Anterior tibial tuberosity (ATT) avulsion fractures are a rare injury that accounts for approximately 0.4–1.7% of all epiphyseal injuries ^[1]. They usually occur during recreational sports such as high jump, volleyball, basketball, and soccer, and are a source of disability ^[2]. They are often associated with a history of Osgood–Schlatter disease ^[3]. Treatment is surgical if the lesion is displaced and orthopedic in cases of non-displaced lesions ^[3]. We report four cases of tibial tubercle avulsion fractures that occurred in young adolescents during sports.

(Table 1)

Case 1: Patient X

A 14-year-old soccer student presented with anterior knee pain, who reportedly experienced severe knee pain on takeoff to head a ball during a soccer game. This resulted in functional impairment of the limb. Physical examination revealed a sub-patellar notch and an impaired extensor function of the leg. Knee radiographs showed an avulsion fracture tibial tuberosity, classified Ogden Type IIB (Fig. 1a and b). The indication for open reduction and internal fixation (ORIF) was made and performed on the 2^nd day of trauma. The approach was medial, and we performed a reduction and screwing of the fragments associated with a steel wire protection frame as cerclage (Fig. 1c and d). Removal of the cerclage wire was done on day 45 and consolidation was obtained at 2 months. Physiotherapy started 14 days after surgery. It consisted of muscular reinforcement by electrostimulation and passive mobilization up to 60° followed by active mobilization up to a range of 135° flexion and 0° extension after the removal of wire. The patient was able to resume sports at 6 months after removal of the screws.

Case 2: Patient Y

A 17-year-old student who was practicing the high jump and experienced severe knee pain during take-off. Physical examination revealed a passive extension deficit of the leg. A radiograph of the knee showed an avulsion fracture, classified as Ogden Type IIB (Fig. 2a). Surgical intervention was indicated and we performed an ORIF by screw fixation with 2 cortical screws associated with a steel wire protection frame as cerclage (Fig. 2b and c). Healing was obtained on the 15^th day, and rehabilitation was started immediately Quadriceps contraction by electrostimulation and passive followed by active mobilization of the knee. The cerclage wire was removed on day 90 and sports was resumed at 6 months’ post-operative.

Case 3: Patient Z

A 16-year-old student reportedly experienced severe knee pain while catching a ball during a basketball game. Clinical examination revealed a partial extension deficit of the leg. An X-ray showed an avulsion fracture of the tibial tuberosity, classified Ogden Type IVB (Fig. 3a). A closed reduction and internal fixation (ORIF) by pinning was done under fluoroscopic guidance on day 2 of trauma (Fig. 3b). Immobilization by a rigid knee splint was done and rehabilitation by reinforcement of the quadriceps and mobilization of the knee began 45 days post-operation.

Case 4: Patient W

A 14-year-old student with no prior history reportedly experienced severe left knee pain on takeoff from a high jump during a basketball game. This resulted in absolute functional impairment of the limb. The physical examination revealed a defective extension of the left leg. An X-ray showed an avulsion fracture of the tibial tuberosity, classified as Ogden Type IIB (Fig. 4a and b). The indication for an ORIF by screw fixation was given and performed (Fig. 4c and d). Consolidation was obtained after 60 days and resumption of sports at 5 months.

It should be noted that all four patients each wore a rigid knee brace in knee extension for 3 weeks after surgery and walked with the aid of a pair of crutches for 2 months. Complete mobilization of the knee was obtained on the 3^rd month for all four patients (Fig. 1e, f, g and 4e, f, g, h).

Tibial tuberosity avulsion fracture is a rare injury that usually occurs in adolescent males [4, 5]. High jump sports are the most incriminated in the genesis of these injuries as seen in basketball, soccer, volleyball, high jump, etc. ^[2]. Our four cases occurred in adolescent males during sports practice (soccer, high jump, and basketball). Indeed, during the practice of these sports, there is a sharp contraction of the quadriceps during knee extension while initiating a jump, which could lead to brutal traction on the tibial tuberosity, thus favoring its fracture by an avulsion [6, 7]. The association with Osgood–Schlatter disease is frequent ^[8]. In our study, only one patient (the 14-year-old) had a history of Osgood–shlatter’s disease with a history of chronic knee pain.

Watson Jones classified avulsion fractures of the tibial tuberosity into three types:

• Type I is an avulsion of a small portion of the tibial tuberosity, distal to the physis of the proximal tibia;
• Type II involves the whole physics, but does not extend to the knee joint;
• Type III corresponds to avulsion that extends proximally to the knee growth plate ^[9].

This classification was modified by Ogden and Southwick who added two other types corresponding to fragmentation and displacement of the fragment. Ryu and Debenham added a Type IV corresponding to the fracture of the ATT with a line that extends onto the posterior inferior metaphysis [10,11]. This type corresponds to an apophyseal detachment of the proximal tibia, Type II of Salter and Harris. Amongst our four patients, three presented with an Ogden’s Type IIB fracture and one with Type IVB.

Treatment is controversial in the literature. It can be non-operative or operative. The choice depends on the position of the fracture line and the displacement. For non-displaced fractures, orthopedic treatment can be performed. Type IA and IIA fractures can also be operated on with CRIF guided by fluoroscopy, followed by immobilization of the knee in extension for 6 weeks. Type IIB and III AB, on the other hand, are treated surgically from the start. Type IB can be treated by orthopedic management except in cases with periosteal interposition ^[11].

For other types (IA and rarely non-displaced Types II and III) they are treated by orthopedic management ^[12]. Type IV is treated surgically. Several means of fixation have been described: Pinning, screwing, and plating [13,14]. Some authors recommend a lateral approach to avoid transecting the infrapatellar nerve, which is a branch of the saphenous nerve. Other authors prefer a direct anterior approach, which allows for a better reduction of the fragments ^[5].

We performed surgery (open screwing of the fragments + protective frame by cerclage wiring) through the anterior approach in patients with Type IIB fractures and percutaneous pinning through the anterior approach under fluoroscopic guidance for the patient with Type IV fracture.

Intra- and post-operative complications have been described, including nerve damage, compartment syndrome due to traumatic section of the branches of the recurrent tibial artery, pulmonary embolism, calcification, and other complications, pulmonary embolism, vicious callus, and quadriceps atrophy. We did not record any complications in our patients.

At an average follow-up of 6 months, all four of our patients had resumed sports activity and the functional results were excellent. Our functional results are comparable to those reported in the literature.

TTA fracture is a rare injury that occurs most often in adolescent athletes. It is due to a sudden contraction of the quadriceps with the leg in extension. Several types are described depending on the location of the fracture line and the displacement. Whether the treatment is orthopedic or surgical, and when it is well conducted, the functional result is generally satisfactory with a return to sport within 6 months.

The avulsion fracture of the tibial tuberosity is a rare injury often occurring in adolescent athletes. Its treatment varies according to its severity. However, an early diagnosis and adequate management allow a return to sport at the same level.