Delaying arthroplasty: The potential of knee joint distraction in young osteoarthritis patients-A prospective case series.

Purpose: Knee joint distraction (KJD) offers a joint preserving alternative for relatively young patients with severe knee osteoarthritis (OA). The aim of this study was to assess the clinical and radiographic success of KJD in patients with severe OA. Methods: This prospective case series comprised 26 consecutive patients undergoing KJD due to severe knee OA. Clinical and radiographic outcomes were collected at baseline and at 1- and 2-year follow-up. Complication, reoperation and conversion rates to a primary knee arthroplasty were collected. The patient-reported outcome measures (PROMs) were the Knee Injury and Osteoarthritis Outcome Score (KOOS), the 36-item Short Form Health Survey (SF-36) and the Visual Analogue Scale (VAS) for pain. The radiographs were analysed using an artificial intelligence (AI) based software package to extract compartmental joint space width (JSW), joint space area (JSA) and compartmental imbalance. Results: Pin tract infections were common, affecting 13 (50%) patients. Five patients (19.2%) received primary knee arthroplasty within the 2-year follow-up period. Significant increases (p < 0.05) were observed in the JSW and JSA of the most affected compartment, leading to significant improvements in compartmental imbalance. Significant improvements were also observed in all KOOS subscales (p < 0.001) which sustained for 2 years. The VAS for pain scores were also significantly improved (p < 0.001), as were the SF-36 subscales (p < 0.05) with the exception of the general health subscale. Conclusion: This case series demonstrates that KJD provides symptomatic relief amongst young patients with knee OA after failed conservative treatment. A significant increase in the JSW and JSA was observed, which may indicate cartilage regeneration. KJD could be an alternative joint-preserving intervention with potential to delay the need for primary arthroplasty. Level of Evidence: Level IV, prospective case series.