Body mass index and knee arthroplasty

Area of Science:

• Orthopedic surgery
• Biostatistics
• Public health

Background:

• Obesity is a growing concern impacting healthcare.
• Understanding its effect on joint replacement timing and outcomes is crucial.

Purpose of the Study:

• To investigate the relationship between Body Mass Index (BMI) and the age of primary knee arthroplasty.
• To assess the association between BMI and post-operative complications.
• To evaluate the impact of BMI on quality of life after knee replacement.

Main Methods:

• A cohort study included 565 patients undergoing primary total knee replacement (TKR) between August 2013 and February 2019.
• Patients were grouped based on BMI (≤30 vs. >30).
• Statistical analysis compared age at surgery, complications, and Oxford Knee Score (OKS) between groups.

Main Results:

• A BMI cutoff of 30 was identified.
• Patients with BMI >30 underwent TKR significantly earlier (average 3.5 years sooner) than those with BMI ≤30 (p=0.0186).
• No statistically significant difference in intra- or post-operative complications was observed between BMI groups. Both groups showed significant OKS improvement.

Conclusions:

• Elevated BMI is associated with earlier knee arthroplasty, but not increased short-to-mid-term surgical risk.
• Total knee arthroplasty significantly enhances quality of life, irrespective of patient BMI.
• The findings suggest obesity influences surgical timing but not immediate surgical outcomes or functional recovery.