Coracoacromial Ligament Release Improves Internal Rotation in Reverse Total Shoulder Arthroplasty; a Cadaver Study

Objectives: Evaluate the effect of Coracoacromial Ligament (CAL) release after Reverse shoulder arthroplasty (RSA) on range of motion (ROM), particularly on internal rotation (IR). Methods: Ten Fresh Frozen cadavers underwent RSA followed by CAL release by a fellowship-trained surgeon. Shoulder ROM was measured by a goniometer pre-and post-CAL release. The IR to the back was measured as the distance between the posterior-lateral acromion and the highest point of thumb elevation behind the back. Measurements of ROM before and after CAL release were compared using a paired sample t-test. Results: CAL release after RSA significantly increased ROM in all planes. The IR to the back improved by an average of four cm. Internal rotation in abduction, external rotation in abduction, external rotation at the side, forward elevation, abduction, and extension increased by 7 degrees, 8 degrees, 9 degrees, 10 degrees, 6 degrees, 11 degrees, respectively. Conclusion: The CAL release following RSA significantly improved IR to the back and all other ROM. CAL release post-RSA could be a potential solution to the ROM deficits, particularly IR, post-RSA. Clinical studies are needed to assess the clinical application of this technique.