Clinical Stability of Slipped Capital Femoral Epiphysis does not Correlate with Intraoperative Stability
ABSTRACT 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.
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?
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.
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.
Current clinical classification systems are limited in accurately diagnosing the physeal stability in SCFE.
Level III, retrospective diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.
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ABSTRACT: BACKGROUND: Traditionally arthrotomy has rarely been performed during surgery for slipped capital femoral epiphysis (SCFE). As a result, most pathophysiological information about the articular surfaces was derived clinically and radiographically. Novel insights regarding deformity-induced damage and epiphyseal perfusion became available with surgical hip dislocation. QUESTIONS/PURPOSES: We (1) determined the influence of chronicity of prodromal symptoms and severity of SCFE deformity on severity of cartilage damage. (2) In surgically confirmed disconnected epiphyses, we determined the influence of injury and time to surgery on epiphyseal perfusion; and (3) the frequency of new bone at the posterior neck potentially reducing perfusion during epimetaphyseal reduction. METHODS: We reviewed 116 patients with 119 SCFE and available records treated between 1996 and 2011. Acetabular cartilage damage was graded as +/++/+++ in 109 of the 119 hips. Epiphyseal perfusion was determined with laser-Doppler flowmetry at capsulotomy and after reduction. Information about bone at the posterior neck was retrieved from operative reports. RESULTS: Ninety-seven of 109 hips (89%) had documented cartilage damage; severity was not associated with higher slip angle or chronicity; disconnected epiphyses had less damage. Temporary or definitive cessation of perfusion in disconnected epiphyses increased with time to surgery; posterior bone resection improved the perfusion. In one necrosis, the retinaculum was ruptured; two were in the group with the longest time interval. Posterior bone formation is frequent in disconnected epiphyses, even without prodromal periods. CONCLUSIONS: Addressing the cause of cartilage damage (cam impingement) should become an integral part of SCFE surgery. Early surgery for disconnected epiphyses appears to reduce the risk of necrosis. Slip reduction without resection of posterior bone apposition may jeopardize epiphyseal perfusion. LEVEL OF EVIDENCE: Level IV, retrospective case series. See Guidelines for Authors for a complete description of levels of evidence.Clinical Orthopaedics and Related Research 02/2013; 471(7). DOI:10.1007/s11999-013-2818-9 · 2.88 Impact Factor
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ABSTRACT: BACKGROUND: The characteristics of patients who sustain unstable slipped capital femoral epiphyses (SCFEs) are not well described compared to their counterparts who sustain stable SCFE. Although patients with unstable slips are usually identified owing to acute symptoms, it is unclear whether these patients have premonitory symptoms that could heighten the awareness of treating physicians to the possibility of an unstable slip and lead to timely diagnosis and treatment. QUESTIONS/PURPOSE: We determined whether most patients experienced pain and limp before developing an unstable SCFE. METHODS: We retrospectively reviewed 582 patients and identified 82 (41 boys, 41 girls; 85 hips) with unstable SCFEs. Patient records were reviewed for sex, age at onset, weight at onset, and presence and location of pain and/or limp before the unstable slip. Boys averaged 13 years of age at the time occurrence and weighed on average in the 77th percentile. Girls averaged 12 years of age at the time of occurrence and weighed on average in the 79th percentile. RESULTS: For all patients, 73 of 82 (88%) had pain in their hips, thighs, or knees for an average of 42 days before sustaining unstable SCFEs. Sex distribution was equal for patients with unstable SCFEs. CONCLUSIONS: Patients who sustained unstable SCFEs had premonitory pain in the limb. Early recognition and an appropriate diagnosis provide a critical opportunity to prevent a morbid unstable SCFE. LEVEL OF EVIDENCE: Level IV, diagnostic study, See Instructions for Authors for a complete description of levels of evidence.Clinical Orthopaedics and Related Research 05/2013; 471(7). DOI:10.1007/s11999-013-3042-3 · 2.88 Impact Factor
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ABSTRACT: With recent changing approaches to the management of slipped capital femoral epiphysis (SCFE), the accurate radiographic assessment of maximum extent of displacement is crucial for planning surgical treatment. To determine what plane best represents the maximum SCFE displacement as quantified by the head-neck angle difference (HNAD), whether HNAD can quantitatively differentiate the SCFE cohort from the normal cohort, based on CT, and how Southwick slip angle (SSA) compares to HNAD. We reviewed 19 children with SCFE (23 affected hips) with preoperative CT scans and 27 age- and sex-matched children undergoing abdominal CT for non-orthopedic problems. Head-neck angle (HNA), the angle between the femoral epiphysis and the neck axis, was measured in three planes on each hip and the HNAD (affected - unaffected hip) was determined. SSA was measured on radiographs. The coronal HNAD (mean 8.7°) was less than both the axial-oblique (mean 30.7°) and sagittal (mean 37.4°) HNADs, which were also greater than the HNADs of the normal cohort. Grouping HNAD measurements by SSA severity classification did not consistently distinguish between SCFE severity levels. Axial-oblique and sagittal planes best represent the maximum SCFE displacement while biplanar radiograph may underestimate the extent of the displacement, thereby potentially altering the management between in situ pinning and capital realignment.Pediatric Radiology 06/2013; 43(12). DOI:10.1007/s00247-013-2733-y · 1.65 Impact Factor