Poster 242. New Trauma Drives Recurrent Shoulder Instability Following Primary Stabilization Surgery in Adolescent Patients

Abstract

Objective: The rate of recurrent shoulder instability following surgical stabilization is relatively high in adolescent patients, ranging from 17-51% in the literature. However, the available literature has no standard definition of 'recurrence,' which is quite variable in terms of etiology and severity. Furthermore, the wide range is likely a result of inconsistent study populations in the literature. Lower recurrences rates are seen in larger studies with mixed adolescent and adult populations, while higher rates are seen in studies focused on subsets of contact athletes. The goal of this study is to examine the etiology and rate of recurrent shoulder instability in a large, heterogenous population of pediatric patients that underwent primary shoulder stabilization surgery at a single institution. Methods: A single pediatric database was queried to identify all shoulder stabilization procedures over the course of a 10-year period at a single institution. 'Recurrence' was defined as any patient that needed a second surgery or a shoulder reduction in the emergency department. Chart review was performed to determine type of instability, incidence of recurrence, and cause of recurrence. The rate of recurrence was calculated for each form of instability as well as the proportion of these recurrences that resulted from traumatic or atraumatic events. Cases were included if patients had at least 6 months of follow-up, however, cases with less than 6 months follow-up were included if they had repeat imaging or revision surgery. Results: 320 surgical cases were included, 56 (17.5%) of which required subsequent surgeries or closed reductions in the Emergency Department. The average age at index surgery was 16.63±1.89 years, the average time between the second surgery or closed reduction was 1.98±1.26 years, the average follow-up was 2.15±1.45 years, and 64% were males. The % of cases who went on to a second surgery or closed reduction by type of index surgery are as follows: 24% (27/114) anterior repairs, 9% (5/54) posterior% (0/13) SLAP, 12.5% (6/48) multi-directional repairs, and 20% (18/91) capsulorraphies. New trauma was associated with 75% (20/27) of subsequent surgeries associated with index anterior repairs, 83% (5/6) of multi-directional repairs. Most of the new trauma involved collision sports or sports with high overhead demands. Conclusions: Overall recurrence in pediatric patients undergoing shoulder stabilization surgery is 17.5%. Atraumatic recurrence after primary shoulder stabilization surgery is less than 10%. In patients with anterior instability, recurrence is 24%, with almost all cases associated with new trauma. This value is on the lower end of the currently reported range and we believe this to be very accurate as this study contains the largest and most heterogenous population of pediatric shoulder instability patients in the literature. The study also highlights the need for new trauma to be considered when analyzing re-surgery or dislocations after shoulder stabilization surgery. Collision and overhead athletes should be counseled pre-operatively about their increased risk of recurrence.