Mylène Jansen

Long-term clinical success of KJD 47 3 Introduction Few possibilities are available for treatment of end-stage (conservative treatment resistant, persistently painful with clear radiographic joint damage) knee osteoarthritis (OA). Although total knee arthroplasty (TKA) has been shown to be effective in reducing pain and regaining function, it comes with an increased risk of future revision surgery, specifically when placed at a relatively young age (<65 years). 1,2 Therefore, joint-preserving surgery such as knee joint distraction (KJD) would be preferable in this younger patient group. In distraction treatment, an external fixation frame is used to gradually separate 2 bony ends of a joint for a few millimeters for a number of weeks. 3,4 KJD has been shown to result in improvement of patient-reported clinical outcomes and improved tissue structure parameters based on digitally analyzed standardized radiographs and magnetic resonance images (MRI), for up to 5 years. 5–10 However, long-term survival of KJD as a joint-preserving treatment has not yet been evaluated. In this study, the 20 patients treated with KJD in an open prospective study were followed to observe long-term clinical and structural changes, as previously reported for up to 5 years of follow-up. 5–7 Additionally, long-term survival of the native knee joint was evaluated and the effect of patient characteristics as well as disease-specific clinical and structural parameters on long-term survival was assessed. Methods Patient selection Between 2006 and 2008, 20 patients with knee OA were included in an open uncontrolled prospective study at the department of orthopedics of the University Medical Center Utrecht (UMCU). Inclusion criteria were age <60 years, Visual Analogue Scale (VAS) of pain ≥60 mm, radiographic signs of joint damage and primarily tibiofemoral OA. The included patients were indicated for TKA surgery, but their relatively young age was reason to propose KJD as an alternative. Exclusion criteria were severe symptoms in both knees, a history of inflammatory or septic arthritis and severe knee malalignment requiring surgical correction (>10°). The study was approved by the medical ethical review committee of the University Medical Center Utrecht (No 04/086) and all patients gave written informed consent. Distraction method The distractionmethod was applied as previously described by Intema et al . 5 An external fixation frame was placed to bridge the knee joint. The frame consisted of 2 dynamic monotubes, both fixed to 2 bone-pins on each end, elongated in stages until at least 5 mm distraction was reached