Objective: To clarify the most reliable choice of prosthesis in Osaka University Model TEA.
Patients and Methods: Fifty-three RA patients who underwent TEA at Osaka Rosai Hospital between 1998 and 2005 were reviewed. They were divided into 3 groups by their types of prostheses. They were Group A: 16 patients with a press fitted humeral prosthesis with short stem, Group B: 21 patients with a standard stem, and Group C: 16 patients with a superficially cemented humeral prosthesis with standard stem and cemented ulnar prosthesis. Operative records and clinical and radiological assessments were investigated retrospectively, and statistically analyzed between those groups.
Results: Great functional amelioration was observed in each group, with no significant difference between groups. Bone quality of the distal humerus was a key factor for implant survival. Two of 16 humeral prostheses in Group A required revision surgery due to aseptic loosening. The press-fitted contact between bone and implant was unreliable in those cases due to their poor bone quality, while a better radiological prognosis was seen in the cases with good bone-implant contact. Two of 37 ulnar prostheses in Group A and B showed radiolucent lines under 2 mm wide, but did not require revision surgery.
Conclusion: Reconstruction of distorted RA elbows with Osaka University Model TEA was mostly good and comparable with other non-constrained prostheses. Our results for short-stem humeral prostheses used in Group A justified their further use as long as bone implant contact can be achieved, but we recommend a standard stem for all RA patients for a more reliable outcome.
