Sebastian Siebenlist

Background: Failure after primary arthroscopic capsulolabral repair for anterior shoulder instability is often multifactorial. Although several patient-related, bony morphologic, and surgical factors have been associated with recurrent instability, their coexistence in patients undergoing revision surgery remains incompletely characterized. Purpose: To describe the prevalence and coexistence of previously reported patient-related, bony morphologic, and anchor-related known risk factors for recurrence in patients undergoing revision surgery after failed primary arthroscopic capsulolabral repair using multiplanar reconstruction (MPR)–corrected computed tomography (CT) scans. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Consecutive patients who underwent revision surgery for recurrent anterior shoulder instability after primary arthroscopic capsulolabral repair between 2013 and 2021 and had CT scans suitable for MPR were included. Patients who underwent additional stabilization procedures at the index surgery were excluded. MPR-corrected CT scans were assessed for glenoid bone loss, Hill-Sachs morphology and glenoid track status, intact anterior articular arc angle, glenoid version, glenoid concavity, bony shoulder stability ratio, and anchor-related factors. The prevalence and coexistence of predefined known risk factors for recurrence were analyzed descriptively. Results: A total of 55 patients were included, 89% of whom were male, with a median age of 27 years. At the time of index surgery, 32% were <20 years of age, and hyperlaxity was present in 47%. The median number of predefined known risk factors for recurrence per patient was 6, and 85% of patients had ≥4. Hill-Sachs lesions were present in 94% of patients, including off-track lesions in 41%. Intact anterior articular arc angle <150° was present in 85%, glenoid concavity depth ≤2 mm in 78%, glenoid retroversion 15% in 45%. Anchor-related abnormalities included peri-implant osteolysis in 53%, use of <3 anchors in 43%, absence of an anchor at the 5:30 position in 41%, extra-anatomical anchor placement in 40%, and anchor coverage <90° in 40%. Conclusion: Failed primary arthroscopic capsulolabral repair was associated with multiple coexisting known risk factors for recurrence. Although descriptive rather than causal, these findings support a comprehensive prerevision assessment for recurrence risk factors, including MPR-corrected CT to evaluate bipolar bone loss, glenoid morphology, Hill-Sachs engagement, and anchor placement before revision surgery.

Purpose: Preoperative planning, currently performed by orthopaedic surgeons (OS), is essential for successful osteotomy, but is labour‐intensive and error‐prone. As such, there is significant potential in the use of automated artificial intelligence (AI) algorithms to augment the abilities of OS in managing lower extremity pathologies in a high‐volume task that demands high precision and reliability. The aim was to develop a deep learning (DL) system capable of fully autonomous planning a medial open wedge high tibial osteotomy (mow‐HTO) on weight bearing anterior posterior (AP) long leg radiographs (LLR) and to validate its agreement with an expert‐derived reference standard, its reliability and processing time of the DL model compared to expert OS on multicentric test data sets (two institutions). Methods: A total of 594 patients (age 41.1 ± 13.2 years, 182 female) who underwent osteotomy between 01/2014 and 01/2021 were retrospectively enrolled. Manual annotations for lower extremity alignment and high tibial landmarks were performed on AP LLR radiographs. The data set was divided into training (60%, n = 399), validation (10%, n = 59) and hold‐out testing (30%, n = 136), with an additional external dataset ( n = 100) for further testing. A DL system with twelve expert networks was trained to identify relevant landmarks for HTO planning. The DL model was then tested on fully automated planning of a medial open wedge HTO based on (1) the desired postoperative intersection of the mechanical axis with the tibial plateau (%‐based) and (2) the desired femorotibial axis (°‐based). Agreement with the expert‐derived reference, reliability and processing time were compared with three expert OS using FDA‐approved preoperative planning software on the test data sets. Results: For preoperative alignment parameter analysis, compared to the ground truth, human preoperative accuracy ranged from 0.13° ± 0.10° to 1.06° ± 1.4°, interrater reliability ranged from intraclass correlation (ICC) 0.84–1.0 and clinically acceptable accuracy ranged from 72% to 100%. Preoperative accuracy of the DL model ranged from 0.22° ± 0.18° to 1.04° ± 1.28°, interrater reliability ranged from ICC 0.93–1.0 and clinically acceptable accuracy ranged from 91% to 100%. For the planning of the osteotomy gap, compared to the ground truth, human accuracy ranged from 0.46 ± 0.65 mm to 0.5 ± 0.88 mm (%‐based) and 0.43 ± 0.55 to 0.52 ± 0.75 mm (°‐based), reliability ranged from ICC 0.9–0.96 and 0.95–0.97 and clinically acceptable accuracy was 93.6%–96.0% (%‐based) and 89.8%–93.9% (°‐based). For the DL model, the accuracy was 0.53 ± 0.63 mm (%‐based) and 0.44 ± 0.53 mm (°‐based), reliability was ICC 0.99 (both methods) and clinically acceptable accuracy was 98.1% (%‐based) and 96.2% (°‐based). The DL‐model significantly and substantially outperformed the OS in intrarater reliability (0.88 vs. 1.0) and processing time for a fully automated alignment analysis (25.3 ± 0.8 s vs. 148.7 ± 10.1 s, p < 0.001). Conclusion: The developed DL model enabled fully automated mow‐HTO planning on AP long‐leg radiographs with reliability comparable to that of expert OS while significantly reducing processing time and improving measurement consistency. These suggest that DL‐based systems may assist orthopaedic providers by accelerating and standardising osteotomy planning. Level of Evidence: Level III, retrospective comparative study.

Purpose: To assess clinical, functional, and radiographic outcomes as well as return‐to‐sports (RTS) rates in adolescent patients (aged 10‐19 years according to the World Health Organization) who underwent the Latarjet procedure. Methods: A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (2020) guidelines and was prospectively registered on PROSPERO‐International Prospective Register of Systematic Reviews (reference: CRD420251003844). A systematic search of the databases PubMed, Web of Science (Clarivate Analytics), Scopus, and Google Scholar was performed, and clinical studies reporting outcomes of adolescent patients aged 10 to 19 years who underwent the Latarjet procedure for the treatment of anterior shoulder instability with a minimum follow‐up of 2 years were included. Studies were excluded if adolescent patients were part of a larger study cohort, but the outcomes were not reported separately. Demographic and surgical data, clinical outcomes, such as instability recurrence, revisions, and overall complication rates, functional outcomes, RTS rates, and radiological outcomes were extracted from each study. Moreover, a descriptive synthesis of the results and analysis of heterogeneity was performed. Results: Eight retrospective studies (6x Level III, 2x Level IV), comprising 265 shoulders in 262 patients, were included. The mean age at surgery ranged from 15.7 to 18.0 years and mean follow‐up ranged from 3.3 to 11.3 years. The rate of recurrent instability ranged from 3.3% to 14.3%, and the revision rate for instability ranged from 0% to 8.3%. The overall complication rate ranged from 6.7% to 25.8%, with screw irritation being reported most frequently. Favorable postoperative patient‐reported outcome measures were reported overall, including a mean subjective shoulder value ranging from 86.2 to 94.0 and a mean Rowe score ranging from 80.0 to 94.0. RTS rates ranged from 71.4% to 100%, with 75.0% to 79.2% of patients returning to their preoperative level of play. Coracoid graft union rates were less consistent (mean 66.7%‐100%). Substantial heterogeneity was observed regarding patient populations, surgical indications, and techniques and types of outcome measures. Conclusions: The Latarjet procedure yields favorable clinical and functional outcomes as well as high RTS rates in adolescent patients. Graft union rates varied but were generally high. The available evidence, however, is limited to retrospective studies with considerable heterogeneity regarding patient populations, surgical indications, and techniques and types of outcome measures assessed. Level of Evidence: Level IV, systematic review of Level III to IV studies.

Purpose: To evaluate shoulder stability and function at long‐term follow‐up after arthroscopic single‐row suture anchor fixation of bony Bankart lesions. Methods: This was a retrospective, single‐center study. Patients with anterior glenoid rim fractures after traumatic shoulder instability who underwent arthroscopic single‐row suture anchor fixation for bony Bankart lesions between 1999 and 2010 were included. Only patients with a minimum follow‐up of 14 years were eligible for the present long‐term analysis. Patients completed a standardized questionnaire including clinical data regarding shoulder stability, reoperation, patient satisfaction, and sports activity as well as patient‐reported outcome measures, including the Constant Score, Subjective Shoulder Value (SSV), American Shoulder and Elbow Surgeons Score, Oxford Instability Score, and Western Ontario Shoulder Instability Index. Changes in patient‐reported outcome measures were evaluated using cohort‐specific minimal clinically important difference thresholds, and patient satisfaction was assessed against a predefined threshold (≥8/10). Paired t‐tests or Wilcoxon signed‐rank tests were used as appropriate, with P < .05 considered significant. Results: Fifty patients were initially identified, of whom 45 were included in a previously published midterm follow‐up study. Of these, 13 patients were unavailable for long‐term follow‐up (7 lost to follow‐up and 6 deceased), resulting in a final cohort of 32 patients with a mean follow‐up of 18.3 years (range, 14.4‐25.1 years). Of patients, 90.6% reported no subjective instability. The redislocation rate was 3.1% (1 patient), and the recurrent subjective instability rate was 9.4% (3 patients). Two patients required revision surgery (1 open reosteosynthesis after traumatic glenoid fracture 9 years postoperatively and 1 reverse shoulder arthroplasty because of cuff arthropathy 21.9 years postoperatively). High satisfaction was reported by 29 of 32 patients (90.6%) based on the predefined threshold, and 96.9% of patients indicated that they would undergo the procedure again. Most patients (92.9%) returned to sports at the same level or higher than compared with their preinjury level. The mean Constant Score was 80.7 points, SSV 87.2%, American Shoulder and Elbow Surgeons 92.4 points, Oxford Instability Score 44.6 points, and Western Ontario Shoulder Instability Index 90.4 points. Although a statistically significant decline in SSV was observed over time ( P < .05), cohort‐specific minimal clinically important difference thresholds were met or exceeded by 12 of 32 patients for SSV (37.5%), 12 of 32 for Western Ontario Shoulder Instability Index (37.5%), and 9 of 32 for Oxford Instability Score (28.1%). Conclusions: Arthroscopic single‐row suture anchor repair of bony Bankart lesions provides excellent long‐term stability with low rates of recurrence and reoperation, high patient satisfaction, and favorable functional outcomes, even after nearly 2 decades. Level of Evidence: Level IV, retrospective case series.

Injuries involving the medial collateral ligament (MCL), or combined injuries to both the anterior cruciate ligament (ACL) and MCL, are common and present considerable diagnostic and therapeutic challenges. Better understanding of MCL anatomy and biomechanics, especially in combined ACL–MCL injuries, has driven the need for updated clinical examination and treatment approaches. The MCL complex comprises the superficial MCL (sMCL), deep MCL (dMCL), and the posteromedial complex (PMC), which includes the posterior oblique ligament (POL). Additional contributors to medial knee stability include the AMR and dynamic structures such as the semimembranosus, semitendinosus, and gracilis tendons. Biomechanically, the sMCL serves as the primary restraint against valgus loading and resists anterior tibial translation, particularly at higher degrees of knee flexion with external tibial rotation. The dMCL functions as a key stabiliser against external tibial rotation at low flexion angles and plays a significant role in anteromedial rotatory instability (AMRI), while the PMC/POL primarily limits internal tibial rotation. Accurate diagnosis requires an integrated approach, including thorough patient history, detailed physical examination, magnetic resonance imaging (MRI), and selective use of stress tests. Clinical assessment remains essential, as overreliance on imaging alone may misrepresent injury severity. Evaluation of medial‐sided structures should be performed bilaterally and for each structure separately, based on their distinct biomechanical roles. The POL should be evaluated in full patient‐specific knee extension. Assessment for AMRI should involve testing both valgus laxity at 20° of knee flexion, anteromedial drawer at 20° and anterior tibial translation at 90° with the tibia in neutral and then externally rotated. Findings of increased anterior tibial translation accompanied by excessive external tibial rotation relative to the contralateral side strongly indicate AMRI. This current concept article reviews the current literature and provides evidence‐based recommendations to develop guidance and optimize treatment strategies for isolated MCL injuries and combined MCL–ACL injuries Level of Evidence: Level V.

Background: Lateral epicondylitis (LE) is a degenerative tendinopathy of the common extensor origin (CEO). Although local glucocorticoid injections are widely used for symptom relief, concerns exist regarding their potential adverse effects on tendon structure. This study aimed to investigate the association between prior glucocorticoid injection and magnetic resonance imaging (MRI)-based structural CEO damage in patients with chronic LE. Methods: In this retrospective, multicenter cross-sectional study, 147 patients with clinically diagnosed LE (symptom duration ≥ 6 months) who underwent elbow MRI between 2015 and 2023 were included. The primary exposure was prior local glucocorticoid injection at the CEO (yes/no and number of injections). Structural tendon damage was assessed using the Walz classification and quantitative lesion size diameters measured in coronal, axial, and sagittal MRI planes. Associations were analyzed using proportional odds ordinal logistic regression and generalized linear models, adjusted for age, sex, occupational workload, study center, and symptom duration. Results: Sixty-three patients (42.9%) had received at least one prior glucocorticoid injection. Prior injection was independently associated with more severe MRI-based tendon damage. Patients with prior injection had higher odds of being classified in a higher Walz grade compared with non-injected patients (adjusted odds ratio (OR) 2.78, 95% confidence interval (CI) 1.30–5.97; p = .008). Longer symptom duration was also associated with higher Walz grades (adjusted OR 1.02 per month, 95% CI 1.00–1.04; p = .031). Among injected patients, the number of injections was not significantly associated with Walz grade. Prior injection was further associated with larger lesion size diameters: +2.07 mm in the coronal plane (95% CI 0.80–3.34; p = .001), + 1.49 mm in the axial plane (95% CI 0.21 − 2.76; p = .022), and a 94% larger sagittal diameter (ratio 1.94, 95% CI 1.15–3.29; p = .013). Conclusions: Prior local glucocorticoid injection at the CEO was associated with more severe MRI-detected structural tendon abnormalities in patients with chronic LE. However, the retrospective cross-sectional design and potential for confounding by indication preclude causal attribution of these structural differences to glucocorticoid exposure. These findings provide imaging-based evidence supporting a cautious and selective approach to glucocorticoid injections.

Purpose: Simple elbow dislocation (SED) is characterized by injuries to soft tissue structures. The aim of the novel Munich Elbow Soft Tissue (MEST) classification is to provide a systematic approach to grade the severity of musculoligamentous lesions after acute SED. The purpose of this study is to determine the reliability of the classification. Methods: All elbow dislocations between 1 January 2012 and 31 December 2024 that presented to a high‐frequency, multilevel trauma centre were screened retrospectively for inclusion criteria. Patients with a history of elbow fractures, chronic instability, previous surgery, previous musculoligamentous injuries, time from injury to magnetic resonance imaging (MRI) > 30 days and a lack of or low‐quality MRI imaging were excluded. In 30 randomly selected patients, injuries were classified according to the MEST system into Grade 1 (ligamentous) and Grade 2 (musculoligamentous), with an extended subclassification comprising eight subtypes based on detailed structure‐specific MRI assessment. Inter‐ and intrarater reliability were evaluated using Fleiss' and Cohen's Kappa ( κ) . Results: Of the randomly selected 30 patients (age 38.1 ± 13.4 years, male 46.7%), the mean time from injury to MRI was 4.2 ± 3.9 days. Interrater reliability across all raters demonstrated substantial agreement for the MEST grade (Fleiss' κ 0.690) and for the MEST subclassification (Fleiss' κ 0.639). Exact agreement was found in 70.0% for the MEST grade and in 43.3% for the MEST subclassification. Agreement between radiologists yielded higher agreement for the MEST subclassification than between the orthopaedics, and vice versa for the MEST grade. The less experienced raters showed higher agreement than the experienced raters. The classification also showed substantial to excellent intrarater reliability, with mean κ values of 0.900 for the MEST grade and 0.800 for the MEST subclassification. Conclusion: The MEST classification represents a comprehensive and reliable classification for injury patterns after acute SED, offering additional guidance in clinical decision‐making. Level of Evidence: Level IV.

Purpose: To evaluate short‐ to mid‐term clinical and radiological outcomes following osteochondral flake refixation with transpatellar, absorbable sutures (parachute technique) combined with concomitant medial patellofemoral ligament (MPFL) reconstruction after acute patellar dislocation. It was hypothesized that the parachute technique would yield favourable clinical and functional outcomes and demonstrate good osteochondral integration on radiographic follow‐up. Methods: A retrospective case series was conducted, including patients who underwent osteochondral flake refixation using the parachute technique following acute patellar dislocation between January 2012 and November 2023 at a minimum follow‐up of 24 months. Clinical outcomes were assessed using the Visual Analogue Scale (VAS), Tegner Activity Scale (TAS), Kujala Score, International Knee Documentation Committee (IKDC) subjective score and Knee Injury and Osteoarthritis Outcome Score (KOOS). Radiological outcomes were evaluated using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 knee score on 3.0‐T magnetic resonance imaging (MRI) by three independent raters and intraclass correlation coefficient (ICC) was assessed. Results: Of 26 identified patients, 20 (77%) were available at final follow‐up (mean age 20.8 ± 5.3 years; mean follow‐up 62.2 ± 20.5 months; mean defect size 2.8 ± 1.5 cm ² ). Clinical outcome scores resulted in a mean VAS of 0.5 ± 1.6, TAS of 6 (interquartile range 4–7), Kujala Score of 89.4 ± 12.5, IKDC of 86.7 ± 14.3 and total KOOS of 87.8 ± 14.1. Of all patients, 95% were satisfied with the overall result, and 90% would be willing to undergo the procedure again if necessary. Two patients (10%) required revision surgery (one patella re‐dislocation, one failed osteochondral integration). The mean MOCART 2.0 score was 84 ± 8 (range: 75–95), indicating good to excellent osteochondral integration. Inter‐rater reliability across the three raters was almost perfect (ICC = 0.84; 95% confidence interval 0.79–0.96). Conclusion: The parachute technique yields favourable clinical and functional outcomes at short‐ to mid‐term follow‐up and demonstrates good to excellent osteochondral integration on MRI following acute patellar dislocation. The technique represents a reliable, simple and single‐stage option for the treatment of retropatellar osteochondral flake fractures. Level of Evidence: Level IV, case series.

Background: Psychological readiness is an essential determinant of safe return to sport (RTS) after injury, yet it is often underrepresented in assessments of patients with elbow instability. The Elbow Instability–Return to Sport after Injury (EI-RSI) scale is a questionnaire designed to evaluate psychological readiness in athletes after lateral ulnar collateral ligament (LUCL) reconstruction for posterolateral rotatory instability of the elbow. Purpose: To develop and validate the EI-RSI scale. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: The EI-RSI was developed from the anterior cruciate ligament return-to-sport index (ACL-RSI) and the shoulder instability return-to-sport index (SI-RSI) with input from 10 patients with LUCL reconstruction (10 elbow joints), then tested in a retrospective cohort (2015-2021). Validity was assessed by correlating with the Mayo Elbow Performance Score (MEPS) and the Patient-Rated Elbow Evaluation (PREE). Reliability was assessed using test-retest analysis. RTS was measured via a questionnaire assessing participation (yes/no), return to preinjury level, and time to return. Statistical analyses included the Mann-Whitney U test and the Cronbach alpha. Results: A total of 47 patients (47 elbow joints; mean age, 40.7 ± 13 years; 22 men) were analyzed, with a median follow-up of 77 months (interquartile range [IQR], 36-110). The EI-RSI demonstrated good construct validity, showing a moderate positive correlation with MEPS ( r = 0.472; P < .001) and moderate negative correlations with the PREE total ( r = −0.572; P < .001), PREE pain ( r = −0.610; P < .001), and PREE function ( r = −0.595; P < .001) scores. Test-retest reliability was excellent (Spearman rho = 0.965; P < .001; ICCsingle = 0.965 [95% CI, 0.935-0.981]; ICCaverage = 0.982 [95% CI, 0.966-0.991]). Internal consistency was high (Cronbach α = 0.982). Patients who returned to sport exhibited significantly higher EI-RSI scores (median, 91.3 [IQR, 83.2-94.6]) compared with those who did not (median, 77.5 [IQR, 52.5-91.7]; P = .017). No floor or ceiling effects were observed. Conclusion: Our study demonstrated that the EI-RSI is a valid and reliable instrument for evaluating psychological readiness to RTS after LUCL reconstruction for posterolateral rotatory elbow instability. Its clinical implementation may facilitate informed RTS decisions and identify patients who could benefit from psychological support before safely resuming athletic activity.