The patient in this case was a 25-year-old obese male with a past medical history of borderline hypertension and diabetes well controlled with medication and a moderate level of physical activity that heard a pop in his knee after playing basketball. The patient ignored his knee injury until 5 months later when he presented to a clinic with instability in his knee, inability to fully straighten his leg, and anterior knee pain with flexion. On physical exam, the patient's preoperative range of motion was 10 to 100 degrees. The patient began experiencing anterior knee pain and tightness after 90 degrees of flexion.
The patient is brought to the operative suite and positioned supine on the operating room table, and general anesthesia is induced. Prior to draping, the contralateral knee is placed in 60 degrees of flexion, and the length of the native patellar tendon is measured (4.5 cm in the case pictured). The operative extremity is prepped and draped to the proximal thigh. A sterile triangle is placed to hold the knee in 60 degrees of flexion. The distance between the inferior pole of the patella and the tibial tubercle is then measured on the injured extremity (8.0 cm). A sterile tourniquet is applied to the thigh but will only be inflated if needed.
A midline longitudinal incision is made from the superior pole of the patella to the tibial tubercle through the skin and subcutaneous tissue. The underlying fascia is identified and incised longitudinally. The peritenon is identified superiorly, and the peritendonous flaps are elevated to reveal the chronic, scarred patellar tendon rupture (approximately 3.5 cm in the midsubstance of the tendon) (Figure 1(a)). The scarred portion of the tendon is debrided along with any redundancy of the medial and lateral retinacula. A Cobb elevator is used to release the superficial and deep aspects of the quadriceps tendon from the surrounding tissues (Figure 1(b)).
The vastus medialis is left intact, and the surgeon ensures that the patella can be reduced to its native position at 60 degrees of flexion as measured on the contralateral knee preoperatively. A four-stranded end-to-end repair is then undertaken using a #5 FiberWire (Arthrex, Naples, FL) in a Krackow fashion (Figure 2(a)). A #2 FiberWire (Arthrex, Naples, FL) is used in a running-locking fashion to imbricate the elongated medial and lateral retinacula and oversew the tendon repair (Figure 2(b)).
Next, the semitendinosus autograft is harvested. The insertion of the pes anserine is visualized through the same incision, and the semitendinosus tendon is identified and detached from its insertion. Once rid of adhesions, the tendon is harvested in standard fashion with a closed tendon harvester. The graft is prepared on the back table with both ends tied in a Krackow manner using #2 FiberWire sutures and then sized when doubled (6.5 mm).
A tibial bone tunnel is created using an appropriately sized (6.5 mm) cannulated reamer (Arthrex, Naples, FL), 3 cm distal to the tibial tubercle and 2 cm posterior from the anterior tibial crest (6.5 x 40 mm). The graft is passed through the bone tunnel from medial to lateral and courses along the lateral aspect of the native patellar tendon. Small rents are created in the medial and lateral retinacula at the level of the superior pole of the patella, and the graft is woven transversely through the distal quadriceps tendon from lateral to medial. The graft is then brought down along the medial border of the native patellar tendon and passed through the bone tunnel from lateral to medial. The free ends cross in opposite directions within the tibial bone tunnel and are secured using interference screws (Tenodesis Screw, BioComposite, 6.25 x 15 mm; Arthrex, Naples, FL):one from medial to lateral and one from lateral to medial (Figure 3(a)).
Finally, an InternalBrace (Arthrex, Naples, FL) is used to augment and protect the reconstruction. Two 4.75 x 15 mm SwiveLock BioComposite suture anchors (Arthrex, Naples, FL) are placed into the distal pole of the patella securing the midpoint of one 2 mm FiberTape suture tape (Arthrex, Naples, FL) each. The free limbs of the FiberTape cross the repair site:one limb straight inferior and the other in an "X" fashion:and are then secured to the tibial tubercle using two 4.75 x 15 mm SwiveLock BioComposite suture anchors (Figure 3(b)). The tension of the InternalBrace is set such that the knee can be passively flexed to 90 degrees. The wounds are thoroughly irrigated, closed, and dressed in the surgeon's usual sterile fashion.
The patient was placed in a locked hinged knee brace and instructed to bear weight as tolerated with crutches in extension for 6 weeks. A supervised physical therapy program lasting 4 months was recommended. At 6 weeks, the patient was able to perform passive and active flexion to 90 degrees. At 12 weeks, the patient discontinued the brace and began zero-resistance straight leg raise exercises, as recommended. The patient began quadriceps strengthening at 12 weeks and ultimately should return to impact cardiovascular activity after 20-24 weeks. This current patient has had a six-month follow-up. He has active range of motion from 0-120 degrees with no extensor lag and has returned to sporting activity.