Aseptic loosening and focal osteolysis are the most common reasons for knee arthroplasty failure. The best treatment remains unclear. We reviewed the literature on the treatment of revision knee arthroplasty using bony structural allografts (476 cases) and porous metal cones (223 cases) to determine if a difference in the revision failure rates was discernable. The failure rates were compared using a logistic regression model with adjustment for discrepancies in FU time and number of grafts used (femoral, tibial, or both). In this analysis, the porous implant shows a significantly decreased loosening rate in AORI 2 and 3 defects. The overall failure rate was also substantially lower in the porous metal group than the structural allograft group; little difference in the infection rates was noted.

Grade III valgus deformity (tibiofemoral alignment > 20°) is present in only 0.5% of patients receiving total knee arthroplasty. Furthermore, cases with a valgus deformity exceeding 40° are even rarer. Since they mostly affect elderly, polymorbid patients, successful outcome means a great challenge. We report on a case of a 90-year-old patient with a valgus deformity of 47°. The patient was preoperatively restricted to a wheel chair, unable to walk, and only able to stand for a few seconds. The maximal knee flexion was 100°, and there was an extension deficit of 15°. The WOMAC score was 91; the EQ-5D-5L Index was 0.048. She was treated with a constrained hinged prosthesis. Postoperatively, the axis was 6° valgus. After 3 months of rehabilitation, she was independent using a wheeled walker. The maximal flexion of the knee was 110° and there was no extension deficit. The WOMAC score was 45; the EQ-5D-5L Index was 0.813. This case demonstrates the possibility of a satisfactory result and an improvement in quality of life and mobility with a plausible timetable and with reasonable use of resources even in advanced age and severe valgus deformity.