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Acute tibial tubercleavulsion fractures
ACUTE TIBIAL TUBERCLE AVULSION FRACTURES CARL L. STANITSKI, MD
Acute tibial tubercle avulsion fractures are commonly seen in athletes involved with jumping sports, especially basketball. These injuries typically occur in well-muscled, mature-appearing boys, 15 to 16 years of age, who generate high tensile forces at the tubercle junction. Possible associated injuries include patellar and quadriceps tendon avulsions, as well as collateral and cruciate ligament and meniscal damage. Treatment is based on the magnitude of injury. Recovery is rapid and the outcome is usually excellent, even in type III injuries. KEY W O R D S : tibial tubercle, fracture, tendon avulsion
Acute avulsion fractures of the tibial tubercle are uncommon. Incidence rates of this injury are reported to represent 0.4% to 2.7% of a]l epiphyseal injuries and <1% of all physeal fractures. 1,2 In Bolesta and Fitch's 1 1986 literature review, 111 such fractures were recorded in 106 patients over the previous 133 years. There have subsequently been an additional 43 cases reported, with bilaterality in 8 cases. In a retrospective analysis of tibial tubercle avulsion fractures treated at Children's Hospital of Michigan over the past 8 years, 24 fractures in 23 patients were recorded. Included in this series, the largest individual series gathered to date, were 5 preadolescent patients (aged 9 to 12 years), including the youngest previously r e c o r d e d ( 9 years) and only the sixth girl reported with this injury. The tibial tubercle first appears in cartilage from during the 15th fetal week and, with further development, migrates distally, inferior to the proximal tibial epiphysis. Ehrenborg et aP divided tubercle development into 4 phases: cartilaginous, apophyseal, epiphyseal, and bony. The cartilage phase is before ossification of the secondary center. With onset of ossification, the apophyseal phase begins, usually between 8 and 12 years of age in girls and 9 and 14 years of age in boys. The epiphyseal stage is observed with coalescence of the tubercle and the main proximal tibial epiphyses. This usually is seen in girls between 10 and 15 years of age and in boys from ages 11 and 17 years. The bony phase represents fusion of the ossified tuberosity with the proximal tibial metaphysis that occurs at about age 15 years in girls and age 17 years in boys. Ogden et al 4 revealed the presence of three distinct histological zones at the tubercle. The proximal portion is of columnar cartilage, the middle is fibrocartilage and the distal is fibrous tissue that blends with the perichondrium. With development, there is a proximal-to-distal metamorphosis of fibrocartilage to columnar cartilage just before
From the Department of Pediatric Orthopaedic Surgery, Children's Hospital of Michigan, Detroit, MI. Address reprint requests to Carl L. Stanitski, MD, Chief, Pediatric Orthopaedic Surgery, Children's Hospital of Michigan, 3901 Beaubien Blvd, Detroit, MI 48201-2196. Copyright © 1998 by W.B. Saunders Company 1060-1872/98/0604-000858.00/0
physiological epiphyseodesis. The change renders the tuberosity junction vulnerable to tensile forces and sets the stage for an acute tubercle avulsion. Classification systems are modifications of the one proposed by Watson-Jones, s who, in 1976, defined 3 types of fractures, based on the extent of the fracture. Ogden's 4 modification takes into account fragment displacement and comminution. Ryu and Debenahm 6 suggested a fourth type, to represent an avulsion of the entire proximal tibial epiphysis. Frankl et al 7 proposed a classification system to describe associated patellar tendon avulsions (Fig 1). The most common cause of injury is high tensile force generated during jumping. An alternative process is during knee flexion when a vigorous quadriceps contraction occurs, such as that during landing from a jump or fall. The vast majority (>70%) of fractures occur during athletic activities, especially ones requiring jumping. Two thirds of the fractures in our series happened during basketball play. These fractures typically occur in well-muscled, mature-appearing boys, usually around 15 or 16 years of age. The male preponderance is hypothesized to reflect the large number of males involved in jumping sports during the final phases of physiological epiphyseodesis about the knee. A possible relationship between Osgood-Schlatter's condition and tubercle avulsion fracture has been suggested because of the localized inflammatory change. Although coincident cases have been reported, scientific cause-effect has not been documented. This is not surprising, especially considering the huge number of children with Osgood-Schlatter's condition and the rarity of acute tubercle avulsion fracture. Other knee injuries may occur in association with tubercle avulsion fractures and include collateral ligament, meniscal, and anterior cruciate ligament injuries in addition to patellar tendon and quadriceps tendon avulsions. In our series, one quadriceps and 3 patellar tendon avulsions occurred. The quadriceps tendon avulsion has not been reported previously. This 17% incidence of associated further extensor mechanism disruption w a s associated with types IIB and IIIB injuries. The goal of treatment is restoration of joint congruency and extensor mechanism isometry. In patients with undisplaced or minimally displaced fragments, closed reduction and cast immobilization is sufficient and is used primarily
Operative Techniques in Sports Medicine, Vol 6, No 4 (October), 1998: pp 243-246
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Fig1. Tibial tubercle fracture classification-Ogden's modification. Type I: (A) undisplaced and (B) minimally displaced tubercle avulsion. Type I1: (C) fracture to proximal physis; (D) fracture with comminution. Type II1: (E) intra-articular extension; (F) extension with comminution. Type IV: (G) entire proximal tibial physeal separation.
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CARL L. STANITSKI
Fig 2. (A) Type IIIB fracture. (B) After open reduction and internal fixation using tension band wiring.
for treatment of types IA, IB, and IIA fractures. Types IIB and higher require open reduction and fixation in general, with repair of associated patellar or quadriceps tendon avulsions. A varielN of fixation methods have been reported, the most popular types being a tension band wiring (Fig 2) or use of a cannulated screw (Fig 3). In patients who are significantly skeletally immature (less
than Tanner grade 3), fixation hardware should avoid the proximal tibial physis. Satisfactory fixation in these children is usually able to be achieved by periosteal suture without damage to the proximal tibial main growth center. The outcome for these injuries is quite good overall, with rapid healing and restoration of full function. 1,4,5Recurvaturn occurrence caused by anterior proximal tibiaI growth
Fig 3. (A) Type IIIB fracture; note patellar alta (thick arrow). (B) After open reduction internal fixation with cannuiated screw fixation. ACUTE TIBIAL TUBERCLE AVULSION FRACTURES
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attenuation has not b e e n reported in a p r e v i o u s l y n o r m a l patient. Because the fracture usually occurs at a time just before physiological epiphyseodesis, little g r o w t h remains to p r o d u c e a n y deformity. Previously r e p o r t e d complications of malunion, nonunion, patellar alta or infera, a n d fixation failure s e e m to reflect technical errors. W h e n the patient is seen after a delay in diagnosis, f r a g m e n t mobilization is required to restore q u a d r i c e p s i s o m e t r y a n d to a v o i d fixation in either patella alta or patella infera positions. In m o s t series o u t c o m e s w e r e good. In our cases, 62% of w h i c h w e r e t y p e IIB or higher g r a d e s of injury, o u t c o m e s w e r e u n i f o r m l y g o o d a n d i n d e p e n d e n t of fracture p a t t e r n or treatment.
CONCLUSION Return to sports is d e p e n d e n t on fracture pattern. Patients w i t h t y p e s I a n d II injuries are usually able to return to all sports within 2 m o n t h s of fracture. Because of the intraarticular c o m p r o m i s e w i t h t y p e III fractures, patients in
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this g r o u p are a d v i s e d to delay their return to i m p a c t and l o w e r extremity loading athletics for 4 to 6 months.
REFERENCES 1. Bolesta M, Fitch R: Tibial tubercle avulsions. J Pediatr Orthop 6:186192, 1986 2. Edwards PH, Grana WA: Physeal fractures about the knee. J Am Acad Orthop Surg 3:63-69, 1995 3. Ehrenborg G: The Osgood-Schlatter lesion: A clinical and experimental study. Acta Chir Scan 288: 1-36, 1962 4. Ogden J, Tross R, Murphy M: Fractures of the tibial tuberosity in adolescents. J Bone Joint Surg Am 62:205-209, 1980 5. Watsonqones R: Fractures and Joint Injuries, vol 2 (ed 5). Baltimore, MD, Williams & Wilkins, 1976, pp 1048-1050 6. Ryu R, Debenham: An unusual avulsion fracture of the proximal tibial epiphysis, case report and proposed addition to the Watson-Jones classification. Clin Orthop 194:181-183, 1985 7. Frankl U, Wasilewski S, Healy W: Avulsion fracture of the tibial tubercle with avulsion of the patellar ligament. Report of two cases. J Bone Joint Surg Am 72:1411-1143, 1990
CARL L. STANITSKI
Acute tibial tubercle avulsion fractures are commonly seen in athletes involved with jumping sports, especially basketball. These injuries typically occur in well-muscled, mature-appearing boys, 15 to 16 years of age, who generate high tensile forces at the tubercle junction. Possible associated injuries include patellar and quadriceps tendon avulsions, as well as collateral and cruciate ligament and meniscal damage. Treatment is based on the magnitude of injury. Recovery is rapid and the outcome is usually excellent, even in type III injuries. KEY W O R D S : tibial tubercle, fracture, tendon avulsion
Acute avulsion fractures of the tibial tubercle are uncommon. Incidence rates of this injury are reported to represent 0.4% to 2.7% of a]l epiphyseal injuries and <1% of all physeal fractures. 1,2 In Bolesta and Fitch's 1 1986 literature review, 111 such fractures were recorded in 106 patients over the previous 133 years. There have subsequently been an additional 43 cases reported, with bilaterality in 8 cases. In a retrospective analysis of tibial tubercle avulsion fractures treated at Children's Hospital of Michigan over the past 8 years, 24 fractures in 23 patients were recorded. Included in this series, the largest individual series gathered to date, were 5 preadolescent patients (aged 9 to 12 years), including the youngest previously r e c o r d e d ( 9 years) and only the sixth girl reported with this injury. The tibial tubercle first appears in cartilage from during the 15th fetal week and, with further development, migrates distally, inferior to the proximal tibial epiphysis. Ehrenborg et aP divided tubercle development into 4 phases: cartilaginous, apophyseal, epiphyseal, and bony. The cartilage phase is before ossification of the secondary center. With onset of ossification, the apophyseal phase begins, usually between 8 and 12 years of age in girls and 9 and 14 years of age in boys. The epiphyseal stage is observed with coalescence of the tubercle and the main proximal tibial epiphyses. This usually is seen in girls between 10 and 15 years of age and in boys from ages 11 and 17 years. The bony phase represents fusion of the ossified tuberosity with the proximal tibial metaphysis that occurs at about age 15 years in girls and age 17 years in boys. Ogden et al 4 revealed the presence of three distinct histological zones at the tubercle. The proximal portion is of columnar cartilage, the middle is fibrocartilage and the distal is fibrous tissue that blends with the perichondrium. With development, there is a proximal-to-distal metamorphosis of fibrocartilage to columnar cartilage just before
From the Department of Pediatric Orthopaedic Surgery, Children's Hospital of Michigan, Detroit, MI. Address reprint requests to Carl L. Stanitski, MD, Chief, Pediatric Orthopaedic Surgery, Children's Hospital of Michigan, 3901 Beaubien Blvd, Detroit, MI 48201-2196. Copyright © 1998 by W.B. Saunders Company 1060-1872/98/0604-000858.00/0
physiological epiphyseodesis. The change renders the tuberosity junction vulnerable to tensile forces and sets the stage for an acute tubercle avulsion. Classification systems are modifications of the one proposed by Watson-Jones, s who, in 1976, defined 3 types of fractures, based on the extent of the fracture. Ogden's 4 modification takes into account fragment displacement and comminution. Ryu and Debenahm 6 suggested a fourth type, to represent an avulsion of the entire proximal tibial epiphysis. Frankl et al 7 proposed a classification system to describe associated patellar tendon avulsions (Fig 1). The most common cause of injury is high tensile force generated during jumping. An alternative process is during knee flexion when a vigorous quadriceps contraction occurs, such as that during landing from a jump or fall. The vast majority (>70%) of fractures occur during athletic activities, especially ones requiring jumping. Two thirds of the fractures in our series happened during basketball play. These fractures typically occur in well-muscled, mature-appearing boys, usually around 15 or 16 years of age. The male preponderance is hypothesized to reflect the large number of males involved in jumping sports during the final phases of physiological epiphyseodesis about the knee. A possible relationship between Osgood-Schlatter's condition and tubercle avulsion fracture has been suggested because of the localized inflammatory change. Although coincident cases have been reported, scientific cause-effect has not been documented. This is not surprising, especially considering the huge number of children with Osgood-Schlatter's condition and the rarity of acute tubercle avulsion fracture. Other knee injuries may occur in association with tubercle avulsion fractures and include collateral ligament, meniscal, and anterior cruciate ligament injuries in addition to patellar tendon and quadriceps tendon avulsions. In our series, one quadriceps and 3 patellar tendon avulsions occurred. The quadriceps tendon avulsion has not been reported previously. This 17% incidence of associated further extensor mechanism disruption w a s associated with types IIB and IIIB injuries. The goal of treatment is restoration of joint congruency and extensor mechanism isometry. In patients with undisplaced or minimally displaced fragments, closed reduction and cast immobilization is sufficient and is used primarily
Operative Techniques in Sports Medicine, Vol 6, No 4 (October), 1998: pp 243-246
243
Fig1. Tibial tubercle fracture classification-Ogden's modification. Type I: (A) undisplaced and (B) minimally displaced tubercle avulsion. Type I1: (C) fracture to proximal physis; (D) fracture with comminution. Type II1: (E) intra-articular extension; (F) extension with comminution. Type IV: (G) entire proximal tibial physeal separation.
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CARL L. STANITSKI
Fig 2. (A) Type IIIB fracture. (B) After open reduction and internal fixation using tension band wiring.
for treatment of types IA, IB, and IIA fractures. Types IIB and higher require open reduction and fixation in general, with repair of associated patellar or quadriceps tendon avulsions. A varielN of fixation methods have been reported, the most popular types being a tension band wiring (Fig 2) or use of a cannulated screw (Fig 3). In patients who are significantly skeletally immature (less
than Tanner grade 3), fixation hardware should avoid the proximal tibial physis. Satisfactory fixation in these children is usually able to be achieved by periosteal suture without damage to the proximal tibial main growth center. The outcome for these injuries is quite good overall, with rapid healing and restoration of full function. 1,4,5Recurvaturn occurrence caused by anterior proximal tibiaI growth
Fig 3. (A) Type IIIB fracture; note patellar alta (thick arrow). (B) After open reduction internal fixation with cannuiated screw fixation. ACUTE TIBIAL TUBERCLE AVULSION FRACTURES
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attenuation has not b e e n reported in a p r e v i o u s l y n o r m a l patient. Because the fracture usually occurs at a time just before physiological epiphyseodesis, little g r o w t h remains to p r o d u c e a n y deformity. Previously r e p o r t e d complications of malunion, nonunion, patellar alta or infera, a n d fixation failure s e e m to reflect technical errors. W h e n the patient is seen after a delay in diagnosis, f r a g m e n t mobilization is required to restore q u a d r i c e p s i s o m e t r y a n d to a v o i d fixation in either patella alta or patella infera positions. In m o s t series o u t c o m e s w e r e good. In our cases, 62% of w h i c h w e r e t y p e IIB or higher g r a d e s of injury, o u t c o m e s w e r e u n i f o r m l y g o o d a n d i n d e p e n d e n t of fracture p a t t e r n or treatment.
CONCLUSION Return to sports is d e p e n d e n t on fracture pattern. Patients w i t h t y p e s I a n d II injuries are usually able to return to all sports within 2 m o n t h s of fracture. Because of the intraarticular c o m p r o m i s e w i t h t y p e III fractures, patients in
246
this g r o u p are a d v i s e d to delay their return to i m p a c t and l o w e r extremity loading athletics for 4 to 6 months.
REFERENCES 1. Bolesta M, Fitch R: Tibial tubercle avulsions. J Pediatr Orthop 6:186192, 1986 2. Edwards PH, Grana WA: Physeal fractures about the knee. J Am Acad Orthop Surg 3:63-69, 1995 3. Ehrenborg G: The Osgood-Schlatter lesion: A clinical and experimental study. Acta Chir Scan 288: 1-36, 1962 4. Ogden J, Tross R, Murphy M: Fractures of the tibial tuberosity in adolescents. J Bone Joint Surg Am 62:205-209, 1980 5. Watsonqones R: Fractures and Joint Injuries, vol 2 (ed 5). Baltimore, MD, Williams & Wilkins, 1976, pp 1048-1050 6. Ryu R, Debenham: An unusual avulsion fracture of the proximal tibial epiphysis, case report and proposed addition to the Watson-Jones classification. Clin Orthop 194:181-183, 1985 7. Frankl U, Wasilewski S, Healy W: Avulsion fracture of the tibial tubercle with avulsion of the patellar ligament. Report of two cases. J Bone Joint Surg Am 72:1411-1143, 1990
CARL L. STANITSKI