Bilateral juvenile osteochondrosis dissecans in monozygotic twins: a case report.

INTRODUCTION: The etiology of osteochondrosis dissecans (OCD), a chondropathy associated with detachment of the subchondral bone and the overlaying cartilage, is not yet fully understood. While repetitive physical exercise-related stress is usually assumed to be the main risk factor for the occurrence of OCD, genetic predisposition could have an underestimated influence on the development of the disease. CASE REPORT: We report a case of monozygotic twins with almost identical stages of bilateral osteochondrosis dissecans of the knee joint. In both patients, initially, a unilateral lesion occurred; despite restricted physical exercise, in the further course of the disease a lesion also developed on the contralateral side. While the lesion found most recently demonstrated an ongoing healing process at a 6-month follow-up, the other three lesions showed a natural course of healing under conservative treatment with significant clinical as well as radiological improvements after one year and complete consolidation in magnetic resonance imaging (MRI) after 2 years. CONCLUSION: There could be a genetic component to the development of OCD, although this has not yet been proven. Based on a two-year MRI follow-up, we were able to show the self-limiting characteristics of juvenile osteochondrosis dissecans.

Malrotated lateral knee radiographs do not allow for a proper assessment of medial or lateral posterior tibial slope.

PURPOSE: The aim of this study was to investigate whether malrotation of lateral knee radiographs influences posterior tibial slope (PTS) measurements. METHODS: Lateral knee radiographs of all patients who underwent knee surgery at a single institution between June 2022 and January 2023 and received multiple lateral knee radiographs were included. Radiographs were categorised as malrotated lateral knee radiographs or lateral knee radiographs based on the radiographic distance between the medial and lateral posterior femoral condyles. Medial PTS (MPTS) and lateral PTS (LPTS) were evaluated on malrotated lateral knee radiographs and lateral knee radiographs and compared using the paired t test. Intra- and interrater reliability between four raters were assessed for MPTS and LPTS measurements. RESULTS: A total of 92 lateral knee radiographs (46 pairs of malrotated lateral knee radiographs and lateral knee radiographs; 50.0% right side) from 46 patients (33.2 ± 12.4 years, 69.6% male) were included. Mean posterior femoral condyle distance in malrotated lateral knee radiographs was 8.1 ± 4.4 mm. Overall, MPTS and LPTS were significantly higher on malrotated lateral knee radiographs versus lateral knee radiographs (medial: 10.5 ± 3.2° vs. 9.7 ± 3.5°, p < 0.05; lateral: 10.6 ± 3.4° vs. 9.7 ± 3.3°, p < 0.05). Mean absolute difference between MPTS and LPTS on malrotated lateral knee radiographs versus lateral knee radiographs were |1.9| ± |1.5|° and |2.0| ± |1.8|°, respectively. Intrarater reliability was 'moderate' and interrater reliability was 'good' for both MPTS and LPTS. CONCLUSION: Malrotation of lateral knee radiographs led to a significant distortion of both the MPTS and LPTS. In clinical practice, attention should be placed on the (mal)rotation of lateral knee radiographs, especially in patients for whom a slope-correcting osteotomy is being discussed. LEVEL OF EVIDENCE: Level IV.

Multicentric development and validation of a multi-scale and multi-task deep learning model for comprehensive lower extremity alignment analysis.

Osteoarthritis of the knee, a widespread cause of knee disability, is commonly treated in orthopedics due to its rising prevalence. Lower extremity misalignment, pivotal in knee injury etiology and management, necessitates comprehensive mechanical alignment evaluation via frequently-requested weight-bearing long leg radiographs (LLR). Despite LLR's routine use, current analysis techniques are error-prone and time-consuming. To address this, we conducted a multicentric study to develop and validate a deep learning (DL) model for fully automated leg alignment assessment on anterior-posterior LLR, targeting enhanced reliability and efficiency. The DL model, developed using 594 patients' LLR and a 60%/10%/30% data split for training, validation, and testing, executed alignment analyses via a multi-step process, employing a detection network and nine specialized networks. It was designed to assess all vital anatomical and mechanical parameters for standard clinical leg deformity analysis and preoperative planning. Accuracy, reliability, and assessment duration were compared with three specialized orthopedic surgeons across two distinct institutional datasets (136 and 143 radiographs). The algorithm exhibited equivalent performance to the surgeons in terms of alignment accuracy (DL: 0.21 ± 0.18°to 1.06 ± 1.3°vs. OS: 0.21 ± 0.16°to 1.72 ± 1.96°), interrater reliability (ICC DL: 0.90 ± 0.05 to 1.0 ± 0.0 vs. ICC OS: 0.90 ± 0.03 to 1.0 ± 0.0), and clinically acceptable accuracy (DL: 53.9%-100% vs OS 30.8%-100%). Further, automated analysis significantly reduced analysis time compared to manual annotation (DL: 22 ± 0.6 s vs. OS; 101.7 ± 7 s, p ≤ 0.01). By demonstrating that our algorithm not only matches the precision of expert surgeons but also significantly outpaces them in both speed and consistency of measurements, our research underscores a pivotal advancement in harnessing AI to enhance clinical efficiency and decision-making in orthopaedics.

Noninvasive and Reliable Quantification of Anteromedial Rotatory Knee Laxity: A Pilot Study on Healthy Individuals.

BACKGROUND: Anteromedial rotatory instability (AMRI) of the knee is a complex and severe condition caused by injury to the anterior cruciate ligament and/or the medial collateral ligament. Clinical studies dealing with AMRI are rare, and objective measurements are nonexistent. PURPOSE/HYPOTHESIS: The objectives of this study were, first, to quantify anteromedial rotatory knee laxity in healthy individuals using a noninvasive image analysis software and, second, to assess intra- and interrater reliability and equivalence in measuring anteromedial knee translation (AMT). It was hypothesized that AMT could be reliably quantified using a noninvasive image analysis software. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This prospective proof-of-concept study included healthy individuals aged 16 to 40 years with no history of knee injury or surgery. Three adhesive surface markers were placed on predefined landmarks on the medial side of the knee. Three independent investigators examined anteromedial rotatory knee laxity with an anterior drawer test in different tibial rotations (neutral tibial rotation, 15° of external tibial rotation, and 15° of internal tibial rotation). The entire examination of each knee was recorded, and AMT including the side-to-side difference (SSD) was assessed using a freely available and validated image analysis software (PIVOT iPad application). Group comparisons were performed using a 1-way analysis of variance with Bonferroni-adjusted post hoc analysis. Intraclass correlation coefficients (ICCs) were calculated to assess inter- and intrarater reliability of AMT measurements. Equivalence of measurements was evaluated using the 2 one-sided t-test procedure. RESULTS: Anteromedial rotatory knee laxity was assessed in 30 knees of 15 participants (53% male) with a mean age of 26.2 ± 3.5 years. In all 3 raters, the highest AMT was observed in neutral tibial rotation (range of means, 2.2-3.0 mm), followed by external tibial rotation (range of means, 2.0-2.4 mm) and internal tibial rotation (range of means, 1.8-2.2 mm; P < .05). Intrarater reliability of AMT (ICC, 0.88-0.96) and SSD (ICC, 0.61-0.96) measurements was good to excellent and moderate to excellent, respectively. However, interrater reliability was poor to moderate for AMT (ICC, 0.44-0.73) and SSD (ICC, 0.12-0.69) measurements. Statistically significant equivalence of AMT and SSD measurements was observed between and within raters for almost all testing conditions. CONCLUSION: Anteromedial rotatory knee laxity could be quantified using a noninvasive image analysis software, with the highest AMT observed during neutral tibial rotation in uninjured individuals. Reliability and equivalence of measurements were good to excellent within raters and moderate between raters.

The importance of interdigitating screw fixation of the trochlea in double plate osteosynthesis of low transcondylar distal humerus fractures: A biomechanical study.

OBJECTIVE: The trochlea is of great importance for the stability of the elbow and its fixation in low transcondylar fractures of the distal humerus is especially challenging. The aim of this study was to determine the optimal trochlea fixation in double plate osteosynthesis of intraarticular distal humerus fractures. METHODS: A low transcondylar, C3-type distal humerus fracture was created in 20 fresh-frozen human cadaveric humeri. The samples were then randomly divided into two groups of 10 specimens each. Double plate osteosynthesis was performed in both groups. In group A, the two most distal screws of the lateral plate were inserted into the trochlea fragment. In group B, these screws did not extend into the trochlea. Displacement under cyclic loading and ultimate failure loads were determined for all specimens. RESULTS: Group A showed significantly less displacement under cyclic loading in each measurement interval (0.92 mm vs. 1.53 mm after 100 cycles, p = 0 0.006; 1.10 mm vs. 1.84 mm after 1000 cycles, p = 0.007; 1.18 mm vs. 1.98 mm after 2000 cycles, p = 0.008). The ultimate failure load was significantly higher in group A than in group B (345.61 ± 120.389 N vs. 238.42 ± 131.61 N, p = 0.037). CONCLUSIONS: Fixation of the trochlea with interdigitating screws in double plate osteosynthesis of low-condylar type C distal humerus fractures results in superior construct stability. LEVEL OF EVIDENCE: not applicable (biomechanical).

Tibiofemoral Subluxation on Radiograph as a Predictor of Location and Size of Osteochondritis Dissecans Lesions of the Knee.

Background: Lower limb malalignment has been associated with osteochondritis dissecans (OCD). However, the location of the OCD lesion often is not concordant with the mechanical leg axis. Other potentially modifiable alignment parameters may influence the propensity for impingement of the femoral condyles. Purpose: To assess differences in lower limb alignment (LLA) and relative tibiofemoral position between patients with medial (MFC-OCD) or lateral OCD (LFC-OCD) of the femoral condyle. Study Design: Cohort study; Level of evidence, 3. Methods: Patients ≤30 years old who were diagnosed with unicondylar OCD between January 2010 and January 2020 were eligible for this study. Included were 55 patients (age, 20.8 ± 4.5 years)-46 with MFC-OCD and 9 with LFC-OCD. Preoperative standing long-leg radiographs were studied to obtain primary outcomes-including LLA and mechanical alignment analyses-and secondary outcomes-including knee joint obliquity angle; rotation angle; medial, central (c-subluxation), and lateral subluxation (L-subluxation) of the tibia relative to the femur in the coronal plane; and tibiofemoral joint line center distance (TFJCD). Results: With regard to primary outcomes, LLA was significantly different between MFC-OCD (1.7°± 3.1° varus) and LFC-OCD (2.7 ± 3.1° valgus) (P < .001), and 78% (36/46) of patients with MFC-OCD had varus alignment, whereas 78% (7/9) of patients with LFC-OCD had valgus alignment (P < 0.002). With regard to secondary outcomes, patients with MFC-OCD had a more medial tibial position in relation to the femur, with a significantly smaller rotation angle (5.6°± 2.4° vs 9.6°± 3.6°; P < .001), a smaller C-subluxation (7.2 ± 6.6 vs 14.9 ± 8.8 mm; P < .01), a smaller L-subluxation (2.3 ± 2.6 vs 4.4 ± 2.7 mm; P < .05), and reduced TFJCD (3.5 ± 1.7 vs 6.6 ± 1.8 mm; P < .001) compared with the LFC-OCD group. For patients with MFC-OCD, the size of the OCD was significantly correlated with C-subluxation (r = 0.412; P = .006). Conclusion: LLA was significantly different according to OCD location. In patients with MFC-OCD, the tibia was subluxated medially, resulting in a change of joint geometry by approximation of the medial tibial eminence toward the medial femoral condyle, potentially causing excessive pressure overload and microtrauma of the cartilage. Interestingly, the extent of subluxation was correlated with OCD size.

Evaluation of the efficiency of an ultrasound-supported infiltration technique in patients with tennis elbow applying the ITEC medical device: a multicenter study.

Background: The treatment of lateral epicondylitis remains unsatisfactory in certain cases. The aim of this study is to investigate the efficiency of an ultrasound-guided infiltration combined with fenestration of the extensor tendon postulating a 50% reduction in pain on exertion within 6 months. Methods: In a prospective, nonrandomized, multicenter study design, 68 patients with chronic lateral epicondylitis and symptoms lasted for at least 6 weeks were included. Each hospital has been assigned for Traumeel (A), autologous whole blood (B), or dextrose (C) in advance. Preinterventional, 6 weeks, 12 weeks, 6 and 12 months after infiltration, patient-related outcome parameter, and dorsal wrist extension strength were documented. Preinterventional (obligate) and after 6 months (optional) radiological evaluation (magnetic resonance imaging) was performed. Results: The Visual Analog Scale showed a significant reduction after 6 months in all groups (A. 4.8-2.5, B. 6.2-2.3, C. 5.8-2.4). Similar results could be observed with Subjective elbow value, Disabilities of Arm, Shoulder, and Hand Score, Mayo Elbow Performance Score, and Patient Rated Tennis Elbow Evaluation. The loss of strength could be completely compensated after about 6 months. Magnetic resonance imaging did not fully reflect clinical convalescence. Re-infiltrations were sometimes necessary for final reduction of symptoms (A = 11, B = 8, C = 4). Switching to surgical intervention was most frequently observed in group C (A = 2, B = 1, C = 5). In 14.5% of the cases, no improvement of the symptoms could be achieved with this method. Conclusion: The primary hypothesis of a significant long-term pain reduction of at least 50% could be achieved regardless of the medication chosen.

Evaluation of Conventional MR Imaging of the Shoulder in the Diagnosis of Lesions of the Biceps Pulley.

RATIONALE AND OBJECTIVES: To determine the diagnostic accuracy and reproducibility of conventional MR imaging (MRI) of the shoulder in evaluating biceps pulley lesions using arthroscopy as the standard of reference. METHODS: In a retrospective study, MR examinations of 68 patients with arthroscopically proven torn or intact biceps pulley were assessed for the presence of pulley lesions by three radiologists. The following criteria were evaluated: displacement of the long head of the biceps tendon (LHBT) relative to the subscapularis tendon (displacement sign), subluxation/dislocation of the LHBT, the integrity of the superior glenohumeral ligament (SGHL) and the coracohumeral ligament (CHL), lesions of the supraspinatus (SSP) and subscapularis (SSC) tendons adjacent to the rotator interval, presence of biceps tendinopathy and subacromial bursitis. RESULTS: There were 42 patients with pulley lesions in the study group. Conventional MR imaging showed an overall sensitivity of 95.2%, 88.1% and 92.9%, a specificity of 61.5%, 73.1%, and 80.8% and an accuracy of 82.4%, 82.4% and 88.2% in the diagnosis of pulley lesions. Interobserver agreement was substantial (multirater k = 0.75). Biceps tendinopathy (97.6%, 95.2%, 97.6%), defects of the SGHL (86.3%, 81.0%, 88.1%) and the displacement sign (88.1%, 81.0%, 85.7%) were the most sensitive diagnostic criteria. Subluxation/dislocation of the LHBT was insensitive (78.6%, 42.9%, 33.3%), but specific (69.2%, 100,0%, 96.2%). CONCLUSION: In the diagnosis of pulley lesions, conventional MR imaging is reproducible and shows high sensitivity and accuracy but moderate specificity.

Osteoarticular Open Flake Fracture Refixation: The "Parachute" Technique.

Osteochondral fractures of the patella, also known as "flake fractures," frequently occur after patellar dislocation. In such fractures, a piece of patellar cartilage with subchondral bone breaks off due to patellar dislocation or subsequent reposition. Various surgical techniques have evolved for surgical therapy with the goal of realigning the patellar cartilage. This article presents a cost-effective surgical technique for achieving stable refixation of large osteochondral fragments in patellar flake fractures. The proposed technique entails creating transosseous tunnels in a confluent fashion at the margins, exactly between the fragment and the natural cartilage. Sutures are passed through the established tunnels for flake refixation. This refixation method ensures evenly distributed pressure without penetration of the fragment itself, resulting in the formation of a characteristic parachute configuration composed of confluent bone tunnels and absorbable sutures. The suitability of flake refixation is assessed through an algorithm, allowing for appropriate patient selection. The described technique offers several advantages, including its simplicity and cost-effectiveness, a flexible configuration of the sutures, and the ability to provide stable refixation for large osteochondral fragments.

Varus osteotomy as a salvage procedure for young patients with symptomatic patellofemoral arthritis and valgus malalignment at short- to mid-term follow-up: a case series.

PURPOSE: The purpose of the study was to report the clinical, functional and radiological outcome following varus osteotomy as a salvage procedure in young to middle-aged patients with patellofemoral arthritis (PFA) and associated valgus malalignment. It was hypothesized that a significant improvement in knee function and reduction in pain would be achieved. Moreover, no conversion to patellofemoral joint arthroplasty could be observed. MATERIAL AND METHODS: Patients (< 50 years of age) that underwent varus osteotomy between 08/2012 and 01/2020 for the treatment of symptomatic PFA and associated valgus malalignment were consecutively included (minimum follow-up: 24 months). Patient-reported outcome measures (PROM; International Knee Documentation Committee subjective knee form [IKDC]), Visual Analog Scale [VAS] for pain, Tegner Activity Scale [TAS], and satisfaction with the postoperative results (1-10-scale, 10 = highest satisfaction) and weight-bearing whole-leg anteroposterior radiographs were conducted pre- and postoperatively. The change in PROM and femorotibial angle (FTA) were tested for statistical significance. RESULTS: In total, 12 patients (14 knees) were included (66.7% female; mean age: 33.8 ± SD 6.6 years). In ten cases, lateral opening-wedge distal femoral osteotomies (DFO) were performed, of which three cases included a concomitant femoral derotation. Three medial closing-wedge DFO and one medial closing-wedge high tibial osteotomy were performed. At follow-up (55.3 ± 29.3 months), a significant improvement in knee function (IKDC: 56.4 ± 14.4 to 69.1 ± 11.2, p = 0.015) and reduction in pain (VAS for pain: 3.5 [interquartile range 2.3-5.8] to 0.5 [0-2.0], p = 0.018) were observed. Patients were able to reach their preoperative sporting activity level (TAS: 3.0 [3.0-4.0] to 3.5 [3.0-4.0], p = 0.854) and were highly satisfied with the postoperative result (9.0 [6.5-10]). Additionally, a significant correction of valgus malalignment was observed (5.0° ± 2.9° valgus to 0.7° ± 3.2° varus, p < 0.001). Regarding complications, two re-osteosyntheses were performed due to loss of correction and delayed union. No conversion to patellofemoral arthroplasty occurred. CONCLUSION: In patients with symptomatic PFA and associated valgus malalignment, varus osteotomy as a salvage procedure achieved a significant improvement in knee function and reduction in pain. No conversion to patellofemoral joint arthroplasty occurred at short- to mid-term follow-up. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

Treatment strategies for simple elbow dislocation - a systematic review.

BACKGROUND: Current treatment concepts for simple elbow dislocation involve conservative and surgical approaches. The aim of this systematic review was to identify the superiority of one treatment strategy over the other by a qualitative analysis in adult patients who suffered simple elbow luxation. STUDY DESIGN: A systematic review in accordance with the PRISMA guidelines and following the suggestions for reporting on qualitative summaries was performed. A literature search was conducted using PubMed and Scopus, including variations and combinations of the following keywords: elbow, radiohumeral, ulnohumeral, radioulnar, luxation, and therapy. Seventeen studies that performed a randomized controlled trial to compare treatment strategies as conservative or surgical procedures were included. Reviews are not selected for further qualitative analysis. The following outcome parameters were compared: range of motion (ROM), Mayo Elbow Performance Score (MEPS), Disabilities of the Arm, Shoulder and Hand outcome measure (Quick-DASH), recurrent instability, pain measured by visual analog scale (VAS) and time to return to work (RW). RESULTS: Early mobilization after conservative treatment strategies showed improved ROM compared to immobilization for up to 3 weeks after surgery with less extension deficit in the early mobilization group (16° ± 13°. vs. 19.5° ± 3°, p < 0.05), as well as excellent clinical outcome scores. Surgical approaches showed similar results compared to conservative treatment, leading to improved ROM (115 vs. 118 ± 2.8) and MEPS: 95 ± 7 vs. 92 ± 4. CONCLUSION: Conservative treatment with early functional training of the elbow remains the first-line therapy for simple elbow dislocation. The surgical procedure provides similar outcomes compared to conservative treatment regarding MEPS and ROM for patients with slight initial instability in physical examination and radiographs. People with red flags for persistent instability, such as severe bilateral ligament injuries and moderate to severe instability during initial physical examination, should be considered for a primary surgical approach to prevent recurrent posterolateral and valgus instability. Postoperative early mobilization and early mobilization for conservatively treated patients is beneficial to improve patient outcome and ROM.

Recreational athletes during downhill-mountain biking (DMB) show high incidence of upper extremity fractures in combination with soft-tissue injuries.

Downhill-mountain biking (DMB) is a high-risk sport and often leads to several injuries, especially in non-professional athletes. We retrospectively analyzed the most common injuries and profiled the injury mechanism. Until now, there is no such analysis of injuries by non-professional mountain bike athletes. We collected patient data from patients who suffered from an injury during DMB. The inclusion criteria were (1) injury during the summer season of 2020 and 2021, (2) injury during off-road and downhill mountain bike sports activity, and (3) treatment at the Department of Traumatology of the Klinik Diakonissen Schladming. Patient data was analyzed regarding the type of injury, location of the injury, patient age and gender of the patients. Most patients with injury are at the age of 26-35. Second most are between 36 and 71 years old. The type of injury differs between age and gender. Mostly upper-extremity injuries occur with a high probability of shoulder injuries. In the elderly patients, we found additional injuries of the thorax and chest. To conclude, most common types of injuries are soft-tissue injuries, often in combination with fractures. The risk for injuries is higher for recreational athletes with different injury characteristics than professional athletes.

Anterior Latissimus Dorsi Transfer for Irreparable Subscapularis Tears Improves Shoulder Kinematics in a Dynamic Biomechanical Cadaveric Shoulder Model.

BACKGROUND: In young patients with irreparable subscapularis deficiency (SSC-D) and absence of severe osteoarthritis, anterior latissimus dorsi transfer (aLDT) has been proposed as a treatment option to restore the anteroposterior muscular force couple to regain sufficient shoulder function. However, evidence regarding the biomechanical effect of an aLDT on glenohumeral kinematics remains sparse. PURPOSE/HYPOTHESIS: The purpose of this study was to investigate the effects of an aLDT on range of glenohumeral abduction motion, superior migration of the humeral head (SM), and cumulative deltoid force (cDF) in a simulated SSC-D model using a dynamic shoulder model. It was hypothesized that an aLDT would restore native shoulder kinematics by reestablishing the insufficient anteroposterior force couple. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen cadaveric shoulders were tested using a validated shoulder simulator. Glenohumeral abduction angle (gAA), SM, and cDF were compared across 3 conditions: (1) native, (2) SSC-D, and (3) aLDT. gAA and SM were measured using 3-dimensional motion tracking, while cDF was recorded in real time during dynamic abduction motion by load cells connected to actuators. RESULTS: The SSC-D significantly decreased gAA (Δ-9.8°; 95% CI, -14.1° to -5.5°; P < .001) and showed a significant increase in SM (Δ2.0 mm; 95% CI, 0.9 to 3.1 mm; P = .003), while cDF was similar (Δ7.8 N; 95% CI, -9.2 to 24.7 N; P = .586) when compared with the native state. Performing an aLDT resulted in a significantly increased gAA (Δ3.8°; 95% CI, 1.8° to 5.7°; P < .001), while cDF (Δ-36.1 N; 95% CI, -48.7 to -23.7 N; P < .001) was significantly reduced compared with the SSC-D. For the aLDT, no anterior subluxation was observed. However, the aLDT was not able to restore native gAA (Δ-6.1°; 95% CI, -8.9° to -3.2°; P < .001). CONCLUSION: In this cadaveric study, performing an aLDT for an irreparable subscapularis insufficiency restored the anteroposterior force couple and prevented superior and anterior humeral head migration, thus improving glenohumeral kinematics. Furthermore, compensatory deltoid forces were reduced by performing an aLDT. CLINICAL RELEVANCE: Given the favorable effect of the aLDT on shoulder kinematics in this dynamic shoulder model, performing an aLDT may be considered as a treatment option in patients with irreparable SSC-D.

[Treatment of osteochondritis dissecans]. / Therapie der Osteochondrosis dissecans.

Osteochondritis dissecans (OD) is a rare condition with an incidence of 30/100,000. It especially affects male patients aged 10-20 years old. During the staged progression the osteochondral fragments can detach from their base. These can damage the adjacent articular cartilage, which can lead to premature osteoarthritis. Most commonly affected are the knee, ankle and elbow joints. The exact pathogenesis of OD has so far not been clearly confirmed. Several risk factors that can lead to the development of OD are discussed. These include repeated microtrauma and vascularization disorders that can lead to ischemia of the subchondral bone and to a separation of the fragments close to the joint and therefore to the development of free joint bodies. For an adequate clarification patients should undergo a thorough radiological evaluation including X­ray imaging followed by magnetic resonance imaging (MRI) to assess the integrity of the cartilage-bone formation with determination of the OD stage. The assessment is based on criteria of the International Cartilage Repair Society (ICRS). The instability of the cartilage-bone fragment increases with higher stages. Stages I and II with stable cartilage-bone interconnection can be treated conservatively. For stages III and IV, i.e., instability of the OD fragment or the presence of free fragments, surgical treatment should be performed. Primarily, refixation of a free joint body should be carried out depending on the size and vitality of the fragment. In cases of unsuccessful conservative treatment or fixation, a debridement, if necessary in combination with a bone marrow stimulating procedure, can be employed corresponding to the size of the defect. For larger cartilage defects, an osteochondral graft transplantation should be considered. Overall, OD lesions in stages I and II show a good healing tendency under conservative treatment. In cases of incipient unstable OD, refixation can also lead to good clinical and radiological results.

[Influence of the bony alignment on the ligaments of the knee joint]. / Einfluss des knöchernen Alignments auf den Bandapparat des Kniegelenks.

In recent years biomechanical and clinical studies have shown that the three-dimensional bony alignment of the lower extremities has a relevant influence on the ligamentous structures of the knee and consequently on the stability of the knee joint. Therefore, in the case of pathological ligamentous damage of the knee joint, a possible malalignment must always be thoroughly evaluated and if necessary, included in the treatment planning. Varus malalignment plays an important role especially with respect to the cruciate ligaments as well as the posterolateral ligamentous structures and has been identified as a significant risk factor for failure after surgical reconstruction of these ligamentous structures. Similar data have also been published for valgus malalignment particularly with respect to its negative influence on the anterior cruciate ligament and the medial capsuloligamentous complex. Alignment deviations in the sagittal plane, especially the inclination of the tibial articular surface (slope), have been extensively investigated in several recent studies. It has been demonstrated that the tibial slope has a relevant influence on the anteroposterior stability of the knee joint and hence on the cruciate ligaments. First clinical studies on the surgical correction of the axis in selected patients showed very promising results with the potential of protecting ligament reconstructions against repeated failure; however, further data especially regarding the importance and the exact indications for an additional alignment correction are necessary.

Pyrocarbon hemiprostheses show little glenoid erosion and good clinical function at 5.5 years of follow-up.

BACKGROUND: The success of traditional shoulder hemiarthroplasty (HA) with cobalt-chromium heads is limited by painful glenoid erosion with problematic bone loss. Hemiprostheses with pyrolytic carbon (PyC) heads have shown reduced glenoid erosion in experimental laboratory studies. Few in vivo data are available. METHODS: We performed a single-center consecutive cohort study of 31 of 34 patients (91%) who underwent PyC HA between September 2013 and June 2018. In 11 of these patients, concentric glenoid reaming was additionally performed. The mean follow-up period was 5.5 years (range, 3.5-7 years). Standardized radiographs were taken, and clinical function (Constant score) and pain (visual analog scale score) were recorded. Anteroposterior radiographs were analyzed according to an established method by 2 independent observers: A line parallel to the superior and inferior glenoid rim was translated to the most medial point of the glenoid surface. A further parallel line was placed on the spinoglenoid notch. The distance between these 2 lines was measured. Measurements were scaled using the known diameter of the implanted humeral head component. To assess eccentric erosion, anteroposterior and axial images were classified according to Favard and Walch, respectively. RESULTS: Mean medial glenoid erosion measured 1.4 mm at an average of 5.5 years of follow-up. In the first year, 0.8 mm of erosion was observed, significantly more than the average erosion per year of 0.3 mm (P < .001). Mean erosion per year was 0.4 mm in patients with glenoid reaming vs. 0.2 mm in those without reaming (P = .09). An evolution of glenoid morphology was observed in 6 patients, of whom 4 had a progression of the erosion grade. The prosthesis survival rate was 100%. The Constant score improved from 45.0 preoperatively to 78.0 at 2-3 years postoperatively and 78.8 at latest follow-up (5.5 years postoperatively) (P < .001). The pain score on a visual analog scale decreased from 6.7 (range, 3-9) preoperatively to 2.2 (range, 0-8) at latest follow-up (P < .001). There was a weak correlation (r = 0.37) between erosion and pain improvement (P = .039) and no correlation between erosion and change in Constant score (r = 0.06). CONCLUSION: PyC HA caused little glenoid erosion and a sustained improvement in clinical function in our cohort at mid-term follow-up. PyC demonstrates a biphasic development of glenoid erosion, with a reduced rate after the first year. PyC HA should therefore be considered as an alternative to cobalt-chromium HA and to anatomical total shoulder arthroplasty for patients with a high risk of glenoid component complications.

The Posterior Tibial Slope Is Not Associated With Graft Failure and Functional Outcomes After Anatomic Primary Isolated Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Biomechanical studies have shown that an increased medial posterior tibial slope (MPTS) may affect anteroposterior knee laxity and tibial shear forces, ultimately increasing the risk for graft failure after anterior cruciate ligament (ACL) reconstruction. Previous clinical studies have, however, reported inconclusive results. PURPOSE: The purpose of this study was to evaluate the relationship between the MPTS and graft failure as well as functional outcomes after anatomic primary isolated ACL reconstruction using a hamstring tendon autograft. It was hypothesized that an increased MPTS would be associated with a higher ACL graft failure rate. Furthermore, a higher MPTS would negatively correlate with functional outcomes in patients without ACL graft failure. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Consecutive patients who underwent isolated primary ACL reconstruction with an anteromedial portal drilling technique between January 2011 and December 2019 were retrospectively reviewed. The MPTS was measured on preoperative lateral knee radiographs. At a minimum of 24 months postoperatively, the ACL graft failure rate and patient-reported outcome measures (PROM; International Knee Documentation Committee subjective knee form, Lysholm score, Tegner Activity Scale, visual analog scale for pain and subjective instability) were evaluated. Differences in the MPTS between patients with and without ACL graft failure as well as the frequency of graft failure between those with an MPTS <12° and those with an MPTS ≥12° were assessed for statistical significance. Binary logistic regression analysis was performed to stratify the risk of graft failure with the following variables: MPTS, age at surgery, and sex. Correlation analysis was performed to evaluate the relationship between the MPTS and PROM in patients without ACL graft failure. RESULTS: In total, 326 patients were included (median follow-up, 71.0 months [IQR, 49.0-104.0 months]). There was no significant difference in the MPTS between patients with and without graft failure (10.6°± 3.2° vs 11.2°± 2.8°, respectively; P = .264). Additionally, there was no significant difference in the frequency of graft failure between patients with an MPTS <12° and those with an MPTS ≥12° (15.6% vs 16.5%, respectively; P = .835). Binary logistic regression showed that younger age at the time of surgery (odds ratio, 1.069 [95% CI, 1.031-1.109]) was associated with graft failure; sex and MPTS were not associated with graft failure. In patients without ACL graft failure, there was no significant correlation between the MPTS and PROM. CONCLUSION: In patients who underwent anatomic primary isolated ACL reconstruction, an increased MPTS was not associated with a higher rate of graft failure or inferior functional outcomes. Younger age was a significant nonmodifiable risk factor for ACL graft failure.

The importance of a structured failure analysis in revision acromioclavicular joint surgery: A multi-rater agreement on the causes of stabilization failure from the ISAKOS shoulder committee.

BACKGROUND: Acromioclavicular joint (ACJ) stabilizations are associated with a high overall failure rate with 9.5% of these patients requiring subsequent revision surgery. Consequently, understanding the specific cause of primary ACJ stabilization failure is paramount to improving surgical decision-making in this challenging patient cohort. PURPOSE: To (1) identify risk factors and mechanisms for failure following primary arthroscopically-assisted ACJ stabilization to highlight the importance of conducting a detailed failure analysis and to (2) establish revision strategies based on real-life cases of primary failed ACJ stabilization. STUDY DESIGN: Level of evidence IV. METHODS: A survey was shared internationally among members of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) shoulder committee. The survey contained failure analysis of 11 real-life cases of failed primary arthroscopically-assisted ACJ stabilization. For each case, a thorough patient history, standardized radiographs, and CT scans were provided. Participants were asked to give their opinion on bone tunnel placement, cause of failure (biological, technical, traumatic, or combined), the stabilization technique used, as well as give a recommendation for revision. RESULTS: Seventeen members of the ISAKOS shoulder committee completed the survey. Biological failure was considered the most common cause of failure (47.1%), followed by technical (35.3%) and traumatic (17.6%) failure. The majority deemed two modifiable factors (i.e., patient's profession and sport) as well as non-modifiable factors (i.e., patient's age and time from trauma to initial surgery) to be risk factors for failure. In 10 of 11 cases, the correct fixation device was used in the primary setting (90.9%; 52.8-82.4% agreement); however, in eight of those cases, the technique was not performed correctly (80.0%; 58.8-100% agreement). In 8 of all 11 cases, the majority recommended an arthroscopically assisted technique with graft augmentation for revision (52.9-58.8% agreement). CONCLUSION: Biological failure and technical failure are the most common reason for failure in primary ACJ stabilization followed by traumatic failure. Besides, biological failure can be triggered by technical errors such as clavicular or coracoidal tunnel misplacement. Consequently, a detailed failure analysis including preoperative CT should be conducted on the causes of primary ACJ failure, and, if possible, an arthroscopically-assisted technique with graft augmentation should be prioritized in revision ACJ surgery. CLINICAL RELEVANCE: ACJ stabilizations are associated with a high overall failure rate - potentially due to biological and technical properties. When encountering failed arthroscopically-assisted ACJ stabilization, a detailed failure analysis should be conducted on the causes of primary ACJ failure. Furthermore, an arthroscopically-assisted revision stabilization is feasible in most cases.