Mylène Jansen

KJD in regular care 111 6 Introduction Knee osteoarthritis (OA) is characterized by articular cartilage degeneration and is an important cause of pain and disability in adults. 1,2 While total knee arthroplasty (TKA) is a widely accepted intervention for end-stage knee OA, it poses a major healthcare burden when placed in younger patients, since they have a higher risk of needing a costly and less effective revision surgery later in life. 3–6 Knee joint distraction (KJD) is a joint-preserving treatment for knee OA for younger patients, where the knee joint is temporarily fully unloaded by distraction of tibia and femur, using an external fixation frame. 7 In an open prospective study (OPS) between 2006 and 2008, 20 knee OA patients below the age of 60, indicated for TKA were treated for 8 weeks with KJD. 8 These patients showed long-term, in the first 2 years progressive, significant clinical benefit and cartilage tissue regeneration. In over 3 quarters of the patients, TKA could be postponed for over 5 years, and half of the patients was still without prosthesis 9 years after treatment. 8–11 After this trial the distraction period was shortened to 6 weeks, as this was considered sufficient. 12 Between 2011 and 2014, the 6-week KJD was studied in comparison to TKA or to high tibial osteotomy (HTO) in 2 separate randomized controlled trials (RCTs). In both trials combined, 41 KJD patients gained significant clinical and structural benefit in the first year, which was shown to be maintained up to at least 2 years after treatment. Both trials demonstrated that KJD was non-inferior to the alternative treatment. 13–15 Since 2014, KJD is offered as a regular care treatment in a limited number of hospitals for knee OA patients under the age of 65. Often when a new treatment proceeds from clinical trial to regular care, indications for treatment broaden and treatment outcome weakens. As such, treatment and surgery details, baseline characteristics, complications during treatment, and treatment efficacy of KJD in regular care were compared with clinical trial (OPS/RCT) conditions. Methods Patients In regular care, at the department of Orthopedic Surgery in our hospital patients are offered KJD in case they are considered for TKA but still younger than 65. According to local guidelines for treating patients with TKA, patients have had sufficient conservative treatment, but with insufficient success and a Kellgren-Lawrence grade (KLG) of at least 2. Patients with presence or history of inflammatory joint condition, joint prosthesis elsewhere in the body (potential risk of prosthetic joint infection), or physical or social conditions that do not support a 6-week distraction period, are ineligible. The standard procedure at the department of orthopedics is that patients are asked for consent to use their anonymized data for future research purposes,