Impact of smoking on femorotibial and hip osteoarthritis progression: 3-year follow-up data from the KHOALA cohort

Objectives: To evaluate the clinical and structural impact of smoking on knee and hip osteoarthritis at baseline and after 3 years.

Methods: Observational data on the progressive effects of smoking at baseline and after 3 years were collected from The Knee and Hip Osteoarthritis Long-Term Assessment cohort comprising a French population of patients aged 40-75 years with symptomatic lower limb osteoarthritis. Clinical (the Western Ontario and McMaster Universities Arthritis Index and Harris scores) and structural (radiography for osteophyte detection and joint-space narrowing assessment) were conducted. The tobacco usage categories were 'never smoker', 'former smoker', and 'current smoker'.

Results: Of the 873 subjects included, 215 (25%) were former smokers and 119 (14%) were current smokers. Multivariate analyses revealed that former and current smokers had fewer knee osteophytes in the medial compartment at baseline (odds ratio [OR]=0.64 [0.41-0.99] and 0.63 [0.36-1.11], respectively), lower osteophyte development in the lateral condyle after 3 years (OR=011 [0.03-0.45] and 0.15 [0.03-0.97]), and lower osteophyte development in the lateral tibial plateau after 3 years (OR=0.22 [0.06-0.75] and 0.68 [0.14-3.35]). Higher tobacco consumption and longer duration of consumption were significantly associated with fewer knee osteophytes at baseline and lower osteophyte development at 3 years.

Conclusion: Although cigarette smoking did not influence knee function, pain, or the need for replacement surgery, current and former smokers developed fewer osteophytes. This relationship may be linked to the quantity and duration of consumption. Our results provide further insight into the smoking-related pathophysiology of osteoarthritis.

Keywords: Hip; Knee; Osteoarthritis; Osteophyte; Smoking; Tobacco.