SLR - January 2021 - Dustin Theis

Relationship Between Sever Disease and Skeletal Maturity

Reference: Duong, Mindy M. BS; Nicholson, Allen D. MD; Li, Samuel Q BA; Gilmore, Allison MD; Cooperman, Daniel R. MD; Liu Raymond W. MD Relationship Between Sever Disease and Skeletal Maturity Journal of Pediatric Orthopaedics: February 2020 – Volume 40 – Issue 2 – p 93-96 doi:10.1097

Level of Evidence: Level 3 retrospective case control study

Scientific Literature Review

Reviewed By: Dustin Theis, DPM
Residency Program: Ascension St. Vincent – Indianapolis, IN

Podiatric Relevance: Severs disease is a common pathology that we see in our pediatric and adolescent patient population. Currently there are no defined radiographic diagnostic criteria for evaluation of Severs disease as radiographs generally show normal appearance of the calcaneus. Recently a skeletal maturity grading system for the calcaneus has been developed dividing the calcaneal apophyseal ossification into six stages. Using the calcaneal system and Severs patients we can better understand the relationship between Severs disease, skeletal maturity and chronological age. The authors hypothesize that Severs disease occurs in a very narrow range of skeletal maturity.

Methods: Retrospective study of a diagnosis of severs disease from 2007-2015. Female individuals between ages 5-15 and males 8-17 were included. Patient without Severs disease were excluded. Patients with available calcaneal or foot x-ray within six weeks of diagnosis were graded using the calcaneal maturity grading system. Stage zero defined as no evident ossification, stage one defined as apophysis covering < 50 percent of metaphysis, stage two the apophysis covering >50 percent, stage three complete extension of the apophysis over the plantar surface (within 2 millimeters of plantar edge) stage four incomplete fusion of the apophysis with the metaphysis, stage five as complete fusion of apophysis. Every patient had controls matched by age, race and sex and excluded any x-rays with congenital foot abnormalities or pathology to the calcaneus.

Results: Thirty-nine of 78 patients had documented severs disease and x-rays within 40 days of diagnosis. Mean calcaneal score was 2.2±0.8 for all patients with x-rays. 2.1±0.9 for males 2.3±0.8 for females. The average chronological age of subjects was 10.1±2.0 years, males 10.5±1.9, females 9.1±2.1. Twenty-one of 38 patients with Severs disease were calcaneal stage two, and 36 of 38 were stages one, two or three. Since stage two was the most frequent, the tightness of distribution was compared to the control subjects. The authors found the distribution to be 0.51±0.68 and 0.95±0.79 (P=0.01) for Severs and control group respectively.

Conclusions: Results from this study demonstrate that Severs disease is commonly seen in subjects with calcaneal stage two and almost always seen in subjects with stages one to three. Although there is a difference in chronological age there is no difference in skeletal maturity score. This is the first study to describe correlation between skeletal maturity and Severs disease. This information is helpful to understand and rule out other diagnoses. If a patient presents with calcaneal stage one to three without any other pathology the clinician can be confident to pursue diagnosis of Severs. Conversely, if a patient stage zero, four or five the physician should strongly consider other diagnoses.

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