Paper 29: Return to Sport Testing vs Time-Based Clearance in Posterior Shoulder Instability

OBJECTIVES: Recurrent pain, instability and loss of function are challenging complications that can occur after arthroscopic treatment of posterior shoulder instability and SLAP tears in athletes. Many surgeons allow return to sport after a designated arbitrary postoperative time point. Recent evidence has demonstrated that a majority of athletes have residual strength and functional limitations at 6 months postoperatively – the time at which most time-based protocols allow full return to sport. Recent data has also been presented that patients undergoing arthroscopic Bankart repair who are required to meet objective return to sport testing criteria have a 4x lower rate of recurrent anterior instability than those who return based on time elapsed since surgery. Considering these findings, the purpose of this study is to investigate the use of a similar objective return to sport testing protocol on recurrence rates following arthroscopic surgery for posterior shoulder instability and SLAP tears. We hypothesized that patients who meet objective return to sport criteria would have a lower rate of reoperation and recurrence of symptoms compared to those who did not undergo the testing and were cleared to return based on time from surgery. METHODS: Consecutive patients (Group 1) who underwent arthroscopic posterior shoulder stabilization surgery with or without SLAP repair by a single surgeon from 2016 to 2019, had a minimum of 1 year follow up, and completed functional and strength testing to evaluate readiness for return to sport were included in this retrospective case-controlled study. These patients were compared to a control group of historical consecutive cases (Group 2) from 2012-2016 who did not undergo return to sports testing and were cleared for sports after a minimum of 6 months following surgery. Failure was defined as recurrent symptoms of pain or instability requiring reoperation. Exclusion criteria were: patients undergoing isolated anterior stabilization procedures with or without concomitant SLAP tears, multidirectional instability, and open procedures. Chi-square, Fisher exact tests and two-tailed Students T-test were performed. Statistical significance was set at p<0.05. RESULTS: There were 33 patients in Group 1 who underwent return to sport testing, and 91 patients in Group 2, the historical control. There were no differences between groups regarding sex (p=0.46), hand dominance (p=0.16), side affected (p= 0.69). The average age of Group 1 (20.8 +/- 4 yrs) was significantly younger than Group 2 (31.5 +/- 9.1 yrs, p< 0.00001). Patients who underwent return to sport criteria-based testing protocol had a rate of recurrent symptoms of pain or instability of 12.1% compared to 18.6% for those who did not (p= 0.43). Similarly, there were no reoperations for in Group 1, while three patients in group 2 (3.3%) underwent revision surgery for recurrent symptoms. This difference, however, did not reach statistical significance (p= 0.5633). CONCLUSIONS: In our cohort of young patients undergoing arthroscopic surgery for posterior shoulder instability, we detected no significant difference in reoperation rate and recurrence of symptoms between athletes who underwent objective return to sport testing and those who were released to sport on a time-based protocol. This may be related to an overall lower rate of reoperation in patients undergoing arthroscopic posterior stabilization or SLAP repairs in general compared to those undergoing arthroscopic anterior stabilization and differences in tolerance and presentation of recurrent posterior instability/SLAP tears versus anterior instability. It is possible that criteria-based return to sport testing prior to clearance to return to sport may be less critical for improving failure rates following arthroscopic posterior stabilization and SLAP repair than for anterior stabilization. Alternatively, given low reoperation rates overall, future studies investigating the role of return to sport testing after arthroscopic surgery for posterior shoulder instability and SLAP repairs may need to include more patients in order to detect differences related to the testing protocol. This study provides a basis upon which further studies, involving larger patient populations, may be conducted to elucidate any impact on functional scores and recurrence rates that may be associated with return-to-sport protocols based on functional testing rather than time since surgery.