Patella Distal Pole Fracture Treated Using Ipsilateral Hamstring Autograft Augmentation and No Additional Hardware

Abstract

Patellar lower-pole fractures occur in relatively young patients after eccentric contraction of the quadriceps or direct trauma. Early diagnosis and adequate treatment lead to excellent outcomes and prevent tendon retraction and scarring. The aim of surgical treatment is to restore articular congruence and reestablish the extensor mechanism of the knee. All surgical treatments (sutures and tension band wiring, separate vertical wiring or augmented with Krackow sutures, wiring through screws, basket plate, hook plate) use additional hardware. We propose a hardware-free technique using ipsilateral hamstring augmentation.

Fig 1

(A) The insertions of the gracilis and semitendinosus, which should be harvested carefully, are left attached to the proximal tibia. The muscle fibers are debrided from the tendon proximal part, and two no. 0 absorbable braided sutures (Vicryl®; Ethicon, Somerville, NJ) are whipstitched through the proximal ends of the tendons. The tendons are sized for later drilling of the patella and the tibia. (B) Preparation of the tibial and femoral tunnel. The diameter of the tibial tunnel must be the same as that of the longest tendon, usually the semitendinosus, and the femoral tunnel must be the size of both tendons. Both tunnels are centered to avoid fracture, especially on the patella. (C) The longest tendon should be passed through the tibial tunnel from medial to lateral; both tendons should be passed subcutaneously from distal to lateral and then through the patella tunnel; the lateral tendon should be passed from lateral to medial; and the medial tendon should be passed from medial to lateral. Make sure to clean both ends of the tunnels of soft tissues so that the tendons can be passed smoothly. In our experience, it is easier to pass each end of the sutures before passing the tendons through the tunnels. The traction should be done in the tunnel direction to avoid fractures. (D) Tension is applied simultaneously to both tendons' proximal ends, with the knee flexed at 30°. After satisfactory restoration of patellar height, the sutures are tied and temporary locked on the proximal part of the other hamstring tendon using small clamps. (E) The 2 tendons are securely sutured using two no. 2 FiberForce® (Wright Medical, Memphis, TN) sutures, starting at each side of the patellar horizontal tunnel then continuing to the distal aspect of the patella, attaching the hamstring tendons to parapatellar soft tissue and paratenon. The arms of the 2 hamstring grafts are tensioned beneath the patellar tendon and sutured to the native patellar tendon, to the level of the distal tubercle insertion. Finally, no. 0 absorbable braided trans osseous sutures (Vicryl®; Ethicon) are placed to stabilize the 2 parts of the fracture after removal of the reduction clamp (Figure 1). The torn medial and lateral retinacula are closed with interrupted no. 0 absorbable braided suture (Vicryl®; Ethicon).