Session VIII - Pediatrics/Spine

Is Anatomic Reduction Necessary for Displaced Physeal Fractures of the Distal Tibia?

Donna M. Pacicca, MD; Kathryn E. Cramer, MD; Steven Nguyen, MD; Abhay Patel, MD; Paul Tornetta, III, MD, Boston Medical Center, Boston, MA

Purpose: Distal tibial physeal fractures in children are of significant concern because of the possible complication of growth disturbance that can lead to limb shortening and angular deformity. Salter-Harris Type-III and IV fractures are more likely to develop physeal disturbance (growth arrest and/or bar formation), but type II fractures have unpredictable results and a higher risk of physeal complications than a minimally displaced type III or IV injury. Based on available literature, it is still unclear whether anatomic reduction is necessary in children with Salter-Harris Type-II fractures, or if these fractures behave similarly to Salter-Harris Type-II fractures of the distal radius, in which only 50% apposition is accepted.

The purpose of this study is to evaluate the relationship of initial displacement and quality of reduction to incidence of physeal disturbance.

Materials and Methods: We retrospectively reviewed all ankle fractures in children with open physes treated at 3 level-I centers between 1993 and 1999. Clinical evaluation included range of motion and Maryland Foot Score. Radiographic evaluation included anteroposterior, lateral and mortise views of the ankle. Radiographs were evaluated pre- and postoperatively for amount of displacement and angulation (anteroposterior and mediolateral). Follow-up radiographs were evaluated for premature physeal closure and physeal bar formation. Fractures were defined as displaced when there was 2 millimeter or greater separation between fragments on any one view. Patients with only fibular fractures or with distal tibial physeal fractures with less than 2-mm displacement were excluded >from this study.

Results: Ninety-six patients were included in this study, with an average age of 11 years, 10 months. All patients were followed to union. The length of follow-up ranged from 1.5 months to 5 years. Fractures were divided into 5 groups based on the Salter-Harris classification of the tibia fracture. All fractures healed within 2 months.

Type I fractures: There were 3 patients, with an average age of 10 years, 8 months. All 3 were treated with closed reduction and casting and had anatomic reduction. There was no evidence of premature physeal closure at last follow-up examination.

Type II fractures: There were 35 patients, with an average age of 10 years, 5 months. Twenty-seven were treated with closed reduction and casting, and 8 were treated surgically. The range of initial displacement was 2 to 15 mm, with an average of 6 mm. Seventy-five percent of patients had an acceptable reduction (less than 2 mm). There were no angular deformities, but one patient had premature physeal closure. She was also noted to have a significantly advanced skeletal age as noted on her bone age films. The average Maryland Foot Score was 97 (range 92-100).

Type III fractures (including juvenile Tillaux): There were 20 patients, with an average age of 12 years, 9 months. Six were treated with closed reduction and casting, and 14 were treated surgically. The range of initial displacement was 2 to 5 mm, with an average of 4 mm; 81% of patients had an anatomic reduction. There was no evidence of physeal bar formation or premature physeal closure at last follow-up examination. The average Maryland Foot Score was 95 (range 85-100).

Type IV fractures: There were 16 patients, with an average age of 12 years, 2 months. Two were treated with closed reduction and casting, and 14 were treated surgically. The range of initial displacement was 3 to 25 mm, with an average of 6 mm. All patients had an anatomic reduction. One patient developed a premature physeal closure; he had K-wire fixation of his medial malleolus fracture and plating of the lateral malleolus fracture. One patient developed a medial physeal bar; she had an open ankle fracture-dislocation. The bar was resected, and she has continued normal physeal growth. The average Maryland Foot Score was 99 (range 97-100).

Triplane fractures: There were 22 patients, with an average age of 13 years, 2 months. Five were treated with closed reduction and casting, and 17 were treated surgically. The range of initial displacement was 3 to 5 mm, with an average of 4 mm. All patients had an anatomic reduction. There was no evidence of physeal bar formation or premature physeal closure at last follow-up examination. The average Maryland Foot Score was 95 (range 85-100).

Discussion: In our series, all physeal fractures went on to heal uneventfully, and by the clinical criteria (Maryland Foot Score) all had excellent results. The overall incidence of physeal disturbance was 5%. We demonstrated two physeal arrests, one in a patient with a Salter-Harris Type-IV injury, and one in a Salter-Harris Type-II injury. The physeal arrest in the S-H Type-IV injury appeared to be a result of choice of fixation rather than mechanism of injury or accuracy of reduction. There was one physeal bar, in a patient who sustained an open ankle fracture dislocation with an S-H Type-IV of the medial malleolus. Despite anatomic reduction, this patient developed a peripheral bar, which was ultimately resected, resulting in an excellent outcome.

The data in this study continue to support the assumption that anatomic reduction in the Salter-Harris Type-III and IV fractures minimizes the incidence of growth arrests. However, with regard to the Salter-Harris II fractures, 25% of these patients had a non-anatomic reduction (2 millimeter or greater residual displacement). Despite this, only one of these patients went on to premature physeal closure. Eight patients had an initial closed reduction attempt that was unsuccessful and required a later reduction done in the operating room. Six of these patients required open reduction; interposed periosteum was noted at the time of surgery in 4 of them.

Based on our findings, the incidence of physeal disturbance after Salter-Harris Type-II fractures is very low. Anatomic reduction may not be necessary, but care should be taken to consider the possibility of interposed periosteum in fractures that do not achieve alignment with less than 2 mm displacement with closed reduction. Interposed periosteum may be a contributing factor in premature physeal closure.