The effect of percutaneous pin fixation in the treatment of distal femoral physeal fractures

Abstract

Distal femoral physeal fractures in children have a high incidence of physeal arrest, occurring in a mean of 40% of cases. The underlying nature of the distal femoral physis may be the primary cause, but other factors have been postulated to contribute to the formation of a physeal bar. The purpose of this study was to assess the significance of contributing factors to physeal bar formation, in particular the use of percutaneous pins across the physis. We reviewed 55 patients with a median age of ten years (3 to 13), who had sustained displaced distal femoral physeal fractures. Most (40 of 55) were treated with percutaneous pinning after reduction, four were treated with screws and 11 with plaster. A total of 40 patients were assessed clinically and radiologically after skeletal maturity or at the time of formation of a bar. The remaining 15 were followed up for a minimum of two years. Formation of a physeal bar occurred in 12 (21.8%) patients, with the rate rising to 30.6% in patients with high-energy injuries compared with 5.3% in those with low-energy injuries. There was a significant trend for physeal arrest according to increasing severity using the Salter-Harris classification. Percutaneous smooth pins across the physis were not statistically associated with growth arrest.

Physeal fractures about the knee

“…They represent 5 % of all physeal injuries [3]. Salter-Harris II fractures are the most common type [1,2,4,5].…”

“…Therefore, Salter-Harris II fractures with Thurston-Holland fragments sizeable enough to accommodate screws should be reduced and fixed with lag screws in the metaphysis, so that the internal fixation can avoid the physis if possible [3,6,13]. Smooth pins are thought to be less likely to cause further physeal injury.…”

“…Late complications are more common than acute complications [6], and overall, growth arrest is the most commonly observed complication [1][2][3]. Growth disturbances, in the form of either leg length discrepancy and/or angular deformity, result from physeal arrest.…”

“…Although there is a greater incidence of absolute growth disturbance in patients treated with fixation, there is a decreased incidence of clinically significant growth disturbance, defined as a leg length discrepancy ≥1.5 cm and/or 5°of varus or valgus deformity [2]. Highenergy distal femur growth plate fractures have a significantly higher rate of growth disturbance compared with low-energy fractures [3]. Physeal arrest correlates with increasing severity based on the Salter-Harris classification [1][2][3].…”

“…Highenergy distal femur growth plate fractures have a significantly higher rate of growth disturbance compared with low-energy fractures [3]. Physeal arrest correlates with increasing severity based on the Salter-Harris classification [1][2][3]. Displaced fractures have a four times greater risk of growth arrest than nondisplaced fractures, and undesirable outcomes after distal femoral physeal fractures are more common in younger patients [2].…”