Doctors do not have one classification system that captures every important aspect of slipped capital femoral epiphysis, or SCFE, according to a review of the field. Existing systems address separate questions: whether the hip is stable, how severe the deformity is, whether cartilage injury or vascular compromise may be involved, and what the long-term functional outlook may be. The review says surgeons therefore often use several systems together. It examines the history, clinical relevance, prognostic value and limitations of these tools, along with their implications for contemporary management.
The authors searched PubMed/MEDLINE, Embase and Scopus from database inception through December 2025 and checked reference lists for additional publications. They selected relevant studies through title and abstract review, followed by full-text assessment when needed. The article is a narrative review, not a systematic review or meta-analysis, so it did not include a formal risk-of-bias assessment or quantitative synthesis.
What the established scales measure
Some systems sort SCFE by the timing of symptoms. Temporal classification calls a case acute when symptoms last less than three weeks, chronic when they last more than three weeks, and acute-on-chronic when a sudden exacerbation occurs on top of a chronic slip. That can describe how a patient presents, but the review says duration alone is not a consistent guide to slip severity or vascular compromise. Its prognostic value is therefore limited.
Loder asks a more immediate question: can the patient walk or bear weight, with or without crutches? A slip is classed as unstable when severe pain prevents ambulation. The distinction has particular importance for osteonecrosis, one of the review’s key outcomes. In a landmark study published in 1993, no patients with stable SCFE developed osteonecrosis, while nearly half of those with unstable slips did. Later studies and systematic reviews supported an association between instability and increased osteonecrosis risk. The finding does not show that the label itself causes the outcome.
Southwick shifts attention from symptoms to the shape of the deformity. It uses the epiphyseal-shaft angle on a radiograph to classify a slip as mild below 30 degrees, moderate from 30 to 50 degrees, or severe above 50 degrees. The measure gives an objective radiographic severity scale used in surgical planning. But the review notes that it can be difficult to measure in severe deformity or on a poorly positioned radiograph. It is useful for one major part of the assessment, but it does not cover every domain clinicians may need.
Wilson uses a different scale, grading displacement by the share of the femoral-neck width involved. Grade I is less than one-third, Grade II is approximately one-third to one-half, and Grade III is more than one-half. The review describes it as a historical system whose contemporary use has declined relative to angular measurements.
More detail, but no finished replacement
The Maranho system uses the relationship between the epiphyseal tubercle and metaphyseal socket on lateral hip radiographs and divides SCFE into five stages, from Stage 0 through Stage 4. In the evidence cited by the review, it showed excellent intraobserver and interobserver reliability, meaning readings were consistent when repeated by the same observer and when made by different observers. Its stages also correlated strongly with Southwick severity and moderately with Loder stability. The review says the system may identify subtle pre-slip stages, but further prospective validation is needed before routine adoption.
MRI may detect physeal edema, cartilage injury and subtle instability before significant radiographic displacement appears. That gives it a potential role in recognizing pre-slip conditions earlier, although the review presents this as a possible use rather than established evidence of better outcomes.
Three-dimensional and statistical shape-modeling approaches examine the deformity in greater detail. In the cited work, increasing SCFE severity was associated with posterior and inferior growth-plate displacement, greater femoral-neck deformation and altered regional strain. Severe slips showed substantial displacement of the femoral head with minimal intrinsic strain. The findings may help explain why a single angle cannot capture all of the deformity, but the review does not validate these approaches for routine clinical use.
The review also warns that reliability varies across systems. Loder depends on a subjective assessment of weight-bearing, while Southwick and Wilson can be affected by patient positioning, radiographic quality and measurement variability. That makes the classifications useful as complementary measures, but less dependable when any one of them is treated as a complete answer.
That gap is especially relevant for young adults after the growth plate has closed. For residual post-SCFE deformity, the review says Southwick should be treated as a measure of the original slip severity, not a complete classification of the hip’s remaining shape. Assessment should also consider three-dimensional femoral morphology, femoroacetabular impingement, cartilage and labral status, limits on range of motion, and patient-reported symptoms. The original angle can still matter without fully describing the hip’s later mechanical and symptomatic consequences.
The proposed direction is a multidomain framework that combines physeal stability, deformity morphology, vascular and biological status, cartilage involvement and patient-specific prognostic factors. But no universally accepted model currently brings those domains together. The review says prospective multicentre validation is required before such a framework can be adopted in routine clinical practice. Until then, the existing systems remain complementary tools, each answering part of the question rather than the whole one.
Paper data and sources
Original title: Current classification systems in slipped capital femoral epiphysis: Clinical relevance, limitations, and future directions
Authors: Desouza C, Kumar V, Thamizholi A et al.
Journal/Repository: SICOT-J
Status: Peer-reviewed
First online: 2026-10-19
DOI: Not available
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