Salter-HarrisFractures Chad Bevan Radiology Clerkship July 2006
Overview • Salter-Harris fractures are fractures through a growth plate (physis); therefore, they are unique to pediatric patients. • Several types of fractures have been categorized by the involvement of the physis, metaphysis, and epiphysis. • The classification of the injury is important because it affect the treatment of the patient and provides clues to possible long-term complications.
Classifications I • pure epiphyseal separation • if non-displaced, joint effusion may be only sign II • metaphyseal fracture + epiphyseal separation III • epiphyseal fracture IV • vertically oriented fx thru epiphysis + metaphysis V • crush injury of epiphysis (not detected acutely)
Mnemonic S – Slipped A – Above L – Lower T – Through (e) R – Raised W. Robert Salter, MD
Histologic Review • Important for understanding prognosis • The germinal layer of the cartilage is on the epiphysis • Cartilage cells grow from the epiphysis towards the metaphysis. The fragments of cells then mineralize.
Histology (cont’d) • Neovascularization occurs from the metaphysis towards the epiphysis. • Damage to either epiphyseal or metaphyseal vascular supply disrupts bone growth • Damage to the layer of cartilage may not be significant if the surfaces are reapposed, and vascular supply to the growing cartilage is not permanently interrupted.
Type I • A type 1 fracture is transverse fracture through the hypertrophic zone of the physis. In this injury, the width of the physis is increased. The growing zone of the physis usually is not injured, and growth disturbance is uncommon. • Usually dx’d by clinical presentation alone. • On clinical examination, the child has point tenderness at the epiphyseal plate, which is suggestive of a type I fracture. • Example: SCFE
Type II • A type II fracture is a fracture through the physis and metaphysis, but the epiphysis is not involved in the injury. • These fractures may cause minimal shortening; however, the injuries rarely result in functional limitations. • Type II is the most common Salter-Harris fracture.
Type III • A type III fracture is a fracture through the physis and the epiphysis. This fracture passes across the hypertrophic layer of the physis and extends to split the epiphysis, inevitably damaging the reproductive layer of the physis. • Prone to chronic disability because, by crossing the physis, it extends into the articular surface of the bone. • Rarely result in significant deformity; therefore, they have a relatively favorable prognosis. • A type of ankle fracture termed a Tillaux fracture is a type of Salter-Harris type III fracture that is prone to disability. • Treatment is often surgical.
Type IV • A Type IV fracture involves all 3 elements of the bone: The fracture passes through the epiphysis, physis, and metaphysis. • Similar to a type III fracture, a type IV fracture also is an intraarticular fracture; thus, it can result in chronic disability. • By interfering with the growing layer of cartilage cells, these fractures can cause premature focal fusion of the involved bone. Therefore, these injuries can cause deformity of the joint.
Type V • A type V injury is a compression or crush injury of the epiphyseal plate with no associated epiphyseal or metaphyseal fracture. • This fracture is associated with growth disturbances at the physis. Initially, diagnosis may be difficult, and it often is made retrospectively after premature closure of the physis is observed. In the older teenagers, the diagnosis is particularly difficult. • The clinical history is paramount in the diagnosis of this fracture. A typical history is that of an axial load injury. • These injuries have a poor functional prognosis.
Rare Salter-Harris Fractures Type VI: This is a rare injury and consists of an injury to the perichondral structures. Type VII: This is an isolated injury to the epiphyseal plate. Type VIII: This is an isolated injury to the metaphysis, with a potential injury related to endochondral ossification. Type IX: This is an injury to the periosteum that may interfere with membranous growth.
Final thoughts • Type II is most common • Types III & IV are more prone to chronic disability • Type V associated with growth disturbances and has a poor functional prognosis • Only 2% of Salter-Harris fractures result in a significant functional disturbance
Special thanks to… • www.pediatriconcall.com • www.fpnotebook.com • www.medicalmnemonics.com • www.emedicine.com • people breaking bones, who made this presentation possible