Mylène Jansen

190 Chapter 10 differences between the trials with regard to the distraction technique and treatment protocol, the general principle remains the same. In all cases, an external frame is placed around the knee joint using bone pins on the medial and lateral sides of the femur and tibia, after which the two joint surfaces are placed at a certain distance for several weeks after which the frame is removed, with in general no imposed follow-up treatment. The frames used are shown in Figure 1 and discussed below. Figure 1 : Different type of frames used for knee joint distraction. From left to right: custom articulated distraction device (Deie et al ., 2007) 14 ; Ilizarov circular frame (Aly et al ., 2011) 15 ; Dynamic Monotubes (Van der Woude et al ., 2017) 16 ; KneeReviver. 17,18 An overview of the presently performed and (to our knowledge) ongoing KJD clinical trials is given in Table 1. The search strategy used to find these studies is summarized in the ‘review criteria’ box. Review criteria To find the studies summarized in Table 1, the MEDLINE, EMBASE, and Web of Science libraries were searched for relevant articles. Search terms were (distraction OR arthrodiatasis OR arthrodiastasis) AND (knee OR tibiofemoral OR tibiofibular), and were applied on title and abstract and, in Web of Science, Keywords+. Only full-text publications about clinical studies in which knee joint distraction with external fixation was applied and the primary outcomes were patient-reported outcomes and/or cartilaginous tissue restoration were included in Table 1. Studies that were found but did not fully meet the criteria were used throughout the text where relevant. The studies in progress with no results published yet were included based on personal communi- cation. The first trial in 2007 was a retrospective study with 6 OA patients who were treated with a combination of hinged KJD and bone marrow stimulation, using a customized frame for 2 – 3 months. 14 Subsequently, in 2010 a case report was published, where 1 patient with an osteochondral defect was treated with hinged distraction and an artificial bone graft using the same customized frame for 3 months. 19 These studies indicate a beneficial effect of the distraction with respect to clinical outcome as well as joint tissue repair including cartilage.