Unicompartmental Knee Arthroplasty Is Not Associated With Increased Revision Rates in Obese Patients

Area of Science:

• Orthopedic Surgery
• Arthroplasty Research
• Biomedical Engineering

Background:

• Controversy exists regarding unicompartmental knee arthroplasty (UKA) suitability for obese patients.
• Current literature lacks consensus on UKA outcomes in patients with varying degrees of obesity.

Purpose of the Study:

• To investigate UKA complications and revision rates in obese (BMI > 30 kg/m²), morbidly obese (BMI > 40 kg/m²), and super morbidly obese (BMI > 50 kg/m²) patients.
• To compare these outcomes against normal weight individuals.

Main Methods:

• Retrospective review of 2178 UKA procedures from 2008-2017.
• Patient categorization by Body Mass Index (BMI): normal (20-30 kg/m²), obese (30.1-40 kg/m²), morbidly obese (40.1-50 kg/m²), and super morbid obese (>50.1 kg/m²).
• Analysis of demographic data, revision rates (timing, type, etiology), and complication causes.

Main Results:

• Overall revision rate was 2.2% across all patients.
• No significant difference in revision rates observed between normal weight (3.0%), obese (2.7%), morbidly obese (1.9%), and super morbid obese (1.8%) groups.
• Progressive osteoarthritis was the primary reason for failure across all BMI categories.

Conclusions:

• Unicompartmental knee arthroplasty (UKA) demonstrates comparable revision rates in obese, morbidly obese, and super morbidly obese patients versus normal BMI individuals.
• Progressive osteoarthritis is the leading cause of UKA failure, irrespective of patient BMI.
• Obesity should not be considered a contraindication for UKA procedures.