Unicompartmental knee arthroplasty: technique through a mini-incision.

UNLABELLED: Unicompartmental knee arthroplasty is a logical procedure when the lesion is limited to one femorotibial compartment. The procedure can now be performed through a mini-incision to provide quicker recovery because the extensor mechanism disruption is minimized. We have found the length of the incision varies according to patient mass and muscle tone. Specific instrumentation limited to the replaced compartment and using either an intra- or extramedullary femoral technique provides femorotibial component alignment and allows slight undercorrection of the deformity. Radiographic assessment demonstrates precise implantation of the components is possible with a mini-incision, which is believed important for the long-term results of the arthroplasty. The functional evaluation of patients implanted with unicompartmental knee arthroplasty performed through a mini-incision suggests appropriate kinematics can be restored after the procedure, enhancing the importance of a functional anterior cruciate ligament. LEVEL OF EVIDENCE: Level V, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.