The Effect of the Remplissage Procedure on Shoulder Range of Motion: A Cadaveric Study Rei Omi, M.D., Ph.D., Alexander W. Hooke, M.A., Kristin D. Zhao, Ph.D., Tomoya Matsuhashi, M.D., Ph.D., Akira Goto, M.D., Ph.D., Nobuyuki Yamamoto, M.D., Ph.D., John W. Sperling, M.D., Scott P. Steinmann, M.D., Eiji Itoi, M.D., Ph.D., and Kai-Nan An, Ph.D. Purpose: The purpose of this in vitro biomechanical study was to assess the effects of the remplissage procedure for small- and large-sized Hill-Sachs lesions (HSLs) on shoulder range of motion (ROM) with a special interest in the apprehension position. Methods: HSLs of 50% and 100% of the glenoid width were simulated in 7 cadaveric shoulders as small and large lesions, respectively, and the postoperative condition was reproduced by placing suture anchors on the articular surface and tying down the infraspinatus at the medial edge of the would-be lesion site. ROMs were measured in abduction, internal rotation, and external rotation with the humerus in the adducted and abducted position. In addition, the ROM was measured in the anterior apprehension position, in which 2 torques of external rotation and extension were applied simultaneously, and external rotation and horizontal extension ROMs were measured with the humerus in different abduction angles (20  , 40  , and 60  ). Results: For standard ROMs, the procedure for the 50% HSL maintained complete ROMs, whereas the procedure for the 100% HSL significantly decreased external rotation ROM with the humerus in both the adducted and abducted positions, as well as abduction ROM. In the apprehension position, remplissage for the 50% HSL decreased extension ROM with the humerus abducted to 40  and 60  . Remplissage for the 100% HSL significantly decreased both external and extension ROMs regardless of the humeral abduction angle. Con- clusions: In the cadaveric model with an intact humeral head and the simulated postoperative condition, the remplissage procedure for a large HSL caused significant restrictions in ROM of abduction in the scapular plane and external rotation with the humerus in both adduction and abduction. It also caused significant restrictions in both external rotation and extension ROMs in the apprehension position. Clinical Relevance: The indication for the remplissage procedure for the larger HSL should be considered carefully, especially for the competitive throwing athlete who needs exceptional external rotation ROM for optimal overhead throwing performance. P osterolateral defects of the humeral head (Hill- Sachs lesions [HSLs]) are one of the most common findings in patients with recurrent anterior dislocations of the shoulder. It has been reported that the HSL is present in over 80% of recurrent instability cases. 1-4 Many studies have investigated the effect of the HSL on recurrent glenohumeral instability and identified it as a contributor to anterior soft-tissue destabilization. 1,4,5 The increased recognition of the HSL in recurrent instability highlights the need to better address the bone deficiency of the humeral head in addition to the arthroscopic Bankart repair (repair of the torn anterior glenoid labrum and capsule). Some procedures directly address the humeral head defect, whereas others manipulate the articular arc length, primarily by aug- menting anterior and inferior glenoid bone to prevent engagement of the HSL. Engagement occurs when the arm is brought into a position of athletic function (defined as 90  of abduction combined with external rotation [ER] in the range between 0  and 135  ). 1 These solutions vary, including the Latarjet procedure, 6,7 rotational humeral osteotomy, 8 osteoarticular allograft transplantation, 9 and transhumeral impaction bone grafting. 10 In 2008 Wolf and colleagues 11 described an arthros- copic method of filling the HSL by infraspinatus tenodesis From the Biomechanics Laboratory, Department of Orthopedic Surgery, Mayo Clinic (R.O., A.W.H., K.D.Z., T.M., A.G., J.W.S., S.P.S., K-N.A.), Rochester, Minnesota, U.S.A.; and Department of Orthopaedic Surgery, Tohoku University School of Medicine (N.Y., E.I.), Sendai, Japan. The study was funded by Mayo Foundation. The authors report the following potential conflict of interest or source of funding: S.P.S. receives support from Arthrex, Wright Medical, DePuy. Received June 20, 2013; accepted November 4, 2013. Address correspondence to Kai-Nan An, Ph.D., Biomechanics Laboratory, Division of Orthopedic Research, Department of Orthopedic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905, U.S.A. E-mail: an@mayo.edu Ó 2014 by the Arthroscopy Association of North America 0749-8063/13414/$36.00 http://dx.doi.org/10.1016/j.arthro.2013.11.003 178 Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 30, No 2 (February), 2014: pp 178-187