsp;0.038), PRUNE scores decreased to 46.86\u0026thinsp;\u0026plusmn;\u0026thinsp;10.35 (p\u0026thinsp;=\u0026thinsp;0.0027), and two-point discrimination improved marginally to 8.33\u0026thinsp;\u0026plusmn;\u0026thinsp;2.24 mm (p\u0026thinsp;=\u0026thinsp;0.047). However, these early results exhibited a wider standard deviation, indicating substantial inter-individual variability in early recovery trajectories (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of Preoperative and Short-Term VAS, PRUNE Scores, and Two-Point Discrimination in All Patients()༈α=0.05༉\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVAS\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePRUNE\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTwo-Point Discrimination(mm)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epre-op\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e50.91\u0026thinsp;\u0026plusmn;\u0026thinsp;10.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e8.87\u0026thinsp;\u0026plusmn;\u0026thinsp;1.89\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epost-op(6M)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e46.86\u0026thinsp;\u0026plusmn;\u0026thinsp;10.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e8.33\u0026thinsp;\u0026plusmn;\u0026thinsp;2.24\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eZ value\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.97\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.038\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.0027\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.047\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003ePre-op: Preoperative;Post-op(6M)༚Postoperative(6 month);VAS༚Visual Analog Scale༛PRUNE༚Patient-Rated Ulnar Nerve Evaluation༛\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eDue to this variability, patients were stratified post hoc based on early postoperative symptom trajectory. A subset of 34 patients (26.8%) who demonstrated clinical deterioration at 2 weeks postoperatively was classified into the symptom aggravation group. Baseline characteristics of this subgroup included a longer disease duration (4.03\u0026thinsp;\u0026plusmn;\u0026thinsp;3.92 years) and a higher prevalence of McGowan grade III (76.47%), suggestive of more advanced disease at presentation (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn the symptom aggravation subgroup, clinical scores demonstrated a paradoxical deterioration during the early postoperative phase. PRUNE scores increased from 51.96\u0026thinsp;\u0026plusmn;\u0026thinsp;9.80 to 53.66\u0026thinsp;\u0026plusmn;\u0026thinsp;9.27 (p\u0026thinsp;=\u0026thinsp;0.0003), indicating a perceived worsening of symptoms. Two-point discrimination worsened from 9.69\u0026thinsp;\u0026plusmn;\u0026thinsp;1.07 mm to 10.75\u0026thinsp;\u0026plusmn;\u0026thinsp;1.27 mm (p\u0026thinsp;=\u0026thinsp;0.0002), suggesting reduced sensory acuity. VAS scores, however, showed only a modest decline from 4.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00 to 4.21\u0026thinsp;\u0026plusmn;\u0026thinsp;1.21 (p\u0026thinsp;=\u0026thinsp;0.0186), indicating that subjective pain perception remained relatively stable during this early interval (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of Preoperative and Short-Term VAS, PRUNE, and Two-Point Discrimination in Patients with Symptom Aggravation()༈α=0.05༉\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVAS\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePRUNE\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTwo-Point Discrimination(mm)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epre\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e51.96\u0026thinsp;\u0026plusmn;\u0026thinsp;9.80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e9.69\u0026thinsp;\u0026plusmn;\u0026thinsp;1.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epost(short-term)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.21\u0026thinsp;\u0026plusmn;\u0026thinsp;1.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e53.66\u0026thinsp;\u0026plusmn;\u0026thinsp;9.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e10.75\u0026thinsp;\u0026plusmn;\u0026thinsp;1.27\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eS-W-p\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.0073/0.0588\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.4635/0.5421\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.0002/0.0033\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSRT-p\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.0186\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.0003\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.0002\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003ePre-op: Preoperative;Post-op(short-term)༚Postoperative(short-term);VAS༚Visual Analog Scale༛PRUNE༚Patient-Rated Ulnar Nerve Evaluation༛\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eElectrophysiological testing in the same subgroup revealed statistically significant declines across all recorded parameters. CMAP decreased from 1.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38 mV preoperatively to 1.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28 mV (p\u0026thinsp;=\u0026thinsp;0.0002), SNCV dropped from 33.08\u0026thinsp;\u0026plusmn;\u0026thinsp;6.18 m/s to 29.58\u0026thinsp;\u0026plusmn;\u0026thinsp;5.55 m/s (p\u0026thinsp;=\u0026thinsp;0.0002), and MNCV fell from 32.83\u0026thinsp;\u0026plusmn;\u0026thinsp;5.56 m/s to 26.41\u0026thinsp;\u0026plusmn;\u0026thinsp;4.62 m/s (p\u0026thinsp;=\u0026thinsp;0.0002). These results reflect a measurable yet transient impairment in nerve conduction during the early postoperative recovery window (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of Preoperative and Short-Term CMAP, SNCV, and MNCV in Patients with Symptom Aggravation()༈α=0.05༉\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCAMP\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSNCV\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMNCV\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epre\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33.08\u0026thinsp;\u0026plusmn;\u0026thinsp;6.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e32.83\u0026thinsp;\u0026plusmn;\u0026thinsp;5.56\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epost(short-term)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29.58\u0026thinsp;\u0026plusmn;\u0026thinsp;5.55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e26.41\u0026thinsp;\u0026plusmn;\u0026thinsp;4.62\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eS-W-p\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.3893/0.1168\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.2901/0.3673\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.5611/0.6112\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSRT-p\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.0002\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.0002\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.0002\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003ePre-op: Preoperative;Post-op(short-term)༚Postoperative(short-term);CMAP༚Compound Muscle Action Potential༛ SNCV ༚Sensory Nerve Conduction Velocity༛MNCV༚Motor Nerve Conduction Velocity༛\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTaken together, these findings confirm the presence of a distinct early symptom aggravation pattern affecting approximately one-quarter of patients. This subgroup displayed both subjective and objective deterioration in the absence of structural failure or surgical complication, with indicators subsequently improving over time as part of a reversible recovery phase.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study confirms the presence of a reproducible pattern of early postoperative worsening in approximately one-quarter of patients undergoing anterior ulnar nerve transposition for cubital tunnel syndrome. Although the majority of patients demonstrated progressive improvement in both clinical and electrophysiological indicators, a subset exhibited transient aggravation of symptoms within the first two weeks after surgery \u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e.This phenomenon manifested as increased subjective burden\u0026mdash;reflected by higher PRUNE scores and worsened two-point discrimination\u0026mdash;as well as measurable reductions in CMAP, SNCV, and MNCV \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Importantly, these deteriorations resolved spontaneously over time, with no indication of structural failure or need for revision, underscoring the reversible nature of this recovery phase \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eSimilar patterns of early symptom exacerbation have been described in previous studies of peripheral nerve decompression \u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e.Ejiri observed transient declines in nerve conduction and sensory symptoms following carpal tunnel release, which were attributed to intraoperative nerve manipulation and postoperative edema \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Ido reported short-term worsening in both symptoms and electrophysiology after anterior ulnar nerve transposition, proposing that repositioning stress and biomechanical adaptation were key contributors \u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e.These findings collectively support the interpretation that early postoperative deterioration is not an anomaly or surgical error, but rather a physiological response to intervention.\u003c/p\u003e\u003cp\u003eSeveral mechanisms may account for this transient worsening. One prominent factor is postoperative inflammatory edema \u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. Surgical handling of the nerve often initiates an inflammatory cascade, leading to the release of cytokines such as IL-1β and TNF-α\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e,\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. These mediators promote perineural and intraneural swelling, which can temporarily increase endoneurial pressure and disrupt axonal conduction, particularly in sensory fibers \u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e,\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. Experimental studies by Olmarker and others have demonstrated that such inflammation-induced swelling impairs nerve signal transmission, resulting in symptoms of numbness and paresthesia \u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e.Furthermore, local inflammation may sensitize nociceptors, amplifying pain perception beyond the level of structural impairment \u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e.This dual influence of mechanical compression and neurochemical sensitization provides a plausible explanation for the early subjective symptom flare-ups observed in our patients.\u003c/p\u003e\u003cp\u003eAnother important contributor is mechanical stress and biomechanical adaptation following nerve transposition. Releasing a chronically compressed nerve and relocating it to a new anatomical bed imposes novel tension forces and glide path requirements \u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e.As noted by Couch and Dowdle, this sudden change in biomechanical environment may induce transient neurapraxia until the nerve adapts to its new trajectory \u003csup\u003e28 29\u003c/sup\u003e. Foran demonstrated that altered tension along the nerve could reduce intraneural blood flow and delay signal propagation \u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e. In our cohort, the early worsening of CMAP and conduction velocities likely reflects these temporary disruptions in mechanical homeostasis. Fortunately, as the nerve acclimates and stabilizes, these metrics tend to recover in parallel with symptom resolution.\u003c/p\u003e\u003cp\u003eTransient ischemia is another plausible mechanism. Peripheral nerves are sensitive to even brief periods of blood flow interruption, and several perioperative factors\u0026mdash;including tourniquet use, tissue retraction, and postoperative swelling\u0026mdash;may compromise perfusion \u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e,\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. Seidel's intraoperative studies found that short-duration ischemia could significantly slow nerve conduction \u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e. Nitz further observed that brief ischemic episodes may result in sensory deficits that resolve after reperfusion \u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e. Although care was taken to preserve epineural vessels in our surgical protocol, minor disruptions in microvascular supply may have contributed to the early electrophysiological decline seen in the symptom-worsening group.\u003c/p\u003e\u003cp\u003eLastly, central sensitization and disinhibition may amplify postoperative discomfort. Surgical trauma to a peripheral nerve not only affects local conduction but also alters central processing of sensory input \u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. Carlton and Kim described how nerve injury increases dorsal horn excitability and reduces descending inhibitory control, leading to heightened pain perception \u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. This central sensitization may explain why VAS scores remained relatively unchanged in our early worsening group, despite objective declines in nerve function \u003csup\u003e36 37\u003c/sup\u003e.In such cases, symptoms are driven more by central amplification than peripheral dysfunction, reinforcing the need for clinician awareness of non-structural contributors to early symptom burden.\u003c/p\u003e\u003cp\u003eTaken together, these findings indicate that early postoperative worsening is a multifactorial phenomenon driven by inflammatory, mechanical, ischemic, and central neural factors. It should not be misinterpreted as surgical failure. Recognition of this transient response pattern can help prevent unnecessary interventions, reduce patient anxiety, and support realistic postoperative counseling.Clinicians should reassure patients that early deterioration is often self-limiting and does not predict long-term outcomes.\u003c/p\u003e\u003cp\u003eThis study has several limitations. First, its retrospective design inherently limits causal inference and may be subject to selection or information bias. Although standardized assessments were used, the interpretation of symptom worsening remains partly subjective, especially regarding PROMs like PRUNE and VAS, which are influenced by psychological and contextual factors. Second, we did not include advanced imaging or biomarker data that could directly validate the proposed mechanisms such as inflammatory edema, ischemia, or central sensitization. Third, while the electrophysiological assessments were objective, their timing may not fully capture the dynamic fluctuations in nerve function during the acute postoperative phase. Lastly, our cohort was derived from a single center, which may limit the generalizability of findings. Prospective, multicenter studies with real-time physiological monitoring are needed to validate and extend these results.\u003c/p\u003e\u003cp\u003eFrom a translational perspective, these insights may guide the development of perioperative strategies aimed at minimizing transient dysfunction.Such approaches may include anti-inflammatory interventions, tension-reducing techniques during transposition, enhanced nerve protection during surgery, and targeted patient education. Future research should focus on prospective validation of these mechanisms using imaging, inflammatory biomarkers, and dynamic nerve tension assessments. Ultimately, integrating biological understanding with clinical observation may help personalize recovery pathways and improve the quality of care in peripheral nerve surgery.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eEarly postoperative worsening is a transient yet clinically relevant phenomenon affecting approximately one-fourth of patients after anterior ulnar nerve transposition for cubital tunnel syndrome. It is characterized by short-term symptom aggravation and electrophysiological decline, which typically resolve without structural failure or long-term impairment.\u003c/p\u003e\u003cp\u003eThis response appears to result from a combination of inflammatory edema, mechanical stress, transient ischemia, and central sensitization. Recognizing this reversible trajectory can prevent unnecessary interventions, guide patient reassurance, and improve postoperative management. Future studies should focus on validating underlying mechanisms and identifying predictive markers to optimize personalized recovery strategies.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eBMI\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eBody Mass Index\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCMAP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eCompound Muscle Action Potential\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCuTS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eCubital Tunnel Syndrome\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eEMG\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eElectromyography\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eFCU\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eFlexor Carpi Ulnaris\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eMNCV\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMotor Nerve Conduction Velocity\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003ePRUNE\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePatient-Rated Ulnar Nerve Evaluation\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eSNCV\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eSensory Nerve Conduction Velocity\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eVAS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eVisual Analog Scale\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical Publication Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe confirm that we have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the findings of this study are available from the corresponding author upon reasonable request. Access to the data is subject to approval by the Ethics Committee of the First Affiliated Hospital of Anhui Medical University to ensure compliance with patient confidentiality and institutional regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisclosure of Conflicts of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone of the authors has any conflict of interest to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study did not receive any specific funding from public, commercial, or not-for-profit agencies.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics Approval and Consent to Participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Institutional Review Board of the First Affiliated Hospital of Anhui Medical University (Approval No. PJ2024-12-17). Written informed consent for participation and data analysis was obtained from all patients involved in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for Publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePermissions for Reproduced Material\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo previously published material was reproduced in this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Trial Registration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was a retrospective cohort study and was not registered in a clinical trial registry.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eIzadpanah A, Gibbs C, Spinner RJ, Kakar S (2021) Comparison of In Situ Versus Subcutaneous Versus Submuscular Transpositions in the Management of McGowan Stage III Cubital Tunnel Syndrome. \u003cem\u003eHand (New York, N.Y.)\u003c/em\u003e 16, 45\u0026ndash;49. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/1558944719831387\u003c/span\u003e\u003cspan address=\"10.1177/1558944719831387\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePagnotta A, Formica VM, Marcovici LL, Molayem I, Taglieri E (2021) A novel local adipofascial flap for the management of recalcitrant ulnar tunnel syndrome. Hand Surg rehabilitation 40:377\u0026ndash;381. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.hansur.2021.03.010\u003c/span\u003e\u003cspan address=\"10.1016/j.hansur.2021.03.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePower HA, Peters BR, Patterson JMM, Padovano WM, Mackinnon SE (2022) Classifying the Severity of Cubital Tunnel Syndrome: A Preoperative Grading System Incorporating Electrodiagnostic Parameters. Plast Reconstr Surg 150:115e\u0026ndash;126e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/prs.0000000000009255\u003c/span\u003e\u003cspan address=\"10.1097/prs.0000000000009255\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen HW et al (2014) Clinical efficacy of simple decompression versus anterior transposition of the ulnar nerve for the treatment of cubital tunnel syndrome: A meta-analysis. Clin Neurol Neurosurg 126:150\u0026ndash;155. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.clineuro.2014.08.005\u003c/span\u003e\u003cspan address=\"10.1016/j.clineuro.2014.08.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDong YM, Han JW, Xu YL (2010) [Cubital tunnel syndrome caused by osteoarthritis of elbow joint with cyst: a case report]. Zhongguo gu shang = China J Orthop Traumatol 23:611\u0026ndash;612\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDavidge KM, Ebersole GC, Mackinnon SE (2019) Pain and Function Following Revision Cubital Tunnel Surgery. Hand (New York N Y) 14:172\u0026ndash;178. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/1558944717743593\u003c/span\u003e\u003cspan address=\"10.1177/1558944717743593\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNakashian MN, Ireland D, Kane PM (2020) Cubital Tunnel Syndrome: Current Concepts. Curr Rev Musculoskelet Med 13:520\u0026ndash;524. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s12178-020-09650-y\u003c/span\u003e\u003cspan address=\"10.1007/s12178-020-09650-y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCross D, Matullo KS (2014) Concomitant endoscopic carpal and cubital tunnel release: safety and efficacy. Hand (New York N Y) 9:43\u0026ndash;47. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11552-013-9552-3\u003c/span\u003e\u003cspan address=\"10.1007/s11552-013-9552-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYian EH et al (2015) Incidence of symptomatic compressive peripheral neuropathy after shoulder replacement. Hand (New York N Y) 10:243\u0026ndash;247. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11552-014-9701-3\u003c/span\u003e\u003cspan address=\"10.1007/s11552-014-9701-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eThomson SE et al (2022) Bioengineered nerve conduits and wraps for peripheral nerve repair of the upper limb. \u003cem\u003eThe Cochrane database of systematic reviews\u003c/em\u003e 12, Cd012574. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/14651858.CD012574.pub2\u003c/span\u003e\u003cspan address=\"10.1002/14651858.CD012574.pub2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEjiri S et al (2012) Short-term results of endoscopic (Okutsu method) versus palmar incision open carpal tunnel release: a prospective randomized controlled trial. Fukushima J Med Sci 58:49\u0026ndash;59. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.5387/fms.58.49\u003c/span\u003e\u003cspan address=\"10.5387/fms.58.49\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIdo Y et al (2016) Postoperative improvement in DASH score, clinical findings, and nerve conduction velocity in patients with cubital tunnel syndrome. Sci Rep 6:27497. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/srep27497\u003c/span\u003e\u003cspan address=\"10.1038/srep27497\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLawand JJ, Saab D, Luan A, Curtin C, Hagert E (2025) Return to play and outcomes of surgically treated upper limb nerve entrapment in athletes: a systematic review. Int Orthop. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00264-025-06473-9\u003c/span\u003e\u003cspan address=\"10.1007/s00264-025-06473-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBurahee AS, Sanders AD, Shirley C, Power DM (2021) Cubital tunnel syndrome. EFORT open reviews 6:743\u0026ndash;750. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1302/2058-5241.6.200129\u003c/span\u003e\u003cspan address=\"10.1302/2058-5241.6.200129\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOsborne NR, Anastakis DJ, Davis KD (2018) Peripheral nerve injuries, pain, and neuroplasticity. J hand therapy: official J Am Soc Hand Therapists 31:184\u0026ndash;194. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jht.2018.01.011\u003c/span\u003e\u003cspan address=\"10.1016/j.jht.2018.01.011\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChang WK, Li YP, Zhang DF, Liang BS (2017) The cubital tunnel syndrome caused by the intraneural or extraneural ganglion cysts: Case report and review of the literature. J Plast Reconstr aesthetic surgery: JPRAS 70:1404\u0026ndash;1408. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.bjps.2017.05.006\u003c/span\u003e\u003cspan address=\"10.1016/j.bjps.2017.05.006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDanoff JR, Lombardi JM, Rosenwasser MP (2014) Use of a pedicled adipose flap as a sling for anterior subcutaneous transposition of the ulnar nerve. J Hand Surg 39:552\u0026ndash;555. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jhsa.2013.12.005\u003c/span\u003e\u003cspan address=\"10.1016/j.jhsa.2013.12.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShi Q, MacDermid JC, Santaguida PL, Kyu HH (2011) Predictors of surgical outcomes following anterior transposition of ulnar nerve for cubital tunnel syndrome: a systematic review. \u003cem\u003eThe Journal of hand surgery\u003c/em\u003e 36, 1996\u0026ndash;2001.e1991-1996. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jhsa.2011.09.024\u003c/span\u003e\u003cspan address=\"10.1016/j.jhsa.2011.09.024\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHu T et al (2025) Improving Short-term Outcomes of Cubital Tunnel Syndrome Decompression with Intraoperative Dexamethasone. World Neurosurg 123885. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.wneu.2025.123885\u003c/span\u003e\u003cspan address=\"10.1016/j.wneu.2025.123885\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMeiling JB, Schappell JB, Twohey EE, Prokop LJ, Cushman DM (2023) Preoperative electrodiagnostic studies and postoperative outcomes for ulnar mononeuropathy at the elbow: A systematic review. PM R: J injury function rehabilitation 15:1326\u0026ndash;1334. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/pmrj.12952\u003c/span\u003e\u003cspan address=\"10.1002/pmrj.12952\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOlmarker K, Rydevik B (2001) Selective inhibition of tumor necrosis factor-alpha prevents nucleus pulposus-induced thrombus formation, intraneural edema, and reduction of nerve conduction velocity: possible implications for future pharmacologic treatment strategies of sciatica. Spine 26:863\u0026ndash;869. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/00007632-200104150-00007\u003c/span\u003e\u003cspan address=\"10.1097/00007632-200104150-00007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShamji MF et al (2009) Gait abnormalities and inflammatory cytokines in an autologous nucleus pulposus model of radiculopathy. Spine 34:648\u0026ndash;654. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/BRS.0b013e318197f013\u003c/span\u003e\u003cspan address=\"10.1097/BRS.0b013e318197f013\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVardeh D, Mannion RJ, Woolf CJ (2016) Toward a Mechanism-Based Approach to Pain Diagnosis. J pain 17:T50\u0026ndash;69. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jpain.2016.03.001\u003c/span\u003e\u003cspan address=\"10.1016/j.jpain.2016.03.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRhee JM, Schaufele M, Abdu WA (2006) Radiculopathy and the herniated lumbar disc. Controversies regarding pathophysiology and management. J bone joint Surg Am 88:2070\u0026ndash;2080. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2106/00004623-200609000-00023\u003c/span\u003e\u003cspan address=\"10.2106/00004623-200609000-00023\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStafford MA, Peng P, Hill DA (2007) Sciatica: a review of history, epidemiology, pathogenesis, and the role of epidural steroid injection in management. Br J Anaesth 99:461\u0026ndash;473. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/bja/aem238\u003c/span\u003e\u003cspan address=\"10.1093/bja/aem238\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXie W et al (2016) Localized Sympathectomy Reduces Mechanical Hypersensitivity by Restoring Normal Immune Homeostasis in Rat Models of Inflammatory Pain. J neuroscience: official J Soc Neurosci 36:8712\u0026ndash;8725. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1523/jneurosci.4118-15.2016\u003c/span\u003e\u003cspan address=\"10.1523/jneurosci.4118-15.2016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eManvell JJ, Manvell N, Snodgrass SJ, Reid SA (2015) Improving the radial nerve neurodynamic test: An observation of tension of the radial, median and ulnar nerves during upper limb positioning. Man Therap 20:790\u0026ndash;796. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.math.2015.03.007\u003c/span\u003e\u003cspan address=\"10.1016/j.math.2015.03.007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCouch B et al (2024) A systematic review of steroid use in peripheral nerve pathologies and treatment. Front Neurol 15:1434429. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3389/fneur.2024.1434429\u003c/span\u003e\u003cspan address=\"10.3389/fneur.2024.1434429\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDowdle SB, Chalmers PN (2020) Management of the Ulnar Nerve in Throwing Athletes. Curr Rev Musculoskelet Med 13:449\u0026ndash;456. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s12178-020-09639-7\u003c/span\u003e\u003cspan address=\"10.1007/s12178-020-09639-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eForan I et al (2016) Regional Ulnar Nerve Strain Following Decompression and Anterior Subcutaneous Transposition in Patients With Cubital Tunnel Syndrome. J Hand Surg 41:e343\u0026ndash;e350. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jhsa.2016.07.095\u003c/span\u003e\u003cspan address=\"10.1016/j.jhsa.2016.07.095\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSeidel GK et al (2025) Electrodiagnostic Assessment of Peri-Procedural Iatrogenic Peripheral Nerve Injuries and Rehabilitation. Muscle Nerve 71:747\u0026ndash;767. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/mus.28364\u003c/span\u003e\u003cspan address=\"10.1002/mus.28364\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNitz AJ, Dobner JJ, Matulionis DH (1986) Pneumatic tourniquet application and nerve integrity: motor function and electrophysiology. Exp Neurol 94:264\u0026ndash;279. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/0014-4886(86)90101-9\u003c/span\u003e\u003cspan address=\"10.1016/0014-4886(86)90101-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNitz AJ, Dobner JJ (1989) Upper extremity tourniquet effects in carpal tunnel release. J Hand Surg 14:499\u0026ndash;504. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s0363-5023(89)80011-5\u003c/span\u003e\u003cspan address=\"10.1016/s0363-5023(89)80011-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCarlton A, Khalid SI (2018) Surgical Approaches and Their Outcomes in the Treatment of Cubital Tunnel Syndrome. Front Surg 5. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3389/fsurg.2018.00048\u003c/span\u003e\u003cspan address=\"10.3389/fsurg.2018.00048\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKang J et al (2020) Regional Hyperexcitability and Chronic Neuropathic Pain Following Spinal Cord Injury. Cell Mol Neurobiol 40:861\u0026ndash;878. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s10571-020-00785-7\u003c/span\u003e\u003cspan address=\"10.1007/s10571-020-00785-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHulsebosch CE, Hains BC, Crown ED, Carlton SM (2009) Mechanisms of chronic central neuropathic pain after spinal cord injury. Brain Res Rev 60:202\u0026ndash;213. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.brainresrev.2008.12.010\u003c/span\u003e\u003cspan address=\"10.1016/j.brainresrev.2008.12.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTran EL, Crawford LK, Revisiting PNS (2020) Plasticity: How Uninjured Sensory Afferents Promote Neuropathic Pain. Front Cell Neurosci 14. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3389/fncel.2020.612982\u003c/span\u003e\u003cspan address=\"10.3389/fncel.2020.612982\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"neurosurgical-review","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nrev","sideBox":"Learn more about [Neurosurgical Review](https://www.springer.com/journal/10143)","snPcode":"10143","submissionUrl":"https://submission.nature.com/new-submission/10143/3","title":"Neurosurgical Review","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Cubital tunnel syndrome, ulnar nerve, early symptom worsening, decompression surgery, nerve conduction, postoperative recovery","lastPublishedDoi":"10.21203/rs.3.rs-6949952/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6949952/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eWhile surgical decompression for cubital tunnel syndrome (CuTS) generally leads to favorable outcomes, some patients experience early postoperative worsening marked by transient symptom flare-ups. The underlying mechanisms remain poorly understood.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eWe retrospectively analyzed 127 patients who underwent anterior ulnar nerve transposition without corticosteroids. Clinical scores (VAS, PRUNE, two-point discrimination) and electrophysiological parameters (CMAP, SNCV, MNCV) were assessed preoperatively, at 2 weeks, and at 6 months. Early worsening was defined as deterioration in any clinical indicator at 2 weeks.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eAt 6 months, most patients improved significantly. However, 26.8% showed early worsening at 2 weeks, with elevated PRUNE scores, reduced sensory discrimination, and declines in CMAP, SNCV, and MNCV (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). These changes resolved spontaneously without surgical failure. Likely contributors include inflammatory edema, mechanical stress, transient ischemia, and central sensitization.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eEarly postoperative worsening affects over one-quarter of CuTS patients but is typically self-limiting. Awareness of this pattern can prevent misdiagnosis, reduce unnecessary interventions, and improve patient counseling. Future research should identify predictive markers and develop mitigation strategies.\u003c/p\u003e","manuscriptTitle":"Short-term Symptom Aggravation after Cubital Tunnel Decompression: Clinical Features and Mechanistic Insights from a Retrospective Cohort Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-11 07:12:22","doi":"10.21203/rs.3.rs-6949952/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-01T10:21:14+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-15T14:32:57+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-15T05:41:08+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-09T02:42:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"116011634326092174675020364550133317277","date":"2025-08-06T18:09:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"175561520054009445281096536310798731993","date":"2025-08-04T22:03:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"97671261356344829300483022279982486016","date":"2025-08-04T09:11:20+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-03T01:33:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-03T01:32:50+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-23T00:30:02+00:00","index":"","fulltext":""},{"type":"submitted","content":"Neurosurgical Review","date":"2025-06-22T14:00:45+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"neurosurgical-review","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nrev","sideBox":"Learn more about [Neurosurgical Review](https://www.springer.com/journal/10143)","snPcode":"10143","submissionUrl":"https://submission.nature.com/new-submission/10143/3","title":"Neurosurgical Review","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"bf23b93f-84a1-431f-a2f3-f917cd05d46c","owner":[],"postedDate":"August 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-01-12T16:02:30+00:00","versionOfRecord":{"articleIdentity":"rs-6949952","link":"https://doi.org/10.1007/s10143-025-03927-x","journal":{"identity":"neurosurgical-review","isVorOnly":false,"title":"Neurosurgical Review"},"publishedOn":"2026-01-10 15:57:55","publishedOnDateReadable":"January 10th, 2026"},"versionCreatedAt":"2025-08-11 07:12:22","video":"","vorDoi":"10.1007/s10143-025-03927-x","vorDoiUrl":"https://doi.org/10.1007/s10143-025-03927-x","workflowStages":[]},"version":"v1","identity":"rs-6949952","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6949952","identity":"rs-6949952","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}