Diagnosis and management of METS-Stanmore Morse taper failure.

We describe clinical semiology in 6 cases of METS-Stanmore distal femoral Morse taper impaction failure: from obvious forms with intraprosthetic dislocation to chronic forms with less obvious symptoms: instability, piston sensation, rotational disorder in gait. The diagnostic procedure in chronic forms is described, notably with dynamic examination under fluoroscopy. Reduction and re-impaction by external maneuver can be attempted; in case of failure or of any suspicion of taper disassembly, the 2 modular implant components have to be replaced. Finally, we provide a review of the literature on this rare but serious complication. LEVEL OF EVIDENCE: IV.