Subscapularis Function Following the Latarjet Coracoid Transfer for Recurrent Anterior Shoulder Instability

Abstract

The Latarjet procedure may be performed with both subscapularis splitting and subscapularis transecting approaches. The subscapularis splitting approach may better preserve subscapularis function and anatomy. The goal of this study was to determine the functional status of the subscapularis after the Latarjet procedure with a subscapularis splitting approach using the quantified belly press test. Thirty patients with traumatic anterior shoulder instability were prospectively enrolled in the study. All patients underwent a Latarjet procedure through a subscapularis splitting approach. Both operative and nonoperative extremities were tested preoperatively with a belly press test using an Isobex muscle strength analyzer (Medical Device Solutions AG, Oberburg, Switzerland). Fifteen patients returned for postoperative Isobex belly press testing at a minimum of 6 months. Average patient age was 23.3 years, and average follow-up interval was 13 months. We detected no significant differences in pre- vs postoperative subscapularis strength in the surgical shoulder (decreased by 0.3 kg [95% CI, -1.0 to 1.7 kg; P=.630]). There was no difference in control vs surgical arm at preoperative (control +0.3 kg stronger; 95% CI, -0.8 to 0.1 kg; P=.124) vs postoperative (control +0.3 kg stronger; 95% CI, -1.1 to 0.5 kg; P=.444) measurements. Neither sex (P=.593) nor surgery in the dominant arm (P=.459) had an effect on recovery of subscapularis strength. Finally, the surgical arm at follow-up was not significantly different from reported height- and weight-based normative values for either men (P=.481) or women (P=.298). This study suggests that subscapularis strength is not significantly altered by the Latarjet procedure with a subscapularis splitting approach.