Mylène Jansen

196 Chapter 10 quality after KJD treatment using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), which indicates glycosaminoglycans (GAG) concentration in the cartilage, and T2-mapping data, representing collagen structure of the cartilage, were gathered. No significant change in dGEMRIC or T2 signal values, when volume increased, up to two years after treatment was found, suggesting the cartilage quality did not change. 39 In other words, the newly formed cartilage (as previously shown with JSW increase and MRI cartilage thickening) was likely of a similar quality as before treatment and not of fibrocartilage quality. In case compared with control groups, KJD generally performed similarly or better in structural results. Aly et al showed that, unlike patients treated with KJD and debridement, those treated with debridement only did not show a JSW increase. 15 In the RCT, HTO patients showed one- and two-year JSW increases that were not significantly different from those shown by KJD patients. 24,25 Since in TKA the knee joint is replaced, KJD could not be compared with TKA in cartilage restoration parameters. Lastly, MRI results from two RCTs showed that, contrary to KJD, HTO patients presented a significant deterioration in cartilage thickness and denuded bone area and results in severe OA patients were significantly better for KJD than for HTO. 40 There was no difference between KJD and HTO with regard to dGEMRIC and T2 measurements. 39 Adverse events These beneficial results regarding PROMS and tissue structure repair come at the expense of side-effects during the distraction treatment, because of the external fixation. All studies reported occurrence of complications, except for Abouheif et al. who reported no complication. 19 In all other trials, pin tract skin infections occurred frequently. While in the studies of Deie et al. only two of the six patients (30%) experienced skin infections, in the other studies this percentage was much higher, ranging from around 60% in both RCTs to 85% in the prospective study. 21,24,26 It might be that the low skin infection rate is due to the positioning and type of pins, with Deie et al . placing the frame more closely to the joint with less soft tissue involvement and thinner pins (k-wires). Aly et al. reports contradictory results of first 18% and then 74% of patients experiencing skin infections. Regardless, the vast majority (~86%) of all pin tract infections could be treated with oral antibiotics, and they did not have a significant influence on one-year PROMs. 13 Furthermore, despite the high occurrence of these infections, patients undergoing TKA surgery years after KJD did not experience additional complications or decreased clinical effect. 41 Superficial skin infections should not be trivialized with respect to burden for the patient and risk of more serious deeper infections. Efforts should be made to decrease the number. Development of a dedicated frame like the KneeReviver might be a way to realize this. 17 Also, care protocols like the use of cadexomer iodine ointment during distraction treatment demonstrating a significant decrease in pin tract infections (from 64% to 32%) might be of help. 42