Rationale and Endoscopic Technique for Anatomic Placement and Rigid Fixation of a Double-Looped Semitendinosus and Gracilis Graft

The double-looped semitendinosus and gracilis (DLSTG) graft is an excellent autogenous graft for replacing a torn anterior cruciate ligament because of its superior structural properties and minimal harvest morbidity. Customized placement of the tibial tunnel for variability in knee anatomy and avoiding roof impingement improves the clinical outcome and is a prerequisite for aggressive rehabilitation. Anatomic placement of the femoral tunnel can be achieved using an endoscopic technique in which an over-the-top femoral aimer is inserted through a customized tibial tunnel. Rigid fixation of the DLSTG graft is required to safely rehabilitate the knee aggressively without a brace and return the patient to unrestricted sports by 4 months postoperatively. The use of a fixation post with bone compaction inside the femoral tunnel through the implant (Bone Mulch Screw) results in reciprocal tensile behavior of the graft. The use of a multiple-spiked washer (WasherLoc, Arthrotek, Inc, Warsaw, IN, U.S.A.) achieves rigid, countersunk fixation inside the tibial tunnel. Fixation methods that rely on suture bridges or interference screws to fix soft tissue grafts have not been shown in the laboratory to withstand the loads imposed by activities of daily living. When stiff fixation methods are used, graft pretensioning should be performed with the knee in full extension to avoid overconstrainmg the knee.