Complications of unicompartmental knee arthroplasty

Unicompartmental replacement of the knee for isolated medial or lateral arthrosis has been a controversial procedure regarding indications, design, efficacy, and longevity since its inception in the late 1950s. While initially popular, it fell out of favor due to early failures, mostly due to progression of the disease process, loosening, and design problems resulting in polyethylene wear and loss of fixation. Technical errors and poor patient selection also contributed to poor results. The evolution of the procedure, indications, design issues, surgical technique, results, complications, and longevity is discussed. Recent renewed interest has led to refinements in design and technique. When properly indicated with a clear understanding of the requirements for success, a contemporary, well-designed unicompartmental prosthesis implanted with meticulous technique has been shown to perform satisfactorily with a high degree of patient satisfaction.