Small tears in the ACL may just require several months of rehab in order to strengthen the surrounding muscles, the hamstring and the quadriceps, so that these muscles can compensate for the torn ligament.
With the patient lying in the supine position, flex the knee 20° to 30° while the heel rests on the end of the exam table. Grasp the femur with the nondominant hand to prevent movement of the upper leg. Then, grasp the lower leg at the proximal tibia and apply a forward tug. This movement should produce a firm endpoint. If the endpoint is not firm or there is increased anterior translation of the tibia, the Lachman test is positive.
The acl can be reconstructed by an orthopedic surgeon using arthroscopic surgery. There are a variety of techniques, depending on the type of tear and what other injuries may be associated. The decision as to what surgical option is appropriate is individualized and tailored to a patient's specific situation. Because of its blood supply and other technical factors, the torn ACL ends are not usually sewn together and instead, a graft is used to replace the ACL. Often an autograft, tissue taken from the patient's own body, is a piece of hamstring or patellar tendon that is used to reconstruct the ACL.