Salter (Rang) type 6 physeal injury.

INTRODUCTION: Type 6 physeal injuries, described by Rang as a displacement of the perichondrial ring usually caused by a lawn-mower scalping mechanism or a closed trauma to the distal femoral physis avulsed by the lateral collateral ligament, are extremely rare. This type of injury was later included in Salter and Harris' classification of physeal injuries as type 6. No large series of type 6 physeal injuries has been described in the literature. The aim of the study is to present a relatively large series of patients with this trauma and offer some new observations.

MATERIAL AND METHODS: Over a 20-year period, 36 children with a type 6 physeal injury were treated in the authors' institution. The affected bone and physis, mechanism of injury, age, gender, method of treatment and sequelae are reported.

RESULTS: Out of 36 patients with type 6 physeal injuries 21 were boys and 15 girls (mean age 11.6 years). The distal fibular physis was most commonly affected, followed by the distal femoral and distal tibial physis. In 29 cases the fracture was undisplaced, while 3 children suffered an open injury with a loss of soft tissue. No injuries were due to lawn-mowers. Two cases were due to gunshot wounds.

DISCUSSION: Although no larger series of type 6 physeal injuries has been described to date, it is clear that the mechanism of trauma has changed from earlier reports of open lawn-mower injuries to closed soccer and athletic sports fractures. Closed type 6 injuries are usually not or only minimally displaced and do not require surgery. Open fractures were associated with soft tissue loss; they were caused by scraping of the ankle (knee, elbow) by a car or bicycle wheel on a road surface or the result of a gunshot injury with the projectile destroying the peripheral portion of the physis.