Knee crepitus and osteoarthritis features in young adults following traumatic knee injury

Objective This study explored the association between knee crepitus and the presence, and worsening, of structural osteoarthritis features and self‐reported outcomes in young adults following traumatic knee injury. Methods One‐year following anterior cruciate ligament reconstruction (ACLR), 112 participants (41 female participants; median age 28 years) self‐reported the presence/absence of knee crepitus using an item from the Knee injury and Osteoarthritis Outcome Score (KOOS). Patellofemoral and tibiofemoral osteoarthritis features (i.e. cartilage lesions, osteophytes, bone marrow lesions) were assessed from MRIs at 1‐ and 5‐years post‐ACLR. Self‐reported outcomes were assessed with two KOOS subscales (pain, quality of life [QoL]) and the International Knee Documentation Committee subjective evaluation form (i.e. self‐reported function). Poisson regression evaluated the relationship between self‐reported crepitus and the presence/worsening of structural osteoarthritis features. General linear models explored the relationship between crepitus and self‐reported outcomes. Results Self‐reported crepitus was associated with full‐thickness patellofemoral cartilage lesions 1‐year post‐ACLR (prevalence ratio 2.70, 95%CI 1.41, 6.39) but not the risk of worsening structural osteoarthritis features between 1‐ and 5‐years post‐ACLR. Those with crepitus reported worse pain (β ‐6.42, 95%CI ‐10.47, ‐2.36), QoL (β ‐10.39, 95%CI ‐18.58, ‐2.20) and function (β ‐5.49, 95%CI ‐10.92, ‐0.06) 1‐year post‐ACLR, but greater improvement in pain and function between 1‐ and 5‐years. Conclusion Self‐reported knee crepitus was associated with the presence of full‐thickness patellofemoral cartilage defects 1‐year post‐ACLR, but was not associated with a greater risk of worsening structural osteoarthritis features up to 5‐years post‐ACLR. One‐year post‐ACLR, those with crepitus reported worse pain, knee‐related QoL, and function.