Mylène Jansen

266 Chapter 13 all p>0.18). Also, the sensitivity analyses using the patients of whom all data were available demonstrated that the observed effects presented with imputed data of the whole group seem solid. Still, it remains important to remember that the long-term whole-group results may be an underestimation or, perhaps more likely, an overestimation of the actual cartilage regeneration effect, since patients were lost to follow-up because of additional surgery, making it likely that the remaining patients experienced greater treatment benefit. Lastly, as validation for the results of the current study, it could have been worthwhile to directly measure the cartilage thickness in the patients undergoing TKA. Unfortunately, in these patients the post-surgery material was not stored and no cartilage thickness was measured. Including this in the study protocol of future studies could give an opportunity for validation of results. Future studies could also include registration of data that could possibly bias the measured cartilage thickness, such as activity monitoring, to further improve reliability of the data. In conclusion, in these young end-stage knee OA patients, KJD treatment results in significant short-term cartilage regeneration in the most affected compartment, of which the effects can still be seen after 10 years. Apparently, an initial boost of cartilaginous tissue repair provides a long-term tissue structure benefit. In the less affected compartment, a delayed regenerative response seems to take place. Male sex and severity of joint damage may predict initial benefit, although this was lost over time. The observed intrinsic cartilage tissue repair activity upon KJD, specifically in the first 2 years, may be used to find the metabolic and mechanical drivers of intrinsic cartilage repair in general, providing novel leads for cartilage tissue repair strategies.