Premature physeal closure more likely to occur with pronation-external rotation ankle fracture patterns

Skeletally immature patients with pronation-external rotation ankle fracture patterns were more likely to experience premature physeal closure associated with angular deformity than patients with supination-external rotation or supination-plantar flexion ankle fracture patterns, according to results.

Perspective from Z. Deniz Olgun, MD

Researchers subclassified confirmed ankle fractures in skeletally immature patients according to the Dias-Tachdjian classification system, including pronation-external rotation, supination-external rotation and supination-plantar flexion injuries which all tend to be Salter-Harris type II fractures. Researchers recorded rates of premature physeal closure, initial operative interventions, subsequent surgical interventions and final angular deformities of the ankle in the coronal plane. Researchers considered deformities significant if there was more than 10° in any plane as measured using the tibial shaft/joint angle.

Of the 141 patients included, researchers found 52 pronation-external rotation, 35 supination-external rotation and 54 supination-plantar flexion injuries. Results showed 28.8%, 24.1% and 11.4% premature physeal closures occurred in the pronation-external rotation, supination-plantar flexion and supination-external rotation groups, respectively. Researchers noted a statistically significant higher rate of resultant angular deformity in the pronation-external rotation group. At the latest follow-up, six patients had resultant angular deformity of the ankle in the pronation-external rotation group compared with no resultant angular deformities in the supination-plantar flexion and the supination-external rotation groups.

“We recommend close follow-up of Salter-Harris II fractures in children with 2 or more years of growth remaining, particularly in [pronation-external rotation] PER fracture patterns, to prevent clinically significant angular deformity,” the authors wrote. – by Casey Tingle

Disclosures: The authors report no relevant financial disclosures.

Perspective

Z. Deniz Olgun, MD

This is a fascinating study by Binkley and colleagues published in a recent issue of the Journal of Orthopaedic Trauma. The authors looked at growth arrest rates and resultant angular deformities in skeletally immature individuals with Salter-Harris II fractures of the distal tibial physis. Their 141 patients were divided into groups according to the Dias-Tachdjian fracture classification and followed with radiographs for a mean follow-up of 21.4 months. While overall physeal arrest rate was 22.7% and there was no statistically significant difference in initial or post-reduction displacement, presence or absence of surgical treatment or fracture type, the fractures in the pronation-external rotation group had a higher incidence of angular deformity as a result of growth arrest induced by their fractures. This might indicate that in this pattern of fracture, more energy is imparted to the physis and that it occurs in physes that are further from natural closure regardless of patient age. The natural history and best treatment for distal tibial physeal fractures remains elusive and this study adds to the existing knowledge by delineating a fracture type that might result in symptomatic growth arrest.

Z. Deniz Olgun, MD

Assistant professor

Pediatric orthopedic surgery

Orthopedic trauma

University of Pittsburgh

Department of orthopedic surgery

Pittsburgh, Pennsylvania

Disclosures: Olgun reports no relevant financial disclosures.

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Source:

Binkley A, et al. J Orthop Trauma. 2019;doi:10.1097/BOT.0000000000001422.