JBJS Journal of Orthopaedics for Physician Assistants:
The Salter‐Harris classification system for physeal‐based fractures in skeletally immature patients has been available for clinicians since 1963. Remembering the fracture types in this classification system can be challenging to the student or new practitioner, especially if orthopaedics is not the primary area of practice. This article presents a simple visual guide to remembering the 5 types of fracture.
1Eastern Virginia Medical School MPA Program, Norfolk, Virginia
Disclosure: The author indicated that no external funding was received for any aspect of this work.
Since the publication of the seminal article by R.B. Salter and W.R. Harris on the classification and description of physeal fractures in 1963, most clinicians practicing in orthopaedics have striven to commit to memory their proposed classification system1. Although in the article, the authors discussed the known histology of the immature physis and postulated as to which injuries may be recoverable, most clinicians will remember only the classification system.
The value of this system is in the prediction of morbidity for a given physeal fracture pattern, with Type I having excellent healing potential and Type V having a poor prognosis1. A number of authors have built on this work, and various articles quantify the percentage risk on the basis of the Salter‐Harris (SH) classification system. A review of this literature will caution the reader that many factors impact the potential morbidity of the physeal fracture. Factors such as displacement, the angulation of fragments, and the adequacy of anatomic reduction impact the natural history of the fracture2. A residual gap after closed reduction has been demonstrated to lead to premature physeal closure rates of 2% to 39.6% for SH Type‐I and II distal tibial physeal fractures and 7.7% to 50% for Types III and IV3. In another study of physeal fractures of the distal aspect of the tibia, premature physeal closure rates were noted to be 0% for SH Type I, 10% for SH Type II, 13% for SH Type III, and 18% for SH Type IV4.
Clearly, despite varying percentages of early physeal closure in various studies, the occurrence alone warrants careful consideration when gaining informed consent to attempt a reduction or plan surgical intervention. Knowledge of the classification system in use by the practicing surgeon population can assist the midlevel clinician in performing initial assessments.
A number of methods have been described for the clinician to remember this classification system. One of the more popular has been the mnemonic “SALTR,” which compares the physeal injury radiograph with a normal standard. In this case, “S” is for “same,” as in, looks the same (Type I); “A” is for “above,” as in, the fracture is above the physis (Type II); “L” is for “be‐low” the physis (Type III); “T” is for “through” the physis (Type IV); and “R” is for “remains” in the physis (Type V). The difficulty with this method has been learning the mnemonic and remembering its application.
While completing the pediatric portion of my fellowship, it occurred to me that a more visual representation may be more easily applied and remembered. This method, devised in 1986, has been used successfully ever since to teach medical and physician assistant students the classification system.
This “new” mnemonic is based on a line drawing of a standardized physis, over which Arabic numerals representing each type in the classification are superimposed. This visual tool requires nothing more than the superimposition of the numeral (Fig. 1). This allows anyone to reproduce the SH classification system on a line drawing in the clinic to explain the fracture and morbidity risk to students and patients.
1. Salter RB, Harris WR. Injuries involving the epiphyseal plate. J Bone Joint Surg Am. 1963 Apr;45:587-622.
2. Nietosvaara Y, Hasler C, Helenius I, Cundy P. Marked initial displacement predicts complications in physeal fractures of the distal radius: an analysis of fracture characteristics, primary treatment and complications in 109 patients. Acta Orthop. 2005 Dec;76(6):873-7.
3. Podeszwa DA, Mubarak SJ. Physeal fractures of the distal tibia and fibula (Salter-Harris Type I, II, III, and IV fractures). J Pediatr Orthop. 2012 Jun;32(Suppl 1):S62-8.
4. Leary JT, Handling M, Talerico M, Yong L, Bowe JA. Physeal fractures of the distal tibia: predictive factors of premature physeal closure and growth arrest. J Pediatr Orthop. 2009 Jun;29(4):356-61.