Mylène Jansen

188 Chapter 10 Abstract Joint distraction has emerged as a joint-preserving treatment for end-stage osteoarthritis, with a gradually growing promise for implementation in regular clinical practice. This review focuses on distraction of the knee, showing prolonged symptomatic improvement in combination with cartilaginous tissue repair in degenerated knee joints, and supporting the concept of cartilage repair translating into real clinical benefit. The reversal of the tissue degenerative process could be the result of any of the supposed mechanisms involved – a combination of partial unloading, synovial fluid pressure oscillation, subchondral mechanical and biochemical bone changes, joint-derived stem cells, and a changed molecular joint milieu. The overall picture that emerges from this combined evidence is relevant for joint distraction as well as translation to other joint-preserving techniques. It remains to be elucidated whether optimizing the biomechanical conditions during distraction can actually cure the disease instead of only providing temporarily relief, but even in the latter case it may be of relevance for society and patients, as it will delay placement of a prosthesis at an early age and with that prevent revision surgery later in life. Most importantly, a better insight in the underlying mechanisms may provide new leads to more targeted treatment options.