Primary Repair of Complete Quadriceps Tendon Rupture with Extensor Mechanism Deficit.

Background: Whereas partial quadriceps tendon ruptures may be treated nonoperatively if the extensor mechanism remains functional, complete ruptures require primary operative repair to achieve optimal functional results^1,2. The 2 most common techniques are the use of transosseous tunnels and the use of suture anchors. The goal of these procedures is to reconstruct and restore mobility of the extensor mechanism of the leg.

Description: The patient is positioned supine with the injured leg exposed. A midline incision to the knee is made over the quadriceps tendon defect, exposing the distal quadriceps and proximal patella. Irrigation is utilized to evacuate the residual hematoma, and the distal quadriceps and proximal patella are debrided of degenerative tissue. When utilizing transosseous tunnels, a nonabsorbable suture is passed full-thickness through the medial or lateral half of the quadriceps tendon in a locked, running pattern (i.e., Krackow). A second nonabsorbable suture is passed full-thickness through the other half of the tendon. There should then be 4 loose strands at the distal quadriceps. The anatomic insertion of the quadriceps tendon is roughened with a sharp curet to expose fresh cancellous bone. Three parallel bone tunnels are created along the longitudinal axis of the patella. The knee is placed in full extension, with a bump under the heel in order to provide slight recurvatum at the knee and to allow for a properly tensioned repair. In pairs, the free ends of the sutures are passed through the tunnels. The sutures are tensioned and tied together in pairs at the distal aspect of the patella. Alternatively, when utilizing suture anchors, Arthrex FiberTape is passed full-thickness through the medial or lateral half of the quadriceps tendon in a Krackow pattern. A second FiberTape is passed full-thickness through the other half of the tendon. There should then be 4 loose tails at the distal quadriceps. The 2 tails of the medial FiberTape are placed into a knotless Arthrex SwiveLock anchor; this step is repeated for the 2 lateral tails. The anatomic insertion of the quadriceps tendon is roughened to expose fresh cancellous bone. With use of a 3.5-mm drill, create 2 parallel drill holes along the longitudinal axis of the patella, with sufficient depth to bury the SwiveLock anchor. Unlike in the transosseous tunnel technique, these drill holes do not run the length of the patella. The holes are then tapped. Following irrigation, the anchors are tensioned into the bone tunnels, and extra tape is cut flush to the bone. For both techniques, additional tears in the medial and lateral retinacula are repaired if present.

Alternatives: Alternatives include nonoperative treatment with use of a hinged knee brace; operative treatment with use of simple sutures; and augmentation with use of wire reinforcement, cancellous screws, the Scuderi technique, the Codivilla technique, tensor fasciae latae reinforcement, and/or MERSILENE tape (Ethicon).

Rationale: Primary operative repair of quadriceps tendon ruptures is a well-documented, successful procedure with biomechanical, clinical, and patient-reported data to support its use^3-7. However, literature comparing the 2 most common surgical techniques remains controversial. Transosseous tunnel repair is the most common technique utilized to repair quadriceps tendon ruptures, but suture anchors have become increasingly popular in the past several years^1,4. Most studies have reported no significant difference in biomechanical, clinical, and patient-reported outcome measures between these 2 techniques^3,4,8-10. Decreased operative time and a smaller incision have been suggested as advantages of suture anchors^4,9. However, this method incurs a higher average cost of surgery and risks a more complex revision in the event of deep infection^9,10. Simple suture repair is a less commonly utilized technique and is now reserved for midsubstance tendon repairs. Nonoperative treatment of complete quadriceps tendon rupture is exceedingly rare and not recommended because of the profound functional consequences. Relative indications for nonoperative treatment include a patient who is unfit for surgery, is not ambulatory at baseline, or retains full extensor mechanism function. Nonoperative treatment is typically reserved for partial quadriceps ruptures and typically involves early immobilization with a hinged knee brace.

Expected outcomes: Primary repair of quadriceps tendon ruptures, utilizing either the transosseous tunnel or suture anchor technique, yields excellent outcomes. Following surgical treatment, patients have near-full recovery in range of motion, with studies reporting a <5° deficit compared with the contralateral, uninjured limb^3,4,10,11. The vast majority of patients (>90%) return to pre-injury levels of function and work^3,4,7,11. The majority of patients also report satisfactory results, as assessed with use of patient-reported outcome measures^3,4,10. The most commonly reported complications are knee stiffness and quadriceps muscle atrophy, which can both be treated with proper rehabilitation. Even in the event of these complications, however, patients can maintain adequate knee function^2,3. More severe complications are rare (<3%) and include deep venous thrombosis and/or pulmonary embolism, superficial and/or deep infection, and tendon rerupture^2-4,10-12. Delayed operative treatment is associated with worse outcomes and increased complication rates^1,3,4,10,11.

Important tips: When performing the Krackow stitch, be sure to tension and remove all slack before performing another tissue pass.Surgical repair should be performed as soon as possible from the time of injury in order to minimize risks and to achieve optimal surgical outcomes.If there is concern that the primary construct would be unstable, it can be augmented with wire reinforcement, cancellous screws, the Scuderi technique, the Codivilla technique, tensor fasciae latae reinforcement, and/or MERSILENE tape.Identify and repair patellar retinaculum tears, which are common concomitant injuries in the setting of complete quadriceps rupture.

Acronyms and abbreviations: MRI = magnetic resonance imaging.