[Rupture of the anterior cruciate ligament. Current status of treatment]

This article summarizes the present knowledge on the diagnosis of and treatment rationales for ruptures of the anterior cruciate ligament (ACL) of the knee. There is an increasing incidence of this injury due to the high number of persons involved in dynamic sports. The most significant diagnostic criterion is a positive pivot shift associated with a pathological anterior translation of the tibia in slight flexion of the knee. Instrumented testing of the knee is becoming increasing important and is standard in follow-up studies. A survey of the literature at present delineates very clearly the importance of an intact ACL for homeostasis of the knee. Loss of this structure leads to a high incidence of secondary meniscus tears with consecutive osteoarthritis of the knee. All valid studies also indicate an involuntary decrease of activity in the patients after loss of the ACL. Risk factors for early decompensation of the knee are a young age, high activity level, rupture of the collateral ligaments, congenital laxity, varus morphotype and high initial laxity. Primary repair of the ACL is possible, but results in stable ligament healing in only a limited percentage of cases. Reconstruction of the ACL with a free patellar tendon graft has become the standard procedure for many surgeons. ACL reconstruction can be performed either arthroscopically or through a "miniarthrotomy" with comparable results. Augmented repair or reconstruction using autologous flexor tendons is an alternative in certain cases. Augmentation with allogeneic material and the use of tendon allografts are still experimental and should be restricted to centers that can perform strict follow-up studies. The rehabilitation program after implantation of a patellar tendon graft can be accelerated markedly without endangering joint stability. Crutches are necessary only for the first 2-3 weeks. The success rate in terms of objective stability with an autologous patellar tendon graft is high, although specific disadvantages such as chronic patellar pain and a risk for loss of motion must be considered.