Total knee arthroplasty for neuropathic joint disease after severe bone destruction eroded the tibial tuberosity.

This article describes a patient in whom total knee arthroplasty was performed for neuropathic joint disease secondary to diabetes mellitus after severe bone destruction eroded the tibial tuberosity. At initial examination, radiographs of the knee showed bone destruction in the medial and anterior regions of the tibia, and fine bone fragments were seen in the joint. Conservative therapy was performed using a brace. However, bone destruction gradually advanced, and 10 months after the initial examination, radiographs of the knee showed bone destruction in the lateral condyle of the femur and advanced bone destruction of the anterior tibia; the tibial tuberosity was missing. It is rare for the tibial tuberosity in the anterior tibia to disappear. If this happens, reconstruction is difficult and total knee arthroplasty becomes complicated. For the bone defect in the tibia, cement was used to recreate the shape of the anterior surface of the tibia. It was possible to minimize the volume of bone resection and morphologically reconstruct the tibial tuberosity. The patient recovered quickly. At postoperative week 5, the patient was able to walk using a cane. Thirty-six months after total knee arthroplasty, knee extension was 0°, flexion was 120°, extension lag was 5°, knee score improved from 40 points to 94 points, and functional score improved from 20 points to 75 points. However, long-term implant stability needs to be carefully monitored.