Background Spontaneous stiffness of the rheumatoid arthritis elbow causes severe functional limitations. Little has been written about the results of total elbow arthroplasty for stiff elbows due to rheumatoid arthritis. Some studies for stiff elbows including cases of post traumatic arthritis in total elbow arthroplasty with a linked implant. However, there has been little information on unlinked arthroplasty in patients with rheumatoid arthritis.
Objectives We retrospectively review the mid-term results about the unlinked elbow arthroplasty for stiff elbows due to rheumatoid arthritis, and we discuss the potential of this treatment.
Methods The inclusion criteria into the study were 1) patients with a preoperative passive arc of elbow motion of 30 degrees or less, 2) age less than 60 years. The elbow with radiological change of Larsen grade five and painful stiffness was excluded. Between September 2002 and Dec 2009, nine elbows in seven patients were treated with unlinked elbow implant, Osaka University Model Elbow System (OUMES), (MMT Co.Ltd., Japan). All patients were women with the average age of 51 years (47-59 years). There were nine stiff elbows and we performed cementless total elbow arthroplasty in all cases. All patients were successfully contacted for this study at our institution at the time of follow-up. Subjective and objective data were collected for calculation of the Mayo elbow performance score. A handheld goniometer was used to measure the arcs of flexion and pronation, and standardized anteroposterior and lateral radiographs were made of all elbows. Clinical evaluation was done with use of the Mayo elbow performance score for pain (maximum score, 45 points), motion (maximum score, 20 points), stability (maximum score, 10 points), and daily functional activities (maximum score, 25 points). A score of 90 to 100 points was defined as an excellent result; 75 to 89 points, as a good result; 60 to 74 points, as a fair result; and less than 60 points, as a poor result.Radiographic evaluation, with use of anteroposterior and lateral views, was done for implant position, radiolucency and ectopic bone formation, at the time of the latest follow-up for all nine elbows.
Results Follow up averaged eight years (range five-nine years). The result was excellent for one elbow, good for five, fair for three. The mean preoperative score was 42 points, and the mean postoperative score was 75 points. Mean flexion improved 77 degrees to 125 degrees, and mean extension improved -56 degrees to -35 degrees. No patients developed infection and ectopic bone formation. One case had mild ulnar nerve symptom. There were no radiolucent lines at the bone-metal interface of any of the humeral or ulnar implant.
Conclusions In stiff elbows, a linked prosthesis is considered to be better applied than unlinked one, because the supportive ligaments are not functional. We hypothesize that the maintenance of the bone stock is also an important factor for selecting the treatment of arthroplasty in young or middle aged patients. Our study demonstrated that for stiff elbows due to rheumatoid arthritis in patients less than 60 years old with satisfactory results can be achieved by the unlinked elbow arthroplasty. Although the number reported here is small, the results are encouraging, and we believe that this method is useful for young or middle adults.
Disclosure of Interest None Declared