Concomitant SLAP repair does not influence the surgical outcome for arthroscopic Bankart repair of traumatic shoulder dislocations

BACKGROUND

Prior studies revealed the presence of superior labrum anterior-to-posterior (SLAP) injury together with Bankart lesions in some patients. The purpose of the study is to compare the clinical results of isolated Bankart repairs with the clinical results of Bankart repairs when performed with concomitant SLAP repairs.

METHODS

The patients who underwent arthroscopic surgery for treatment of anterior glenohumeral instability were evaluated retrospectively. Group 1 consisted of 19 patients who had arthroscopic SLAP repair together with Bankart repair. The mean age of the patients was 23. Group 2 consisted of 38 patients who underwent isolated Bankart repair. The mean age was 24. Knotless anchors were used in both groups.

RESULTS

The mean follow-up was 34 months (range: 26-72). In group 1, the mean preoperative Constant score was 84 (range: 74-90, standard deviation (SD): 5.91) and Rowe score was 64.1 (range: 40-70, SD: 8.14). In group 2, the preoperative Constant score was 84.4 (range: 70-96, SD: 5.88) and Rowe score was 60 (range: 45-70, SD: 7.95). In group 1, the postoperative mean Constant score raised to 96.8 (range: 88-100, SD: 2.91) and the mean Rowe score raised to 92.3 (range: 85-100, SD: 5.17). In group 2, the postoperative mean Constant score was 94.9 (range: 88-100, SD: 3.70) and the mean Rowe score was 94.2 (range: 80-100, SD: 4.71). The difference between the scores of two groups was insignificant ( p > 0.05). When the numbers of redislocations and range of motion were compared, no significant difference was found ( p > 0.05).

CONCLUSION

Accompanying SLAP repair in surgical treatment with Bankart repair for shoulder instability does not affect the results negatively. Properly repaired labral tears extending from anterior inferior to the posterior superior of the glenoid in instability treatment have the same outcome in overall results as repaired isolated Bankart lesions.

Outcome of arthroscopic repair of type II SLAP lesions in worker's compensation patients

PURPOSE

Arthroscopic stabilization has become the accepted treatment for type II superior labral anterior and posterior (SLAP) lesions. Short-term results using a variety of techniques were promising, but most reports focus on motivated athletes. The purpose of our report is to evaluate the results of arthroscopic fixation of type II SLAP lesions in 21 patients who suffered a work-related injury and are receiving workers' compensation. The hypothesis was that in patients with a single event trauma who were receiving workers' compensation, clinical results would be inferior to those previously reported.

METHODS

Twenty-two consecutive workers' compensation patients with type II SLAP lesions underwent arthroscopic stabilization between October 1994 and December 1996. All patients received suture anchors with nonabsorbable suture secured around the labrum for definitive fixation. Average age at surgery was 43 and average follow-up time was 27.9 months. Seventeen patients (89%) had an acromioplasty at the time of labral stabilization. Outcome was assessed by analysis of visual analog pain scale, simple shoulder test (SST) and general health status questionnaire (SF-36), subjective patient satisfaction, and ability to return to work.

RESULTS

Visual analog pain scales improved by an average of 3 points although all patients had significant complaints of pain at follow-up. Simple shoulder test responses showed improvement in 9 out of 12 categories. The SF-36 results showed significant improvements only in the bodily pain category and role: physical category. Five patients required reoperation for persistent pain. However, only seven patients (437%) returned to work at their previous functional level, nine patients (47%) returned to work but at less strenuous jobs, and three patients (16%) did not return to work.

CONCLUSIONS

Currently recommended treatment for type II SLAP lesions is arthroscopic stabilization. When this procedure is performed in workers' compensation, patients a with single event trauma to the shoulder, objective parameters, and patient self-assessment surveys do show improvement. However, results are inferior to those previously reported in the literature.

Functional cloning of Src-like adapter protein-2 (SLAP-2), a novel inhibitor of antigen receptor signaling

In an effort to identify novel therapeutic targets for autoimmunity and transplant rejection, we developed and performed a large-scale retroviral-based functional screen to select for proteins that inhibit antigen receptor-mediated activation of lymphocytes. In addition to known regulators of antigen receptor signaling, we identified a novel adaptor protein, SLAP-2 which shares 36% sequence similarity with the known Src-like adaptor protein, SLAP. Similar to SLAP, SLAP-2 is predominantly expressed in hematopoietic cells. Overexpression of SLAP-2 in B and T cell lines specifically impaired antigen receptor-mediated signaling events, including CD69 surface marker upregulation, nuclear factor of activated T cells (NFAT) promoter activation and calcium influx. Signaling induced by phorbol myristate acetate (PMA) and ionomycin was not significantly reduced, suggesting SLAP-2 functions proximally in the antigen receptor signaling cascade. The SLAP-2 protein contains an NH2-terminal myristoylation consensus sequence and SH3 and SH2 Src homology domains, but lacks a tyrosine kinase domain. In antigen receptor-stimulated cells, SLAP-2 associated with several tyrosine phosphorylated proteins, including the ubiquitin ligase Cbl. Deletion of the COOH terminus of SLAP-2 blocked function and abrogated its association with Cbl. Mutation of the putative myristoylation site of SLAP-2 compromised its inhibitory activity and impaired its localization to the membrane compartment. Our identification of the negative regulator SLAP-2 demonstrates that a retroviral-based screening strategy may be an efficient way to identify and characterize the function of key components of many signal transduction systems.