Mylène Jansen

122 Chapter 6 was previously seen in the RCTs, where around half of patients experienced infections. 13–15 This could be because in regular practice patients receive a standard antibiotics prescription and do not have to visit the hospital before starting their course, which makes it likely that antibiotics are also used in case of doubtful infection. Pin tract infections had no significant influence on the clinical outcome at 1 year follow-up. Furthermore, despite the high occurrence of pin tract infections, patients undergoing TKA surgery several years after KJD have not experienced additional complications or diminished clinical efficacy. 17 Nevertheless, it is a major burden and effort should be made to reduce pin tract infections further. A new joint distraction device (KneeReviver) has been developed, which makes pin care easier. A clinical trial to evaluate this new device is currently ongoing. Additionally, new care protocols are encouraging, appearing to decrease the number of pin tracts significantly. Not only pin tract infections, but complications in general did not significantly influence the clinical response. Complications other than pin tract infections did not occur with a frequency allowing statistical evaluation. However, the 17 patients who received full KJD treatment in regular care and experienced other complications than pin tract infections all returned to the outpatient clinic after treatment and 14 of them (82%) were satisfied with their KJD treatment and indicated that they had less OA complaints than before treatment. Only the other 3 patients (1 who experienced pneumonia and flexion limitation, 1 a corpus liberum and 1 a broken bone pin) did not report success of the treatment. Clearly, there is room for improvement to decrease complications of the treatment to further improve the balance of benefit over burden. A decrease in range of motion was seen as adverse effect previously in the clinical trials. In both regular care and clinical trials, the decrease that was seen shortly after KJD, recovered within months and normalized after a year, with the observed changes being minimal and less than the minimally detectable difference reported in literature. 27 As such, the differences are considered not to be clinically relevant and within variation of measurement. The clinical benefit that was demonstrated previously in all clinical trials was also observed in regular care. In the clinical trials, the clinical benefit seemed slightly better, which was partly due to slightly better effects of the OPS treated patients. Although all not statistically significant, this may be the benefit of subtle differences in patient selection as well as the small difference in distraction duration (in favor of the OPS patients), as has been discussed before. 12 Moreover, no difference in the percentage of responders according to OMERACT-OARSI criteria at 1 year was observed either. Neither being a patient from a clinical trial or regular care, nor any of the other baseline data predicted clinical outcome.