Quadriceps Tendon Reconstruction With Achilles Tendon Bone Block Allograft

QT ruptures are uncommon injuries that can lead to significant disability for the patient and can be technically challenging for the orthopaedic surgeon. Chronic QT ruptures may lead to worse functional outcomes, which are believed to be due to scar tissue formation, distal retraction of the patella, quadriceps muscle atrophy, and large tendon gapping. Due to the rarity of chronic QT ruptures in developed countries due to rapid treatment and early repair, there are very few studies with large sample sizes to evaluate which technique may be superior.^, Primary repair for chronic ruptures is relatively uncommon but can be performed when tendon lengthening is not required. The Scuderi technique has been used infrequently for chronic QT ruptures due to vastus advancement rarely being required. The Codivilla V-Y lengthening technique has been historically used for QT tendon gaps up to 2 cm in length. Reconstruction of the extensor mechanism with the use of synthetic mesh in 2 cases that failed primary QT repair has been reported by Hartline et al. with good outcomes. Reconstruction with autografts and allografts has been primarily indicated for poor tissue quality or large tendon gaps that are not amenable to vastus advancement or V-Y plasty. To our knowledge, there are no studies with large sample sizes for chronic QT repair with autografts or allografts and most of the current literature is composed of individual case reports. Leopardi et al. reported using ipsilateral hamstring autografting for a 5.5-month chronic QT rupture in which the patient demonstrated 5° to 130° of active knee range of motion, mild quadriceps atrophy, along with a 5° extensor lag at 3 years postoperatively.^, McCormick et al. reported a good outcome and full, painless return to sports activity at 37 months postoperatively using an autologous hamstring tendon in a patient with chronic QT re-rupture.^, Alternatively, Watson et al. described a novel technique focusing on restoring patellar height from patellar tendon lengthening and performing a primary repair of the native QT in the setting of chronic rupture without the use of grafts.

Achilles tendon bone block allografts have been commonly used for patellar tendon reconstruction but have been considered a recent novel technique for repair of chronic QT rupture. Forslund et al. describe the use of an Achilles tendon bone block allograft in a patient who previously failed a QT V-Y reconstruction 3 months prior. At 13 months postoperatively, the patient demonstrated a 7° extensor lag and 90° flexion.^, Wise et al. report 17 extensor mechanism reconstructions following total knee arthroplasty using an Achilles tendon allograft, 7 of which were QTs. Their outcomes for QT reconstruction demonstrated an average extensor lag of 2.9° and 103° flexion with an average quadriceps strength of 4/5 at a minimum follow-up of 2 years. Kunze et al. describe the use of a trapezoidal-shaped Achilles allograft bone plug for revision QT repair in which the bone plug is inserted into a prepared anterior patellar slot and secured with wire fixation. Reported disadvantages to their technique include potential graft mismatch, which may lead to graft laxity, overconstraint, or an extensor lag. Okay et al. report QT reconstruction with Achilles tendon allograft and suture anchors into the superior aspect of the patella in a case that previously failed primary repair. This case demonstrated a satisfactory outcome and graft incorporation at the 6-year follow-up. The goal of our technique is to present surgeons with an additional option for chronic QT repair that may provide a greater mechanical load to failure and greater allograft acceptance. We hypothesize that placing the bone block at the distal patellar pole and passing FiberWire sutures through the patella proximally with the use of an ENDOBUTTON provides a maximal amount of surface area and tension to achieve sufficient bony fixation (Table 1). Furthermore, securing the Achilles tendon allograft with FiberWire sutures at the distal patellar pole with the anterior patella bursal layer may provide a stronger construct to reduce the risk of re-rupture. This multilayer repair can theoretically act as a checkrein and potentially reduce the risk of a complete re-rupture. Disadvantages to this technique include the risk, albeit potentially reduced, of allograft rejection and the technically demanding nature of this procedure (Table 2). Further studies with long-term outcomes are needed to evaluate if this technique can restore the extensor mechanism with reduced re-rupture rates.