Augmentation of Patellar Tendon Repair With Autologous Semitendinosus Graft-Porto Technique

Abstract

Patellar tendon ruptures can lead to significant functional deficiency of the extensor mechanism of the knee. These injuries, because of their inherent nature and associated complications, may require a complex treatment and remains a challenge for orthopaedic surgeons. Current surgical techniques present significant complications, including patellar fracture, damage to patellar articular cartilage, and abnormal patella height. This note describes a surgical technique to provide an additional reinforcement to the patellar tendon repair with a semitendinous autograft, without the necessity to perform any transosseous tunnels at the patella bone. First, the patellar tendon is repaired with an end-to-end technique and the semitendinous tendon is harvested. A transosseous tunnel at the tibial tubercle is drilled and 2 rents are made, both medial and lateral to the retinaculum at the level of the intermedial segment of the patella close to the patellar margin. The graft is passed through the tunnel and rents in a U-shaped form. The graft is sutured along the length of the patellar tendon on both margins in tension at 30° of knee flexion. Fluoroscopy imaging is performed to assess the patella height. This technique provides a significant augmentation of patellar tendon, avoiding the potential patella bone tunnel complications.

Fig 1

Patient supine, left leg. Under anesthesia, the patellar tendon integrity is tested by palpation with the knee in full extension. In the figure, it is possible to observe an infrapatellar depression.

Fig 2

Patient supine, left leg. While flexing the knee, it is possible to observe the patella proximal mobilization (indicated by an arrow), exhibiting the absence of patellar tendon integrity.

Fig 3

Patient supine, left leg. After dissection, the patellar tendon ends are exposed and visualized (exposed area displayed within the dotted circle).

Fig 4

Patient supine, left leg. The semitendinosus tendon is identified and isolated at the pes anserine insertion, and harvested ipsilaterally using a tendon stripper.

Fig 5

The harvested semitendinosus graft is prepared, cleaned, and measured to ensure that it is at least 22 cm long.

Fig 6

Patient supine, left leg. The graft is placed over the borders of the patellar tendon and quadricipital retinaculum in a U-shaped fashion to confirm the graft length suitability.

Fig 7

Patient supine, left leg. The 4.5 mm transversal transosseous tunnel is made from medial to the lateral side (arrow), at 1 cm posterior to the tibial tubercle.

Fig 8

Patient supine, left leg. The graft is passed through the tibial tunnel, from medial to lateral (arrow).

Fig 9

Patient supine, left leg. Two incision rents are made, medially and laterally to the retinaculum, at the level of the intermedial segment of the patella close to the patellar margin. The second rent should be made 5 mm proximally to the initial rent (dotted line).

Fig 10

Patient supine, left leg. The graft is then inserted through the retinaculum rents. This should be accomplished from the distal rent to the proximal one (arrow).

Fig 11

Patient supine, left leg. The graft is looped over the retinaculum rents (indicated by the curved arrow).

Fig 12

Patient supine, left leg. The graft is sutured on its own substance, creating an anchorage.

Fig 13

Patient supine, left leg. The graft is sutured in tension along the patellar tendon on both medial and lateral margins.

Fig 14

Patient supine, left leg. Final result of the repair and reinforced patellar tendon.

Fig 15

Postoperative follow-up radiograph (3 months) of a patient with patellar tendon repair using the semitendinous augmentation showing no differences in the patellar height when compared to the contralateral side. (L, left; R, right.)