1. Derotational osteotomy in SCFE complicated with avascular necrosis YUMC Hui Wan Park, Hyun Woo Kim Yonsei University College of Medicine

2. Female /14 CC : Out-toeing gait with painful LOM of left hip

3. PH 2000. 05 - pinning-in-situ for SCFE lt. 2000. 09. -- removal of penetrated screw due to AVN 2001. 05. 31. – adductor tenotomy 2002. 01. 03. -- cheilectomy

4. Hinge abduction Cheilectomy 02. 01. 01. 02. 01. 12.

5. Improvement after cheilectomy Further flexion of hip 75 95 Further abduction 0 15

6. PE AGF : 90 IR : -10, ER : 50 Leg length discrepancy : 84.2/82.5 (1.7cm)

7. Aspherical incongruous head 04. 07. 21.

9. Subtrochanteric osteotomy 30 o derotation internally 04. 07. 21. 05. 07. 15.

10. Improvement after derotation osteotomy ( one year F/U ) Less pain around hip & knee j. during gait Easier abduction IR : -10 o 10 o

11. Causes of increased external rotation in SCFE Decreased anteversion – retroversion Collapse of femur head due to avascular necrosis

12. Mechanical factors in SCFE Prichett (1988) Slipped epiphysis patients have relative retroversion, and this generates increased saggital plane shear stress at the proximal femoral growth plate

13. Rt. ; retroversion 9 o Lt. : retroversion 2 o

14. Retroversion of femur head A cause of pain & osteoarthritis Tonnis (1991) Rotation of the femur internally or externally from neutral position necessitates increased abductor muscle force to maintain a level pelvis Merchant (1965) A predictor of risk for stress fracture Gilardi et al (1987)