Mylène Jansen

98 Chapter 5 Although KJD has shown promise in the treatment of knee OA, the current scientific basis remains small and literature on long-term outcomes is lacking. 39 Therefore, patient counseling should include these existing uncertainties, and the fact that TKA showed an overall better response in clinical outcome parameters at 2 years, including the total KOOS, VAS pain and EQ-5D, compared to KJD in the only RCT to date. 28 Yet, 15 out of 18 patients in the KJD group, who were initially indicated for TKA, had still not undergone TKA at 5 years follow- up. 26 Based on these findings, the authors concluded that KJD should not be considered a TKA replacement but rather a new treatment option to possibly postpone primary TKA. 26,28 Regarding sport and work participation, a significantly increased revision risk has been reported in younger, active TKA patients. 6,7 Clearly, maintaining the native knee joint decreases the future risk of prosthesis wear and associated revision procedures if KA is eventually performed. Thus, for patients with invalidating knee OA who wish to return to sport and work activities, KJD may become a viable treatment option and a possible alternative to HTO. Yet, much work remains to be done in order to provide a broader scientific basis for KJD. In the only RCT to date, KJD and HTO showed similar clinical outcomes. 27,28 However, 13 KJD patients (59%) developed pin tract infections, the most frequent complication after KJD. 27 Nine patients were treated with oral antibiotics, while 3 patients were administered intravenous antibiotics and 2 patients required surgical debridement. In contrast, only 2 HTO patients (4%) developed wound infections, treated with oral and intravenous antibiotics respectively. Also, KJD patients experienced more discomfort with activities of daily living the first postoperative weeks due to the distraction device. 40 While KJD patients require standard surgical removal of the distraction device 6 weeks postoperatively, up to 71% of HTO patients require hardware removal, i.e. a new operation with its associated risks, due to hardware irritation. 41 Obviously, all the above should be discussed with the patient when considering KJD and HTO as treatment options for invalidating knee OA. The most important limitation of the present study is the small group size for KJD, which limited statistical power for comparisons between the HTO- and KJD group. However, this was expected given that only 103 KJD cases have been described in prospective studies worldwide. 39 Therefore, our findings may be considered a general indication of the expected RTS and RTW after KJD, and no definite conclusions can be drawn yet. Another limitation is our retrospective design. Preferably, future prospective studies on KJD should include sport- and work outcome measures to control for this limitation. Finally, the small group size also complicates the generalizability and thus external validity of the present findings. Especially for KJD, distinct eligibility criteria as well as long-term outcome data clearly need to be established prior to broader implementation of this novel technique. In conclusion, in the present first albeit small cohort study, knee joint distraction in patients indicated for high tibial osteotomy resulted in comparable postoperative participation in