Differences in presentation, progression and rates of arthroplasty between hip and knee osteoarthritis: Observations from an osteoarthritis cohort study-a clear role for conservative management

Aim: To describe the natural progression and the rates of arthroplasty of a cohort of hip and knee osteoarthritis (OA) patients. Methods: An observational study of 247 consecutive patients who attended an OA clinic between May 2008 and August 2009. Follow-up survey was conducted from July 2014 to December 2014, with the primary end point being joint replacement surgery. Results: One hundred and sixty-seven patients had knee OA and 80 patients had hip OA. When adjusted for other variables (age, gender, body mass index, Kellgren-Lawrence stage, symptom duration, presence of OA elsewhere and pain score), patients with hip OA demonstrated 86% increased hazard of surgery compared to knee OA patients (95% CI increase of 19% to 193%). At 6 years after initial consultation, 67% of patients with knee OA did not require a knee replacement surgery, while 40% (30, 51) of hip OA patients did not undergo surgery (95% CI: 59-74%). Overall at 6 years, 58% of patients (95% CI: 51-64%) did not undergo joint replacement surgery. Conclusion: Knee and hip OA patients appear to behave differently, with hip OA patients more likely to undergo arthroplasty. There is a significant number of both hip OA and knee OA patients who did not require arthroplasty at the end of 6 years, suggesting a major role for conservative therapy.