Revision surgery (a second procedure) to reconstruct a ruptured anterior cruciate ligament (ACL) is fairly rare — thank goodness! They call this a low volumesurgery. But that makes it difficult to study the results of the first surgery and predict outcomes for the second (revision) procedure.
That’s why a group of surgeons from the American Orthopaedic Society for Sports Medicine (AOSSM) got together and formed the MARS group. MARS stands for Multicenter ACL Revision Study Group. By combining patients from multiple centers under the care of multiple surgeons (87 total), it was possible to gather data on 460 patients.
By combining data from a large number of patients, it is possible to conduct a research analysis called a multivariable analyses. With all the various factors that could affect treatment outcomes, this type of research design allows the surgeons to find variables that might predict treatment success or failure.
This study showed that multiple factors are probably the reason(s) why ACL grafts fail. The results of previous (much smaller) studies seemed to point to technical problems such as tunnel malposition for the graft as the most likely reason for graft failure.
And, in fact, this study confirmed that technical considerations are important. But age, type of graft (bone-patellar tendon-bone), and injury to the knee cartilage were also significant factors. The source of the graft (whether taken from the patient or from a donor bank) might be important but this study was unable to prove that one way or the other.
Women tended to reinjure their knees after the first surgery at an earlier age than men. Most ACL failures (62 per cent) occurred two or more years after the initial reconstructive surgery. About one-third presented during the first or second year post-op.
Most reinjuries occur as a result of trauma. Sports that require jumping or cutting/changing directions suddenly top the list of activities patients are engaged in when a previously reconstructed ACL gives way.
Soccer and basketball are the two sports activities named most often but skiing, volleyball, gymnastics, football, and baseball or softball were also reported. A smaller number of patients were engaged in “other” activities listed as biking, cheerleading, dancing, martial arts, roller skating, tennis, hockey, jumping on a trampoline, or wrestling.
Why you? It’s not usually a clear-cut ‘this’ or ‘that’ reason for these types of injuries. Your surgeon may be able to glean some of the reasons ‘why’ but usually it is a combination of many factors.
There is a risk that your revision surgery will fail but your chances for a good outcome are much greater than the risk of a second failure. Your surgeon is really the best one to assess your risk factors and likelihood of a surgical success.