Age and Body Mass Index Has No Adverse Effect on Clinical Outcome of Unicompartmental Knee Replacement - Midterm Followup Study

Introduction: Unicompartmental knee replacement (UKR) is well-established procedure for the anteromedial compartment of knee arthritis with intact anterior cruciate ligament. The significance of age and body mass index (BMI) is not clear in the outcomes of UKR. Our hypothesis was that age and BMI does not affect the clinical and functional outcome following fixed bearing UKR.

Materials And Methods: The study cohort of 148 was selected after stringent inclusion criteria and average followup was 5.6 years (range 2-10 years). The fixed bearing Miller Galante UKR procedure was carried out on all patients.

Results: In the study cohort of 175, the average age of the cohort was 61.7 years. The sample size aged ≤55 years and aged ≥55 years was 38 and 137, respectively. The mean BMI of the cohort was 29.2 kg/m (range: 21-38 kg/m). The sample size of BMI ≤30 kg/m and BMI ≥30 kg/m was 117 and 58, respectively. In the cohort group, BMI ≤30 kg/m and BMI ≥30 kg/m, there was no statistically significant difference in the Knee Society Score clinical scores, functional scores, and knee range of motion scores, ( > 0.05). This study infers no statistically significant difference in the clinical and functional outcome between age group ≤55 years and age ≥55 years, ( > 0.05). The failure rates of the group of BMI ≤30 kg/m and BMI ≥30 kg/m were 4.27% (5 knees) 3.44% (2 knees), respectively. The failure rates in the age group ≤55 years and group ≥55 years were 2 knees (3.44%) and 5 knees (4.27%), respectively.

Conclusion: This study confirms that age and BMI does not influence the functional outcome and clinical outcome following fixed bearing UKR.