Long-term prognosis of Salter-Harris type 2 injuries of the distal femoral physis.

The objective of this study was to assess long-term sequelae of Salter-Harris type 2 injuries on growth of the distal femoral physis. A retrospective study of 20 patients with Salter-Harris type 2 distal femoral injuries, who were managed between 1994 and 2003, was carried out. The average period of follow-up was 4 years and 2 months. Mean age of fracture was 11 years (range 8-15 years). We classified radiologically these fractures into three types according to initial displacement on anteroposterior and lateral radiographs (type 1=less than 2 mm; type 2=more than 2 mm, contact between fragments; type 3=no contact). Further subdivision into A and B was made according to the absence or presence of metaphyseal comminution. Clinical and radiological outcomes were evaluated at latest follow-up. Two patients with type 1 injuries were treated conservatively, with no complication. All type 2 and 3 fractures (18) were reduced under general anesthesia. At latest follow-up, 14 patients (70%) sustained a complication due to either epiphysiodesis (12), femoral over-lengthening (1) or associated loss of knee motion (5). Seven out of the 12 epiphysiodeses were initial type B injuries. All type 3 fractures ended with complications. The prognosis of these fractures, often caused by a high-energy trauma, can be severe. Additional subdivision of Salter-Harris type 2 distal femoral physeal injuries is proposed to warn the clinician on specific fracture patterns with higher complication risk. Greater awareness of the numerous growth problems that may occur is needed in type 2B, in which the germinal layer of the physeal cells is damaged.