Salter-Harris type II fractures of the distal tibia: Residual postreduction displacement and outcomes-a STROBE compliant study

Abstract

We assessed factors associated with premature physeal closure (PPC) and outcomes after closed reduction of Salter-Harris type II (SH-II) fractures of the distal tibia. We reviewed patients with SH-II fractures of the distal tibia treated at our center from 2010 to 2015 with closed reduction and a non-weightbearing long-leg cast. Patients were categorized by immediate postreduction displacement: minimal, <2 mm; moderate, 2 to 4 mm; or severe, >4 mm. Demographic data, radiographic data, and Lower Extremity Functional Scale (LEFS) scores were recorded.Fifty-nine patients (27 girls, 31 right ankles, 26 concomitant fibula fractures) were included, with a mean (±SD) age at injury of 12.0 ± 2.2 years. Mean maximum fracture displacements were 6.6 ± 6.5 mm initially, 2.7 ± 2.0 mm postreduction, and 0.4 ± 0.7 mm at final follow-up. After reduction, displacement was minimal in 23 patients, moderate in 21, and severe in 15. Fourteen patients developed PPC, with no significant differences between postreduction displacement groups. Patients with high-grade injury mechanisms and/or initial displacement ≥4 mm had 12-fold and 14-fold greater odds, respectively, of PPC. Eighteen patients responded to the LEFS survey (mean 4.0 ± 2.1 years after injury). LEFS scores did not differ significantly between postreduction displacement groups (P = .61).The PPC rate in this series of SH-II distal tibia fractures was 24% and did not differ by postreduction displacement. Initial fracture displacement and high-grade mechanisms of injury were associated with PPC. LEFS scores did not differ significantly by postreduction displacement.Level of Evidence: Level IV, case series.

Figure 1

Depiction of how initial and residual postreduction fracture displacement was measured. The largest distances (red lines) between the metaphysis and epiphysis or the fracture fragments at the level of the physis were chosen in the anteroposterior (AP), lateral, and mortise views.

Figure 2

Lower Extremity Functional Scale (LEFS) questionnaire, which was created in 1999 and is used to evaluate the functional status of patients with musculoskeletal conditions of the lower extremity. It consists of 20 items each rated on a 5-point scale (0–4). Scores range from 0 (lowest function) to 80 (highest function).

Figure 3

Dias-Tachdjian modification of the Lauge-Hansen classification of ankle fractures in children showing Salter-Harris type II fractures caused by A) supination–external rotation, (B) supination–plantar flexion, and (C) pronation-eversion–external rotation mechanisms.

Figure 4

Radiographs of a 13-year-old boy with a Salter-Harris type II distal tibia fracture after a sports-related contact injury (A) [anteroposterior view (top) and lateral view (bottom)], who underwent closed reduction and long-leg casting (B) [anteroposterior view (top) and lateral view (bottom)]. He healed well radiographically 3 months later (C) [anteroposterior view (top) and lateral view (bottom)]. However, follow-up CT scan demonstrated physeal bar formation >50% (D) [coronal view (top) and axial view (bottom)] with a limb length discrepancy of 1 cm 1 year later on standing radiographs (E). He underwent bilateral epiphysiodesis to prevent further limb length discrepancy (F) (fluoroscopy view).

Figure 5

Radiographs of a 9-year-old boy with a 7.4-mm anteriorly displaced Salter-Harris type II distal tibia fracture (A) immediately after closed reduction and application of a long-leg cast, and (B) 5 months later. This patient had a perfect Lower Extremity Functional Scale score of 80 two years after his injury.