Salter-Harris Type III Fractures of the Distal Femur Plain Radiographs can be Deceptive

Cincinnati Children's Hospital Medical Center, Division of Orthopaedics, Cincinnati, OH 45229, USA.
Journal of pediatric orthopedics (Impact Factor: 1.47). 09/2010; 30(6):598-605. DOI: 10.1097/BPO.0b013e3181e4f55b
Source: PubMed

ABSTRACT Salter-Harris (SH) III fractures of the distal femur, although rare, can have devastating effects. The purposes of this study were to: (1) compare the intra-articular fracture displacement measured on plain x-ray and magnetic resonance imaging (MRI) or computed tomography (CT) scan and (2) report the outcomes of patients with a SH III fracture of the distal femur.
All SH III distal femur fractures treated at a large Children's Hospital with a Level I Pediatric Trauma Center between 1995 and 2006 were retrospectively reviewed. A total of 14 patients (average age: 13 y, 11 mo; range: 7 y, 8 mo to 17 y, 11 mo) with an average follow-up time of 21.50 months (range: 2 to 47 mo) were included in this study. Fracture displacement on plain x-ray was compared with the fracture displacement measured on MRI or CT scan. The average time between the initial plain x-ray and MRI or CT scan was 37.48 days (range: 3 h to 6 mo).
Plain x-rays significantly underestimated the displacement of SH III fractures versus MRI or CT scan. Six patients who had both plain x-ray and MRI or CT scan had a measured displacement of 0.42 mm and 2.70 mm, respectively (paired Student t test, P=0.005). Ten of the 14 patients (71%) had no physical limitations and full knee motion at their most recent follow-up visit. The treatment of 4 patients (29%) was changed based on the findings of the additional MRI or CT scan.
This study and earlier studies have shown a high rate of poor results with SH III fractures of the distal femur. This type of fracture pattern is extremely unstable and the true displacement is often underestimated by x-rays. Thus, it is strongly recommended that an MRI or CT scan be obtained on every SH III fracture of the distal femur. Moreover, any SH III fracture visible on plain radiographs should be treated with open reduction, internal fixation.
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    • "They are classified according to the Salter-Harris classification. Salter-Harris type 2 is the most encountered form [1,5-7]. In 1894, Hutchinson reported that rotation or traction of the femur was the pathogenic mechanism of the femoral epiphysiolysis [2,6]. "
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    ABSTRACT: Introduction: Both the isolated distal femoral epiphysiolysis and the isolated proximal tibial epiphysiolysis are the least common epiphyseal injuries. Even though they are uncommon, they have a high incidence rate of complications. Case presentation: We present a case with Gustilo-Anderson grade 3b open and Salter-Harris type 1 epiphysiolysis of the distal femur and proximal tibia caused by a farm machinery accident. The patient was a 10-year-old boy, treated by open reduction and internal fixation. Conclusion: Although distal femoral and proximal tibial growth plate injuries are rarely seen benign fractures, their management requires meticulous care. Anatomic reduction is important, especially to minimize the risk of growth arrest and the development of degenerative arthritis. However, there is a high incidence of growth arrest and neurovascular injury with these type of fractures. Keywords: Knee, Growth plate, Epiphysiolysis, Surgical treatment
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