Clinical Stability of Slipped Capital Femoral Epiphysis does not Correlate with Intraoperative Stability

Abstract

Background The most important objective of clinical classifications of slipped capital femoral epiphysis (SCFE) is to identify hips associated with a high risk of avascular necrosis (AVN) -so-called unstable or acute slips; however, closed surgery makes confirmation of physeal stability difficult. Performing the capital realignment procedure in SCFE treatment we observed that clinical estimation of physeal stability did not always correlate with intraoperative findings at open surgery. This motivated us to perform a systematic comparison of the clinical classification systems with the intraoperative observations. Questions/purposes We asked: (1) Is the classification of an acute versus chronic slip based on the duration of symptoms sensitive and specific in detecting intraoperative disrupted physes in patients with SCFE? (2) Is the stable/ unstable classification system based on clinical symptoms sensitive and specific in detecting intraoperative disrupted physes in patients with SCFE? Methods We retrospectively reviewed 82 patients with SCFE treated by open surgery between 1996 and 2009. We classified the clinical stability of all hips using the classifications based on onset of symptoms and on function. We classified intraoperative stability as intact or disrupted. We determined the sensitivity and specificity of two classification systems to determine intraoperative stability. Results Complete physeal disruption at open surgery was seen in 28 of the 82 hips (34%). With classification as acute, acute-on-chronic, and chronic, the sensitivity for disrupted physes was 82% and the specificity was 44%. With the classification of Loder et al., the values were 39% and 76%, respectively. Conclusion Current clinical classification systems are limited in accurately diagnosing the physeal stability in SCFE.

Slipped Capital Femoral Epiphysis: Relevant Pathophysiological Findings With Open Surgery

“…Data from a subcohort of the cohort presented here were used in prior publications. Forty of the patients were reported in earlier publications dealing with treatment results [19,30,33,36], 82 patients were used to compare clinical and intraoperative stability [35], and 13 patients were used to report early acetabular cartilage damage in SCFE [17].…”

Evidence based treatment for unstable slipped upper femoral epiphysis: Systematic review and exploratory patient level analysis

“…Ziebarth [40] found that clinical stability of SUFE as defined by Loder does not correlate with intra-operative stability. They retrospectively reviewed 82 patients with SUFE treated by open surgery.…”

Controversies in management of slipped capital femoral epiphysis

“…Also, physeal stability confirmed by clinical methods did not always matched with intraoperative findings at surgery. Ziebarth et al [5] compared the clinical classifications with the intraoperative findings. Classifying SCFE by the duration of symptoms had a low specificity of 44% and a sensitivity of 82%.…”

“…Based on the eligibility to walk, the sensitivity was a low 39% and specificity was 76%. Ziebarth et al [5] concluded that the current clinical systems are not accurate to judge physeal stability in SCFE.…”