Magnetic Resonance Imaging Derived Cartilage Morphological Changes and their Correlation with Patient-Reported Outcome Measures Following Knee Joint Distraction for Osteoarthritis: A 12-Month Cohort Study

AimsKnee osteoarthritis (OA) is a significant source of morbidity and socioeconomic burden, exacerbated by aging populations and rising body mass index. Total Knee Replacement (TKR) is effective but may result in dissatisfaction or revision, particularly in young patients. Knee Joint Distraction (KJD) offers a joint-preserving alternative that may delay or avoid replacement. This study assessed cartilage morphology changes using magnetic resonance imaging (MRI) of patients up to 1-year post-KJD in patients from a randomized controlled trial (RCT). The primary aim was to evaluate cartilage volumes at 12 months post-KJD. Secondary aims were to evaluate additional MRI parameters for cartilage morphology and compare the MRI parameters with Patient-Reported Outcome Measure (PROM) scores at 3 and 12 months.MethodsA subset of participants from an RCT comparing TKR and KJD were analyzed. The MRI and PROMs, including Knee Injury & Osteoarthritis Outcomes Score (KOOS), Oxford Knee Score (OKS), and pain visual analogue scale (VAS), were collected at baseline, 3 months, and 12 months postintervention. Cartilage segmentation using commercial software and grading using the MRI Osteoarthritis Knee Score (MOAKS) were performed.ResultsTen patients were included. Increases in mean cartilage volume were observed in all regions except the trochlear at both follow-ups. Mean cartilage thickness increased in all areas except the lateral tibia. Mean denuded bone area decreased in all regions at 12 months and in the lateral femur at 3 months. Baseline cartilage status was predictive of treatment response.ConclusionKJD led to improvements in cartilage morphology up to 12 months, suggesting its potential as a joint-preserving strategy for knee OA. Further long-term studies are needed to confirm benefits and understand mechanisms.