Paeds · rheumatology-musculoskeletal-and-sports
Slipped capital femoral epiphysis
Also known as slipped upper femoral epiphysis · SCFE · SUFE · adolescent coxa vara · epiphysiolysis capitis femoris · Drehmann sign
A fellowship approach to the overweight adolescent with an antalgic gait and referred knee pain: the Loder stability classification that separates stable from unstable slipped capital femoral epiphysis and predicts the risk of avascular necrosis, the Southwick angle that grades slip severity on the frog-lateral radiograph, Klein's line that reveals the subtle slip on the AP view, the single-screw in-situ pinning that is the gold standard for stable slips, the urgent reduction strategy for the unstable slip, and the endocrine work-up that the atypical age-weight presentation demands.
On this page
Study tools
Your progress
Saved on this device.
Practise this topic
Target exams
Red flags
- Knee pain in an overweight adolescent is slipped capital femoral epiphysis until proven otherwise — the hip refers to the knee, and the child who limps and externally rotates must have both joints imaged or the slip is missed
- An unstable slipped capital femoral epiphysis — the child who cannot bear weight even with crutches — carries an avascular necrosis risk approaching fifty per cent and is an orthopaedic emergency requiring urgent reduction and fixation
- Never manipulate a chronic slip acutely or attempt forceful reduction of a stable slip — iatrogenic avascular necrosis from rough handling of the retinacular vessels is the most preventable disaster in this disease
- A child under ten or over sixteen, or one whose weight is below the fiftieth percentile, has an atypical slipped capital femoral epiphysis that demands an endocrine, renal, and chromosomal work-up — the slip may be the first clue to hypothyroidism, growth hormone deficiency, or a pituitary lesion
- Slip the contralateral hip in up to forty per cent — every child diagnosed with a slipped capital femoral epiphysis must have the opposite hip assessed at presentation and monitored throughout growth, because the second slip is often silent until it becomes unstable
- Do not let the child bear weight on a confirmed or suspected slip until it is stabilised — weight-bearing across an unstable physis worsens the displacement and threatens the femoral head blood supply
Life stages
Care settings
Clinical exam formats
Board mappings
- Musculoskeletal medicine - the limping adolescent and the slipped capital femoral epiphysis
- Acute presentations - hip and knee pain in the older child
- Growth and development - the adolescent growth spurt and physeal vulnerability
- Orthopaedics and musculoskeletal medicine - apply the Loder stability classification and the Southwick angle and plan in-situ fixation
- Endocrinology - investigate the atypical age-weight presentation for endocrine and renal disease
- Acute presentations - the unstable slipped capital femoral epiphysis and the avascular necrosis risk
- Rheumatology 10-12
- Acute presentations 10-12
- Clinical Applications
- Long Cases
- Short Cases
- 9. Musculoskeletal medicine - slipped capital femoral epiphysis and the limping adolescent
- 2. Growth and development - the adolescent growth spurt and endocrine associations
- 4. Professional skills and knowledge: Patient management
- Foundation of Practice (FOP)
- Theory and Science (TAS)
- Applied Knowledge in Practice (AKP)
- Clinical
- History
- Communication
- Video
- General Pediatrics Content Outline - Musculoskeletal disorders
- General Pediatrics Content Outline - Universal Task 4: Management and Treatment
- General Pediatrics Content Outline - Endocrine disorders
- Patient Care 4: Clinical Reasoning
- Patient Care 5: Patient Management
- Medical Knowledge 1: Musculoskeletal disorders and adolescent medicine
- Medical Expert
- Pediatrics: Foundations EPA - Acute care of the limping adolescent
- Pediatrics: Rheumatology and orthopaedics applied domain
A thirteen-year-old boy with a body mass index above the ninety-fifth percentile presents to the emergency department with three weeks of left knee pain and a limp that has worsened over two days to the point where he cannot put any weight on the leg. Or a twelve-year-old girl is brought to the general practitioner with a six-month history of an intermittent aching hip that she has attributed to growing pains, with a recent acute worsening that now stops her walking. Or an eight-year-old boy with known hypothyroidism and a short stature develops a limp and an externally rotated leg. In each, the question is the same — is this a slipped capital femoral epiphysis, is it stable or unstable, and how urgently does the physis need stabilising? [1] [3]
Run the pathway as six moves. Classify the slip by the Loder stability criteria — stable if the child can bear weight with or without crutches, unstable if they cannot — because the unstable slip carries an avascular necrosis risk approaching fifty per cent. Confirm with the frog-lateral radiograph, grading the Southwick angle into mild below thirty degrees, moderate thirty to fifty, and severe above fifty. Crane the Klein's line along the superior femoral neck on the AP view and watch it miss the epiphysis, the Trethowan sign that catches the subtle slip. Crack the physis with single-screw in-situ pinning, the gold standard that stabilises without manipulating the retinacular vessels. Cage the unstable slip as an emergency, with urgent gentle reduction and fixation or the modified Dunn surgical dislocation, because every hour of delay threatens the femoral head. Companion the contralateral hip, because up to forty per cent slip bilaterally and the second slip is often silent until it becomes unstable. [1] [2]
Overview & Definition
Slipped capital femoral epiphysis is the displacement of the capital femoral epiphysis — the growing head of the femur — relative to the metaphysis of the femoral neck, occurring through the physis during the period of adolescent skeletal immaturity. The epiphysis slips posteroinferiorly while the metaphysis rotates anteriorly and superiorly, producing the characteristic external rotation deformity and the loss of internal rotation that the examiner detects at the bedside. It is the commonest hip disorder of adolescence, and its importance lies in the twin threats of progressive slip with weight-bearing and of avascular necrosis of the femoral head, both of which can produce a permanent, crippling deformity if the diagnosis is delayed. [7] [4]
The fellowship framing rests on a single clinical decision that the Loder stability classification makes explicit. A slip is stable when the child can bear weight, even with crutches, and unstable when the child cannot bear weight at all, and this single distinction predicts the risk of avascular necrosis — approximately zero per cent in the stable slip and approaching fifty per cent in the unstable slip. This is why the stability classification drives the urgency: the stable slip is fixed electively, and the unstable slip is an orthopaedic emergency that goes to theatre for urgent reduction and fixation. [1] [6]
The clinical importance comes from what happens if the slip is missed or the unstable slip is left. Progressive displacement under weight-bearing worsens the deformity and increases the risk of avascular necrosis, chondrolysis, femoroacetabular impingement from the residual cam lesion, and early osteoarthritis. In the atypical child — the one who is younger than ten or older than sixteen, or whose weight is below the fiftieth percentile — the slip is the first clue to an underlying endocrinopathy, renal osteodystrophy, or chromosomal syndrome, and the work-up extends beyond the hip. [3] [7]
References10ShowHide
- [1]Loder RT, Richards BS, Shapiro PS, Reznick LR. Acute slipped capital femoral epiphysis: the importance of physeal stability. J Bone Joint Surg Am, 1993.PMID 8354671
- [2]Southwick WO. Osteotomy through the lesser trochanter for slipped capital femoral epiphysis. J Bone Joint Surg Am, 1967.PMID 6029256
- [3]Loder RT, Greenfield ML. Clinical characteristics of children with atypical and idiopathic slipped capital femoral epiphysis: description of the age-weight test and implications for further diagnostic investigation. J Pediatr Orthop, 2001.PMID 11433161
- [4]Loder RT, Skopelja EN. The epidemiology and demographics of slipped capital femoral epiphysis. ISRN Orthop, 2011.PMID 24977061
- [5]Navarre P. Slipped Capital Femoral Epiphysis: A Review of the New Zealand Literature. J Bone Joint Surg Am, 2020.PMID 32453109
- [6]Loder RT, Gunderson Z, Sun S. Idiopathic Slipped Capital Femoral Epiphysis: Demographic Differences and Similarities between Stable, Unstable, and Valgus Types. Children (Basel), 2023.PMID 37761517
- [7]Dussa CU. Slipped capital femoral epiphysis: pathomechanism, clinical presentation, diagnosis, natural history and treatment. A review of the literature. Orthopadie (Heidelb), 2026.PMID 41951777
- [8]Gladstein AZ, van Dijck S, Wasserman JD, Howard A. Painful Hips and a Nodular Neck: Bilateral Slipped Capital Femoral Epiphysis Leading to the Diagnosis of Multiple Endocrine Neoplasia: A Case Report. JBJS Case Connect, 2015.PMID 29252812
- [9]Herngren B, Stenmarker M, Vavruch L, Hagglund G. Slipped capital femoral epiphysis: a population-based study. BMC Musculoskelet Disord, 2017.PMID 28720145
- [10]Xu Z, Zhu L, Kong L, Qian Y. Risk factors associated with avascular necrosis following unstable slipped capital femoral epiphysis in pediatric patients: A systematic review and meta-analysis. PLoS One, 2025.PMID 40737348