Purpose This study tests the hypothesis that the results of release of elbow stiffness related to heterotopic ossification (HO) are comparable whether there is partial or complete restriction ... Show morePurpose This study tests the hypothesis that the results of release of elbow stiffness related to heterotopic ossification (HO) are comparable whether there is partial or complete restriction (ankylosis) of flexion and extension. Methods Eighteen patients who had surgical release of complete bony ankylosis between the humerus and ulna were retrospectively compared to 27 matched patients who had surgical release of partial restriction of elbow flexion and extension related to HO. Patients were evaluated a minimum of 10 months after surgery, using the Disabilities of the Arm, Shoulder, and Hand questionnaire and the Broberg and Morrey rating system. Results An average of 22 months after surgery (range, 10 to 62 mo), the arc of flexion and extension averaged 95 degrees in the ankylosis cohort and 93 degrees in the partial HO cohort. Forearm rotation averaged 131 degrees versus 134 degrees; the mean Disabilities of the Arm, Shoulder, and Hand score was 28 versus 30 points; and the mean Broberg and Morrey score was 81 versus 84 points, respectively. Conclusions After controlling for other factors, patients with elbow stiffness related to HO can recover comparable motion after surgical release at short-term follow-up whether they have complete ankylosis or only partial restriction of motion. (J Hand Surg 2010;35A:1115-1119. (C) 2010 Published by Elsevier Inc. on behalf of the American Society for Surgery of the Hand.) Show less