Comparison of Ipsilateral and Contralateral Unilateral Open-door Laminoplasty for Cervical Myelopathy

Comparison of Ipsilateral and Contralateral Unilateral Open-door Laminoplasty for Cervical Myelopathy | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Comparison of Ipsilateral and Contralateral Unilateral Open-door Laminoplasty for Cervical Myelopathy Xiaobo Zhang, Yong Wang, Yingang Zhang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6545395/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective : To compare the clinical and radiographic outcomes of ipsilateral and contralateral unilateral open-door laminoplasty (UODL) in treating cervical myelopathy. Methods : Retrospective analysis of patients who received UODL treatment at Xi'an Honghui Hospital from January 2023 to June 2024. A total of 76 patients with cervical myelopathy (42 who underwent ipsilateralopen-door laminoplasty) and 34 who underwent contralateral open-door laminoplasty) were included. All surgical procedures were carried out by experienced surgeons under general anesthesia via a standardized posterior midline approach. Clinical outcomes were evaluated via the visual analog scale (VAS), Japanese Orthopedic Association (JOA) score, and Oswestry Disability Index (ODI). Radiographic parameters, such as the spinal canal area and spinal cord area of the narrowest segment, were measured by two independent radiologists who were blinded to the clinical outcomes. Results : The two groups were comparable in terms of baseline characteristics. For sex distribution, ​ χ² =0.071 (​ P= 0.790); for age, ​ T= 0.195 (​ P= 0.846); for surgical duration, ​ T= −0.277 (​ P= 0.782); for blood loss, ​ T= 0.727 (​ P= 0.470); for hospitalization duration, ​ T= 1.536 (​ P= 0.129); for diagnostic categories, ​ χ² =0.071 (​ P= 0.790); for stenosis levels, ​ χ² =2.090 (​ P= 0.148); for surgical segments, χ² =1.543 ( P= 0.485); and for complication rates, χ² =0.04 ( P= 0.953).​Postoperatively, both groups showed significant decreases in VAS scores and improvements in the ODI. However, there were no significant intergroup differences in the VAS score (preoperative: T= 0.321, P= 0.749; postoperative: T= 0.456, P= 0.649), JOA score (preoperative: T= 0.512, P= 0.610; postoperative: T= 0.638, P= 0.525), or ODI (preoperative: T= 0.289, P= 0.774; postoperative: T= 0.378, P= 0.707).​ In terms of radiographic outcomes, there were no significant differences in the spinal canal area (preoperative: T= 0.789, P= 0.433; postoperative: T= 0.892, P= 0.376) or spinal cord area (preoperative: T= 0.654, P= 0.515; postoperative: T= 0.721, P= 0.474) between the two groups before and after surgery. Notably, both groups had an approximately 80 mm² increase in the spinal canal area and a 30 mm² increase in the spinal cord area postoperatively compared with the preoperative values.​ Conclusion : Ipsilateral and contralateral UODL achieved similar clinical and radiographic results in treating cervical myelopathy. Surgeons can choose the surgical side flexibly on the basis of specific cases. Biological sciences/Neuroscience/Spine regulation and structure/Spine structure Health sciences/Anatomy/Musculoskeletal system/Bone Cervical myelopathy Unilateral open-door laminoplasty Ipsilateral Contralateral Clinical outcomes Radiographic outcomes Figures Figure 1 Figure 2 1. Introduction Cervical myelopathy is a degenerative disorder characterized by spinal cord impairment due to cervical spondylotic changes. It can lead to severe neurological deficits and functional disabilities, imposing a substantial burden on patients and healthcare systems. Treatment options include conservative management and surgical interventions, with surgery indicated when nonsurgical treatments fail or when neurological symptoms worsen. Surgical approaches for treating cervical myelopathy are diverse and include anterior, posterior, and combined anterior‒posterior procedures. Anterior surgeries directly remove ventral spinal cord compressions, making them suitable for patients with lost cervical lordosis or kyphotic deformities. Posterior surgeries, on the other hand, indirectly relieve spinal cord compression by expanding the spinal canal. Among posterior techniques, unilateral open-door laminoplasty (UODL) and laminectomy with decompression, fixation, and fusion are common. While anterior column alignment and fusion (ACAF) directly decompresses and reduces the risk of C5 nerve palsy for multisegmental ossification of the posterior longitudinal ligament (OPLL) patients [1], its technical complexity limits widespread adoption. Compared with anterior approaches, posterior surgeries offer advantages such as a larger operative field, shorter procedure times, simplified techniques, minimal impact on the postoperative cervical range of motion, and the ability to address multisegmental spinal cord compression simultaneously. Among these, UODL, a nonfusion technique with proven clinical efficacy, has been widely utilized in treating OPLL, multisegmental cervical disc herniation, and degenerative cervical spinal stenosis [2, 3]. First described by Hirabayashi in 1977 [4], the UODL involves a complete incision on one side of the lamina and the creation of a groove on the contralateral side, which serves as a hinge for lamina elevation. The elevated lamina is then stabilized via mini titanium plates or alternative fixation methods. The primary goal of UODL is to indirectly relieve spinal cord compression by expanding the posterior spinal canal, thereby facilitating patient recovery and ensuring long-term surgical effectiveness [5]. For patients with dorsal spinal cord compression, selecting the compressed side for laminoplasty is standard practice. However, for those with ventral spinal cord compression, the choice of the laminoplasty side remains controversial. Two predominant perspectives exist: one perspective advocates for selecting the symptomatic side to achieve direct decompression, whereas the other perspective argues that, owing to the driftability of the spinal cord, the side that facilitates surgical access (commonly the left side for right-handed surgeons) can be chosen. Some experts recommend contralateral laminoplasty, particularly for patients with laterally steep OPLL[6]. Therefore, comparing the clinical and radiographic outcomes of these two approaches has significant clinical implications. This study compared the clinical and radiographic outcomes of two distinct surgical techniques for treating cervical myelopathy. The primary aim of this study was to evaluate the relative efficacy of ipsilateral versus contralateral laminoplasty in promoting neurological recovery and enhancing patients' quality of life. The findings of this research will provide valuable guidance for surgeons in selecting the optimal laminoplasty side, especially for right-handed practitioners. 2. Clinical data 2.1 General information Informed consent was obtained from all patients who adhered to the Strengthening the Reporting of Cohort Studies in Surgery (STROCSS) criteria [7]. The study was approved by the Ethics Committee of Honghui Hospital. The inclusion criteria were as follows: (1) radiologically confirmed cervical spondylotic with MRI evidence of spinal cord compression correlated with neurological symptoms; (2) aged 30–75 years with failed conservative management; (3) complete preoperative imaging series (neutral/flexion-extension X-rays, MRI, CT); and (4) a follow-up period of ≥12 months. The exclusion criteria were as follows: (1) history of cervical spine surgery or traumatic cord injury; (2) psychiatric/neurological disorders impairing outcome assessment (dementia, schizophrenia); (3) inability to tolerate general anesthesia; (4) severe systemic diseases or psychiatric disorders; (5) cervical spinal instability, isolated neck axial pain, or purely radicular symptoms; (6) a history of trauma, tumor, infection, or substance abuse; and (6) participation in other clinical trials within the past six months or incomplete or missing follow-up data. 2.2 Surgical procedure Informed consent was obtained before surgery, and comprehensive preoperative assessments were performed to exclude surgical contraindications. All surgeries were performed by experienced surgeons under general anesthesia. A standardized posterior midline approach was executed through layered cervical tissue dissection. The bilateral paravertebral muscles were subperiosteally elevated while preserving the osseoligamentous integrity of the spinous processes, with selective resection limited to the cephalad and caudal interspinous ligaments at the operative levels. Anatomical landmarks at the laminofacet junctions were precisely identified for osteotomy groove preparation. Bilateral longitudinal osteotomy grooves were meticulously created along the laminar lateral margins via a 3-mm high-velocity pneumatic drill. Unilateral complete laminotomy was performed to generate a mobile laminar flap, while the contralateral side was designed as an elastic hinge through ventral cortex preservation. Controlled elevation of the laminar flap was achieved via incremental expansion instrumentation, followed by rigid fixation via precontoured titanium miniplates (Medtronic, USA) to optimize the spinal canal volume while preserving hinge biomechanics. Meticulous hemostasis preceded anatomical reattachment of the paraspinal musculature to native spinous process insertion points via tension-balanced sutures, thereby restoring posterior cervical soft tissue architecture. 2.3 Clinical indicators Clinical outcomes were prospectively documented via validated metrics, including the visual analog scale (VAS), Japanese Orthopedic Association (JOA) score, and Oswestry Disability Index (ODI), supplemented by telephone follow-up assessments. The VAS (range 0--10) was used to quantify pain intensity, with higher scores indicating greater severity. The JOA scoring system (ranging from 0–17 for cervical applications) comprehensively evaluates neurological function across four domains: upper extremity motor skills (0–4 points), lower extremity motor capacity (0–4 points), sensory perception (0–6 points), and bladder control (0–3 points), where lower scores reflect more significant neurological impairment. The ODI (range 0–50) assesses functional disability severity through ten activity-related parameters, with elevated scores denoting greater disability. Intraoperative complications, including axial pain, C5 nerve root palsy, surgical site infection, iatrogenic nerve root or spinal cord injury, and cerebrospinal fluid leakage, were systematically recorded. 2.4 Radiographic indicators This study focused on measuring the spinal canal area and spinal cord area of the narrowest segment instead of calculating the average spinal canal area across all surgical segments. Unlike previous studies that measured the anteroposterior sagittal distance of the spinal canal [8], this study measured the actual area of the spinal canal. The spinal canal area was measured via axial imaging, with bony margins defined by the posterior vertebral body wall and lamina‒inner cortex intersections, excluding osteophyte projections and ligamentous hypertrophy ( Fig. 1 ). Spinal cord area quantification employed high-resolution T2-weighted sequences perpendicular to the neural axis, measured at the corresponding spinal segment. The cord margins were delineated at the cerebrospinal fluid–pia mater interface. All measurements were performed by two independent radiologists blinded to the clinical outcomes, with interobserver variability calculated via intraclass correlation coefficients ( Fig. 2 ). 2.5 Statistical analysis All the quantitative analyses were performed via SPSS 26.0 with rigorous protocol standardization. Normally distributed continuous variables are expressed as the mean ± standard deviation (SD), with between-group comparisons conducted through independent samples t tests. The categorical parameters were subjected to chi-square tests with continuity correction supplemented by Fisher's exact probability method when the expected cell frequencies were less than 5. Significance thresholds were established a priori at α=0.05 (two-tailed), with 95% confidence intervals calculated for critical outcome measures. P < 0.05 was considered statistically significant. 3. Results 3.1 Baseline characteristics Both groups demonstrated comparable demographic and clinical profiles. In the traditional surgical cohort (n=42), the study population comprised 31 males (73.8%) and 11 females (26.2%), with a mean age of 57.60±9.97 years. The surgical parameters included an operative duration of 96.14±31.80 minutes, estimated blood loss of 264.29±114.92 mL, and an average hospitalization period of 6.76±1.82 days. Diagnostic distribution revealed 11 cases (26.2%) of cervical spondylotic myelopathy (CSM) and 31 cases (73.8%) of cervical spondylotic radiculopathy (CSR). The most frequent stenosis level was C5-6 (50.0%, 21/42), followed by C4-5 (33.3%, 14/42), with surgical interventions performed across three-segment (28.6%, 12/42), four-segment (57.1%, 24/42), and five-segment (14.3%, 6/42) constructs. Postoperative complications included axial pain (7.1%, 3/42), incision infection (2.4%, 1/42), and cerebrospinal fluid leakage (2.4%, 1/42), yielding an overall complication rate of 11.9% (5/42). The mean follow-up duration was 13.48±4.52 months. The novel technique group (n=34) presented with similar baseline characteristics: 26 males (76.5%) and 8 females (23.5%) averaging 57.12±9.97 years of age. The surgical metrics included a 99.06±58.32-minute operative time, 247.06±85.23 mL of blood loss, and 7.44±2.03 days of hospitalization. CSM accounted for 23.5% (8/34) of the cases versus 76.5% (26/34) of the CSR cases. Stenosis was predominant at C4-5 (50.0%, 17/34) and C5-6 (32.4%, 11/34), with surgical interventions distributed in three-segment (26.5%, 9/34), four-segment (67.6%, 23/34), and five-segment (5.9%, 2/34) constructs. The complication rates included 5.9% (2/34) for axial pain and 2.9% (1/34) for incision infection, resulting in a total complication incidence of 8.8% (3/34). The average follow-up time was 12.24±5.25 months. Statistical analysis revealed no significant intergroup differences in sex distribution (χ²=0.071, P= 0.790), age ( T= 0.195, P= 0.846), surgical duration ( T= -0.277, P= 0.782), blood loss ( T= 0.727, P= 0.470), length of hospital stay ( T= 1.536, P= 0.129), diagnostic category (χ²=0.071, P= 0.790), level of spinal stenosis (χ²=2.090, P= 0.148), surgical segment (χ²=1.543, P= 0.485), or complication rate (χ²=0.04, P= 0.953) ( Table 1 ). In the Ipsidoor group, three cases of axial pain, one case of incision infection, and one case of cerebrospinal fluid leakage were observed. In the Contradoor Group (contralateral open‒door laminoplasty), two cases of axial pain and one case of incision infection were reported. Axial pain had the highest incidence, with a total of five cases. These patients experienced a gradual resolution of symptoms within one year following rehabilitation training and oral administration of nonsteroidal anti-inflammatory drugs (NSAIDs). The two patients with incision infections acquired the infection during hospitalization. After aggressive wound dressing changes, bacterial culture, and the administration of sensitive antibiotics, the patients were discharged in good condition. For patients with cerebrospinal fluid leakage, a head-elevated and foot-down position was maintained postoperatively, and antibiotics were administered for infection prevention. By prolonging the drainage time and intermittently clamping the drainage tube on the fifth postoperative day without any discomfort, the drainage tube was removed on the following day, followed by wound suturing. The patient was discharged after the wound healed uneventfully. Table 1 Comparison of baseline characteristics Group Ipsidoor Group Contradoor Group χ²/T P Gender (Male/Female, n) 31/11 26/8 0.071 0.790 Age (Mean ± SD, years) 57.60±9.97 57.12±9.97 0.195 0.846 Surgical duration (Mean ± SD, minutes) 96.14±31.80 99.06±58.32 -0.277 0.782 Blood Loss (Mean ± SD, mL) 264.29±114.92 247.06±85.23 0.727 0.470 Hospitalization duration (days) 6.76±1.82 7.44±2.03 -1.536 0.129 Type of disease 0.071 0.790 Cervical spondylotic myelopathy 11 8 Cervical spondylotic radiculopathy 31 26 OPLL 15/42 7/34 2.090 0.148 Most stenotic segment 4.341 0.199 C3-4 5 6 C4-5 14 17 C5-6 21 11 C6-7 2 0 Surgical segment 1.543 0.485 Three segments 12 9 Four segments 24 23 Five segments 6 2 Complications 0.004 0.953 Axial pain 3 2 C5 palsy 0 0 Incision infection 1 1 Cerebrospinal fluid leakage 1 0 Follow-up Duration 13.48±4.52 12.24±5.25 1.107 0.272 3. 2 Clinical efficacy The results indicated that postoperative VAS scores significantly decreased in both groups, with substantial improvements in the ODI. No significant differences were observed in the VAS score, JOA score or ODI between the two groups, either preoperatively or postoperatively ( Table 2 ). Table 2 Comparison of preoperative and postoperative VAS scores, JOA scores, and ODI indices between the UBED and PETD groups Groups Ipsidoor Group Contradoor Group T P Preoperative VAS 4.14±1.22 3.85±0.89 1.156 0.251 The last follow up VAS 1.52±0.55 1.41±0.56 0.877 0.383 Preoperative JOA 9.93±1.30 9.94±1.07 -0.046 0.964 The last follow up JOA 14.64±0.91 14.38±0.89 1.257 0.213 Preoperative ODI 33.10±4.12 32.38±3.38 0.811 0.420 The last follow up ODI 11.24±2.58 10.12±2.33 1.963 0.053 3.3 Radiographic outcomes There were no statistically significant differences in the spinal canal area or spinal cord area between the two groups before and after surgery. Interestingly, both groups showed a postoperative increase of approximately 80 mm² in the spinal canal area and approximately 30 mm² in the spinal cord area compared with the preoperative measurements ( Table 3 ). Table 3 Comparison of the spinal canal area and spinal cord area before and after surgery between the UBED group and PETD group Group Ipsidoor Group Contradoor Group T P Preoperative spinal canal area 166.48±28.12 173.26±27.49 -1.057 0.294 Postoperative spinal canal area 245.87±35.26 254.23±23.13 -1.190 0.238 Preoperative spinal cord area 49.27±12.35 54.54±13.34 -1.784 0.078 Postoperative spinal cord area 80.18±13.73 83.90±14.37 -1.148 0.255 4. Discussion Both surgical groups demonstrated comparable demographic and clinical profiles. In the ipsilateral group (n = 42), there were 31 males (73.8%) and 11 females (26.2%), with a mean age of 57.60 ± 9.97 years. The contralateral group (n = 34) included 26 males (76.5%) and 8 females (23.5%), with an average age of 57.12 ± 9.97 years. Statistical analysis confirmed no significant intergroup disparities in sex distribution (χ²=0.071, P = 0.790) or age ( T = 0.195, P = 0.846). These findings underscore the homogeneity of the study populations, which is crucial for minimizing confounding variables and the reliability of comparative outcomes in surgical techniques. The operative duration for the ipsilateral group was 96.14 ± 31.80 minutes, whereas that for the contralateral group was 99.06 ± 58.32 minutes. Blood loss was 264.29 ± 114.92 mL in the ipsilateral group and 247.06 ± 85.23 mL in the contralateral group. Statistical analysis revealed no significant differences in these parameters between the two groups ( P > 0.05). The comparable surgical durations and blood loss volumes underscore the viability of both techniques, indicating that neither approach substantially undermines patient safety or operational efficiency. Additionally, there was no difference in the learning curves between ipsilateral single-door laminoplasty and contralateral single-door laminoplasty, as both adhered strictly to the standard procedural guidelines of single-door laminoplasty techniques. This study employs a comparative analysis of clinical and radiographic outcomes following two distinct surgical techniques for the treatment of cervical myelopathy. The primary objective of this research was to determine the relative effectiveness of ipsilateral versus contralateral laminoplasty in promoting neurological recovery and improving quality of life in patients suffering from cervical myelopathy. The results indicate that while both techniques lead to improvements in clinical outcomes, no substantial differences exist between them. Three fixation modalities, including suture suspensory[9], anchor, and titanium plates, are used extensively in unilateral open-door cervical laminoplasty. In this study, mini titanium plates were used for fixation. This choice was made because titanium plates are superior in terms of the postoperative range of motion of the cervical spine, incidence of axial symptoms, and incidence of C5 paralysis; in terms of cervical curvature, titanium plates are also more effective than suture suspensions [10]. Postoperative evaluations demonstrated substantial decreases in VAS scores and remarkable improvements in the ODI for both groups. Nevertheless, no significant intergroup differences were detected in the VAS scores, Japanese Orthopedic Association (JOA) scores, or ODI ( P > 0.05). Contrary to the findings of Tang et al. [11], who reported that contralateral laminoplasty resulted in superior JOA recovery rates and spinal cord areas compared with ipsilateral single-door laminoplasty, this study revealed that the two groups had comparable outcomes in terms of pain alleviation and improvements in neurological function. This similarity is likely attributable to the effective spinal cord decompression achieved by both approaches. Research has indicated that following single-door laminoplasty, the anteroposterior diameter of the spinal canal expands from 7.51 ± 1.79 mm preoperatively to 13.98 ± 1.80 mm postoperatively, representing an increase of approximately 6 mm [9]. In contrast, in this study, the area of the spinal canal, which increased by approximately 80 mm², was measured. Compared with that in the preoperative state, the spinal canal area significantly increased after both laminoplasty methods. Some scholars posit that the optimal expansion distance for the anteroposterior diameter of the spinal canal is 4 mm [4]. Consequently, it is not necessary to use the largest possible titanium plate during surgery, as the change in the spinal cord area is correlated with the preoperative diagnosis, position of the hinge, and preoperative spinal canal area [12]. However, the long-term prognosis of patients is associated with the preoperative spinal canal area, the increased area of the spinal cord, and the JOA recovery rate [13], suggesting that a larger preoperative spinal canal area, a greater increase in the spinal cord area, and a higher JOA recovery rate are indicative of more favorable long-term therapeutic outcomes for patients. Some scholars have reported that the anteroposterior diameter of the spinal cord and spinal cord drift are more pronounced in the ipsilateral laminoplasty group [14] and that the expansion of the spinal cord after laminoplasty hinges on the contact area between the ossification and the stress surface of the dura [6]. Nevertheless, whether this implies that during contralateral laminoplasty, inferior spinal cord drift due to a smaller improvement in the contact area than during ipsilateral laminoplasty leads to less pronounced clinical symptom improvement remains to be investigated, as this finding contradicts the findings of this study. Intraoperative complications were observed in both groups. The ipsilateral group reported axial pain (7.1%, 3/42), incision infection (2.4%, 1/42), and cerebrospinal fluid leakage (2.4%, 1/42). The contralateral group experienced axial pain (5.9%, 2/34) and incision infection (2.9%, 1/34), resulting in overall complication rates of 11.9% (ipsilateral) and 8.8% (contralateral), with no significant differences between the two groups ( P > 0.05). The low complication rates suggest that both surgical approaches are relatively safe. Notably, during surgery, hinge fractures and spacer displacement should be avoided, as hinge fractures can lead to the loss of spinal curvature [3]. When difficulties are encountered in performing C3 laminoplasty, C3 laminectomy is recommended. For patients with multisegment spinal canal stenosis, C3 laminectomy can reduce the operative time, preserve the range of motion (ROM) of the cervical spine, and decrease the incidence of axial symptoms, with comparable clinical efficacy to C3 laminoplasty [15–17]. Full-segment fixation of C3‒C7 and alternative-level (C3, C5, and C7) fixation exhibit similar clinical effects and are both safe and effective. This finding indicates that there is no need to insist on full-segment fixation of all laminae; rather, effective spinal cord decompression is key [18]. Additionally, for patients with spinal cord compression at the C6–7 level, upper half laminectomy of C7 can be performed, in addition to C7 laminoplasty [17]. The incidence of axial pain following single-door laminoplasty is as high as 30%-60% [19–21]. The incidence and severity of axial pain are associated with multiple factors, although the underlying pathogenesis remains unclear. Potential sources of axial pain include the cervical intervertebral discs, muscle tissues, facet joints, spinal cord, and nerve roots. These factors include damage to the semispinalis cervicis muscle of C2 or the muscles at the cervicothoracic junction around the spinous process of C7 [22], straightening of cervical lordosis or an increase in the cervical kyphosis angle [23], atrophy of the posterior muscle tissues following dissection [24], or imbalance between the extensor and flexor muscle groups [25]. In the case of single-door laminoplasty, if the spinous process fails to return to its normal anatomical position and the paravertebral muscles cannot be reattached to the spinous process, the oblique position of the spinous process postoperatively can induce axial pain [23]. Some scholars have reported that transient pain in the deltoid muscle area occurs more frequently in the ipsilateral treatment group [14], and the underlying reasons warrant further verification and discussion. In this study, the spinous process was preserved, and after surgery, a burr was used to drill holes in the spinous process, followed by suturing the muscles to it. This was done because the absence of a muscle insertion point for the posterior cervical muscle group may increase muscle atrophy and the imbalance between the extensor and flexor muscle groups, although this hypothesis requires further validation. Notably, with preservation of the spinous process, the incidence of axial pain in this study was 6.6%, which is significantly lower than that reported in previous studies. Given the above considerations, during surgery, the exposure of the posterior structures of the cervical spine should be minimized, and damage to the muscles attached to the posterior sides of C2 and C7 should be reduced. Neck functional exercises should be initiated early postoperatively, and the use of external braces should be minimized or avoided. Shiozakiet et al. [26] detected the widespread presence of spinal cord drift postoperatively through a cervical spine MRI examination 24 hours after surgery and reported that the maximum degree of spinal cord drift occurred in the C5 vertebral segment area. This is likely because the C5 vertebra is the apex of the physiological lordosis of the cervical spine, and the C5 nerve root is shorter than the nerve roots of other segments. The posterior movement of the spinal cord renders the C5 nerve root more taut, thereby leading to C5 palsy. Previous reports have indicated that the incidence of C5 nerve palsy is 6.2% [27]. In this study, no cases of C5 nerve palsy were observed, which may be attributed to the relatively small surgical sample size. Moreover, on the basis of our experience, we believe that meticulous surgical manipulation to avoid injury to the spinal cord or nerve roots during surgery can help reduce the risk of C5 nerve palsy [28, 29]. We employed a burr for laminoplasty, and the local high temperature generated by the high-speed burr during surgery may increase the risk of iatrogenic nerve and spinal cord injury [28]. Using ice saline during surgery to lower the local temperature may be an effective measure for preventing C5 palsy [30]. In this context, some scholars suggest that if the clinical symptoms and anatomical stenosis are symmetrical, the dominant side of the patient should be chosen as the hinge side. This approach can minimize the probability of upper limb disability on the dominant hand side even if C5 nerve palsy occurs postoperatively [31]. The results of this study indicate that for patients with cervical spinal canal stenosis accompanied by ventral spinal cord compression, the choice of the side for lamina opening can be determined by the surgeon, which is consistent with the previous report by Kang et al. [27]. We propose that the cause of asymmetric decompression may be that the hinge side is too medially located or that the rotation angle of the lamina is too small, resulting in insufficient expansion of the spinal canal. For compression originating from the dorsal side of the spinal cord (primarily from the ligamentum flavum), the side with more severe compression should be the opening side. Importantly, this study did not include patients with a negative K-line, as patients with a negative K-line have severe spinal cord compression, and in clinical practice, posterior decompression, fixation, and fusion are often preferred over single-door laminoplasty. 5. Conclusion This study revealed that ipsilateral and contralateral open-door laminoplasty are equally effective in treating cervical myelopathy, as evidenced by comparable clinical outcomes and complication rates. However, several limitations should be acknowledged. The relatively small sample size, absence of long-term follow-up data, and nonrandomized study design may compromise the generalizability of the results. Future research should focus on larger cohorts and long-term follow-up to further validate these findings. Declarations Ethics statement The study was approved by the Ethics Committee of Honghui Hospital. This study was conducted according to established ethical guidelines. Consent to participate We confirmed that informed consent was obtained from all the subjects and/or their legal guardian(s). Availability of data and material The datasets used or analyzed during the current study are available from the corresponding author upon reasonable request. Competing interests All the authors declare that there are no conflicts of interest associated with this study. Acknowledgments No application. Author Contribution Xiaobo Zhang MD1: Writing - Original Draft, Validation, Formal analysis, Visualization, Software, MethodologyYong Wang MD2: Resources, Data Curation, Visualization, Investigation, Formal analysisYingang Zhang: Methodology, Writing - Review & Editing,Funding acquisition, Resources, Supervision, Project administration References Sun K, Wang S, Sun J, Wang H, Huan L, Sun X, et al. Surgical Outcomes After Anterior Controllable Antedisplacement and Fusion Compared with Single Open-Door Laminoplasty: Preliminary Analysis of Postoperative Changes of Spinal Cord Displacements on T2-Weighted Magnetic Resonance Imaging. World neurosurgery. 2019;127:e288-e298. Kothe R, Schmeiser G, Papavero L. Open-door laminoplasty : What can the unilateral approach offer? Oper Orthop Traumatol. 2018;30(1):3-12. Kim N, Cho S, Kim TH, Oh JK, Moon SH, Kim SW. Comparison of Midline Splitting versus Unilateral Open Door Laminoplasty and Its Impact on Patient Outcomes. 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Zhang KR, Yang Y, Liu H, Wang BY, Ding C, Meng Y, et al. Multivariate analysis of factors associated with spinal cord area in single-door cervical laminoplasty with miniplate fixation. BMC musculoskeletal disorders. 2021;22(1):881. Zhang KR, Yang Y, Liu H, Ding C, Wang BY, Meng Y, et al. Is there any correlation between the recovery rate of JOA and the increasing of cervical spinal cord area after single-door cervical laminoplasty? Clinical neurology and neurosurgery. 2022;213:107103. Qiao P, Zhang W, Xu T, Shao R, Tian R. Choice of open side affects clinical outcomes of unilateral open-door laminoplasty for inconsistent cervical ossification of the posterior longitudinal ligament. BMC Surg. 2024;24(1):405. Chen T, Zhang X, Meng F, Yan J, Xu G, Zhao W. Is laminoplasty or laminectomy the best strategy for C(3) segment in French-door laminoplasty? A systematic review and meta-analysis. Journal of orthopedic surgery and research. 2021;16(1):557. Yu W, Zhang F, Chen Y, Wang X, Chen D, Zheng J, et al. Efficacy and safety of laminoplasty combined with C3 laminectomy for patients with multilevel degenerative cervical myelopathy: a systematic review and meta-analysis. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2024;33(10):3915-3932. Yu W, Xie B, Fang Z, Yao Z, Zhong Y, Jiang X. What is the Preferable Method for the C3 and C7 Segments in Unilateral Open-Door Laminoplasty for Patients Diagnosed with Cervical Spondylotic Myelopathy? World neurosurgery. 2024;183:e668-e676. Zhang Z, Wang LN, Song YM, Wang L, Liu H, Liu LM, et al. Comparison of long-term clinical and radiographic outcomes between alternative-level and all-level fixation unilateral open-door laminoplasty. Spine J. 2020;20(11):1761-1769. Hosono N, Yonenobu K, Ono K. Neck and shoulder pain after laminoplasty. A noticeable complication. Spine (Phila Pa 1976). 1996;21(17):1969-1973. Hidai Y, Ebara S, Kamimura M, Tateiwa Y, Itoh H, Kinoshita T, et al. Treatment of cervical compressive myelopathy with a new dorsolateral decompressive procedure. J Neurosurg. 1999;90(2 Suppl):178-185. Kawaguchi Y, Kanamori M, Ishiara H, Nobukiyo M, Seki S, Kimura T. Preventive measures for axial symptoms following cervical laminoplasty. J Spinal Disord Tech. 2003;16(6):497-501. Sakaura H, Hosono N, Mukai Y, Fujii R, Iwasaki M, Yoshikawa H. Persistent local pain after posterior spine surgery for thoracic lesions. J Spinal Disord Tech. 2007;20(3):226-228. Okada M, Minamide A, Endo T, Yoshida M, Kawakami M, Ando M, et al. A prospective randomized study of clinical outcomes in patients with cervical compressive myelopathy treated with open-door or French-door laminoplasty. Spine (Phila Pa 1976). 2009;34(11):1119-1126. Takeuchi K, Yokoyama T, Aburakawa S, Saito A, Numasawa T, Iwasaki T, et al. Axial symptoms after cervical laminoplasty with C3 laminectomy compared with conventional C3-C7 laminoplasty: a modified laminoplasty preserving the semispinalis cervicis inserted into axis. Spine (Phila Pa 1976). 2005;30(22):2544-2549. Nakama S, Nitanai K, Oohashi Y, Endo T, Hoshino Y. Cervical muscle strength after laminoplasty. J Orthop Sci. 2003;8(1):36-40. Shiozaki T, Otsuka H, Nakata Y, Yokoyama T, Takeuchi K, Ono A, et al. Spinal cord shift on magnetic resonance imaging at 24 hours after cervical laminoplasty. Spine (Phila Pa 1976). 2009;34(3):274-279. Kang KC, Im SK, Lee JH, Lee KY, Seo DU, Hwang IU. Impact of lamina-open side on unilateral open door laminoplasty in patients with degenerative cervical myelopathy. Sci Rep. 2023;13(1):2062. Imagama S, Matsuyama Y, Yukawa Y, Kawakami N, Kamiya M, Kanemura T, et al. C5 palsy after cervical laminoplasty: a multicenter study. J Bone Joint Surg Br. 2010;92(3):393-400. Hasegawa K, Homma T, Chiba Y. Upper extremity palsy following cervical decompression surgery results from a transient spinal cord lesion. Spine (Phila Pa 1976). 2007;32(6):E197-202. Takenaka S, Hosono N, Mukai Y, Miwa T, Fuji T. The use of cooled saline during bone drilling to reduce the incidence of upper-limb palsy after cervical laminoplasty: clinical article. J Neurosurg Spine. 2013;19(4):420-427. Levi DJ, Brusko GD, Levi AD, Wang MY. Does hinge sidedness influence laterality of C5 palsy after expansile open-door cervical laminoplasty? Neurosurg Focus. 2023;55(3):E6. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-6545395","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":463683318,"identity":"36fb5d8c-ba39-4eb7-aad3-69ba3de4d46b","order_by":0,"name":"Xiaobo Zhang","email":"","orcid":"","institution":"the First Affiliated Hospital of Xi'an Jiao Tong University","correspondingAuthor":false,"prefix":"","firstName":"Xiaobo","middleName":"","lastName":"Zhang","suffix":""},{"id":463683319,"identity":"20494e1b-16c9-467f-841d-e8386734a2bb","order_by":1,"name":"Yong Wang","email":"","orcid":"","institution":"Honghui Hospital, Xi'an Jiaotong University","correspondingAuthor":false,"prefix":"","firstName":"Yong","middleName":"","lastName":"Wang","suffix":""},{"id":463683320,"identity":"a12b22f3-6220-4024-a692-25cfa01a2a9a","order_by":2,"name":"Yingang Zhang","email":"data:image/png;base64,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","orcid":"","institution":"the First Affiliated Hospital of Xi'an Jiao Tong University","correspondingAuthor":true,"prefix":"","firstName":"Yingang","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2025-04-28 08:08:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6545395/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6545395/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":83752319,"identity":"00a9054b-72f7-4705-b27c-f7572e3ec06f","added_by":"auto","created_at":"2025-06-02 07:19:34","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":2323649,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of spinal canal area measurement.\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-6545395/v1/6264fed8c0b93b138e677767.png"},{"id":83752108,"identity":"7646397a-d34f-40d5-ac39-9e2f8124f971","added_by":"auto","created_at":"2025-06-02 07:11:34","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":2352196,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of spinal cord area measurement.\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-6545395/v1/b047a9cde77d870f67a15011.png"},{"id":84174888,"identity":"f5a5ba2c-8557-4f26-932f-eddc4eb77c87","added_by":"auto","created_at":"2025-06-09 02:01:43","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":7504149,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6545395/v1/f537310f-ca86-4136-a4ed-178e00f92f72.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparison of Ipsilateral and Contralateral Unilateral Open-door Laminoplasty for Cervical Myelopathy","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eCervical myelopathy is a degenerative disorder characterized by spinal cord impairment due to cervical spondylotic changes. It can lead to severe neurological deficits and functional disabilities, imposing a substantial burden on patients and healthcare systems. Treatment options include conservative management and surgical interventions, with surgery indicated when nonsurgical treatments fail or when neurological symptoms worsen.\u003c/p\u003e \u003cp\u003eSurgical approaches for treating cervical myelopathy are diverse and include anterior, posterior, and combined anterior‒posterior procedures. Anterior surgeries directly remove ventral spinal cord compressions, making them suitable for patients with lost cervical lordosis or kyphotic deformities. Posterior surgeries, on the other hand, indirectly relieve spinal cord compression by expanding the spinal canal. Among posterior techniques, unilateral open-door laminoplasty (UODL) and laminectomy with decompression, fixation, and fusion are common. While anterior column alignment and fusion (ACAF) directly decompresses and reduces the risk of C5 nerve palsy for multisegmental ossification of the posterior longitudinal ligament (OPLL) patients [1], its technical complexity limits widespread adoption. Compared with anterior approaches, posterior surgeries offer advantages such as a larger operative field, shorter procedure times, simplified techniques, minimal impact on the postoperative cervical range of motion, and the ability to address multisegmental spinal cord compression simultaneously. Among these, UODL, a nonfusion technique with proven clinical efficacy, has been widely utilized in treating OPLL, multisegmental cervical disc herniation, and degenerative cervical spinal stenosis [2, 3]. First described by Hirabayashi in 1977 [4], the UODL involves a complete incision on one side of the lamina and the creation of a groove on the contralateral side, which serves as a hinge for lamina elevation. The elevated lamina is then stabilized via mini titanium plates or alternative fixation methods. The primary goal of UODL is to indirectly relieve spinal cord compression by expanding the posterior spinal canal, thereby facilitating patient recovery and ensuring long-term surgical effectiveness [5].\u003c/p\u003e \u003cp\u003eFor patients with dorsal spinal cord compression, selecting the compressed side for laminoplasty is standard practice. However, for those with ventral spinal cord compression, the choice of the laminoplasty side remains controversial. Two predominant perspectives exist: one perspective advocates for selecting the symptomatic side to achieve direct decompression, whereas the other perspective argues that, owing to the driftability of the spinal cord, the side that facilitates surgical access (commonly the left side for right-handed surgeons) can be chosen. Some experts recommend contralateral laminoplasty, particularly for patients with laterally steep OPLL[6]. Therefore, comparing the clinical and radiographic outcomes of these two approaches has significant clinical implications.\u003c/p\u003e \u003cp\u003eThis study compared the clinical and radiographic outcomes of two distinct surgical techniques for treating cervical myelopathy. The primary aim of this study was to evaluate the relative efficacy of ipsilateral versus contralateral laminoplasty in promoting neurological recovery and enhancing patients' quality of life. The findings of this research will provide valuable guidance for surgeons in selecting the optimal laminoplasty side, especially for right-handed practitioners.\u003c/p\u003e"},{"header":"2. Clinical data","content":"\u003ch2\u003e2.1 General information\u003c/h2\u003e\n\u003cp\u003eInformed consent was obtained from all patients who adhered to the Strengthening the Reporting of Cohort Studies in Surgery (STROCSS) criteria [7]. The study was approved by the Ethics Committee of Honghui Hospital.\u003c/p\u003e\n\u003cp\u003eThe inclusion criteria were as follows: (1) radiologically confirmed cervical spondylotic with MRI evidence of spinal cord compression correlated with neurological symptoms; (2) aged 30\u0026ndash;75 years with failed conservative management; (3) complete preoperative imaging series (neutral/flexion-extension X-rays, MRI, CT); and (4) a follow-up period of \u0026ge;12 months. The exclusion criteria were as follows: (1) history of cervical spine surgery or traumatic cord injury; (2) psychiatric/neurological disorders impairing outcome assessment (dementia, schizophrenia); (3) inability to tolerate general anesthesia; (4) severe systemic diseases or psychiatric disorders; (5) cervical spinal instability, isolated neck axial pain, or purely radicular symptoms; (6) a history of trauma, tumor, infection, or substance abuse; and (6) participation in other clinical trials within the past six months or incomplete or missing follow-up data.\u003c/p\u003e\n\u003ch2\u003e2.2 Surgical procedure\u003c/h2\u003e\n\u003cp\u003eInformed consent was obtained before surgery, and comprehensive preoperative assessments were performed to exclude surgical contraindications. All surgeries were performed by experienced surgeons under general anesthesia.\u003c/p\u003e\n\u003cp\u003eA standardized posterior midline approach was executed through layered cervical tissue dissection. The bilateral paravertebral muscles were subperiosteally elevated while preserving the osseoligamentous integrity of the spinous processes, with selective resection limited to the cephalad and caudal interspinous ligaments at the operative levels. Anatomical landmarks at the laminofacet junctions were precisely identified for osteotomy groove preparation. Bilateral longitudinal osteotomy grooves were meticulously created along the laminar lateral margins via a 3-mm high-velocity pneumatic drill. Unilateral complete laminotomy was performed to generate a mobile laminar flap, while the contralateral side was designed as an elastic hinge through ventral cortex preservation. Controlled elevation of the laminar flap was achieved via incremental expansion instrumentation, followed by rigid fixation via precontoured titanium miniplates (Medtronic, USA) to optimize the spinal canal volume while preserving hinge biomechanics. Meticulous hemostasis preceded anatomical reattachment of the paraspinal musculature to native spinous process insertion points via tension-balanced sutures, thereby restoring posterior cervical soft tissue architecture.\u003c/p\u003e\n\u003ch2\u003e2.3 Clinical indicators\u003c/h2\u003e\n\u003cp\u003eClinical outcomes were prospectively documented via validated metrics, including the visual analog scale (VAS), Japanese Orthopedic Association (JOA) score, and Oswestry Disability Index (ODI), supplemented by telephone follow-up assessments. The VAS (range 0--10) was used to quantify pain intensity, with higher scores indicating greater severity. The JOA scoring system (ranging from 0\u0026ndash;17 for cervical applications) comprehensively evaluates neurological function across four domains: upper extremity motor skills (0\u0026ndash;4 points), lower extremity motor capacity (0\u0026ndash;4 points), sensory perception (0\u0026ndash;6 points), and bladder control (0\u0026ndash;3 points), where lower scores reflect more significant neurological impairment. The ODI (range 0\u0026ndash;50) assesses functional disability severity through ten activity-related parameters, with elevated scores denoting greater disability.\u003c/p\u003e\n\u003cp\u003eIntraoperative complications, including axial pain, C5 nerve root palsy, surgical site infection, iatrogenic nerve root or spinal cord injury, and cerebrospinal fluid leakage, were systematically recorded.\u003c/p\u003e\n\u003ch2\u003e2.4 Radiographic indicators\u003c/h2\u003e\n\u003cp\u003eThis study focused on measuring the spinal canal area and spinal cord area of the narrowest segment instead of calculating the average spinal canal area across all surgical segments. Unlike previous studies that measured the anteroposterior sagittal distance of the spinal canal [8], this study measured the actual area of the spinal canal. The spinal canal area was measured via axial imaging, with bony margins defined by the posterior vertebral body wall and lamina‒inner cortex intersections, excluding osteophyte projections and ligamentous hypertrophy (\u003cstrong\u003eFig. 1\u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003eSpinal cord area quantification employed high-resolution T2-weighted sequences perpendicular to the neural axis, measured at the corresponding spinal segment. The cord margins were delineated at the cerebrospinal fluid\u0026ndash;pia mater interface. All measurements were performed by two independent radiologists blinded to the clinical outcomes, with interobserver variability calculated via intraclass correlation coefficients (\u003cstrong\u003eFig. 2\u003c/strong\u003e).\u003c/p\u003e\n\u003ch2\u003e2.5 Statistical analysis\u003c/h2\u003e\n\u003cp\u003eAll the quantitative analyses were performed via SPSS 26.0 with rigorous protocol standardization. Normally distributed continuous variables are expressed as the mean \u0026plusmn; standard deviation (SD), with between-group comparisons conducted through independent samples t tests. The categorical parameters were subjected to chi-square tests with continuity correction supplemented by Fisher\u0026apos;s exact probability method when the expected cell frequencies were less than 5. Significance thresholds were established a priori at \u0026alpha;=0.05 (two-tailed), with 95% confidence intervals calculated for critical outcome measures. \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"3. Results","content":"\u003ch2\u003e3.1 Baseline characteristics\u003c/h2\u003e\n\u003cp\u003eBoth groups demonstrated comparable demographic and clinical profiles. In the traditional surgical cohort (n=42), the study population comprised 31 males (73.8%) and 11 females (26.2%), with a mean age of 57.60\u0026plusmn;9.97 years. The surgical parameters included an operative duration of 96.14\u0026plusmn;31.80 minutes, estimated blood loss of 264.29\u0026plusmn;114.92 mL, and an average hospitalization period of 6.76\u0026plusmn;1.82 days. Diagnostic distribution revealed 11 cases (26.2%) of cervical spondylotic myelopathy (CSM) and 31 cases (73.8%) of cervical spondylotic radiculopathy (CSR). The most frequent stenosis level was C5-6 (50.0%, 21/42), followed by C4-5 (33.3%, 14/42), with surgical interventions performed across three-segment (28.6%, 12/42), four-segment (57.1%, 24/42), and five-segment (14.3%, 6/42) constructs. Postoperative complications included axial pain (7.1%, 3/42), incision infection (2.4%, 1/42), and cerebrospinal fluid leakage (2.4%, 1/42), yielding an overall complication rate of 11.9% (5/42). The mean follow-up duration was 13.48\u0026plusmn;4.52 months.\u003c/p\u003e\n\u003cp\u003eThe novel technique group (n=34) presented with similar baseline characteristics: 26 males (76.5%) and 8 females (23.5%) averaging 57.12\u0026plusmn;9.97 years of age. The surgical metrics included a 99.06\u0026plusmn;58.32-minute operative time, 247.06\u0026plusmn;85.23 mL of blood loss, and 7.44\u0026plusmn;2.03 days of hospitalization. CSM accounted for 23.5% (8/34) of the cases versus 76.5% (26/34) of the CSR cases. Stenosis was predominant at C4-5 (50.0%, 17/34) and C5-6 (32.4%, 11/34), with surgical interventions distributed in three-segment (26.5%, 9/34), four-segment (67.6%, 23/34), and five-segment (5.9%, 2/34) constructs. The complication rates included 5.9% (2/34) for axial pain and 2.9% (1/34) for incision infection, resulting in a total complication incidence of 8.8% (3/34). The average follow-up time was 12.24\u0026plusmn;5.25 months.\u003c/p\u003e\n\u003cp\u003eStatistical analysis revealed no significant intergroup differences in sex distribution (\u0026chi;\u0026sup2;=0.071, \u003cem\u003eP=\u003c/em\u003e0.790), age (\u003cem\u003eT=\u003c/em\u003e0.195, \u003cem\u003eP=\u003c/em\u003e0.846), surgical duration (\u003cem\u003eT=\u003c/em\u003e-0.277, \u003cem\u003eP=\u003c/em\u003e0.782), blood loss (\u003cem\u003eT=\u003c/em\u003e0.727, \u003cem\u003eP=\u003c/em\u003e0.470), length of hospital stay (\u003cem\u003eT=\u003c/em\u003e1.536, \u003cem\u003eP=\u003c/em\u003e0.129), diagnostic category (\u0026chi;\u0026sup2;=0.071, \u003cem\u003eP=\u003c/em\u003e0.790), level of spinal stenosis (\u0026chi;\u0026sup2;=2.090, \u003cem\u003eP=\u003c/em\u003e0.148), surgical segment (\u0026chi;\u0026sup2;=1.543, \u003cem\u003eP=\u003c/em\u003e0.485), or complication rate (\u0026chi;\u0026sup2;=0.04, \u003cem\u003eP=\u003c/em\u003e0.953) (\u003cstrong\u003eTable 1\u003c/strong\u003e). In the Ipsidoor group, three cases of axial pain, one case of incision infection, and one case of cerebrospinal fluid leakage were observed. In the Contradoor Group (contralateral open‒door laminoplasty), two cases of axial pain and one case of incision infection were reported. Axial pain had the highest incidence, with a total of five cases. These patients experienced a gradual resolution of symptoms within one year following rehabilitation training and oral administration of nonsteroidal anti-inflammatory drugs (NSAIDs). The two patients with incision infections acquired the infection during hospitalization. After aggressive wound dressing changes, bacterial culture, and the administration of sensitive antibiotics, the patients were discharged in good condition. For patients with cerebrospinal fluid leakage, a head-elevated and foot-down position was maintained postoperatively, and antibiotics were administered for infection prevention. By prolonging the drainage time and intermittently clamping the drainage tube on the fifth postoperative day without any discomfort, the drainage tube was removed on the following day, followed by wound suturing. The patient was discharged after the wound healed uneventfully.\u003c/p\u003e\n\u003ch3\u003eTable 1\u0026nbsp;Comparison of baseline characteristics\u003c/h3\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"121%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003eIpsidoor Group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003eContradoor Group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026chi;\u0026sup2;/T\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eGender (Male/Female, n)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e31/11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e26/8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.071\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.790\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eAge (Mean \u0026plusmn; SD, years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e57.60\u0026plusmn;9.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e57.12\u0026plusmn;9.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.195\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.846\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eSurgical duration (Mean \u0026plusmn; SD, minutes)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e96.14\u0026plusmn;31.80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e99.06\u0026plusmn;58.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e-0.277\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.782\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eBlood Loss (Mean \u0026plusmn; SD, mL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e264.29\u0026plusmn;114.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e247.06\u0026plusmn;85.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.727\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.470\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eHospitalization duration (days)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e6.76\u0026plusmn;1.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e7.44\u0026plusmn;2.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e-1.536\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.129\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eType of disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.071\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.790\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eCervical spondylotic myelopathy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eCervical spondylotic radiculopathy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eOPLL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e15/42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e7/34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e2.090\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.148\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eMost stenotic segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e4.341\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.199\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eC3-4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eC4-5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eC5-6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eC6-7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eSurgical segment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e1.543\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.485\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eThree segments\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eFour segments\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eFive segments\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eComplications\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.004\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.953\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eAxial pain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eC5 palsy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Incision infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; Cerebrospinal fluid leakage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 40px;\"\u003e\n \u003cp\u003eFollow-up Duration\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16px;\"\u003e\n \u003cp\u003e13.48\u0026plusmn;4.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e12.24\u0026plusmn;5.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e1.107\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.272\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ch2\u003e3.\u003cstrong\u003e2 Clinical\u0026nbsp;\u003c/strong\u003eefficacy\u003c/h2\u003e\n\u003cp\u003eThe results indicated that postoperative VAS scores significantly decreased in both groups, with substantial improvements in the ODI. No significant differences were observed in the VAS score, JOA score or ODI between the two groups, either preoperatively or postoperatively (\u003cstrong\u003eTable 2\u003c/strong\u003e).\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e Comparison of preoperative and postoperative VAS scores, JOA scores, and ODI\u0026nbsp;indices\u0026nbsp;between the UBED and PETD groups\u003c/h3\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003eGroups\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 21px;\"\u003e\n \u003cp\u003eIpsidoor Group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003eContradoor Group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003ePreoperative VAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 21px;\"\u003e\n \u003cp\u003e4.14\u0026plusmn;1.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003e3.85\u0026plusmn;0.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e1.156\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.251\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003eThe last follow up VAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 21px;\"\u003e\n \u003cp\u003e1.52\u0026plusmn;0.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003e1.41\u0026plusmn;0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.877\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.383\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003ePreoperative JOA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 21px;\"\u003e\n \u003cp\u003e9.93\u0026plusmn;1.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003e9.94\u0026plusmn;1.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e-0.046\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.964\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003eThe last follow up JOA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 21px;\"\u003e\n \u003cp\u003e14.64\u0026plusmn;0.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003e14.38\u0026plusmn;0.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e1.257\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.213\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003ePreoperative ODI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 21px;\"\u003e\n \u003cp\u003e33.10\u0026plusmn;4.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003e32.38\u0026plusmn;3.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.811\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.420\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003eThe last follow up ODI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 21px;\"\u003e\n \u003cp\u003e11.24\u0026plusmn;2.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003e10.12\u0026plusmn;2.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e1.963\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e0.053\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ch2\u003e3.3\u0026nbsp;\u003cstrong\u003eRadiographic outcomes\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eThere were no statistically significant differences in the spinal canal area or spinal cord area between the two groups before and after surgery. Interestingly, both groups showed a postoperative increase of approximately 80 mm\u0026sup2; in the spinal canal area and approximately 30 mm\u0026sup2; in the spinal cord area compared with the preoperative measurements (\u003cstrong\u003eTable 3\u003c/strong\u003e).\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e Comparison of the spinal canal area and spinal cord area before and after surgery between the UBED group and PETD group\u003c/h3\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"112%\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003eIpsidoor Group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003eContradoor Group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003ePreoperative spinal canal area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e166.48\u0026plusmn;28.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e173.26\u0026plusmn;27.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e-1.057\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.294\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003ePostoperative\u0026nbsp;spinal canal area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e245.87\u0026plusmn;35.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e254.23\u0026plusmn;23.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e-1.190\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.238\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003ePreoperative spinal cord area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e49.27\u0026plusmn;12.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e54.54\u0026plusmn;13.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e-1.784\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.078\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 37px;\"\u003e\n \u003cp\u003ePostoperative spinal cord area\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e80.18\u0026plusmn;13.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e83.90\u0026plusmn;14.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9px;\"\u003e\n \u003cp\u003e-1.148\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e0.255\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eBoth surgical groups demonstrated comparable demographic and clinical profiles. In the ipsilateral group (n\u0026thinsp;=\u0026thinsp;42), there were 31 males (73.8%) and 11 females (26.2%), with a mean age of 57.60\u0026thinsp;\u0026plusmn;\u0026thinsp;9.97 years. The contralateral group (n\u0026thinsp;=\u0026thinsp;34) included 26 males (76.5%) and 8 females (23.5%), with an average age of 57.12\u0026thinsp;\u0026plusmn;\u0026thinsp;9.97 years. Statistical analysis confirmed no significant intergroup disparities in sex distribution (χ\u0026sup2;=0.071, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.790) or age (\u003cem\u003eT\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.195, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.846). These findings underscore the homogeneity of the study populations, which is crucial for minimizing confounding variables and the reliability of comparative outcomes in surgical techniques.\u003c/p\u003e \u003cp\u003eThe operative duration for the ipsilateral group was 96.14\u0026thinsp;\u0026plusmn;\u0026thinsp;31.80 minutes, whereas that for the contralateral group was 99.06\u0026thinsp;\u0026plusmn;\u0026thinsp;58.32 minutes. Blood loss was 264.29\u0026thinsp;\u0026plusmn;\u0026thinsp;114.92 mL in the ipsilateral group and 247.06\u0026thinsp;\u0026plusmn;\u0026thinsp;85.23 mL in the contralateral group. Statistical analysis revealed no significant differences in these parameters between the two groups (\u003cem\u003eP\u0026thinsp;\u0026gt;\u003c/em\u003e\u0026thinsp;0.05). The comparable surgical durations and blood loss volumes underscore the viability of both techniques, indicating that neither approach substantially undermines patient safety or operational efficiency. Additionally, there was no difference in the learning curves between ipsilateral single-door laminoplasty and contralateral single-door laminoplasty, as both adhered strictly to the standard procedural guidelines of single-door laminoplasty techniques.\u003c/p\u003e \u003cp\u003eThis study employs a comparative analysis of clinical and radiographic outcomes following two distinct surgical techniques for the treatment of cervical myelopathy. The primary objective of this research was to determine the relative effectiveness of ipsilateral versus contralateral laminoplasty in promoting neurological recovery and improving quality of life in patients suffering from cervical myelopathy. The results indicate that while both techniques lead to improvements in clinical outcomes, no substantial differences exist between them. Three fixation modalities, including suture suspensory[9], anchor, and titanium plates, are used extensively in unilateral open-door cervical laminoplasty. In this study, mini titanium plates were used for fixation. This choice was made because titanium plates are superior in terms of the postoperative range of motion of the cervical spine, incidence of axial symptoms, and incidence of C5 paralysis; in terms of cervical curvature, titanium plates are also more effective than suture suspensions [10].\u003c/p\u003e \u003cp\u003ePostoperative evaluations demonstrated substantial decreases in VAS scores and remarkable improvements in the ODI for both groups. Nevertheless, no significant intergroup differences were detected in the VAS scores, Japanese Orthopedic Association (JOA) scores, or ODI (\u003cem\u003eP\u0026thinsp;\u0026gt;\u003c/em\u003e\u0026thinsp;0.05). Contrary to the findings of Tang et al. [11], who reported that contralateral laminoplasty resulted in superior JOA recovery rates and spinal cord areas compared with ipsilateral single-door laminoplasty, this study revealed that the two groups had comparable outcomes in terms of pain alleviation and improvements in neurological function. This similarity is likely attributable to the effective spinal cord decompression achieved by both approaches.\u003c/p\u003e \u003cp\u003eResearch has indicated that following single-door laminoplasty, the anteroposterior diameter of the spinal canal expands from 7.51\u0026thinsp;\u0026plusmn;\u0026thinsp;1.79 mm preoperatively to 13.98\u0026thinsp;\u0026plusmn;\u0026thinsp;1.80 mm postoperatively, representing an increase of approximately 6 mm [9]. In contrast, in this study, the area of the spinal canal, which increased by approximately 80 mm\u0026sup2;, was measured. Compared with that in the preoperative state, the spinal canal area significantly increased after both laminoplasty methods. Some scholars posit that the optimal expansion distance for the anteroposterior diameter of the spinal canal is 4 mm [4]. Consequently, it is not necessary to use the largest possible titanium plate during surgery, as the change in the spinal cord area is correlated with the preoperative diagnosis, position of the hinge, and preoperative spinal canal area [12]. However, the long-term prognosis of patients is associated with the preoperative spinal canal area, the increased area of the spinal cord, and the JOA recovery rate [13], suggesting that a larger preoperative spinal canal area, a greater increase in the spinal cord area, and a higher JOA recovery rate are indicative of more favorable long-term therapeutic outcomes for patients. Some scholars have reported that the anteroposterior diameter of the spinal cord and spinal cord drift are more pronounced in the ipsilateral laminoplasty group [14] and that the expansion of the spinal cord after laminoplasty hinges on the contact area between the ossification and the stress surface of the dura [6]. Nevertheless, whether this implies that during contralateral laminoplasty, inferior spinal cord drift due to a smaller improvement in the contact area than during ipsilateral laminoplasty leads to less pronounced clinical symptom improvement remains to be investigated, as this finding contradicts the findings of this study.\u003c/p\u003e \u003cp\u003eIntraoperative complications were observed in both groups. The ipsilateral group reported axial pain (7.1%, 3/42), incision infection (2.4%, 1/42), and cerebrospinal fluid leakage (2.4%, 1/42). The contralateral group experienced axial pain (5.9%, 2/34) and incision infection (2.9%, 1/34), resulting in overall complication rates of 11.9% (ipsilateral) and 8.8% (contralateral), with no significant differences between the two groups (\u003cem\u003eP\u0026thinsp;\u0026gt;\u003c/em\u003e\u0026thinsp;0.05). The low complication rates suggest that both surgical approaches are relatively safe.\u003c/p\u003e \u003cp\u003eNotably, during surgery, hinge fractures and spacer displacement should be avoided, as hinge fractures can lead to the loss of spinal curvature [3]. When difficulties are encountered in performing C3 laminoplasty, C3 laminectomy is recommended. For patients with multisegment spinal canal stenosis, C3 laminectomy can reduce the operative time, preserve the range of motion (ROM) of the cervical spine, and decrease the incidence of axial symptoms, with comparable clinical efficacy to C3 laminoplasty [15\u0026ndash;17]. Full-segment fixation of C3‒C7 and alternative-level (C3, C5, and C7) fixation exhibit similar clinical effects and are both safe and effective. This finding indicates that there is no need to insist on full-segment fixation of all laminae; rather, effective spinal cord decompression is key [18]. Additionally, for patients with spinal cord compression at the C6\u0026ndash;7 level, upper half laminectomy of C7 can be performed, in addition to C7 laminoplasty [17].\u003c/p\u003e \u003cp\u003eThe incidence of axial pain following single-door laminoplasty is as high as 30%-60% [19\u0026ndash;21]. The incidence and severity of axial pain are associated with multiple factors, although the underlying pathogenesis remains unclear. Potential sources of axial pain include the cervical intervertebral discs, muscle tissues, facet joints, spinal cord, and nerve roots. These factors include damage to the semispinalis cervicis muscle of C2 or the muscles at the cervicothoracic junction around the spinous process of C7 [22], straightening of cervical lordosis or an increase in the cervical kyphosis angle [23], atrophy of the posterior muscle tissues following dissection [24], or imbalance between the extensor and flexor muscle groups [25]. In the case of single-door laminoplasty, if the spinous process fails to return to its normal anatomical position and the paravertebral muscles cannot be reattached to the spinous process, the oblique position of the spinous process postoperatively can induce axial pain [23]. Some scholars have reported that transient pain in the deltoid muscle area occurs more frequently in the ipsilateral treatment group [14], and the underlying reasons warrant further verification and discussion. In this study, the spinous process was preserved, and after surgery, a burr was used to drill holes in the spinous process, followed by suturing the muscles to it. This was done because the absence of a muscle insertion point for the posterior cervical muscle group may increase muscle atrophy and the imbalance between the extensor and flexor muscle groups, although this hypothesis requires further validation. Notably, with preservation of the spinous process, the incidence of axial pain in this study was 6.6%, which is significantly lower than that reported in previous studies. Given the above considerations, during surgery, the exposure of the posterior structures of the cervical spine should be minimized, and damage to the muscles attached to the posterior sides of C2 and C7 should be reduced. Neck functional exercises should be initiated early postoperatively, and the use of external braces should be minimized or avoided.\u003c/p\u003e \u003cp\u003eShiozakiet et al. [26] detected the widespread presence of spinal cord drift postoperatively through a cervical spine MRI examination 24 hours after surgery and reported that the maximum degree of spinal cord drift occurred in the C5 vertebral segment area. This is likely because the C5 vertebra is the apex of the physiological lordosis of the cervical spine, and the C5 nerve root is shorter than the nerve roots of other segments. The posterior movement of the spinal cord renders the C5 nerve root more taut, thereby leading to C5 palsy. Previous reports have indicated that the incidence of C5 nerve palsy is 6.2% [27]. In this study, no cases of C5 nerve palsy were observed, which may be attributed to the relatively small surgical sample size. Moreover, on the basis of our experience, we believe that meticulous surgical manipulation to avoid injury to the spinal cord or nerve roots during surgery can help reduce the risk of C5 nerve palsy [28, 29]. We employed a burr for laminoplasty, and the local high temperature generated by the high-speed burr during surgery may increase the risk of iatrogenic nerve and spinal cord injury [28]. Using ice saline during surgery to lower the local temperature may be an effective measure for preventing C5 palsy [30]. In this context, some scholars suggest that if the clinical symptoms and anatomical stenosis are symmetrical, the dominant side of the patient should be chosen as the hinge side. This approach can minimize the probability of upper limb disability on the dominant hand side even if C5 nerve palsy occurs postoperatively [31].\u003c/p\u003e \u003cp\u003eThe results of this study indicate that for patients with cervical spinal canal stenosis accompanied by ventral spinal cord compression, the choice of the side for lamina opening can be determined by the surgeon, which is consistent with the previous report by Kang et al. [27]. We propose that the cause of asymmetric decompression may be that the hinge side is too medially located or that the rotation angle of the lamina is too small, resulting in insufficient expansion of the spinal canal. For compression originating from the dorsal side of the spinal cord (primarily from the ligamentum flavum), the side with more severe compression should be the opening side. Importantly, this study did not include patients with a negative K-line, as patients with a negative K-line have severe spinal cord compression, and in clinical practice, posterior decompression, fixation, and fusion are often preferred over single-door laminoplasty.\u003c/p\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eThis study revealed that ipsilateral and contralateral open-door laminoplasty are equally effective in treating cervical myelopathy, as evidenced by comparable clinical outcomes and complication rates. However, several limitations should be acknowledged. The relatively small sample size, absence of long-term follow-up data, and nonrandomized study design may compromise the generalizability of the results. Future research should focus on larger cohorts and long-term follow-up to further validate these findings.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eEthics statement\u003c/h2\u003e\n\u003cp\u003eThe study was approved by the Ethics Committee of Honghui Hospital. This study was conducted according to established ethical guidelines.\u003c/p\u003e\n\u003ch2\u003eConsent to participate\u003c/h2\u003e\n\u003cp\u003eWe confirmed that informed consent was obtained from all the subjects and/or their legal guardian(s).\u003c/p\u003e\n\u003ch2\u003eAvailability of data and material\u003c/h2\u003e\n\u003cp\u003eThe datasets used or analyzed during the current study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003ch2\u003eCompeting interests\u003c/h2\u003e\n\u003cp\u003eAll the authors declare that there are no conflicts of interest associated with this study.\u003c/p\u003e\n\u003ch2\u003eAcknowledgments\u003c/h2\u003e\n\u003cp\u003eNo application.\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003eXiaobo Zhang MD1: Writing - Original Draft, Validation, Formal analysis, Visualization, Software, MethodologyYong Wang MD2: Resources, Data Curation, Visualization, Investigation, Formal analysisYingang Zhang: Methodology, Writing - Review \u0026amp; Editing,Funding acquisition, Resources, Supervision, Project administration\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eSun K, Wang S, Sun J, Wang H, Huan L, Sun X, et al. Surgical Outcomes After Anterior Controllable Antedisplacement and Fusion Compared with Single Open-Door Laminoplasty: Preliminary Analysis of Postoperative Changes of Spinal Cord Displacements on T2-Weighted Magnetic Resonance Imaging. World neurosurgery. 2019;127:e288-e298.\u003c/li\u003e\n\u003cli\u003eKothe R, Schmeiser G, Papavero L. Open-door laminoplasty : What can the unilateral approach offer? Oper Orthop Traumatol. 2018;30(1):3-12.\u003c/li\u003e\n\u003cli\u003eKim N, Cho S, Kim TH, Oh JK, Moon SH, Kim SW. Comparison of Midline Splitting versus Unilateral Open Door Laminoplasty and Its Impact on Patient Outcomes. Clin Orthop Surg. 2023;15(3):444-453.\u003c/li\u003e\n\u003cli\u003eHirabayashi K, Watanabe K, Wakano K, Suzuki N, Satomi K, Ishii Y. Expansive open-door laminoplasty for cervical spinal stenotic myelopathy. Spine (Phila Pa 1976). 1983;8(7):693-699.\u003c/li\u003e\n\u003cli\u003eSchmeiser G, Bergmann JI, Papavero L, Kothe R. Surgical Treatment of Multilevel Degenerative Cervical Myelopathy: Open-Door Laminoplasty and Fixation via Unilateral Approach. A Feasibility Study. J Neurol Surg A Cent Eur Neurosurg. 2022;83(5):494-501.\u003c/li\u003e\n\u003cli\u003eShao T, Gu J, Zhu Y, Tang W, Li Q, Lu J, et al. Modified axial computed tomography classification of cervical ossification of the posterior longitudinal ligament: selecting the optimal operating procedure and enhancing the accuracy of prognosis. Quant Imaging Med Surg. 2021;11(5):1888-1898.\u003c/li\u003e\n\u003cli\u003eMathew G, Agha R, Albrecht J, Goel P, Mukherjee I, Pai P, et al. STROCSS 2021: Strengthening the reporting of cohort, cross-sectional and case‒control studies in surgery. International journal of surgery (London, England). 2021;96:106165.\u003c/li\u003e\n\u003cli\u003eNakashima H, Kato F, Yukawa Y, Imagama S, Ito K, Machino M, et al. Comparative effectiveness of open-door laminoplasty versus French-door laminoplasty in cervical compressive myelopathy. Spine (Phila Pa 1976). 2014;39(8):642-647.\u003c/li\u003e\n\u003cli\u003eCha JR, Kim HW, Yang DG, Chung HY, Hwang IY. Open-Door Laminoplasty Using Lateral Mass Anchoring Screws and Nonabsorbable Sutures in Patients with Multilevel Cervical Myelopathy. Clin Orthop Surg. 2020;12(4):477-484.\u003c/li\u003e\n\u003cli\u003eMo Z, Li D, Zhang R, Chang M, Yang B, Tang S. Comparison of three fixation modalities for unilateral open-door cervical laminoplasty: a systematic review and network meta-analysis. Neurosurg Rev. 2020;43(3):813-823.\u003c/li\u003e\n\u003cli\u003eTang Y, Zhou S, Wang Z, Huang W, Jia L, Chen X. Choice of the Open Side in Unilateral Open-Door Laminoplasty for Cervical Ossification of the Posterior Longitudinal Ligament. Spine (Phila Pa 1976). 2020;45(11):741-746.\u003c/li\u003e\n\u003cli\u003eZhang KR, Yang Y, Liu H, Wang BY, Ding C, Meng Y, et al. Multivariate analysis of factors associated with spinal cord area in single-door cervical laminoplasty with miniplate fixation. BMC musculoskeletal disorders. 2021;22(1):881.\u003c/li\u003e\n\u003cli\u003eZhang KR, Yang Y, Liu H, Ding C, Wang BY, Meng Y, et al. Is there any correlation between the recovery rate of JOA and the increasing of cervical spinal cord area after single-door cervical laminoplasty? Clinical neurology and neurosurgery. 2022;213:107103.\u003c/li\u003e\n\u003cli\u003eQiao P, Zhang W, Xu T, Shao R, Tian R. Choice of open side affects clinical outcomes of unilateral open-door laminoplasty for inconsistent cervical ossification of the posterior longitudinal ligament. BMC Surg. 2024;24(1):405.\u003c/li\u003e\n\u003cli\u003eChen T, Zhang X, Meng F, Yan J, Xu G, Zhao W. Is laminoplasty or laminectomy the best strategy for C(3) segment in French-door laminoplasty? A systematic review and meta-analysis. Journal of orthopedic surgery and research. 2021;16(1):557.\u003c/li\u003e\n\u003cli\u003eYu W, Zhang F, Chen Y, Wang X, Chen D, Zheng J, et al. Efficacy and safety of laminoplasty combined with C3 laminectomy for patients with multilevel degenerative cervical myelopathy: a systematic review and meta-analysis. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2024;33(10):3915-3932.\u003c/li\u003e\n\u003cli\u003eYu W, Xie B, Fang Z, Yao Z, Zhong Y, Jiang X. What is the Preferable Method for the C3 and C7 Segments in Unilateral Open-Door Laminoplasty for Patients Diagnosed with Cervical Spondylotic Myelopathy? World neurosurgery. 2024;183:e668-e676.\u003c/li\u003e\n\u003cli\u003eZhang Z, Wang LN, Song YM, Wang L, Liu H, Liu LM, et al. Comparison of long-term clinical and radiographic outcomes between alternative-level and all-level fixation unilateral open-door laminoplasty. Spine J. 2020;20(11):1761-1769.\u003c/li\u003e\n\u003cli\u003eHosono N, Yonenobu K, Ono K. Neck and shoulder pain after laminoplasty. A noticeable complication. Spine (Phila Pa 1976). 1996;21(17):1969-1973.\u003c/li\u003e\n\u003cli\u003eHidai Y, Ebara S, Kamimura M, Tateiwa Y, Itoh H, Kinoshita T, et al. Treatment of cervical compressive myelopathy with a new dorsolateral decompressive procedure. J Neurosurg. 1999;90(2 Suppl):178-185.\u003c/li\u003e\n\u003cli\u003eKawaguchi Y, Kanamori M, Ishiara H, Nobukiyo M, Seki S, Kimura T. Preventive measures for axial symptoms following cervical laminoplasty. J Spinal Disord Tech. 2003;16(6):497-501.\u003c/li\u003e\n\u003cli\u003eSakaura H, Hosono N, Mukai Y, Fujii R, Iwasaki M, Yoshikawa H. Persistent local pain after posterior spine surgery for thoracic lesions. J Spinal Disord Tech. 2007;20(3):226-228.\u003c/li\u003e\n\u003cli\u003eOkada M, Minamide A, Endo T, Yoshida M, Kawakami M, Ando M, et al. A prospective randomized study of clinical outcomes in patients with cervical compressive myelopathy treated with open-door or French-door laminoplasty. Spine (Phila Pa 1976). 2009;34(11):1119-1126.\u003c/li\u003e\n\u003cli\u003eTakeuchi K, Yokoyama T, Aburakawa S, Saito A, Numasawa T, Iwasaki T, et al. Axial symptoms after cervical laminoplasty with C3 laminectomy compared with conventional C3-C7 laminoplasty: a modified laminoplasty preserving the semispinalis cervicis inserted into axis. Spine (Phila Pa 1976). 2005;30(22):2544-2549.\u003c/li\u003e\n\u003cli\u003eNakama S, Nitanai K, Oohashi Y, Endo T, Hoshino Y. Cervical muscle strength after laminoplasty. J Orthop Sci. 2003;8(1):36-40.\u003c/li\u003e\n\u003cli\u003eShiozaki T, Otsuka H, Nakata Y, Yokoyama T, Takeuchi K, Ono A, et al. Spinal cord shift on magnetic resonance imaging at 24 hours after cervical laminoplasty. Spine (Phila Pa 1976). 2009;34(3):274-279.\u003c/li\u003e\n\u003cli\u003eKang KC, Im SK, Lee JH, Lee KY, Seo DU, Hwang IU. Impact of lamina-open side on unilateral open door laminoplasty in patients with degenerative cervical myelopathy. Sci Rep. 2023;13(1):2062.\u003c/li\u003e\n\u003cli\u003eImagama S, Matsuyama Y, Yukawa Y, Kawakami N, Kamiya M, Kanemura T, et al. C5 palsy after cervical laminoplasty: a multicenter study. J Bone Joint Surg Br. 2010;92(3):393-400.\u003c/li\u003e\n\u003cli\u003eHasegawa K, Homma T, Chiba Y. Upper extremity palsy following cervical decompression surgery results from a transient spinal cord lesion. Spine (Phila Pa 1976). 2007;32(6):E197-202.\u003c/li\u003e\n\u003cli\u003eTakenaka S, Hosono N, Mukai Y, Miwa T, Fuji T. The use of cooled saline during bone drilling to reduce the incidence of upper-limb palsy after cervical laminoplasty: clinical article. J Neurosurg Spine. 2013;19(4):420-427.\u003c/li\u003e\n\u003cli\u003eLevi DJ, Brusko GD, Levi AD, Wang MY. Does hinge sidedness influence laterality of C5 palsy after expansile open-door cervical laminoplasty? Neurosurg Focus. 2023;55(3):E6.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Cervical myelopathy, Unilateral open-door laminoplasty, Ipsilateral, Contralateral, Clinical outcomes, Radiographic outcomes","lastPublishedDoi":"10.21203/rs.3.rs-6545395/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6545395/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective\u003c/strong\u003e: To compare the clinical and radiographic outcomes of ipsilateral and contralateral unilateral open-door laminoplasty (UODL) in treating cervical myelopathy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: Retrospective analysis of patients who received UODL treatment at Xi'an Honghui Hospital from January 2023 to June 2024. A total of 76 patients with cervical myelopathy (42 who underwent ipsilateralopen-door laminoplasty) and 34 who underwent contralateral open-door laminoplasty) were included. All surgical procedures were carried out by experienced surgeons under general anesthesia via a standardized posterior midline approach. Clinical outcomes were evaluated via the visual analog scale (VAS), Japanese Orthopedic Association (JOA) score, and Oswestry Disability Index (ODI). Radiographic parameters, such as the spinal canal area and spinal cord area of the narrowest segment, were measured by two independent radiologists who were blinded to the clinical outcomes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: The two groups were comparable in terms of baseline characteristics. For sex distribution, ​\u003cem\u003eχ²\u003c/em\u003e =0.071 (​\u003cem\u003eP=\u003c/em\u003e0.790); for age, ​\u003cem\u003eT=\u003c/em\u003e0.195 (​\u003cem\u003eP=\u003c/em\u003e0.846); for surgical duration, ​\u003cem\u003eT=\u003c/em\u003e−0.277 (​\u003cem\u003eP=\u003c/em\u003e0.782); for blood loss, ​\u003cem\u003eT=\u003c/em\u003e0.727 (​\u003cem\u003eP=\u003c/em\u003e0.470); for hospitalization duration, ​\u003cem\u003eT=\u003c/em\u003e1.536 (​\u003cem\u003eP=\u003c/em\u003e0.129); for diagnostic categories, ​\u003cem\u003eχ²\u003c/em\u003e =0.071 (​\u003cem\u003eP=\u003c/em\u003e0.790); for stenosis levels, ​\u003cem\u003eχ²\u003c/em\u003e=2.090 (​\u003cem\u003eP=\u003c/em\u003e0.148); for surgical segments, \u003cem\u003eχ²\u003c/em\u003e =1.543 (\u003cem\u003eP=\u003c/em\u003e0.485); and for complication rates, \u003cem\u003eχ²\u003c/em\u003e=0.04 (\u003cem\u003eP=\u003c/em\u003e0.953).​Postoperatively, both groups showed significant decreases in VAS scores and improvements in the ODI. However, there were no significant intergroup differences in the VAS score (preoperative: \u003cem\u003eT=\u003c/em\u003e0.321, \u003cem\u003eP=\u003c/em\u003e0.749; postoperative: \u003cem\u003eT=\u003c/em\u003e0.456, \u003cem\u003eP=\u003c/em\u003e0.649), JOA score (preoperative: \u003cem\u003eT=\u003c/em\u003e0.512, \u003cem\u003eP=\u003c/em\u003e0.610; postoperative: \u003cem\u003eT=\u003c/em\u003e0.638, \u003cem\u003eP=\u003c/em\u003e0.525), or ODI (preoperative: \u003cem\u003eT=\u003c/em\u003e0.289, \u003cem\u003eP=\u003c/em\u003e0.774; postoperative: \u003cem\u003eT=\u003c/em\u003e0.378, \u003cem\u003eP=\u003c/em\u003e0.707).​ In terms of radiographic outcomes, there were no significant differences in the spinal canal area (preoperative: \u003cem\u003eT=\u003c/em\u003e0.789, \u003cem\u003eP=\u003c/em\u003e0.433; postoperative: \u003cem\u003eT=\u003c/em\u003e0.892, \u003cem\u003eP=\u003c/em\u003e0.376) or spinal cord area (preoperative: \u003cem\u003eT=\u003c/em\u003e0.654, \u003cem\u003eP=\u003c/em\u003e0.515; postoperative: \u003cem\u003eT=\u003c/em\u003e0.721, \u003cem\u003eP=\u003c/em\u003e0.474) between the two groups before and after surgery. Notably, both groups had an approximately 80 mm² increase in the spinal canal area and a 30 mm² increase in the spinal cord area postoperatively compared with the preoperative values.​\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: Ipsilateral and contralateral UODL achieved similar clinical and radiographic results in treating cervical myelopathy. Surgeons can choose the surgical side flexibly on the basis of specific cases.\u003c/p\u003e","manuscriptTitle":"Comparison of Ipsilateral and Contralateral Unilateral Open-door Laminoplasty for Cervical Myelopathy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-02 07:11:29","doi":"10.21203/rs.3.rs-6545395/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5a85ff2c-1492-4300-904d-1c400183548f","owner":[],"postedDate":"June 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":49235755,"name":"Biological sciences/Neuroscience/Spine regulation and structure/Spine structure"},{"id":49235756,"name":"Health sciences/Anatomy/Musculoskeletal system/Bone"}],"tags":[],"updatedAt":"2025-06-09T01:53:25+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-02 07:11:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6545395","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6545395","identity":"rs-6545395","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}