Anterior cruciate ligament surgery: Which factors negatively impact therapeutic results after revision surgery?
Knee bracing immediately after revision surgery produces unfavourable results. Revision operations often produce poorer results than the primary surgical intervention following an anterior cruciate ligament rupture.
The reasons for this have until now been unclear. This is why the scientists of the MARS Group (see box) decided to study the predicators for this therapeutic result. Amongst other things, they included demographic factors, type of injury, operation technique, rehabilitation schemes (e.g. full load versus partial load, (non-) limitation of movement) and patients’ validated self-questionnaires. Two years after revision surgery patients were re-examined and the data was compared with the initial data in a regression analysis. 82% of the 843 patients were available for re-examination after two years. 57% were male and approx. 27 years old (median). There were two relevant predicators for the therapeutic outcome of rehabilitation: the patients who had been given a derotating brace for sports activities showed significantly better values in the Knee Injury and Osteoarthritis Outcome Score (KOOS). Wearing the brace, they experienced a 50% higher probability for better KOOS outcomes in the subscale sports and leisure. By contrast, patients wearing the brace during post-operative rehabilitation, underwent 2.3 times as many revision operations over the same period. Whether patients were wearing a brace when re-staring sports or not, however, did not have a significant impact on the risk of a re-rupture. In general, there was a correlation between poorer initial examination results and poorer results in post-examination. The authors concluded therefore that after the first post-operative weeks following a revision operation the focus should be on gradually increasing the ability to cope with load as well as on the improvement of motion and function – without a knee brace. This should only be worn from the point in time rehabilitation is completed and patients return to sport.
MARS is short for “Multicenter ACL Revision Study”. The MARS Group encompasses many renowned surgeons who jointly carried out a multi-centric, prospective cohort study on revision operations after anterior cruciate ligament surgery. Since every surgeon performs this operation an average of less than ten times a year, viable figures for analysing predicators for therapy outcomes could only be acquired by means of cooperation. The group is made up of physicians from university clinics (44%) and private practices (56%) and is supported by the American Orthopedic Society for Sports Medicine (AOSSM). The aim is to research the factors influencing the therapy outcome of revision operations after anterior cruciate ligament surgery. To this end patients should be examined two, six and ten years after the revision operation.
MARS Group. 2019. Rehabilitation predictors of clinical outcome following revision ACL reconstruction in the MARS cohort. J. Bone Joint Surg. Am. 101, 9:779–86