Mylène Jansen

Return to sport and work after KJD and HTO 97 5 studies on HTO reported median postoperative Tegner scores ranging from 2.5 to 5.9, where the latter was found in a specific population (athletes). 21 Next, participation in low-, intermediate- and high-impact sports did not differ either. Here, we observed the same trend of lower postoperative participation in intermediate- and high-impact sports that was described previously after distal femoral osteotomy, HTO and KA. 22,36,37 Lastly, sports participation in terms of level, times per week and hours per week showed similar trends between both groups, namely postoperative participation at a lower level and less frequently. This decline is also in line with previous findings after HTO and KA. 21,37 Still, at final follow-up patients reported sports participation levels and frequencies comparable to 1 year postoperatively, indicating a sustained treatment effect over 5 years. Thus, our initial findings appear to be in line with previous studies on RTS after joint-sparing surgery for knee OA. The reported RTW rates for KJD and HTO (94% resp. 97%) were higher than expected, since a systematic review found a pooled estimate of 85% RTW after HTO. 21 For KJD, this was the first study to report RTW, hampering comparison with existing literature. Still, 94% RTW is an encouraging finding, possibly facilitated by maintaining the native knee joint, as well as removing all external material after 6 weeks, compared to plate removal after 1–2 years in the HTO group. Again, larger cohort studies are mandatory to verify RTW rates after KJD. Next, time to RTW did not differ overall, although 53% of KJD patients returned after ≤4 months compared to 72% in the HTO group. As stated, this difference might be explained by the 6-week period of knee immobilization for KJD, which limits rehabilitation and thus slows the return to work activities. RTW outcomes should be further analyzed in adequately powered studies, since slower RTW after KJD may be clinically meaningful to the patient, and also has a negative societal impact given the financial consequences of slower RTW. Next, the improvement in WORQ scores was significantly higher in the HTO group (16 points versus 6 points), compared to KJD. While Kievit et al . reported a difference of 13 points for the WORQ to be clinically meaningful to the patient 33 , a difference of 10 points in favor of HTO may certainly indicate a better postoperative ability to perform knee-demanding activities, compared to KJD. Additionally, the mean WORQ score of 73 in the HTO group was above the satisfaction threshold of 71 33 , while the mean score of 69 in the KJD group was slightly below this threshold. In comparison, Kievit et al . reported mean WORQ scores of 71 after total KA (TKA) and 77 after unicompartmental KA (UKA). 38 As expected, kneeling and crouching presented most difficulty for both groups postoperatively. Yet, both groups appeared to experience less postoperative difficulty with these activities compared to TKA and UKA patients 38 , although this comparison is hampered by the difference in mean age (50 years in our cohort versus 60 years in the KA cohort). Thus, regarding work-related outcome measures, HTO showed better outcomes than KJD in the present study.