Tibial tuberosity fractures are rare, accounting for 3% of all epiphyseal injuries and only 1% of physeal injuries.1–4 This injury occurs most often in the adolescent male population, due to later fusion of the tibial epiphysis and participation in more vigorous physical activities.2 The most common mechanisms are flexion of the knee during quadriceps contraction and significant quadriceps contraction during knee extension.1 Maximal quadriceps contraction occurs frequently during take-off or landing, as was the mechanism in this case.1
A 14-year-old male football player (height = 185.4 cm; weight = 83 kg) sustained an acute injury to his right knee. No history of previous lower extremity injuries was noted. The athlete participated in a strength and conditioning program during the summer prior to the injury. The injury occurred when landing after jumping over a defender during a football scrimmage. The on-the-field examination by the athletic trainer noted the right leg positioned in 45° of knee flexion, swelling, and displacement of the patella. The athlete reported significant pain and an inability to actively extend the knee. A patellar fracture or dislocation was suspected initially. The involved knee was splinted in a flexed position, neurovascular checks were performed, and the athlete was transported to the emergency department via emergency medical service.
On arrival to the emergency department, the splint was removed and intranasal fentanyl was administered. The physician passively extended the athlete's leg into full extension, noting pain and deformity over the proximal anterior tibia. Radiographs showed a significantly displaced fracture (29.6 mm) of the right tibial tuberosity (Figure 1).
A significantly displaced fracture of the right tibial tuberosity.
Surgical intervention consisted of an open reduction, internal fixation performed that evening. A segment of displaced periosteum and hematoma were removed and the patellar tendon was cleared from the fracture site. The procedure was completed using four 4-0 cannulated screws with washers to secure the fracture. Following the fixation, fluoroscopic images were obtained to ensure a secure fixation of the fracture site. Following surgery, the athlete was prescribed a knee immobilizer and non-weight–bearing status for 5 weeks. A wheel-chair for long-distance ambulation and a front-wheeled walker for transfers and short-distance ambulation were used. Ankle pumps were performed daily during the 5-week period.
The follow-up radiographs at 5 weeks showed a stable alignment and progression of healing at the fracture site. The athlete was referred to physical therapy with instructions to advance weight bearing with assistive devices, as tolerated. Initial therapy and home exercise program included the following: active and passive knee range of motion exercises; patellar mobilization strengthening exercises (eg, gluteal and quad sets, terminal knee extensions, standing mini squats, standing weight shifts, and side lying hip abduction/clams); and gait training using an Alter G treadmill (AlterG, Freemont, CA). Therapy progressed to include leg curls, step-ups, partial squats, BOSU ball (BOSU PRO Balance Trainer; BOSU, Ashland, OH), biking, and elliptical. Three months after surgery, therapy consisted of leg press, hip sled, hex-bar squats, single-leg exercises, and plyometric and reaction drills.
Twenty-one weeks after surgery, radiographs showed a healed fracture site (Figure 2). A clinical examination noted an extension lag but was otherwise unremarkable. Instructions for advancing physical therapy included exercises to increase strength, range of motion, and overall confidence in the knee with functional activities. Following the return-to-play program, the athlete continued to exhibit functional weakness and balance deficits. Physical therapy was resumed one to two times per week for 10 weeks, focusing on aggressive strengthening of the right leg, functional activities (eg, agility ladders, plyometric activities, and running), and balance exercises.
The healed fracture site 21 weeks after surgery.
Due to the traumatic nature of the injury, concurrent injuries often occur with a tibial tuberosity fracture. These may include quadriceps and patellar tendon strains, anterior cruciate ligament and medial collateral ligament sprains, and tibial plateau fractures.1 Another significant concern following a tibial tuberosity fracture is compartment syndrome in the lower leg due to the trauma occurring at the proximal tibia.1 A prophylactic fasciotomy may be performed to prevent compartment syndrome of the anterior compartment.3 Patients with Osgood-Schlatter's disease and osteogenesis imperfecta are predisposed to sustaining a tibial tuberosity fracture.4 However, neither disease was present in this patient.
An open reduction, internal fixation technique is used to repair displaced fractures.1,2,4 If no displacement has occurred at the fracture site, a closed reduction, internal fixation procedure has shown to be sufficient.4 Following either type of procedure, a period of immobilization in an extended position and non-weight–bearing status for approximately 6 weeks is recommended.
For successful return to participation, full range of motion, acceptable strength, and overall confidence when performing functional activities must be restored. Range of motion and strength exercises begin once the cast or knee immobilizer is removed. Full range of motion is typically achieved between 8 and 10 weeks after surgical fixation.1 Strength exercises begin with simple isometric exercises and progress to open and closed chain activities. Regaining strength takes more time than range of motion but can be restored as early as 6 months after injury.2 Case reports reviewed reported return to full activity between 6 months and 1 year after injury.1–4
Implications for Clinical Practice
Fractures of the tibial tuberosity are rare but significant injuries. Clinicians working with adolescent populations should consider a tibial tuberosity fracture and concurrent injuries when trauma to the knee has occurred. Common signs of a tibial tuberosity fracture are severe anterior knee pain, displacement of the patella (alta), swelling, and inability to actively extend the knee or bear weight.1–4 Compartment syndrome can occur secondary to the fracture injury. As in this case, appropriate diagnosis with referral and management are key. This case illustrates the importance and length of rehabilitation required to return to the prior level of activity. Although extension lag and continued strength deficits were present in this case, the athlete returned to full activity 1 year after injury, similar to other reported cases.2,4
When compared to the literature, this case is rare because no concurrent injuries (eg, meniscal damage, ligament strains, or tendon disruptions) occurred, making this case an isolated tibial tuberosity fracture. Surgical fixation and a period of immobilization are necessary following a displaced fracture. Quality rehabilitation focusing on strength, range of motion, and confidence in the injured limb are key to return the athlete to full participation in activity and sport.
- Nicolini AP, Carvalho RT, Ferretti M, Cohen M. Simultaneous bilateral tibial tubercle avulsion fracture in a male teenager: case report and literature review. J Pediatr Orthop. 2018;27:40–46. doi:10.1097/BPB.0000000000000313 [CrossRef]
- Georgiou G, Dimitrakopoulou A, Siapkara A, Kazakos K, Provelengios S, Dounis E. Simultaneous bilateral tibial tubercle avulsion fracture in an adolescent: a case report and review of the literature. Knee Surg Sports Traumatol Arthrosc. 2007;15:147–149. doi:10.1007/s00167-006-0164-0 [CrossRef]
- Zrig M, Annabi H, Ammari T, Trabelsi M, Mbarek M, Ben Hassine H. Acute tibial tubercle avulsion fractures in the sporting adolescent. Arch Orthop Trauma Surg. 2008;128:1437–1442. doi:10.1007/s00402-008-0628-4 [CrossRef]
- Inoue G, Kuboyama K, Shido T. Avulsion fractures of the proximal tibial epiphysis. Br J Sports Med. 1991;25:52–56. doi:10.1136/bjsm.25.1.52 [CrossRef]