Intensive diet or knee arthroplasty for severe knee osteoarthritis: The inka randomised trial

Area of Science:

• Orthopedics
• Weight Management
• Clinical Trials

Background:

• Knee osteoarthritis (OA) is a leading cause of disability.
• Obesity significantly exacerbates knee OA and is a common comorbidity in patients eligible for knee arthroplasty (KA).
• Intensive dietary interventions are explored as alternatives to surgical management for knee OA.

Purpose of the Study:

• To compare the non-inferiority of an intensive dietary weight loss program (IN) versus knee arthroplasty (KA) in improving knee pain and function.
• To evaluate symptom improvement in obese individuals with knee OA eligible for KA.

Main Methods:

• A randomized comparative effectiveness trial was conducted.
• Participants with obesity (BMI ≥30 kg/m² ) and knee OA were randomized to either an intensive dietary program (12-week low-calorie meal replacement with group sessions) or knee arthroplasty.
• The primary outcome was the Oxford Knee Score (OKS) assessed at 6 months, with a non-inferiority margin of 4 points.

Main Results:

• 92 participants were randomized (45 to IN, 47 to KA).
• The mean OKS at 6 months was 28.2 for IN and 36.5 for KA, a difference of -8.2 favoring KA (95% CI: -11.5 to -5.0).
• The IN group achieved significant weight loss (-11.0 kg) compared to the KA group (-1.3 kg).

Conclusions:

• The intensive weight loss program was not non-inferior to knee arthroplasty for improving knee OA symptoms.
• Knee arthroplasty demonstrated clinically superior improvements in patient-reported knee pain and function at 6 months.
• While effective for weight loss, the dietary intervention did not meet the non-inferiority threshold compared to surgery for knee OA management.