A 62-year-old woman with advanced rheumatoid arthritis has severe elbow pain with radiographic destruction of the distal humerus and proximal ulna, marked collateral ligament incompetence and 40 degrees of fixed flexion deformity. Which implant design is most appropriate?
- A Unlinked (unconstrained) surface replacement arthroplasty
- B Fully constrained hinged arthroplasty with rigid fixation
- C Linked semi-constrained total elbow arthroplasty such as the Coonrad-Morrey ✓
- D Interposition arthroplasty with an Achilles tendon graft
Correct answer: C. Linked semi-constrained total elbow arthroplasty such as the Coonrad-Morrey
Explanation
The Coonrad-Morrey implant is a linked, semi-constrained hinge with polyethylene bushings that permit a few degrees of varus-valgus and rotational play. This offloads the bushings while providing stability when collateral ligaments are destroyed, exactly the situation in advanced rheumatoid disease. Unlinked designs require intact ligaments, and fully rigid hinges transmit all stress to the cement-bone interface causing early loosening, so B is the classic trap.
Reference: Campbell's Operative Orthopaedics, 14th ed.
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Written and medically reviewed by the StethoPrep medical team.