Clinical Relevance of Postoperative Radial Neck Osteolysis After Radial Head Arthroplasty: A Retrospective Radiographic–functional Correlation Study

Clinical Relevance of Postoperative Radial Neck Osteolysis After Radial Head Arthroplasty: A Retrospective Radiographic–functional Correlation Study | 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 Research Article Clinical Relevance of Postoperative Radial Neck Osteolysis After Radial Head Arthroplasty: A Retrospective Radiographic–functional Correlation Study Abderraouf Elhadi, Ernst Chavannes, Philippe Wodecki This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9181917/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 12 You are reading this latest preprint version Abstract Introduction: Radial head arthroplasty (RHA) is widely used in the treatment of unreconstructable radial head fractures, particularly in complex elbow injuries. While functional outcomes are generally favorable, postoperative radiographic anomalies—such as radial neck osteolysis, stress shielding, and heterotopic ossifications—are frequently observed. The clinical relevance of these so-called “silent” anomalies remains controversial. Methods: We conducted a retrospective monocentric study at the Centre Hospitalier Intercommunal de Villeneuve-Saint-Georges (CHIV) between 2010 and 2023. Sixteen adult patients undergoing modular press-fit radial head arthroplasty were included. Clinical evaluation at final follow-up included the Mayo Elbow Performance Score (MEPS), QuickDASH, VAS for pain, and range of motion (ROM). Radiographic anomalies were assessed through standardized X-rays and postoperative CT scans, and their correlation with functional outcomes was analyzed. Results: Radial neck osteolysis ≥ 3 mm was the most common anomaly (62.5%) and was significantly associated with lower MEPS scores (ρ = − 0.88, p < 0.001) and higher pain (VAS) scores (ρ = +0.86, p < 0.001). Other anomalies, including stress shielding (31.2%), Delta sign (37.5%), and Brooker grade ≥ II heterotopic ossifications (43.7%), showed trends toward poorer outcomes but without statistical significance. Patients with complex injury patterns (terrible triad, olecranon fractures) had worse MEPS and higher osteolysis rates. These associations should be interpreted cautiously given the limited sample size. Conclusion: Radial neck osteolysis ≥ 3 mm may represent a clinically relevant radiographic finding and appears to be a key marker of reduced function and increased pain following RHA. The cumulative burden of radiographic anomalies may help identify high-risk patients who warrant closer follow-up. This study supports integrating structured radiographic assessment into postoperative surveillance protocols. Level of Evidence: Level IV; retrospective case series Radial head arthroplasty osteolysis stress shielding Delta sign elbow trauma radiographic anomalies functional outcomes Figures Figure 1 Figure 2 Figure 3 Introduction Radial head arthroplasty (RHA) is widely recognized as a valuable option in the management of unreconstructable radial head fractures, particularly in cases involving elbow instability or complex dislocation patterns. Its role in restoring joint congruence and facilitating early mobilization is well documented [ 1 ]. Despite generally satisfactory clinical outcomes, a number of studies have reported the occurrence of postoperative radiographic anomalies, such as periprosthetic radiolucency, radial neck osteolysis, and signs of stress shielding [ 2 ]. These findings are often considered benign or clinically silent; however, this assumption has been increasingly challenged. Rafla et al. described early loosening around press-fit prostheses that could precede clinical symptoms [ 3 ]. In a long-term follow-up, Chen et al. observed that bone resorption around the radial neck was associated with a decline in elbow function [ 4 ]. Similarly, Claessen et al. identified radiographic features that correlated with suboptimal functional recovery, suggesting a predictive value of imaging beyond its diagnostic role [ 5 ]. Jung et al. highlighted a reduced return to sports in patients treated with RHA, attributing part of the limitation to biomechanical alterations not always captured by standard assessments [ 6 ]. In parallel, Wegmann et al. emphasized that subtle misalignment or implant overlengthening may result in abnormal load distribution, contributing to bone remodeling or persistent pain [ 7 ]. In this context, the clinical impact of so-called “silent” radiographic changes remains uncertain and insufficiently explored. This study was designed to assess the prevalence of such anomalies after RHA and to examine their association with functional outcomes. We hypothesized that certain radiographic findings—particularly osteolysis of the radial neck—are not neutral and correlate with poorer clinical scores, including increased pain and reduced elbow mobility. Materials and Methods This retrospective monocentric observational study was conducted at the Centre Hospitalier Intercommunal de Villeneuve-Saint-Georges (CHIV), France, between January 2010 and December 2023. Consecutive adult patients (≥ 18 years) who underwent radial head arthroplasty (RHA) for unreconstructable radial head fractures, with or without associated elbow injuries, were included. Exclusion criteria were incomplete medical records, follow-up shorter than 12 months, or loss to follow-up. Institutional review board approval was obtained prior to data collection, and all patients provided informed consent. To account for heterogeneity in trauma severity, injuries were classified as simple (isolated Mason type III or IV fractures) or complex (terrible triad injuries or associated olecranon fractures). This classification was used for descriptive subgroup analyses. All procedures were performed using a lateral approach, most commonly through the Kocher interval, with implantation of a modular press-fit pyrocarbon radial head prosthesis. Associated lesions were treated during the same procedure when present, including ligament reinsertion, coronoid fixation, or olecranon plate osteosynthesis. Postoperatively, all patients followed a standardized rehabilitation protocol consisting of immobilization with an articulated brace for 14–21 days, followed by progressive range-of-motion exercises under physiotherapist supervision for at least three months. Primary clinical outcomes were the Mayo Elbow Performance Score (MEPS) and pain intensity assessed using a visual analogue scale (VAS). Secondary outcomes included the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score and elbow range of motion, including flexion–extension and pronation–supination arcs, evaluated at final follow-up. Radiographic outcomes focused on the presence and severity of predefined anomalies: radial neck osteolysis ≥ 3 mm, periprosthetic radiolucency, stress shielding, heterotopic ossification (Brooker grade ≥ II), Delta sign (asymmetric humero-ulnar joint space), and humero-ulnar osteoarthritis. Osteolysis was defined as circumferential bone resorption ≥ 3 mm at the radial neck on standard anteroposterior or lateral radiographs. Stress shielding was characterized by cortical thinning or proximal radial shaft resorption, and the Delta sign was defined as irregular or asymmetric humero-ulnar alignment suggestive of overlengthening or malposition. All patients underwent systematic computed tomography at final follow-up to confirm osteolysis and assess implant alignment. Radiographic assessments were independently performed by two orthopedic surgeons. Interobserver agreement was substantial for osteolysis and heterotopic ossification (κ > 0.7) and moderate for stress shielding and the Delta sign (κ = 0.5–0.7); disagreements were resolved by consensus. Data were retrospectively extracted from medical records, operative reports, and follow-up consultations. When clinical scores were missing, patients were evaluated during a clinical visit or through a structured telephone interview. Statistical analyses were performed using SPSS version 28. Continuous variables were expressed as means ± standard deviation or medians with interquartile ranges. Associations between radiographic findings and clinical outcomes were assessed using Spearman correlation coefficients. Group comparisons were performed using the Mann–Whitney U test or Student’s t-test, as appropriate. A p-value < 0.05 was considered statistically significant. Given the sample size, all analyses were considered exploratory and hypothesis-generating. Results The study comprised sixteen patients (Table 1 ). The majority of patients (62.5%) were female, and the mean age was 47 years (± 13, range 29–66). The follow-up period ranged from 12 to 110 months, with an average of 36 months. Three of the five patients (60%) who had a severe triad injury had ligamentous reinsertion. Plate osteosynthesis was used to treat the associated olecranon fractures in two patients. The average length of postoperative immobilization was 17 days (IQR: 14–21), and the median time between trauma and surgery was 8 days (IQR: 5–10). Table 1 Demographic and Surgical Characteristics of the Patient Cohort Variable Value / Description Number of patients 16 Mean age (± SD) 47 ± 13 years Sex distribution 10 females (62.5%), 6 males (37.5%) Dominant side involved 9 (56.2%) Triad injuries 5 (31.2%) Associated olecranon fractures 2 (12.5%) Ligamentous reinsertion performed 3 (18.7%) Median delay to surgery (IQR) 8 days (5–10) Immobilization duration (IQR) 17 days (14–21) Mean follow-up duration 36 months (12 to 110) The primary outcome measure, the Mayo Elbow Performance Score (MEPS), averaged 81 ± 12. With mean ranges of motion of 140° for flexion, 15° for extension deficit, 83° for pronation, and 82° for supination, most patients clinically recovered almost normal mobility. The mean QuickDASH score was 21 ± 7, and the average pain intensity (VAS) was 2.8 ± 1.7. Radial neck osteolysis ≥ 3 mm was the most prevalent radiographic anomaly, occurring in 10 out of 16 patients (62.5%) with a mean osteolytic depth of 3.16 ± 0.55 mm. Of the patients, 37.5% had the Delta River sign (radial-humeral asymmetry), 50% had humeroulnar osteoarthritis, 43.7% had Brooker grade ≥ II heterotopic ossifications, and 31.2% had stress shielding. The average peri-prosthetic radiolucency was 1.1 ± 1.3 mm. According to statistical analysis, there was a strong positive correlation with pain scores (VAS; ρ = +0.86, p < 0.001) and a significant negative correlation with the MEPS score (ρ = − 0.88, p < 0.001) when radial neck osteolysis was present. Additionally, there was a tendency for overall mobility to decline. Although there were trends toward worse clinical outcomes (reduced MEPS and range of motion) for other radiographic anomalies like stress shielding, the Delta River sign, and heterotopic ossifications, these correlations did not reach statistical significance. There was only one significant issue noted: a patient's progressive clinical decline necessitated revision surgery involving a total elbow arthroplasty. Table 2 Functional Outcomes Functional Measure Mean ± SD Range MEPS 81 ± 12 60–100 QuickDASH 21 ± 7 11–36 Pain VAS (0–10) 2.8 ± 1.7 0–6 Flexion (°) 140 ± 10 120–155 Extension deficit (°) 15 ± 5 5–25 Pronation (°) 83 ± 7 70–90 Supination (°) 82 ± 8 65–90 Table 3 Postoperative radiographic abnormalities in the study cohort Radiographic Finding Number of Patients (n) Percentage (%) Radial neck osteolysis ≥ 3 mm 10 62.5% Humeroulnar osteoarthritis 8 50.0% Heterotopic ossification (Brooker ≥ II) 7 43.7% Delta sign (overlengthening) 6 37.5% Stress shielding 5 31.2% A subgroup comparison was performed between patients with isolated radial head fractures (simple) and those with complex elbow injuries (e.g., terrible triad, Monteggia-like, Essex-Lopresti). Functional outcomes and osteolysis rates were compared. Table 4 Functional outcomes and prevalence of osteolysis according to injury type in the study cohort Type of Injury n MEPS (Mean ± SD) VAS (Mean) Osteolysis (%) Simple 9 84 ± 10 2.2 44.4% Complex 7 77 ± 13 3.4 85.7% Discussion The main finding of this study is that certain radiographic alterations observed after radial head arthroplasty (RHA), particularly proximal radial neck osteolysis, appear to be associated with impaired clinical outcomes. Despite being historically considered "radiologically silent," these changes—when quantitatively analyzed—appear to carry prognostic value, especially regarding elbow function and pain intensity. In our series, radial neck osteolysis ≥ 3 mm was observed in 62.5% of cases and showed a strong negative correlationwith MEPS (ρ = − 0.88) and a positive correlation with VAS (ρ = +0.86). These findings are in line with Chen et al. [ 4 ], who highlighted that such osteolytic changes, although frequently underdiagnosed, may reflect chronic micromotion at the bone-implant interface or low-grade inflammatory responses. Rafla et al. [ 3 ] similarly emphasized that early radiographic signs of loosening can evolve silently but compromise long-term implant stability. Ceccarelli et al. [ 8 ] and Gauci et al. [ 9 ] also noted that radial neck osteolysis is prevalent in mid-to-long-term follow-up, with potential functional consequences, particularly when exceeding 3 mm. Van Riet et al. [ 1 ] underlined the anatomical variability and biomechanical sensitivity of the radial column, making it particularly vulnerable to eccentric loading and asymmetric stresses. This anatomical consideration could partly explain why even minimal malalignment or stress concentration around the implant neck may lead to bone remodeling or resorption. Other radiographic findings—although less strongly correlated with functional scores—also deserve attention: Delta River sign (asymmetry between radius and ulna at the trochlear notch) was present in 37.5% of patients. According to Wegmann et al. [ 7 ], this sign likely reflects overlengthening or angular malpositioning, both of which disrupt the physiological axis of force transmission through the elbow. Although statistical significance was not reached in our cohort, a trend toward increased VAS and decreased MEPS was evident. Stress shielding, observed in 31.2%, is consistent with the findings by Chanlalit et al. [ 10 ] and Page et al. [ 11 ], who reported periprosthetic cortical thinning due to biomechanical mismatch. Rigid or oversized implants may transfer less load to adjacent bone, triggering localized osteopenia. Heterotopic ossifications (HO), Brooker grade ≥ II, were found in 43.7%. Their clinical impact varies by location and volume. While our cohort did not exhibit major motion restriction, limitations in pronation-supination were observed in more severe cases. HO remains a common complication in post-traumatic elbows, especially in complex dislocations, as emphasized by Laumonerie et al. [ 12 , 13 ] and Bonnevialle [ 14 ]. Humero-ulnar osteoarthritis (50%) likely represents a degenerative response secondary to altered kinematics or unrecognized instability. Katthagen et al. [ 15 ] and Dunn et al. [ 16 ] reported similar findings, particularly in patients with terrible triad injuries or incomplete ligamentous healing. Interestingly, Claessen et al. [ 5 ] attempted to identify radiographic predictors of poor short-term outcomes and emphasized that subtle imaging anomalies—especially early periprosthetic radiolucency or misalignment—should not be overlooked. Our results reinforce that notion by demonstrating statistically and clinically meaningful correlations with validated functional measures. Although the QuickDASH and range of motion (ROM) were not as strongly associated with radiographic abnormalities as MEPS or VAS, this likely reflects their multifactorial nature and lower sensitivity to subtle joint instability or pain during specific movements, as highlighted by Jung et al. [ 6 ]. Patients with complex injuries had lower MEPS scores (77 ± 13 vs. 84 ± 10), higher pain levels (VAS 3.4 vs. 2.2), and a markedly increased prevalence of radial neck osteolysis (85.7% vs. 44.4%). Although statistical significance could not be demonstrated due to the limited sample size, this trend suggests a cumulative biomechanical burden in the setting of combined injuries. These findings are consistent with those reported by Ciais et al. [ 17 ], who observed that patients with terrible triad injuries were more likely to develop radiocapitellar complications and require prolonged rehabilitation. It is likely that altered load transmission, soft-tissue compromise, and surgical complexity contribute to these less favorable outcomes in complex cases. Several limitations should be acknowledged: The retrospective nature of the study limits causal inference and may introduce selection bias. The small sample size (n = 16) restricts the statistical power, especially for subgroup comparisons. Heterogeneity in trauma patterns (simple fractures vs terrible triad) and surgical timing may have influenced both radiographic evolution and functional recovery. Despite standardized radiographic analysis with dual reading, some anomalies (e.g., stress shielding or Delta sign) are inherently subject to observer interpretation, as previously noted by Lobo-Escolar et al. [ 18 ]. Although the sample size is limited (n = 16), this study aligns with several published series addressing rare or complex indications such as radial head arthroplasty with detailed radiographic analysis [ 13 , 15 , 19 ]. The homogeneity of surgical technique and follow-up protocol adds strength to the internal validity, and the consistent correlation observed for radial neck osteolysis suggests a robust signal that warrants further validation in larger multicenter cohorts. Correlation coefficients may be overestimated in small retrospective series and should therefore be interpreted cautiously. The originality of this study lies in its focused, cross-sectional radioclinical evaluation. While most prior reports analyze either functional or radiological outcomes separately, we provide a correlation matrix between specific imaging anomalies and validated clinical scores. This approach, aligned with the recommendations of Thyagarajan [ 20 ], advocates for a risk-stratified follow-up based on early radiographic warning signs. Our data support the notion proposed by Ciais et al. [ 17 ] that radiographic anomalies—especially when quantified—can guide postoperative surveillance and even influence rehabilitation strategies. We suggest that radial neck osteolysis ≥ 3 mm may represent a potential radiographic warning sign of poorer functional recovery and should not be dismissed as incidental. Moreover, this study strengthens the call from Laumonerie et al. [ 2 ] and Allieu et al. [ 21 ] to develop composite severity scores, integrating radiological and clinical findings to anticipate revision needs or prolonged disability. From a clinical standpoint, the presence of radial neck osteolysis ≥ 3 mm should prompt careful clinical and radiographic surveillance rather than immediate revision. Table 5 Selected studies reporting postoperative radiographic abnormalities after radial head arthroplasty and their potential clinical relevance Study Study design Radiographic finding evaluated Functional correlation Antoni et al., 2023 Retrospective cohort study Proximal radial neck osteolysis Demonstrated Lee et al., 2022 Retrospective cohort study Stress shielding Investigated Pehlivanoglu et al., 2021 Retrospective long-term follow-up study Radiographic loosening Demonstrated Samra et al., 2022 Mid-term clinical cohort Implant loosening and radiographic abnormalities Investigated Marsh et al., 2016 Clinical cohort study Postoperative radiographic changes Limited / Laumonerie et al., 2017 Retrospective cohort study Radiographic evolution after RHA Reported qualitatively Conclusion This study highlights that certain radiographic anomalies observed after radial head arthroplasty—particularly proximal radial neck osteolysis ≥ 3 mm— may be associated with impaired functional outcomes and should not systematically be considered a purely incidental radiographic finding. While traditionally considered benign or “silent,” these changes may reflect altered load transmission or subclinical implant–bone interactions., with measurable clinical consequences. Although secondary findings such as stress shielding, Delta River sign, and heterotopic ossifications showed less consistent impact, their presence warrants systematic evaluation during follow-up. These results support the integration of targeted radiographic assessments into routine postoperative surveillance, and the development of a composite severity score may help clinicians identify at-risk patients earlier. Further prospective, multicenter studies with larger cohorts are necessary to validate these associations and guide evidence-based management of subtle implant-related changes. The authors declare that they have no competing interests. No financial support or benefits have been received from any commercial entity related to the subject of this article. This study was conducted in accordance with the Declaration of Helsinki. Given its retrospective and non-interventional design, formal ethical approval was not required. All data were anonymized. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Declarations Author Contribution A.E. conceived and designed the study, performed data collection and statistical analysis, and drafted the manuscript.E.C. contributed to patient management, data acquisition, and critical revision of the manuscript.P.W. contributed to study supervision, surgical management, and critical revision of the manuscript for important intellectual content.All authors reviewed and approved the final version of the manuscript. Data Availability The datasets generated and analyzed during the current study are not publicly available due to institutional data protection regulations and patient confidentiality but are available from the corresponding author on reasonable request and subject to approval by the institutional ethics committee. References Van Riet RP, Van Glabbeek F, Neale PG, Bimmel R, Bortier H, Morrey BF et al (2004) Anatomical considerations of the radius. Clin Anat 17(7):564–569 Laumonerie P, Ancelin D, Reina N, Tibbo ME, Kerezoudis P, Delclaux S et al (2017 July) Causes for early and late surgical re-intervention after radial head arthroplasty. Int Orthop 41(7):1435–1443 Rafla S, Carroll EA, Wiesler ER, Li Z, Tuohy CJ, Nunez Sr F et al (2021) Early to midterm radiographic loosening of the press fit radial head prosthesis. Injury 52(12):3605–3610 Chen ACY, Cheng YH, Chiu CH, Cheng CY, Chan YS (2021) Long-Term Outcomes of Radial Head Arthroplasty in Complex Elbow Fracture Dislocation. JCM 10(16):3488 claessen femke, Rens B, Kodde i, Doornberg J, van den Bekerom M, Eygendaal D Radiographic Predictors for Short-term Functional Outcome after Radial Head Arthroplasty in patients with persistent symptoms after treatment for radial head fracture. ABJS [Internet]. 2019 Aug [cited 2024 Nov 13];(Online First). Available from: https://doi.org/10.22038/abjs.2019.31727.1832 Jung M, Groetzner-Schmidt C, Porschke F, Grützner PA, Guehring T, Schnetzke M (2019) Low return-to-sports rate after elbow injury and treatment with radial head arthroplasty. J Shoulder Elbow Surg 28(8):1441–1448 Wegmann K, Hackl M, Leschinger T, Burkhart KJ, Müller LP (2021 Sept) Overlengthening of the radial column in radial head replacement: a review of the literature and presentation of a classification system. Arch Orthop Trauma Surg 141(9):1525–1539 Ceccarelli R, Winter M, Barret H, Bronsard N, Gauci MO (2021) Pyrocarbon unipolar radial head prosthesis: clinical and radiologic outcomes at long-term follow-up. J Shoulder Elbow Surg 30(12):2886–2894 Gauci MO, Winter M, Dumontier C, Bronsard N, Allieu Y (2016) Clinical and radiologic outcomes of pyrocarbon radial head prosthesis: midterm results. J Shoulder Elbow Surg 25(1):98–104 Chanlalit C, Shukla DR, Fitzsimmons JS, An KN, O’Driscoll SW (2012) Stress shielding around radial head prostheses. J Hand Surg Am 37(10):2118–2125 Page RS, Paltoglou NG, Arora V, Eng K, Gill SD (2021 Sept) Retrospective review of pyrocarbon radial head replacement. JSES Rev Rep Tech 3(4):376–380 Laumonerie P, Tibbo ME, Kerezoudis P, Gauci MO, Reina N, Bonnevialle N et al (2018) Short to midterm outcomes of one hundred and seventy one MoPyC radial head prostheses: meta-analysis. Int Orthop (SICOT) 42(10):2403–2411 Laumonerie P, Reina N, Gutierrez C, Delclaux S, Tibbo ME, Bonnevialle N et al (2018) Tight-fitting radial head prosthesis: does stem size help prevent painful loosening? Int Orthop (SICOT) 42(1):161–167 Bonnevialle N (2016) Radial head replacement in adults with recent fractures. Orthop Traumatology: Surg Res 102(1, Supplement):S69–79 Katthagen JC, Jensen G, Lill H, Voigt C (2013) Monobloc radial head prostheses in complex elbow injuries: results after primary and secondary implantation. Int Orthop (SICOT) 37(4):631–639 Dunn JC, Kusnezov NA, Koehler LR, Eisenstein ED, Kilcoyne KG, Orr JD et al (2017) Radial Head Arthroplasty in the Active Duty Military Service Member With Minimum 2-Year Follow-Up. The Journal of Hand Surgery. ;42(8):660.e1-660.e7 Ciais G, Tibbo M, Massin V, Barret H, Abdellaoui M, Theopol D et al (2024) Short to Midterm Outcomes of 139 Pyrocarbon Monopolar Radial Arthroplasties. J Shoulder Elbow Surg Lobo-Escolar L, Abellán-Miralles C, Escolà-Benet A (2021) Outcomes of press-fit radial head arthroplasty following complex radial head fractures. Orthopaedics & Traumatology: Surgery & Research. ;107(2):102645 Laumonerie P, Tibbo ME, Reina N, Pham TT, Bonnevialle N, Mansat P (2019 July) Radial head arthroplasty: a historical perspective. Int Orthop (SICOT) 43(7):1643–1651 Thyagarajan DS (2023) Radial head replacement – A comprehensive review. J Orthop 36:51–56 Allieu Y, Winter M, De Pequignot JP (2006) Radial head replacement with a pyrocarbon head prosthesis: preliminary results of a multicentric prospective study. Eur J Orthop Surg Traumatol 16(1):1–9 Additional Declarations No competing interests reported. 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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-9181917","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":615495796,"identity":"b65bae4f-1db1-4823-a92f-b7c085736812","order_by":0,"name":"Abderraouf 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1","display":"","copyAsset":false,"role":"figure","size":128215,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eflowchart study\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-9181917/v1/0ca2bc465e2ad5a30c8f8b93.png"},{"id":106094857,"identity":"a2acabb9-8549-4cee-9fd7-6733f8c999da","added_by":"auto","created_at":"2026-04-03 11:43:26","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":289243,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative postoperative radiographic abnormalities after radial head arthroplasty \u003cstrong\u003e(A)\u003c/strong\u003e Lateral radiograph showing \u003cstrong\u003eproximal radial neck osteolysis (≥3 mm)\u003c/strong\u003e around the prosthetic stem. \u0026nbsp;\u003cstrong\u003e(B) \u003c/strong\u003e\u0026nbsp;Lateral radiograph illustrating \u003cstrong\u003estress shielding with prosthetic stem fracture (C)\u003c/strong\u003e Lateral radiograph demonstrating \u003cstrong\u003eperiprosthetic radiolucency\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-9181917/v1/eca87247f873a13abcf206e6.png"},{"id":106094235,"identity":"65b1ad2c-ac79-49f8-9968-82d9ad4cf54d","added_by":"auto","created_at":"2026-04-03 11:41:50","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":94621,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDistribution of Radiographic Anomalies Post-Arthroplasty\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-9181917/v1/6e908927b49a69c1ee704f12.png"},{"id":106402112,"identity":"3ffe90d0-a418-4f01-a909-9b2b3d2ae5d7","added_by":"auto","created_at":"2026-04-08 09:11:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1414763,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9181917/v1/427da95c-9e0d-4463-a535-f05881c135f9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eClinical Relevance of Postoperative Radial Neck Osteolysis After Radial Head Arthroplasty: A Retrospective Radiographic–functional Correlation Study\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRadial head arthroplasty (RHA) is widely recognized as a valuable option in the management of unreconstructable radial head fractures, particularly in cases involving elbow instability or complex dislocation patterns. Its role in restoring joint congruence and facilitating early mobilization is well documented [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite generally satisfactory clinical outcomes, a number of studies have reported the occurrence of postoperative radiographic anomalies, such as periprosthetic radiolucency, radial neck osteolysis, and signs of stress shielding [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. These findings are often considered benign or clinically silent; however, this assumption has been increasingly challenged. Rafla et al. described early loosening around press-fit prostheses that could precede clinical symptoms [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In a long-term follow-up, Chen et al. observed that bone resorption around the radial neck was associated with a decline in elbow function [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Similarly, Claessen et al. identified radiographic features that correlated with suboptimal functional recovery, suggesting a predictive value of imaging beyond its diagnostic role [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eJung et al. highlighted a reduced return to sports in patients treated with RHA, attributing part of the limitation to biomechanical alterations not always captured by standard assessments [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In parallel, Wegmann et al. emphasized that subtle misalignment or implant overlengthening may result in abnormal load distribution, contributing to bone remodeling or persistent pain [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn this context, the clinical impact of so-called \u0026ldquo;silent\u0026rdquo; radiographic changes remains uncertain and insufficiently explored. This study was designed to assess the prevalence of such anomalies after RHA and to examine their association with functional outcomes. We hypothesized that certain radiographic findings\u0026mdash;particularly osteolysis of the radial neck\u0026mdash;are not neutral and correlate with poorer clinical scores, including increased pain and reduced elbow mobility.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eThis retrospective monocentric observational study was conducted at the Centre Hospitalier Intercommunal de Villeneuve-Saint-Georges (CHIV), France, between January 2010 and December 2023. Consecutive adult patients (\u0026ge;\u0026thinsp;18 years) who underwent radial head arthroplasty (RHA) for unreconstructable radial head fractures, with or without associated elbow injuries, were included. Exclusion criteria were incomplete medical records, follow-up shorter than 12 months, or loss to follow-up. Institutional review board approval was obtained prior to data collection, and all patients provided informed consent.\u003c/p\u003e \u003cp\u003eTo account for heterogeneity in trauma severity, injuries were classified as simple (isolated Mason type III or IV fractures) or complex (terrible triad injuries or associated olecranon fractures). This classification was used for descriptive subgroup analyses.\u003c/p\u003e \u003cp\u003eAll procedures were performed using a lateral approach, most commonly through the Kocher interval, with implantation of a modular press-fit pyrocarbon radial head prosthesis. Associated lesions were treated during the same procedure when present, including ligament reinsertion, coronoid fixation, or olecranon plate osteosynthesis. Postoperatively, all patients followed a standardized rehabilitation protocol consisting of immobilization with an articulated brace for 14\u0026ndash;21 days, followed by progressive range-of-motion exercises under physiotherapist supervision for at least three months.\u003c/p\u003e \u003cp\u003ePrimary clinical outcomes were the Mayo Elbow Performance Score (MEPS) and pain intensity assessed using a visual analogue scale (VAS). Secondary outcomes included the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score and elbow range of motion, including flexion\u0026ndash;extension and pronation\u0026ndash;supination arcs, evaluated at final follow-up.\u003c/p\u003e \u003cp\u003eRadiographic outcomes focused on the presence and severity of predefined anomalies: radial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm, periprosthetic radiolucency, stress shielding, heterotopic ossification (Brooker grade\u0026thinsp;\u0026ge;\u0026thinsp;II), Delta sign (asymmetric humero-ulnar joint space), and humero-ulnar osteoarthritis. Osteolysis was defined as circumferential bone resorption\u0026thinsp;\u0026ge;\u0026thinsp;3 mm at the radial neck on standard anteroposterior or lateral radiographs. Stress shielding was characterized by cortical thinning or proximal radial shaft resorption, and the Delta sign was defined as irregular or asymmetric humero-ulnar alignment suggestive of overlengthening or malposition.\u003c/p\u003e \u003cp\u003eAll patients underwent systematic computed tomography at final follow-up to confirm osteolysis and assess implant alignment. Radiographic assessments were independently performed by two orthopedic surgeons. Interobserver agreement was substantial for osteolysis and heterotopic ossification (κ\u0026thinsp;\u0026gt;\u0026thinsp;0.7) and moderate for stress shielding and the Delta sign (κ\u0026thinsp;=\u0026thinsp;0.5\u0026ndash;0.7); disagreements were resolved by consensus.\u003c/p\u003e \u003cp\u003eData were retrospectively extracted from medical records, operative reports, and follow-up consultations. When clinical scores were missing, patients were evaluated during a clinical visit or through a structured telephone interview. Statistical analyses were performed using SPSS version 28. Continuous variables were expressed as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or medians with interquartile ranges. Associations between radiographic findings and clinical outcomes were assessed using Spearman correlation coefficients. Group comparisons were performed using the Mann\u0026ndash;Whitney U test or Student\u0026rsquo;s t-test, as appropriate. A p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant. Given the sample size, all analyses were considered exploratory and hypothesis-generating.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe study comprised sixteen patients (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The majority of patients (62.5%) were female, and the mean age was 47 years (\u0026plusmn;\u0026thinsp;13, range 29\u0026ndash;66). The follow-up period ranged from 12 to 110 months, with an average of 36 months. Three of the five patients (60%) who had a severe triad injury had ligamentous reinsertion. Plate osteosynthesis was used to treat the associated olecranon fractures in two patients. The average length of postoperative immobilization was 17 days (IQR: 14\u0026ndash;21), and the median time between trauma and surgery was 8 days (IQR: 5\u0026ndash;10).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cb\u003eDemographic and Surgical Characteristics of the Patient Cohort\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eValue / Description\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of patients\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean age (\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e47\u0026thinsp;\u0026plusmn;\u0026thinsp;13 years\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex distribution\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 females (62.5%), 6 males (37.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDominant side involved\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (56.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTriad injuries\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (31.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAssociated olecranon fractures\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (12.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLigamentous reinsertion performed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (18.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian delay to surgery (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 days (5\u0026ndash;10)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eImmobilization duration (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17 days (14\u0026ndash;21)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean follow-up duration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36 months (12 to 110)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe primary outcome measure, the Mayo Elbow Performance Score (MEPS), averaged 81\u0026thinsp;\u0026plusmn;\u0026thinsp;12. With mean ranges of motion of 140\u0026deg; for flexion, 15\u0026deg; for extension deficit, 83\u0026deg; for pronation, and 82\u0026deg; for supination, most patients clinically recovered almost normal mobility. The mean QuickDASH score was 21\u0026thinsp;\u0026plusmn;\u0026thinsp;7, and the average pain intensity (VAS) was 2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7.\u003c/p\u003e \u003cp\u003eRadial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm was the most prevalent radiographic anomaly, occurring in 10 out of 16 patients (62.5%) with a mean osteolytic depth of 3.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55 mm.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eOf the patients, 37.5% had the Delta River sign (radial-humeral asymmetry), 50% had humeroulnar osteoarthritis, 43.7% had Brooker grade\u0026thinsp;\u0026ge;\u0026thinsp;II heterotopic ossifications, and 31.2% had stress shielding. The average peri-prosthetic radiolucency was 1.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3 mm.\u003c/p\u003e \u003cp\u003eAccording to statistical analysis, there was a strong positive correlation with pain scores (VAS; ρ = +0.86, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and a significant negative correlation with the MEPS score (ρ = \u0026minus;\u0026thinsp;0.88, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) when radial neck osteolysis was present. Additionally, there was a tendency for overall mobility to decline. Although there were trends toward worse clinical outcomes (reduced MEPS and range of motion) for other radiographic anomalies like stress shielding, the Delta River sign, and heterotopic ossifications, these correlations did not reach statistical significance.\u003c/p\u003e \u003cp\u003eThere was only one significant issue noted: a patient's progressive clinical decline necessitated revision surgery involving a total elbow arthroplasty.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cb\u003eFunctional Outcomes\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFunctional Measure\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRange\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMEPS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e81\u0026thinsp;\u0026plusmn;\u0026thinsp;12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e60\u0026ndash;100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuickDASH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e21\u0026thinsp;\u0026plusmn;\u0026thinsp;7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11\u0026ndash;36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePain VAS (0\u0026ndash;10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u0026ndash;6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFlexion (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e140\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e120\u0026ndash;155\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eExtension deficit (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e15\u0026thinsp;\u0026plusmn;\u0026thinsp;5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u0026ndash;25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePronation (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e83\u0026thinsp;\u0026plusmn;\u0026thinsp;7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70\u0026ndash;90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSupination (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e82\u0026thinsp;\u0026plusmn;\u0026thinsp;8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e65\u0026ndash;90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cb\u003ePostoperative radiographic abnormalities in the study cohort\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRadiographic Finding\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of Patients (n)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePercentage (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRadial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e62.5%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHumeroulnar osteoarthritis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e50.0%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHeterotopic ossification (Brooker\u0026thinsp;\u0026ge;\u0026thinsp;II)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e43.7%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDelta sign (overlengthening)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e37.5%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStress shielding\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e31.2%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eA subgroup comparison was performed between patients with isolated radial head fractures (simple) and those with complex elbow injuries (e.g., terrible triad, Monteggia-like, Essex-Lopresti). Functional outcomes and osteolysis rates were compared.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cb\u003eFunctional outcomes and prevalence of osteolysis according to injury type in the study cohort\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of Injury\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMEPS (Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eVAS (Mean)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eOsteolysis (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSimple\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e84\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e44.4%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eComplex\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e77\u0026thinsp;\u0026plusmn;\u0026thinsp;13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e85.7%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe main finding of this study is that certain radiographic alterations observed after radial head arthroplasty (RHA), particularly proximal radial neck osteolysis, appear to be associated with impaired clinical outcomes. Despite being historically considered \"radiologically silent,\" these changes\u0026mdash;when quantitatively analyzed\u0026mdash;appear to carry prognostic value, especially regarding elbow function and pain intensity.\u003c/p\u003e \u003cp\u003eIn our series, radial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm was observed in 62.5% of cases and showed a strong negative correlationwith MEPS (ρ = \u0026minus;\u0026thinsp;0.88) and a positive correlation with VAS (ρ = +0.86). These findings are in line with Chen et al. [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], who highlighted that such osteolytic changes, although frequently underdiagnosed, may reflect chronic micromotion at the bone-implant interface or low-grade inflammatory responses. Rafla et al. [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] similarly emphasized that early radiographic signs of loosening can evolve silently but compromise long-term implant stability. Ceccarelli et al. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] and Gauci et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] also noted that radial neck osteolysis is prevalent in mid-to-long-term follow-up, with potential functional consequences, particularly when exceeding 3 mm.\u003c/p\u003e \u003cp\u003eVan Riet et al. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] underlined the anatomical variability and biomechanical sensitivity of the radial column, making it particularly vulnerable to eccentric loading and asymmetric stresses. This anatomical consideration could partly explain why even minimal malalignment or stress concentration around the implant neck may lead to bone remodeling or resorption.\u003c/p\u003e \u003cp\u003eOther radiographic findings\u0026mdash;although less strongly correlated with functional scores\u0026mdash;also deserve attention:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eDelta River sign (asymmetry between radius and ulna at the trochlear notch) was present in 37.5% of patients. According to Wegmann et al. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], this sign likely reflects overlengthening or angular malpositioning, both of which disrupt the physiological axis of force transmission through the elbow. Although statistical significance was not reached in our cohort, a trend toward increased VAS and decreased MEPS was evident.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eStress shielding, observed in 31.2%, is consistent with the findings by Chanlalit et al. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] and Page et al. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], who reported periprosthetic cortical thinning due to biomechanical mismatch. Rigid or oversized implants may transfer less load to adjacent bone, triggering localized osteopenia.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eHeterotopic ossifications (HO), Brooker grade\u0026thinsp;\u0026ge;\u0026thinsp;II, were found in 43.7%. Their clinical impact varies by location and volume. While our cohort did not exhibit major motion restriction, limitations in pronation-supination were observed in more severe cases. HO remains a common complication in post-traumatic elbows, especially in complex dislocations, as emphasized by Laumonerie et al. [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] and Bonnevialle [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eHumero-ulnar osteoarthritis (50%) likely represents a degenerative response secondary to altered kinematics or unrecognized instability. Katthagen et al. [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] and Dunn et al. [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] reported similar findings, particularly in patients with terrible triad injuries or incomplete ligamentous healing.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eInterestingly, Claessen et al. [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] attempted to identify radiographic predictors of poor short-term outcomes and emphasized that subtle imaging anomalies\u0026mdash;especially early periprosthetic radiolucency or misalignment\u0026mdash;should not be overlooked. Our results reinforce that notion by demonstrating statistically and clinically meaningful correlations with validated functional measures.\u003c/p\u003e \u003cp\u003eAlthough the QuickDASH and range of motion (ROM) were not as strongly associated with radiographic abnormalities as MEPS or VAS, this likely reflects their multifactorial nature and lower sensitivity to subtle joint instability or pain during specific movements, as highlighted by Jung et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePatients with complex injuries had lower MEPS scores (77\u0026thinsp;\u0026plusmn;\u0026thinsp;13 vs. 84\u0026thinsp;\u0026plusmn;\u0026thinsp;10), higher pain levels (VAS 3.4 vs. 2.2), and a markedly increased prevalence of radial neck osteolysis (85.7% vs. 44.4%). Although statistical significance could not be demonstrated due to the limited sample size, this trend suggests a cumulative biomechanical burden in the setting of combined injuries. These findings are consistent with those reported by Ciais et al. [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], who observed that patients with terrible triad injuries were more likely to develop radiocapitellar complications and require prolonged rehabilitation. It is likely that altered load transmission, soft-tissue compromise, and surgical complexity contribute to these less favorable outcomes in complex cases.\u003c/p\u003e \u003cp\u003eSeveral limitations should be acknowledged:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eThe retrospective nature of the study limits causal inference and may introduce selection bias.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThe small sample size (n\u0026thinsp;=\u0026thinsp;16) restricts the statistical power, especially for subgroup comparisons.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eHeterogeneity in trauma patterns (simple fractures vs terrible triad) and surgical timing may have influenced both radiographic evolution and functional recovery.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eDespite standardized radiographic analysis with dual reading, some anomalies (e.g., stress shielding or Delta sign) are inherently subject to observer interpretation, as previously noted by Lobo-Escolar et al. [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eAlthough the sample size is limited (n\u0026thinsp;=\u0026thinsp;16), this study aligns with several published series addressing rare or complex indications such as radial head arthroplasty with detailed radiographic analysis [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The homogeneity of surgical technique and follow-up protocol adds strength to the internal validity, and the consistent correlation observed for radial neck osteolysis suggests a robust signal that warrants further validation in larger multicenter cohorts. Correlation coefficients may be overestimated in small retrospective series and should therefore be interpreted cautiously.\u003c/p\u003e \u003cp\u003eThe originality of this study lies in its focused, cross-sectional radioclinical evaluation. While most prior reports analyze either functional or radiological outcomes separately, we provide a correlation matrix between specific imaging anomalies and validated clinical scores. This approach, aligned with the recommendations of Thyagarajan [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], advocates for a risk-stratified follow-up based on early radiographic warning signs.\u003c/p\u003e \u003cp\u003eOur data support the notion proposed by Ciais et al. [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] that radiographic anomalies\u0026mdash;especially when quantified\u0026mdash;can guide postoperative surveillance and even influence rehabilitation strategies. We suggest that radial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm may represent a potential radiographic warning sign of poorer functional recovery and should not be dismissed as incidental.\u003c/p\u003e \u003cp\u003eMoreover, this study strengthens the call from Laumonerie et al. [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] and Allieu et al. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] to develop composite severity scores, integrating radiological and clinical findings to anticipate revision needs or prolonged disability. From a clinical standpoint, the presence of radial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm should prompt careful clinical and radiographic surveillance rather than immediate revision.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cb\u003eSelected studies reporting postoperative radiographic abnormalities after radial head arthroplasty and their potential clinical relevance\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStudy\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eStudy design\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRadiographic finding evaluated\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFunctional correlation\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAntoni et al., 2023\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRetrospective cohort study\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eProximal radial neck osteolysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eDemonstrated\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLee et al., 2022\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRetrospective cohort study\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStress shielding\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eInvestigated\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePehlivanoglu et al., 2021\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRetrospective long-term follow-up study\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRadiographic loosening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eDemonstrated\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSamra et al., 2022\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMid-term clinical cohort\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eImplant loosening and radiographic abnormalities\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eInvestigated\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMarsh et al., 2016\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eClinical cohort study\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePostoperative radiographic changes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eLimited /\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLaumonerie et al., 2017\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRetrospective cohort study\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRadiographic evolution after RHA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eReported qualitatively\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study highlights that certain radiographic anomalies observed after radial head arthroplasty\u0026mdash;particularly proximal radial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm\u0026mdash; may be associated with impaired functional outcomes and should not systematically be considered a purely incidental radiographic finding. While traditionally considered benign or \u0026ldquo;silent,\u0026rdquo; these changes may reflect altered load transmission or subclinical implant\u0026ndash;bone interactions., with measurable clinical consequences. Although secondary findings such as stress shielding, Delta River sign, and heterotopic ossifications showed less consistent impact, their presence warrants systematic evaluation during follow-up.\u003c/p\u003e \u003cp\u003eThese results support the integration of targeted radiographic assessments into routine postoperative surveillance, and the development of a composite severity score may help clinicians identify at-risk patients earlier. Further prospective, multicenter studies with larger cohorts are necessary to validate these associations and guide evidence-based management of subtle implant-related changes.\u003c/p\u003e \u003cp\u003eThe authors declare that they have no competing interests. No financial support or benefits have been received from any commercial entity related to the subject of this article.\u003c/p\u003e \u003cp\u003e This study was conducted in accordance with the Declaration of Helsinki. Given its retrospective and non-interventional design, formal ethical approval was not required. All data were anonymized.\u003c/p\u003e \u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eA.E. conceived and designed the study, performed data collection and statistical analysis, and drafted the manuscript.E.C. contributed to patient management, data acquisition, and critical revision of the manuscript.P.W. contributed to study supervision, surgical management, and critical revision of the manuscript for important intellectual content.All authors reviewed and approved the final version of the manuscript.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated and analyzed during the current study are not publicly available due to institutional data protection regulations and patient confidentiality but are available from the corresponding author on reasonable request and subject to approval by the institutional ethics committee.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eVan Riet RP, Van Glabbeek F, Neale PG, Bimmel R, Bortier H, Morrey BF et al (2004) Anatomical considerations of the radius. Clin Anat 17(7):564\u0026ndash;569\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaumonerie P, Ancelin D, Reina N, Tibbo ME, Kerezoudis P, Delclaux S et al (2017 July) Causes for early and late surgical re-intervention after radial head arthroplasty. Int Orthop 41(7):1435\u0026ndash;1443\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRafla S, Carroll EA, Wiesler ER, Li Z, Tuohy CJ, Nunez Sr F et al (2021) Early to midterm radiographic loosening of the press fit radial head prosthesis. Injury 52(12):3605\u0026ndash;3610\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen ACY, Cheng YH, Chiu CH, Cheng CY, Chan YS (2021) Long-Term Outcomes of Radial Head Arthroplasty in Complex Elbow Fracture Dislocation. JCM 10(16):3488\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eclaessen femke, Rens B, Kodde i, Doornberg J, van den Bekerom M, Eygendaal D Radiographic Predictors for Short-term Functional Outcome after Radial Head Arthroplasty in patients with persistent symptoms after treatment for radial head fracture. ABJS [Internet]. 2019 Aug [cited 2024 Nov 13];(Online First). Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.22038/abjs.2019.31727.1832\u003c/span\u003e\u003cspan address=\"10.22038/abjs.2019.31727.1832\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJung M, Groetzner-Schmidt C, Porschke F, Gr\u0026uuml;tzner PA, Guehring T, Schnetzke M (2019) Low return-to-sports rate after elbow injury and treatment with radial head arthroplasty. J Shoulder Elbow Surg 28(8):1441\u0026ndash;1448\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWegmann K, Hackl M, Leschinger T, Burkhart KJ, M\u0026uuml;ller LP (2021 Sept) Overlengthening of the radial column in radial head replacement: a review of the literature and presentation of a classification system. Arch Orthop Trauma Surg 141(9):1525\u0026ndash;1539\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCeccarelli R, Winter M, Barret H, Bronsard N, Gauci MO (2021) Pyrocarbon unipolar radial head prosthesis: clinical and radiologic outcomes at long-term follow-up. J Shoulder Elbow Surg 30(12):2886\u0026ndash;2894\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGauci MO, Winter M, Dumontier C, Bronsard N, Allieu Y (2016) Clinical and radiologic outcomes of pyrocarbon radial head prosthesis: midterm results. J Shoulder Elbow Surg 25(1):98\u0026ndash;104\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChanlalit C, Shukla DR, Fitzsimmons JS, An KN, O\u0026rsquo;Driscoll SW (2012) Stress shielding around radial head prostheses. J Hand Surg Am 37(10):2118\u0026ndash;2125\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePage RS, Paltoglou NG, Arora V, Eng K, Gill SD (2021 Sept) Retrospective review of pyrocarbon radial head replacement. JSES Rev Rep Tech 3(4):376\u0026ndash;380\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaumonerie P, Tibbo ME, Kerezoudis P, Gauci MO, Reina N, Bonnevialle N et al (2018) Short to midterm outcomes of one hundred and seventy one MoPyC radial head prostheses: meta-analysis. Int Orthop (SICOT) 42(10):2403\u0026ndash;2411\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaumonerie P, Reina N, Gutierrez C, Delclaux S, Tibbo ME, Bonnevialle N et al (2018) Tight-fitting radial head prosthesis: does stem size help prevent painful loosening? Int Orthop (SICOT) 42(1):161\u0026ndash;167\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBonnevialle N (2016) Radial head replacement in adults with recent fractures. Orthop Traumatology: Surg Res 102(1, Supplement):S69\u0026ndash;79\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKatthagen JC, Jensen G, Lill H, Voigt C (2013) Monobloc radial head prostheses in complex elbow injuries: results after primary and secondary implantation. Int Orthop (SICOT) 37(4):631\u0026ndash;639\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDunn JC, Kusnezov NA, Koehler LR, Eisenstein ED, Kilcoyne KG, Orr JD et al (2017) Radial Head Arthroplasty in the Active Duty Military Service Member With Minimum 2-Year Follow-Up. The Journal of Hand Surgery. ;42(8):660.e1-660.e7\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCiais G, Tibbo M, Massin V, Barret H, Abdellaoui M, Theopol D et al (2024) Short to Midterm Outcomes of 139 Pyrocarbon Monopolar Radial Arthroplasties. J Shoulder Elbow Surg\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLobo-Escolar L, Abell\u0026aacute;n-Miralles C, Escol\u0026agrave;-Benet A (2021) Outcomes of press-fit radial head arthroplasty following complex radial head fractures. Orthopaedics \u0026amp; Traumatology: Surgery \u0026amp; Research. ;107(2):102645\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaumonerie P, Tibbo ME, Reina N, Pham TT, Bonnevialle N, Mansat P (2019 July) Radial head arthroplasty: a historical perspective. Int Orthop (SICOT) 43(7):1643\u0026ndash;1651\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThyagarajan DS (2023) Radial head replacement \u0026ndash; A comprehensive review. J Orthop 36:51\u0026ndash;56\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAllieu Y, Winter M, De Pequignot JP (2006) Radial head replacement with a pyrocarbon head prosthesis: preliminary results of a multicentric prospective study. Eur J Orthop Surg Traumatol 16(1):1\u0026ndash;9\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-orthopaedic-surgery-and-traumatology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejos","sideBox":"Learn more about [European Journal of Orthopaedic Surgery \u0026 Traumatology](http://link.springer.com/journal/590)","snPcode":"590","submissionUrl":"https://submission.springernature.com/new-submission/590/3","title":"European Journal of Orthopaedic Surgery \u0026 Traumatology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Radial head arthroplasty, osteolysis, stress shielding, Delta sign, elbow trauma, radiographic anomalies, functional outcomes","lastPublishedDoi":"10.21203/rs.3.rs-9181917/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9181917/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction:\u003c/h2\u003e \u003cp\u003eRadial head arthroplasty (RHA) is widely used in the treatment of unreconstructable radial head fractures, particularly in complex elbow injuries. While functional outcomes are generally favorable, postoperative radiographic anomalies\u0026mdash;such as radial neck osteolysis, stress shielding, and heterotopic ossifications\u0026mdash;are frequently observed. The clinical relevance of these so-called \u0026ldquo;silent\u0026rdquo; anomalies remains controversial.\u003c/p\u003e\u003ch2\u003eMethods:\u003c/h2\u003e \u003cp\u003eWe conducted a retrospective monocentric study at the Centre Hospitalier Intercommunal de Villeneuve-Saint-Georges (CHIV) between 2010 and 2023. Sixteen adult patients undergoing modular press-fit radial head arthroplasty were included. Clinical evaluation at final follow-up included the Mayo Elbow Performance Score (MEPS), QuickDASH, VAS for pain, and range of motion (ROM). Radiographic anomalies were assessed through standardized X-rays and postoperative CT scans, and their correlation with functional outcomes was analyzed.\u003c/p\u003e\u003ch2\u003eResults:\u003c/h2\u003e \u003cp\u003eRadial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm was the most common anomaly (62.5%) and was significantly associated with lower MEPS scores (ρ = \u0026minus;\u0026thinsp;0.88, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and higher pain (VAS) scores (ρ = +0.86, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Other anomalies, including stress shielding (31.2%), Delta sign (37.5%), and Brooker grade\u0026thinsp;\u0026ge;\u0026thinsp;II heterotopic ossifications (43.7%), showed trends toward poorer outcomes but without statistical significance. Patients with complex injury patterns (terrible triad, olecranon fractures) had worse MEPS and higher osteolysis rates. These associations should be interpreted cautiously given the limited sample size.\u003c/p\u003e\u003ch2\u003eConclusion:\u003c/h2\u003e \u003cp\u003eRadial neck osteolysis\u0026thinsp;\u0026ge;\u0026thinsp;3 mm may represent a clinically relevant radiographic finding and appears to be a key marker of reduced function and increased pain following RHA. The cumulative burden of radiographic anomalies may help identify high-risk patients who warrant closer follow-up. This study supports integrating structured radiographic assessment into postoperative surveillance protocols.\u003c/p\u003e\u003ch2\u003eLevel of Evidence:\u003c/h2\u003e \u003cp\u003eLevel IV; retrospective case series\u003c/p\u003e","manuscriptTitle":"Clinical Relevance of Postoperative Radial Neck Osteolysis After Radial Head Arthroplasty: A Retrospective Radiographic–functional Correlation Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-03 06:22:33","doi":"10.21203/rs.3.rs-9181917/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-05T16:05:22+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"327552112835453080284634135547040460234","date":"2026-04-04T05:45:22+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-31T19:47:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"78017072082882872959102822943596015270","date":"2026-03-31T19:44:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"260728358892227478670644342487006432982","date":"2026-03-30T16:14:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"152515783958266331208599599220586738773","date":"2026-03-30T14:38:02+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-29T18:47:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"257559834960824688143193860364071810724","date":"2026-03-29T18:24:57+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-29T16:00:53+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-23T04:03:26+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-23T04:02:56+00:00","index":"","fulltext":""},{"type":"submitted","content":"European Journal of Orthopaedic Surgery \u0026 Traumatology","date":"2026-03-20T20:37:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-orthopaedic-surgery-and-traumatology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejos","sideBox":"Learn more about [European Journal of Orthopaedic Surgery \u0026 Traumatology](http://link.springer.com/journal/590)","snPcode":"590","submissionUrl":"https://submission.springernature.com/new-submission/590/3","title":"European Journal of Orthopaedic Surgery \u0026 Traumatology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"44dca8e1-0ebb-4809-8a0b-081ec3d8ed67","owner":[],"postedDate":"April 3rd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-12T01:38:14+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-03 06:22:33","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9181917","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9181917","identity":"rs-9181917","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}