Table 1.

Tips and Pitfalls During Ipsilateral Quadriceps Tendon–Bone Revision ACL Reconstruction After Failed Primary BPTB ACL Reconstruction With Persistent Distal Patellar Bone Defect

Tips & Pitfalls During Surgery
Tips
•Accounting for the quadriceps–patellar bone deep insertion: During the CT-based preoperative planning as well as during surgery, it is important to account for the deep insertion of the quadriceps tendon into the patellar bone since this is where the proximal patellar bone plug practically starts. Failure to account for this anatomic detail, which adds about 5 mm length to the plug compared to the superficial insertion, may result in harvesting an unnecessary too long proximal bone plug, which may jeopardize patellar bone mechanical strength.
•Avoiding long tourniquet times: Thigh tourniquet cuff is not inflated during the arthroscopic procedure but only during the step of graft harvest.
•Femoral socket preparation: During femoral socket preparation, reusing the existing metal screw socket may be possible by creating a “snowman configuration.” In addition, reaming a 9.5-mm diameter new femoral socket for the graft bone plug, instead of a more common 10-mm socket, can decrease the risk of posterior socket wall breakage.
•Graft harvest: It is important to start the quadriceps harvest proximally instead of distally. This allows lifting the tendinous part first and identifying the quadriceps–patella bone deep insertion before marking the proximal patellar plug harvest lines.
•Graft passage and femoral fixation: Using the tip of a probe enables manipulating the bone plug into the femoral socket such that the free bony margin is facing the metal screw socket. This will avoid the metal screw later from inadvertently damaging the tendinous margin of the plug in the socket and weakening the construct. Alternatively, surgeons may use a PEEK 7 × 20-mm interference screw (Arthrex) if available, which is less abrasive to a tendinous tissue.
Pitfalls
•Harvesting a patellar bone plug longer than 15 to 18 mm may result in a narrow patella “safety” bone bridge between the proximal and distal patella plug harvest sites, while harvesting a bone plug shorter then 15 mm may result in a risky tendon graft abrasion in the femoral socket if using a titanium 7 × 20-mm screw.
•Femoral socket posterior wall breakage may not allow interference screw fixation. In this case, a cortical button can be a good fixation alternative.

ACL, anterior cruciate ligament; BPTB, bone–patellar tendon–bone; CT, computed tomography.