Slipped Upper Femoral Epiphysis


A 13 Year old overweight boy is brought in by his mother. He is limping and complaining of pain in his left hip.


Imaged sourced from: used under CC BY-SA 3.0

This is a frog leg lateral plane film radiograph of an unknown skeletally immature patients Left Hip. The most obvious abnormality is a disruption in Kline’s line (Trathawan’s sign positive) representing a slipped upper femoral epiphysis.

I would take a full history. Pertinent features in the history would include: infection, sepsis, endocrine history (esp if under 10), hx of trauma or NAI.

I would then examine the joint and the joints above and below

I would then perform investigations: XR AP and frog leg lateral, bloods including inflammatory markers and endocrinological bloods (TFTs, Creatinine, urea)

Loder classification



Able to bear weight with or without crutches

Minimal risk of osteonecrosis

Good prognosis 96%

Unable to bear weight

Associated with higher risk of osteonecrosis

Good prognosis in 47%


Southwick angle



<30 degree


30-50 degrees


>50 degrees

Line drawn along the superolateral margin of the femoral neck.

Trathawan’s sign is when klines line does not intersect the epiphysis.

Main supply is medial femoral circumlex artery

Lateral circumflex contributes

Superior and inferior gluteal arteries also contribute

Arteries of ligamentum teres (obturator)

Operative treatment

  • Percutaneous insitu fixation
    • Goal to stabilise the epiphysis from further slippage
    • Screw perpendicular to physis
    • 5 threads must cross the physis
    • Stable slips can bear weight
    • Unstable partial weight bearing
  • 2 screws higher biomechanical stability. Capsulotomy also controversial

Fixing the contralateral side

  • Initial split <10 years
  • Those with open triradiate cartilate
  • Obese males
  • Endocrine disorders

There is obligate external rotation on flexion of the hip and loss of internal rotation