NINETY-THREE PERCENT OF PATIENTS SLIPPED CAPITAL FEMORAL EPIPHYSIS FOLLOWING MODIFIED DUNN PROCEDURE HAVE A GOOD CLINICAL RESULT WITHOUT OSTEOARTHRITIS PROGRESSION AT TEN YEARS

Introduction Hips following in-situ pinning for slipped capital femoral epiphysis (SCFE) have an altered morphology of the proximal femur with cam type deformity. This deformity can result in femoroacetabular impingement and early joint degeneration. The modified Dunn procedure allows to reorientate the slipped epiphysis to restore hip morphology and function. Objectives To evaluate (1) hip pain and function, (2) 10-year survival rate and (3) subsequent surgeries and complications in hips undergoing modified Dunn procedure for SCFE. Methods Between April 1998 and December 2005 we performed the modified Dunn procedure for 43 patients (43 hips) with SCFE. Twenty-five hips (58) presented with an acute or acute on chronic slip. The mean slip angle was 43° (range, 15° – 80°). A majority of 53% of procedures were performed in male patients and the mean age at operation was 13 years (10 – 19 years). We could followup all except one hip (followup of 5.5 year) for a minimum of 10 years (mean followup 13 [10 – 18 years]). We used the anterior impingement test to assess pain and the Merle d9Aubigne- ostel score to assess function. Survivorship calculation was performed using the method of Kaplan and Meier and any of the following factors as a definition of failure: radiographic evidence of worsening osteoarthritis (OA), or a Merle d9Aubigne-Postel score less than 15. Results (1) The prevalence of a positive anterior impingement test decreased from 100% to 16% (p Conclusion The modified Dunn procedure is a safe method to correct the morphology of the proximal femur in hips with SCFE. Ninety-free percent of the hips showed no progression of OA and a good clinical result at the 10-year followup. Twelve percent required revision surgery for complications all including screw breakage with nonunion of the greater trochanter.