1 3 Knee Surg Sports Traumatol Arthrosc (2016) 24:489–495 DOI 10.1007/s00167-015-3915-y SHOULDER Biomechanical comparison of the modified Bristow procedure with and without capsular repair Michael H. Abdulian 1 · Curtis J. Kephart 1 · Michelle H. McGarry 2 · James E. Tibone 1 · Thay Q. Lee 2,3,4 Received: 20 July 2015 / Accepted: 30 November 2015 / Published online: 24 December 2015 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) (outside the USA) 2015 and altered normal glenohumeral kinematics in external rotation positions. Conclusion Repairing the capsule in a Bristow procedure decreases rotational range of motion yet does not offer any added anterior–inferior translational stability. Capsular repair also significantly alters normal glenohumeral kin- ematics. Capsule repair with a Bristow procedure may not add additional glenohumeral stability in positions of appre- hension and may potentially over constrain the joint and cause altered kinematics. Keywords Anterior instability · Bankart lesion · Bone loss · Bristow · Capsule · Coracoid transfer Introduction The coracoid transfer in shoulder surgery is performed to treat anterior instability. This surgery involves osteotomy of all or a portion of the coracoid process and transposing it to the anterior aspect of the glenoid. It is usually taken with the conjoint tendon, which aids in the overall stabil- ity and efficacy of the procedure [5]. Originally, this pro- cedure involved removal of a portion of the coracoid. This was known as the Bristow procedure. Variations of the pro- cedure have been described, which involve transfer of the entire coracoid to the anterior surface of the glenoid. This is known as the Latarjet procedure. Both procedures are used as effective treatment options for anterior instability of the glenohumeral joint. There has been much debate on whether repair of the capsule is necessary with a Bristow procedure. In the origi- nal description of the Bristow procedure, a capsule repair was recommended [5]. However, several authors have reported good clinical results with low recurrence rates Abstract Purpose The Bristow procedure has become an effec- tive surgical option for recurrent anterior instability of the shoulder; however, there is no consensus on whether a cap- sule repair following a Bristow procedure is necessary to restore glenohumeral stability. The purpose of this study was to evaluate whether capsular repair with a modified Bristow procedure affects rotational range of motion and glenohumeral stability. Methods Rotational range of motion, glenohumeral translation and kinematics were measured in eight cadav- eric shoulders in 90° shoulder abduction in the scapular and coronal planes for four conditions: intact, 20 % bony Bankart lesion, modified Bristow without capsular repair and modified Bristow with capsular repair. Results Creation of the bony Bankart led to a signifi- cant increase in total range of motion and anterior–inferior translation compared to the intact shoulder. The modified Bristow procedure significantly decreased anterior–infe- rior translation compared to the bony Bankart but did not decrease total range of motion. Capsular repair decreased total range of motion in the scapular and coronal planes * Thay Q. Lee tqlee@va.gov; tqlee@uci.edu 1 Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA 2 Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System, 5901 East 7th. Street (09/151), Long Beach, CA 90822, USA 3 Department of Orthopaedic Surgery, University of California, Irvine, Irvine, CA, USA 4 Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA