Combined Tibial Tubercle Fracture and Patellar Tendon Avulsion: Surgical Technique and Case Report

Abstract

Introduction: Isolated tibial tubercle fractures or patellar tendon ruptures are common injuries in adolescents. However, combined tubercle fractures with patellar tendon ruptures are rare, and hence, there are no definitive methods of surgical fixation or post-operative protocols.

Case report: A 13-year-old healthy girl sustained an extensor mechanism injury after the left knee hyperflexion during a fall from skateboarding. On examination, the extensor mechanism was not functional against gravity. Radiographic imaging revealed a displaced tibial tubercle fracture with patella alta, and magnetic resonance imaging revealed a concomitant patellar tendon avulsion from the tubercle. From a supine position on a radiolucent table, under general anesthesia and a femoral nerve block, the tibial tubercle fracture was fixed using two fully-threaded cortical screws. The patellar tendon was repaired with Fiber Wire through the Krakow method and secured through a tibial transosseous tunnel. A supplemental Fiber Wire was passed through a patellar tunnel and into a tibial tunnel to mitigate tension on the tendon repair. Post-operative knee motion was limited for 1 week to 60° of passive flexion, and full weight-bearing was permitted in a knee immobilizer.

Conclusion: Given the rarity of this combined extensor mechanism injury in adolescents and despite several different fixation methods reported in the literature, there is no clearly superior surgical technique. This case demonstrates a technique allowing for stability of the tubercle fracture and robust repair of the patellar tendon that permits early range of motion and weight-bearing.

Keywords: Tibial tubercle fracture; patellar tendon avulsion; surgery; technique.

Figure 1

Anteroposterior (a) and lateral, (b) radiographs of the left knee demonstrating a displaced and rotated tibial tubercle fracture extending superiorly to the level of the proximal tibial physis and a high-riding patella.

Figure 2

Sagittal plane T1 (a), T2 (b), and axial T2 (c) cuts from the magnetic resonance imaging study demonstrate the tibial tubercle fracture as well as the distal patellar tendon rupture occurring off of its tubercle insertion. The tubercle fragment is rotated 180°, as seen in the axial plane (c).

Figure 3

Diagram depicting the construct and technique of repair used to fix the tibial tubercle fracture with concomitant patellar tendon rupture.

Figure 4

Anteroposterior (a) and lateral (b) views of the left knee obtained from intraoperative fluoroscopy demonstrating fixation of the tibial tubercle fracture with the use of two fully-threaded cortical screws. After FiberWire fixation of the patellar tendon, patellar height appears restored on the lateral view as compared with the lateral view in Figure 1.a

Figure 5

Anteroposterior and lateral radiographs of the left knee at 4 weeks (a) and 5 months (b) postoperatively showing healing of the tibial tubercle fracture with the two cortical screws in proper position. On the lateral views, the position of the transverse drill holes can be visualized in the patella and the proximal tibia.