Unicompartmental versus computer-assisted total knee replacement for medial compartment knee arthritis: a matched paired study

Patients older than 60 with unicompartmental knee arthritis can be treated with total or unicompartmental knee replacement. The aim of this study was to compare the results of matched paired groups of patients with isolated medial compartment knee arthritis replaced with either UKR (group A) or computer-assisted TKR (group B). The results included 68 knees at a minimum follow-up of 3 years. All patients had a varus deformity no greater than 8º and a BMI lower than 30. Patients were matched in terms of preoperative arthritis severity, age, gender and preoperative range of motion. In the computer-assisted TKR group, all the implants were positioned within 4º of the correct hip-knee-ankle angle and frontal tibial component angle. The surgical time and hospital stay were statistically longer in the CA TKR group. During the study no implant required revision. The results showed higher scores for a UKR in the treatment of isolated primary unicompartmental knee arthritis in patients older than 60 compared to a computer-assisted TKR. In this study a computer-assisted alignment system for TKR with optimal implant positioning did not produce equivalent clinical results compared to a UKR, but did increase the financial costs.