VOL. 87-B, No. 2, FEBRUARY 2005 191 Primary semi-constrained arthroplasty for chronic fracture-dislocations of the elbow M. A. Mighell, R. C. Dunham, E. A. Rommel, M. A. Frankle From The Florida Orthopaedic Institute, Temple Terrace, Florida, USA  M. A. Mighell, MD, Orthopaedic Surgeon  E. A. Rommel, BA, Research Assistant  M. A. Frankle, MD, Orthopaedic Surgeon Florida Orthopaedic Institute, 13020 Telecom Parkway N, Temple Terrace, Florida 33637, USA.  R. C. Dunham, DO, Orthopaedic Surgeon 72nd Medical Group, Tinker Air Force Base, 5700 Arnold Street, Building 5801, Tinker AFB, Oklahoma 73145, USA. Correspondence should be sent to Dr M. A. Mighell; e-mail: mmighell@floridaortho.com ©2005 British Editorial Society of Bone and Joint Surgery doi:10.1302/0301-620X.87B2. 15130 $2.00 J Bone Joint Surg [Br] 2005;87-B:191-5. Received 11 November 2003; Accepted after revision 27 May 2004 We present six patients with chronic dislocation of the elbow who were treated by primary semiconstrained total elbow arthroplasty. All were women with a mean age of 65 years (51 to 76), the mean interval between dislocation and surgery was 17 weeks (5 to 52) and the mean follow-up 58 months (24 to 123). The most dramatic improvement was in function. The mean American Shoulder and Elbow Surgeon score was 5.2 times better (p < 0.001) and the mean total range of movement increased from 33˚ to 121˚ (p < 0.001) after operation. Three patients developed wear of polyethylene. One required revision for a periprosthetic fracture, and another required a bushing exchange. Primary semiconstrained elbow arthroplasty provides significant, predictable functional improvement. Potential solutions for wear of polyethylene include a different operative technique or design of implant. Despite the high incidence of such wear, total elbow arthroplasty should be considered as a viable treatment option for chronic dislocation of the elbow in elderly patients. Recurrent instability of the elbow can often be successfully treated by ligament repair or reconstruction, 1-4 whereas chronic or un- reduced dislocation is associated with signifi- cant soft-tissue contracture. The latter requires extensive soft-tissue release to reduce the joint, and in this setting, articular congruency can only be maintained by strict immobilisation and probable loss of movement or by ligamen- tous reconstruction and the application of a dynamic external fixator. 4-13 Even if disloca- tion of the elbow is treated quickly, satisfactory results are not guaranteed, especially in older patients. Ring et al 11 reported a series of 11 patients with a mean age of 49 years (17 to 70) with complex posterior dislocations of the elbow which had been treated by primary open reduction and internal fixation (ORIF). Seven had an unsatisfactory result at the latest fol- low-up examination. There are many ways to treat chronic frac- ture-dislocation of the elbow, including ORIF and arthroplasty. Although open reduction with soft-tissue reconstruction or minimal fix- ation has been successfully reported by a few authors, 14-16 most of the patients in these stud- ies were less than 60 years of age. The rate of complications of ORIF is relatively high. Nerve injury, most commonly transient, has been reported in up to 40% of cases. 7 Naidoo 16 reviewed a series of 23 patients with a mean age of 30 years (10 to 60), with unreduced pos- terior dislocation of the elbow. The duration of the dislocation ranged from one month to two years. Open reduction was performed in all cases with release of contracture and pinning of the ulno-humeral joint. Only ten of the 23 patients achieved an arc of movement greater than 90˚. While ORIF can be effective for relief from pain, the functional results are unpredict- able and often unsatisfactory because patients are unable to perform the essential activities of daily living. Furthermore, in elderly patients with inflammatory or post-traumatic arthritis, ORIF may restore movement but the joint remains painful. There have been few reports of treatment by primary total elbow arthroplasty for chronic dislocation, 17-20 despite the fact that elbow arthroplasty after trauma or nonunion is well accepted. 21-28 Ramsey et al 20 described 19 patients with chronic instability who had been treated by semiconstrained total elbow arthro- plasty. Most had an unstable nonunion of a fracture of the distal humerus and had had a mean of 2.3 previous operations. The mean Mayo score improved from 44 points before to 86 after operation. 29 The mean post-operative range of movement was 25˚ to 128˚. Sixteen patients described little or no pain after the