Atraumatic Acromioclavicular Dislocation: A Case Report and Review of the Literature.

Acromioclavicular dislocation (AC dislocation) is a common injury of the shoulder. In contrast to a traumatic cause, nontraumatic dislocation is very rare. We report on a 17-year-old female that presented with voluntary recurrent dislocation of the right AC joint followed by recurrent pain without instability of the ipsilateral shoulder. Clinical examination showed crepitation as well as palpitation pain and dislocation of the AC joint. There were no symptoms of Marfan or Ehlers-Danlos syndrome as other joint examinations were also negative for hypermobility. Considering age as well as minor complaints, nonoperative treatment by postural therapy without taping was recommended. After one year, the patient experienced fewer symptoms and she was able to participate in daily activities.

Technical aspects of revision and functional outcome after revision of the Oxford unicompartmental knee arthroplasty.

BACKGROUND: This study analysed the technical aspects of revision of the Oxford unicompartmental knee arthroplasty (OUKA) and functional results after revision. METHODS: In a historic cohort study we analysed all revised OUKAs that were primarily implanted at our clinic over a 10-year period (1998-2009). The primary aim was to investigate surgical difficulties encountered during revision surgery of the OUKA. Outcomes were the knee society score (KSS), WOMAC (Western Ontario and McMaster Universities), SF-36, VAS pain and VAS satisfaction after revision. RESULTS: During the study period, 331 OUKAs were inserted. With an average follow-up of six years and five months (range one month to nine years and eight months), there were 44 (13.3%) OUKAs that needed one or more revision surgery procedures. The average time to revision was three years and eight months (range one month to nine years and five months). The main reasons for revision surgery were bearing dislocation, malpositioning or loosening of a component and progression of osteoarthritis. Most revisions, mainly conversion to primary total knee arthroplasty (TKA), gave few surgical problems. Minor bone loss that needed no augmentation was seen most frequently. The functional outcomes after revision surgery were moderate. CONCLUSION: A limited amount of surgical difficulty during revision of OUKA was found; in all total revision cases a primary TKA was implanted. However, in most patients there were moderate functional results as well as disappointing pain and satisfaction scores after revision.

Rotator cuff repair: an ex vivo analysis of suture anchor repair techniques on initial load to failure.

PURPOSE: To determine the best combination of anchors and suture techniques for repairing torn rotator cuff tendons. TYPE OF STUDY: Ex vivo biomechanical investigation. METHODS: Sixty fresh-frozen sheep infraspinatus tendons were repaired using 6 different repair techniques: transosseous sutures with 2 sutures and mattress stitches; 2 suture anchors with 1 suture per anchor using either simple stitches, mattress stitches, or modified Kessler stitches; 2 suture anchors with 2 sutures per anchor using simple stitches; or 5 suture anchors with 1 suture per anchor and a mattress stitch pattern. RESULTS: No difference was identified between transosseous sutures (mean +/- SD, 147 +/- 68 N) and suture anchors (140 +/- 36 N) when 2 mattress stitches were used. The weakest construct with suture anchors was when the tendon was grasped with 2 suture anchors with 1 suture per anchor and a simple stitch pattern (72 +/- 25 N). Repair strength increased 2-fold with 2 suture anchors single loaded and a mattress stitch configuration (140 +/- 36 N; P = .026), 3-fold with 2 suture anchors single loaded and a modified Kessler stitch pattern (204 +/- 32 N; P < .001), and 3-fold with 2 suture anchors double loaded and a simple stitch suture pattern (212 +/- 39 N; P < .001). The highest tensile load was observed with 5 suture anchors in a double-row configuration, single loaded, that grasped the tendon with mattress stitches (336 +/- 59 N; P < .001). CONCLUSIONS: This study shows that in an ovine model, initial rotator cuff repair strength can be enhanced by increasing the number of suture anchors used in the repair and by using anchors that are double loaded with suture and suture configurations that pass more frequently through the tendon. CLINICAL RELEVANCE: The clinical relevance of this ex vivo investigation is that the initial load to failure of a rotator cuff repair may be increased by increasing the number of suture anchors, the number of sutures per anchor, or using suture patterns that grab more adjacent tendon fibers.

The effects of thermal capsular shrinkage on the outcomes of arthroscopic stabilization for primary anterior shoulder instability.

BACKGROUND: The effectiveness of arthroscopic thermal capsulorrhaphy in the prevention of recurrent instability in primary anterior stabilization is undetermined. PURPOSE: To determine if patients with recurrent anterior shoulder instability who have labral repair plus arthroscopic thermal capsulorrhaphy have better outcomes than those with labral repair alone. STUDY DESIGN: Cohort study; Level of evidence, 3. METHOD: There were 72 patients who underwent arthroscopic anterior shoulder stabilization with Suretac II tacks (n = 32) during 1996 to 1999 or with Suretac II tacks plus arthroscopic radiofrequency capsular shrinkage (n = 40) from 1999 to 2002. Standardized patient-determined and examiner-determined outcome measures were obtained preoperatively and at 3, 6, 12, and 24 months postoperatively. Statistical analyses included a Kaplan-Meier analysis of time to recurrent instability. RESULTS: Of the 72 patients, 66 had complete follow-up, including 28 patients treated with the Suretac stabilization and 38 patients with the Suretac plus radiofrequency shrinkage, for a mean follow-up of 58 and 30 months, respectively. All patients had a Bankart lesion. Both groups had similar results with respect to patient-determined and examiner-determined outcome measures. The only adverse outcome was postoperative recurrent instability in 6 of 28 cases in the Suretac group alone and 8 of 38 cases in the Suretac-plus -shrinkage group. Most recurrent instability occurred between 6 and 24 months. Kaplan-Meier analysis for time to recurrent instability showed no differences in the rate of instability recurrence between the 2 groups. CONCLUSION: Arthroscopic thermal capsulorrhaphy neither enhanced nor impaired the outcomes of arthroscopic labral repair with biodegradable tacks in patients with primary recurrent anterior shoulder instability.