Br J Sp Med 1991; 25(1) Br J Sports Med: first published as 10.1136/bjsm.25.1.52 on 1 March 1991. Downloaded from Avulsion fractures of the proximal tibial epiphysis G. Inoue MD', K. Kuboyama MD2 and T. Shido MD3 'Department of Orthopaedic Surgery, Branch Hospital, Nagoya University School of Medicine, Nagoya, Japan 2Kuboyama Orthopaedic Clinic, Shizuoka, Japan 3Department of Orthopaedic Surgery, Hamamatsu Medical Centre, Hamamatsu, Japan Fractures of the tibia through the proximal epiphysis are sporting activities: two boys were injured during a rare. This injury usually results from severe direct or high jump, one in a long jump, and one during indirect force about the knee, and has not been described basketball. In three of the five fractures, the patients as resulting from a patellar tendon avulsion injury. Four patients presented with five avulsion fractures of the felt that their injuries occurred on take-off for their proximal tibial epiphysis. All were older adolescent males jump while the remaining two injuries occurred on who had been engaged in jumping sports when the injury landing. All patients presented with pain and occurred; one had bilateral injury. All the patients were swelling about the anteromedial part of the proximal treated by closed reduction and plaster cast immobi- end of the tibia. Three patients were unable to extend lization for 4-8 weeks, with satisfactory results. On the the involved knee or bear weight. basis of our cases and five cases previously reported, the Radiographs revealed a Salter-Harris type II authors would agree with Ryu and Debenham's sugges- fracture of the proximal tibial epiphysis4: this was an tion that the Watson-Jones classification, which divides avulsion fracture of the tibial tuberosity with the avulsion fractures of the tibial tubercle into three types, fracture line extending through the proximal tibial should be expanded to include this fourth type - avulsion physis and metaphysis into the posterior cortex. fracture of the proximal tibial epiphysis. Displacement of the fragment with posterior angula- Keywords: Avulsion fracture, tibia, epiphysis, jumping tion was noted in four fractures: these were treated sports by closed reduction and long-leg cast immobilization for 4-8 weeks. One of these injuries required percutaneous pinning to stabilize the fracture. One Fractures of the proximal tibial epiphysis are rare fracture, where there was no displacement of the adolescent injuries which are produced by two fragment, was treated in a cylinder cast for 4 weeks. different mechanisms: severe direct or indirect force An undisplaced fibular fracture at the same level as about the knee separating the tibia through the full the tibial fracture was recognized in two patients. No http://bjsm.bmj.com/ width of the proximal tibial epiphysis or an avulsion neurovascular damage was noted in our series. force separating the anterior portion of the proximal tibial epiphysis. The former is usually caused by a high-energy motor accident or collision during a Results contact sport, while the latter is caused by a In all patients the fractures healed uneventfully and high-tensile load to the tibial tuberosity during a full weight-bearing was allowed after 4-8 weeks. The jumping sport. A total fracture-separation of the patients were able to return to full activity after on September 27, 2021 by guest. Protected copyright. proximal tibial epiphysis caused by an avulsion force approximately 3 months. They had a minimum is extremely rare. The authors have found only five follow-up of 1 year, with a mean follow-up of 15 1-3 fractures reported in the literature' . months. All patients had a full range of knee In the present report, five such fractures are movement and normal quadriceps function with no described in four patients who were injured in muscle atrophy. Although premature closure of the jumping sports. involved tibial physis was recognized in two patients, there was no discrepancy in length or angular Material and methods deformity of the legs. Table 1 summarizes the clinical information on these Case reports patients. All were boys, two aged 15 years and two Case 1 A 16-year-old boy, experienced sudden right aged 16. Three patients showed unilateral involve- knee pain with 'a pop' when he took-off for a long ment and one bilaterial involvement, and all fractures jump off his right leg. He landed with both knees were closed. All of the injuries were sustained during flexed. The patient noted severe pain in both knees and was unable to stand up. Examination revealed and tenderness the antero- Address for correspondence: G. Inoue MD, Department of gross swelling along Orthopaedic Surgery, Branch Hospital, Nagoya University School medial proximal metaphysis. The patient was unable of Medicine, 1-1-20 Daikominami, Higashi-ku, Nagoya 461, Japan to extend either leg. He had a history of clinically ©) 1991 Butterworth-Heinemann Ltd. asymptomatic Osgood-Schlatter disease of both knee 0306-3674/91/010052-05 joints. 52 Br J Sp Med 1991; 25(1) Avulsion fractures of the proximal tibial epiphysis: M. D. Inoue et al. Table 1. Summary of cases Br J Sports Med: first published as 10.1136/bjsm.25.1.52 on 1 March 1991. Downloaded from Case no. Involved Age at Mechanism Treatment Follow-up Remarks limb Injury ofinjury (months) (years) 1 R 16 Long jump Cast 12 PCP (take-off) L 16 Long jump Cast 12 PCP (landing) Fibular fracture 2 L 16 High jump Cast 16 (take-off) 3 R 15 High jump Cast 12 Fibular fracture (take-off) 4 L 15 Basketball Cast 36 PCP (landing) Percutaneous pinning L, left; PCP, premature closure of the physis; R, right Radiographs showed a Salter-Harris type II frac- pain and swelling over the tibial tuberosity. He was ture in both legs in an anteroposterior plane through able to extend his knee against gravity. the proximal tibial physis and metaphysis, with Radiographs revealed that the tongue-like projec- posterior angulation (Figure 1). There was also a tion of the anterior tibial epiphysis was lifted upward fibular fracture in the left leg. The fractures were and a fracture line extended obliquely downward reduced by a closed manipulation with the knee across the metaphysis into the posterior cortex (Figure extended and direct manual pressure over the tibial 3). The limb was immobilized in a cylinder cast for 4 tubercle. Both knees were immobilized in long-leg weeks, and then full weight-bearing was allowed casts for 6 weeks. Follow-up examination 1 year later with progression to full activity. One year after revealed no bony abnormality and full range of injury, he had full range of movement in the knee, no movement in both knee joints, although radiographs length discrepancy, and no complaints. Radiographs showed premature closure of both tibial physes showed no abnormality in the knee. (Figure 2). Case 2 A 16-year-old boy sustained injury to the left Discussion knee while doing the high jump. He felt that his Fracture of the proximal tibial epiphysis is a rare injury occurred on take-off. At examination he had injury, accounting for between 0.5% reported by http://bjsm.bmj.com/ on September 27, 2021 by guest. Protected copyright. a b Figure 1. Case 1 a Initial lateral radiograph of the right knee showing an avulsion fracture of the tibial tubercle with a Salter-Harris type 11 fracture of the proximal epiphysis. b Initial lateral radiograph of the left knee showing a similar findings to that of the right knee. Note a greenstick fracture of the fibula Br J Sp Med 1991; 25(1) 53 Avulsion fractures of the proximal tibial epiphysis: M. D. Inoue et al. Br J Sports Med: first published as 10.1136/bjsm.25.1.52 on 1 March 1991. Downloaded from a Figure 3. Case 2 Initial lateral radiograph demonstrates that the entire tongue formed by the anterior tibial epiphysis is hinged upward, and a fracture line passes obliquely downward across the metaphysis (arrows) the tubercle is avulsed and displaced upward. In the second type, the secondary centre of ossification in the tubercle has already coalesced with the remainder of the proximal epiphysis and the entire tongue formed by the tibial tuberosity on the epiphysis is http://bjsm.bmj.com/ hinged upward. In the third type, the line of fracture passes upward and backward across the proximal articular surface of the tibia. Burkhart and Peterson8, and Shelton and Canale6 include Watson-Jones type III fracture in their reviews of proximal tibial epiphyseal fractures. However, avulsion fractures of the tibial tubercle seem to constitute a specific subgroup that may be considered to be a separate on September 27, 2021 by guest. Protected copyright. group. b The avulsion type of fracture of the proximal tibial Figure 2. Case 1 Lateral radiographs of both knees (a, epiphysis is extremely rare, especially those fractures right; b, left) 1 year after injury showing premature closure which start at the tibial tubercle and extend up into of the tibial physes. There is no deformity the proximal tibial epiphysis, separating both struc- tures. We found only five cases cited in the literature surveyed. Silberman and Murphy' described a Peterson and Peterson5 and 3.06% reported by Salter-Harris type I fracture of the proximal tibial Shelton and Canale6 of all epiphyseal injuries. This epiphysis in a 12-year-old boy who sustained right injury can occur from direct or indirect force. A direct knee injury after 'pushing off' in a high jump. Ryu injury usually occurs in high-energy motor vehicle and Debenham3 reported a Salter-Harris type II accidents while indirect injury can occur from passive fracture of the proximal tibial epiphysis that occurred hyperextension, abduction or adduction of the legs when a 16-year-old boy jumped for a basketball; they during sports activities or falls.