Mid-term performance of a unicompartmental knee prosthesis.

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Knee arthroplasty

Background:

• Unicompartmental knee replacement (UKR) is an alternative to total knee replacement for isolated medial compartment osteoarthritis.
• Midterm outcomes and survivorship data are crucial for evaluating the efficacy of UKR systems.
• The Medacta MOTO Medial prosthesis offers specific design features aimed at improving surgical flexibility and patient outcomes.

Purpose of the Study:

• To evaluate the midterm patient-reported outcomes (PROs) of the Medacta MOTO Medial Unicompartmental prosthesis.
• To assess the survivorship and complication rates associated with this specific unicompartmental knee arthroplasty system.
• To analyze the surgical technique and its impact on functional outcomes.

Main Methods:

• Prospective, multicentre study with 207 adult patients (aged 43-85).
• Follow-up at 2 and 5 years, collecting PROs (FJS, OKS, KOOS) and radiographic data.
• Analysis of complications, revisions, and Kaplan-Meier survivorship.

Main Results:

• Statistically significant improvements in all PROs were observed from 6 months through 5 years.
• Excellent correction of preoperative varus deformity was maintained, with minimal change in mechanical axis.
• Kaplan-Meier survivorship was high at 98.5% at 2 years and 98.1% at 5 years, with low revision rates (four revisions to total knee arthroplasty).

Conclusions:

• The Medacta MOTO Medial Unicompartmental prosthesis demonstrates promising midterm results with excellent functional outcomes and high survivorship.
• The findings support the use of this UKR system in properly indicated patients, challenging previous reports of higher revision rates.
• The implant system's design facilitates surgical flexibility and independent balancing, contributing to favorable clinical outcomes.