Low impact injury resulting in a Schenck type IV classified anterior knee dislocation as well as biceps femoris rupture: A Case Report.

Introduction: Dislocations of the knee joint represent very rare injuries in the literature, accounting for less than 0.02% of all musculoskeletal injuries. Case Report: This report describes a patient suffered a knee joint dislocation of the knee joint caused by a low impact injury following a stumbling trauma during volunteer of a sport competition. Anterior knee joint dislocation with incipient compartment syndrome was clinically prognosed. Vascular and nerve injuries were radiologically examined. Taken together the injury was classified as Schenck type IV CN, and surgical management of the current knowledge was pursued. A satisfying range of motion was examined during surgery next to solid vascular und nerve conditions post-surgery. Conclusion: In case of severe knee joint dislocations, the current standard of a closed reduction with subsequent diagnostic is recommended. Compartment syndrome, nerve, and vascular tears indicate emergency surgery.

Concomitant Glenohumeral Pathologies in Patients with Acromioclavicular Joint Dislocations: How Do Acute and Chronic Instabilities Differ?

Background: Concomitant glenohumeral pathologies may be present in patients with acromioclavicular joint (ACJ) dislocations. This study aims to record and compare the prevalence and treatment of CGP in cases with acute and chronic ACJ dislocations. Methods: This retrospective cross-sectional binational, bicentric study included patients that underwent arthroscopically assisted stabilization for acute (group A) and chronic (group C) ACJ dislocations. Intraoperatively, CGPs and eventual treatments (debridement and reconstructive measures) were recorded. Results: The study included 540 patients (87% men; mean age 39.4 years), with 410 (75.9%) patients in group A and 130 (24.1%) in group C. Patients in group C were older (p < 0.001). The CGP prevalence was 30.7%, without a difference between groups A and C (p = 0.19). Supraspinatus tendon (SSP) and labral lesions were most common. Within group C, CGPs were more prevalent in surgery-naïve patients (p = 0.002). Among 49 patients with previous surgical treatment, CGPs tended to be more common in patients with prior open surgery than arthroscopically assisted surgery (p = 0.392). Increased CGP prevalence was associated with higher age (r = 0.97; p = 0.004) (up to 63% in the oldest age group, but also 17% for youngest age group) and higher in cases with Rockwood type-IIIB injuries compared to type-V injuries (p = 0.028), but type-IIIB injuries included more group C cases (p < 0.001). The most frequently found CGPs were treated by debridement rather than reconstructive interventions (SSP and labrum: p < 0.001, respectively). Conclusions: This study shows that one in three patients with ACJ instabilities has a CGP, especially elderly patients. Most of the CGPs were treated by debridement rather than constructive interventions.

The V angle compliments radiographic assessment of acute acromioclavicular joint dislocations by differentiating between Rockwood types III versus V and by considering dynamic horizontal translation in coronal radiographs.

PURPOSE: Acromioclavicular joint (ACJ) dislocations are usually graded radiographically according to Rockwood, but differentiation between Rockwood types III and V may be ambiguous. The potentially clinically relevant horizontal instability is barely addressed in coronal radiographs. It was hypothesized that a new radiologic parameter (V angle) would complement ACJ diagnostics on anteroposterior radiographs by differentiating between cases of Rockwood III and V while also considering the aspect of dynamic horizontal translation (DHT). METHODS: Ninety-five patients with acute ACJ dislocations (Rockwood types III and V) were included retrospectively between 2017 and 2020. On anteroposterior views (weightbearing: n = 62, non-weight-bearing: n = 33), the coracoclavicular (CC) distance and the newly introduced V angle for assessing scapular orientation were measured bilaterally. This angle is referenced between the spinal column and a line crossing the superior scapular angle and the crossing point between the supraspinatus fossa and the medial base of the coracoid process, reported as the side-comparative difference (non-injured side *minus* injured side). DHT on Alexander views was divided into stable, partially unstable or completely unstable. RESULTS: The V angle on the injured side alone (mean 50.0°; 95% confidence interval (CI), 48.6°-51.3°) showed no correlation with the side-comparative CC distance [%] (r = - 0.040; n.s.). Thus, the V angle on the non-injured side was considered, displaying a normal distribution (n.s.) with a mean of 58.0° (95% CI, 56.6°-59.4°). The side-comparative V angle showed a correlation with the side-comparative CC distance (r = 0.83; p < 0.001) and was able to differentiate between Rockwood types III (4.7°; 95% CI, 3.9°-5.5°; n = 39) and V (10.3°; 95% CI, 9.7°-11.0°; n = 56) (p < 0.001). A cut-off value of 7° had a 94.6% sensitivity and an 82.1% specificity (area under curve, AUC: 0.954; 95% CI, 0.915-0.994). The side-comparative V angle was greater for cases with complete DHT (8.7°; 95% CI, 7.9°-9.5°; n = 78) than for cases with partial DHT (4.8°; 95% CI, 3.3°-6.3°; n = 16) (p < 0.001). A cut-off value of 5° showed a sensitivity of 84.6% and a specificity of 66.7% (AUC 0.824; 95% CI, 0.725-0.924). CONCLUSION: The scapular-based V angle on anteroposterior radiographs distinguishes between Rockwood types III and V as well as cases with partial or complete DHT. STUDY DESIGN: Diagnostic study. LEVEL OF EVIDENCE: Level II.

Clavicular Tunnel Widening After Acromioclavicular Stabilization Shows Implant-Dependent Correlation With Postoperative Loss of Reduction.

PURPOSE: To radiographically describe, quantify, and compare clavicular tunnel widening (cTW) of 2 different types of stabilization devices and investigate a possible correlation between cTW and loss of reduction. METHODS: In a retrospective analysis of single-center registry data, we compared patients who were treated for an acute AC dislocation (Rockwood types III to V) with either the AC Dog Bone (DB) or low-profile AC (LP) repair systems. On 6-week and 6-month postoperative radiographs, we measured clavicle height and tunnel diameter. We calculated the button/clavicle filling (B/C) ratio to quantify how much of the clavicular tunnel height is covered by the low-profile inlet. The association between B/C ratio and the extent of cTW was defined, and we also compared cTW between treatment groups. Reduction of the AC joint was graded as either stable, partially dislocated or dislocated depending on the AC ratio. A 2-sample t-test was used for comparing cTW progression between the 2 groups. For continuous variables between more than 2 groups, the Kruskal-Wallis test was used. RESULTS: Of 65 eligible patients, there were 37 and 28 included in the DB and LP groups, respectively. Overall, cTW was conically shaped with transclavicular widening noted in the DB group and cTW developing strictly inferior to the button in the LP group. For both implants, mean maximal cTW was 7.1 mm and located at the inferior cortex; the B/C ratio was not associated with increased inferior cTW (r = -0.23, P = .248). Only LP patients with complete loss of reduction had significantly increased cTW (P = .049). CONCLUSIONS: Conical-shaped cTW is a common implant-independent phenomenon after AC stabilization using suture-button devices. It occurs only at the suture-bone interface and is less excessive for the LP implant. There is an association between increased cTW and loss of reduction specific to the LP implant only. LEVEL OF EVIDENCE: Level III, therapeutic study.

Management of Acute High-Grade Acromioclavicular Joint Dislocations: Comparable Clinical and Radiological Outcomes After Bidirectional Arthroscopic-Assisted Stabilization With the Single Low-Profile Suture Button Technique Versus Double-Suture Button Technique.

PURPOSE: To compare the 2-year clinical and radiological outcomes of an arthroscopic-assisted bidirectional stabilization procedure using a single low-profile (LPSB) or double-suture button (DSB) technique with additional percutaneous acromioclavicular (AC) cerclage fixation for patients with acute high-grade AC joint dislocation. METHODS: This retrospective cohort study compared male patients aged between 18 and 56 years with acute high-grade AC joint dislocation fixed with either a LPSB or DSB technique. Patients were examined at least 24 months after surgery. Subjective Shoulder Value (SSV), Taft (TF), and Acromioclavicular Joint Instability (ACJI) scores were evaluated. Coracoclavicular difference, ossification, AC joint osteoarthritis, and dynamic posterior translation (DPT) were assessed on bilateral anteroposterior stress radiographs and modified Alexander views. The revision rate due to implant conflict and duration of surgery were reported. Group outcome differences were analyzed using standardized hypothesis tests. RESULTS: 28 patients aged 39.2 (LPSB) and 36.4 years (DSB) (P = .319; CI: -2.77-8.34) were eligible per cohort. The follow-up was 30.5 (LPSB) and 37.4 months (DSB) (P = .02; CI: -12.73-1.08). LPSB patients rated a significantly higher SSV (93.2% vs 81.9% [DSB]; P = .004). TF and ACJI scores were similar between the groups. Coracoclavicular difference markedly decreased from 12 mm to 3 mm for both cohorts (P < .001). Ossification was identified in over 85% in both cohorts (P = .160; CI -0.77-0.13) and osteoarthritis in 21.4% (LPSB) and 39.3% (DSB) (P = .150). Persistent DPT was found in around 30% for both cohorts (P = .561; CI -0.26-0.48). The revision rates were 0% (LPSB) and 7% (DSB) (P = .491). LPSB surgery was shorter (59.7 vs 71.5 mins [DSB]) (P = .011). CONCLUSIONS: The results of the LPSB and DSB techniques with additional percutaneous AC cerclage fixation showed comparable outcomes with excellent clinical and satisfactory radiological results. The assessment of the subjective patient satisfaction was in favor of the LPSB technique and no postoperative revision event was observed following this procedure. LEVEL OF EVIDENCE: Level III, retrospective comparative therapeutic trial.

[Minimally Invasive Techniques for the Treatment of Acute and Chronic Acromioclavicular Joint Instabilities]. / Minimalinvasive Techniken zur Therapie der Schultereckgelenksprengung.

Acromioclavicular joint instabilities are one of the most common injuries of the shoulder girdle. Diagnostic measures include the vertical and horizontal components of instability. The main goals of treatment include pain reduction, joint stabilization, and return to physical activity. For operative treatment, there are numerous techniques available. Recently, minimally-invasive techniques were developed and showed equal results as with open approach. These procedures facilitate simultaneous treatment of concomitant shoulder lesions and reduce soft tissue trauma as well as the risk of infection. This article presents an overview of such minimally-invasive techniques for both acute and chronic instabilities. Both techniques address the aspect of horizontal instability, which was found to compromise clinical results. For an acute injury, we describe the use of a low-profile button system combined with an additional acromioclavicular cerclage. In the chronic setting with a bidirectional (vertical and horizontal) instability, a free tendon graft combined with a single TightRope augmentation is recommended.

Complication and Infection Risk Using Bone Substitute Materials to Treat Long Bone Defects in Geriatric Patients: An Observational Study.

Background and Objectives: he treatment of large bone defects in geriatric patients often presents a major surgical challenge because of age-related bone loss. In such patients, the scarcity of healthy makes autologous grafting techniques hard to perform. On the one hand, clinicians' fear of possible infections limits using bone substitute materials (BSM). On the other hand, BSM is limitless and spares patients another surgery to harvest autologous material. Materials and Methods: To address the aptness of BSM in geriatric patients, we performed a retrospective analysis of all patients over the age of 64 years who visited our clinic between the years 2011-2018. The study assessed postoperative complications clinically and healing results radiologically. The study included 83 patients with bone defects at the distal radius, proximal humerus, and proximal tibia. The defect zones were filled with BSM based on either nanocrystalline hydroxyapatite (NHA) or calcium phosphate (CP). For comparison, a reference group (empty defect, ED) without the void filling with a BSM was also included. Results: 106 patients sustained traumatic fractures of the distal radius (71.7%), proximal humerus (5.7%), and proximal tibia (22.6%). No difference was found between the BSM groups in infection occurrence (p = 1.0). Although not statistically significant, the BSM groups showed a lower rate of pseudarthrosis (p = 0.09) compared with the ED group. Relative risk (RR) of complications was 32.64% less in the BSM groups compared with the ED group. The additional beneficial outcome of BSM was demonstrated by calculating the number needed to treat (NNT). The calculation showed that with every six patients treated, at least one complication could be avoided. Radiological assessment of bone healing showed significant improvement in the bridging of the defect zone (p < 0.001) when BSM was used. Conclusions: In contrast to previous studies, the study showed that BSM could support bone healing and does not present an infection risk in geriatric patients. The NNT calculation indicates a wider potential benefit of BSM.

In vivo analysis of the circles measurement supports its use in evaluating acromioclavicular joint dislocations.

BACKGROUND: Classification and treatment of acromioclavicular joint (ACJ) dislocations according to the Rockwood classification is controversial. The "circles measurement" on Alexander views was proposed to enable a clear assessment of displacement in ACJ dislocations. However, the method and its ABC classification were introduced on a Sawbones model based on exemplary Rockwood scenarios without soft tissue. This is the first in vivo study to investigate the circles measurement. We aimed to compare this new measurement method with the Rockwood classification and the previously described semiquantitative degree of dynamic horizontal translation (DHT). METHODS: A total of 100 consecutive patients (87 men and 13 women) with acute ACJ dislocations between 2017 and 2020 were included retrospectively. The mean age was 41 years (range, 18-71 years). ACJ dislocations on panoramic stress views were classified according to Rockwood type (type II, n = 8; type IIIA, n = 9; type IIIB, n = 24; type IV, n = 7; and type V, n = 52). On Alexander views, where the hand of the affected arm rested on the contralateral shoulder, the circles measurement and the semiquantitative degree of DHT (none, n = 6; partial, n = 15; or complete, n = 79) were assessed. Convergent and discriminant validity of the circles measurement (including its ABC classification according to displacement) with the coracoclavicular distance and Rockwood types, as well as the semiquantitative degree of DHT, was tested. RESULTS: The circles measurement showed a strong correlation with the coracoclavicular distance according to the Rockwood classification (r = 0.66, P < .001) and differentiated between Rockwood types according to the ABC classification, including types IIIA and IIIB. The circles measurement correlated with the semiquantitative method of assessing DHT (r = 0.61, P < .001). Measurement values were smaller in cases without DHT than in cases with partial DHT (P = .008). Cases with complete DHT had respectively larger measurement values (P < .001). CONCLUSION: In this first in vivo study, the circles measurement allowed differentiation between Rockwood types according to the ABC classification in acute ACJ dislocations with a single measurement and correlated with the semiquantitative degree of DHT. On the basis of these validations of the circles measurement, its use for evaluating ACJ dislocations is recommended.

Surgical treatment of a symptomatic os acromiale by arthroscopy-assisted double-button fixation: a case report.

CASE: We present the case of a symptomatic os acromiale in a 51-year-old female patient. Arthroscopy-assisted treatment was performed using a double-button fixation system and additional suture cerclage. The patient presented with complete radiographic bone union, pain relief, improved range of motion and did not require hardware removal at the 12-month follow-up. CONCLUSION: The achievement of persistent consolidation between the two fragmented bone surfaces, without further need for hardware removal and improved clinical outcome, suggests that our minimally invasive technique is appropriate for this specific indication. To our knowledge, this technique has not been described in the literature yet.