This is the foundational outcomes study of the modified Coonrad-Morrey semiconstrained (loose-hinge) total elbow replacement in rheumatoid arthritis. It reports pain relief, motion, stability, complications, and survivorship in 68 elbows. The design question: can a coupled loose hinge deliver stability without the loosening that ruined the earlier rigid hinges?
When you see a rheumatoid elbow with severe bone loss, gross instability, or a failed prior reconstruction, the semiconstrained (loose-hinge) implant is the answer that resurfacing designs cannot provide.
The key mental model: constraint is a spectrum. Rigid hinges loosen because they dump varus-valgus and rotational forces into the bone-cement interface. Resurfacing implants avoid that but need intact bone and ligaments and carry roughly 10% instability. The loose hinge splits the difference by allowing about 8 degrees of play so soft tissues absorb those forces.
That is why this series showed zero loosening and 94% seven-year survivorship despite treating severe deformity. Remember the trade-off: infection is the dominant threat in elbow arthroplasty, higher than hip or knee because the joint is subcutaneous. It was the only complication here that ruined results.
Counsel patients on the permanent ~5 kg lifting limit. The one ulnar component fracture happened in a man hauling 23 kg buckets against advice.
This is the foundational outcomes study of the modified Coonrad-Morrey semiconstrained (loose-hinge) total elbow replacement in rheumatoid arthritis. It reports pain relief, motion, stability, complications, and survivorship in 68 elbows. The design question: can a coupled loose hinge deliver stability without the loosening that ruined the earlier rigid hinges?
When you see a rheumatoid elbow with severe bone loss, gross instability, or a failed prior reconstruction, the semiconstrained (loose-hinge) implant is the answer that resurfacing designs cannot provide.
The key mental model: constraint is a spectrum. Rigid hinges loosen because they dump varus-valgus and rotational forces into the bone-cement interface. Resurfacing implants avoid that but need intact bone and ligaments and carry roughly 10% instability. The loose hinge splits the difference by allowing about 8 degrees of play so soft tissues absorb those forces.
That is why this series showed zero loosening and 94% seven-year survivorship despite treating severe deformity. Remember the trade-off: infection is the dominant threat in elbow arthroplasty, higher than hip or knee because the joint is subcutaneous. It was the only complication here that ruined results.
Counsel patients on the permanent ~5 kg lifting limit. The one ulnar component fracture happened in a man hauling 23 kg buckets against advice.