Purpose To evaluate the kinematics/kinetics of the ankle, knee, hip in the sagittal plane in adolescents with recurrent patellar dislocation in comparison to a healthy control. Methods Case-control study. Eighty-eight knees (67 patients) with recurrent patellar dislocation (mean age 14.8 years ± 2.8 SD) were compared to 54 healthy knees (27 individuals, 14.9 years ± 2.4 SD). Kinematics/kinetics of ankle, knee, hip, and pelvis were captured using 3D-gait analysis (VICON, 12 cameras, 200 Hz, Plug-in-Gait, two force plates). One cycle (100%) consisted of 51 data-points. The mean of six trials was computed. ResultsThe loading-response increased by 0.02 s ± 0.01SE (10.8%) with dislocations (0.98% of total gait, P < 0.01). The mid-stance-phase decreased equally (P < 0.01). Dislocation decreased knee flexion during the entire gait cycle (P < 0.01), with the largest difference during mid-stance (9.0° ± 7.2 SD vs. 18.5° ± 6.7 SD). Dislocation increased plantar-flexion during loading response 4.1° ± 0.4 SE with (P < 0.01), afterward, the dorsal-extension decreased 3.2° ± 0.3 SE, (P < 0.01). Dislocation decreased hip flexion during all phases (P < 0.01). Maximal difference: 7.5° ± 0.5 SE during mid-stance. 80% of all patients developed this gait pattern. Internal moments of the ankle increased, of the knee and hip decreased during the first part of stance. Conclusion Recurrent patellar dislocation decreases knee flexion during the loading-response and mid-stance phase. A decreased hip flexion and increased plantar-flexion, while adjusting internal moments, indicate a compensation mechanism. Level of evidence III.

Background: Primary traumatic anterior shoulder dislocations can be associated with displaced anterior glenoid rim fractures. Nonoperative treatment of such fractures has been shown to have excellent results in a small cohort of patients; as such, we have been treating these fractures nonoperatively, regardless of fragment size and degree of displacement, provided that post-reduction computed tomography scans revealed an anteroposteriorly centered humeral head. The aim of this study was to analyze the medium- to long-term results of nonoperative treatment of displaced anterior glenoid rim fractures, assessing in particular the residual instability and development of osteoarthritis. Methods: In a 2-center study, 30 patients with a mean age of 48 years (range, 29 to 67 years) were evaluated clinically with use of the Subjective Shoulder Value, Constant score, American Shoulder and Elbow Surgeons score, and Western Ontario Shoulder Instability index, as well as radiographically with use of radiographs and computed tomography scans at a mean follow-up of 9 years (range, 5 to 14 years). Results: Fracture-healing was documented in all patients. Seven patients (23%) had post-fracture onset of osteoarthritis (5 with Samilson grade I and 2 with Samilson grade IV). Of these, 1 patient had recurrent instability that was successfully treated with hemiarthroplasty 9 years after the index injury (relative Constant score, 101%), and was excluded from further analysis. No other patient had a recurrent redislocation, subluxation, or positive apprehension. The other 6 patients with new-onset radiographic osteoarthritis were pain-free (mean Constant score pain scale, 15 points) with good shoulder function (relative Constant score, 84% to 108%). A total of 26 patients (90%) rated their functional outcome as good or very good, and 3 patients (10%) rated it as fair. The mean relative Constant score was 97% (range, 61% to 108%), the mean American Shoulder and Elbow Surgeons score was 92 points (range, 56 to 100 points), and the mean Western Ontario Shoulder Instability index score was 126 points (range, 0 to 660 points). All patients returned to full-time work. Conclusions: Nonoperative treatment of anterior glenoid rim fractures following primary traumatic anterior shoulder dislocation results in excellent clinical outcomes with a very low rate of residual instability and, thus, treatment failure. Asymptomatic radiographic osteoarthritis occurred in roughly 1 of 4 patients. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Purpose To investigate if a trochleoplasty increases knee flexion angles and extensor moments in the gait of patients with patellar instability and to compare postoperative gait to a healthy control group. Methods A bilateral dislocation group (6 patients) and a unilateral dislocation group (14 patients) were treated with bilateral and unilateral trochleoplasty, respectively. Kinematics and kinetics of the lower extremity were captured using 3D‐gait analysis (VICON, 12 cameras, 200 Hz, plug‐in‐gait, two force plates). The mean of six trials was computed. The gait cycles were compared pre to postoperatively for each group. The gait of the two groups was compared to each other and the gait of a healthy population (54 knees). Results After trochleoplasty, the knee flexion angles and knee extensor moments only increased in the bilateral dislocation group, whereas the gait pattern of the unilateral dislocation group remained unchanged. Compared to the healthy population, the postoperative gait pattern of the bilateral dislocation group did not differ. In contrast, knee flexion angles and extensor moments of the unilateral dislocation group were still lower. Conclusion In adolescents with bilateral recurrent patellar dislocations, trochleoplasty of both knees increases knee flexion angles and knee extensor moments comparable to normal gait. Unilateral symptomatic patients undergoing a unilateral trochleoplasty did not achieve normal walking. These findings point out that patellar instability should be considered as a bilateral problem, even in patients with unilateral dislocations. Level of evidence III.

Background: Shortcomings to tibial-side fixation have been reported as causes of failure after anterior cruciate ligament reconstruction. Adjustable-loop suspensory devices have become popular; however, no comparison with hybrid fixation (ie, interference screw and cortical button) exists to our knowledge. Purpose: The purpose of this study was to compare the biomechanical properties of adjustable loop devices (ALDs) in full-tunnel and closed-socket configurations in relation to hybrid fixation. We hypothesized that primary stability of fixation by a tibial ALD will not be inferior to hybrid fixation. Study Design: Controlled laboratory study. Methods: Tibial fixation of a quadrupled tendon graft was biomechanically investigated in a porcine tibia–bovine tendon model using 5 techniques (n = 6 specimens each). The tested constructs included hybrid fixation with a cortical fixation button and interference screw (group 1), single cortical fixation with the full-tunnel technique using an open-suture strand button (group 2) or an ALD (group 3), or closed-socket fixation using 2 different types of ALDs (groups 4 and 5). Each specimen was evaluated using a materials testing machine (1000 cycles from 50-250 N and pull to failure). Force at failure, cyclic displacement, stiffness, and ability to pretension the graft during insertion were compared among the groups. Results: No differences in ultimate load to failure were found between the ALD constructs (groups 3, 4, and 5) and hybrid fixation (group 1). Cyclic displacement was significantly higher in group 2 vs all other groups ( P < .001); however, no difference was observed in groups 3, 4, and 5 as compared with group 1. The remaining tension on the construct after fixation was significantly higher in groups 3 and 4 vs groups 1, 2, and 5 ( P < .02 for all comparisons), irrespective of whether a full-tunnel or closed-socket approach was used. Conclusion: Tibial anterior cruciate ligament graft fixation with knotless ALDs achieved comparable results with hybrid fixation in the full-tunnel and closed-socket techniques. The retention of graft tension appears to be biomechanically more relevant than tunnel type. Clinical Relevance: The study findings emphasize the importance of the tension at which fixation is performed.

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