title: Medial percutaneous hemi-epiphysiodesis improves the valgus tilt of the femoral head in developmental dysplasia of the hip (DDH) type-II avascular necrosis.
abstract: OBJECTIVE
  Avascular necrosis (AVN) is a major cause of disability after treatment of developmental dysplasia of the hip (DDH), leading to femoral head deformity, acetabular dysplasia, and osteoarthritis in adult life. Type-II AVN is characterized by retarded growth in the lateral aspect of the physis or by premature lateral fusion, which produces a valgus deformity of the head on the neck of the femur. We investigated the effect of medial percutaneous hemi-epiphysiodesis as a novel technique in the treatment of late-diagnosed type-II AVN.
  
  
  METHODS
  9 patients (11 hips) with a diagnosis of type-II AVN who underwent medial percutaneous hemi-epiphysiodesis after the surgical treatment for DDH were included in the study. 10 patients (12 hips) with the same diagnosis but who did not undergo hemi-epiphysodesis were chosen as a control group. Preoperative and postoperative articulotrochanteric distances, head-shaft angles, CE (center-edge) angles, and physeal inclination angles were measured. The treatment group underwent medial hemi-epiphysodesis at a mean age of 8 years. The mean ages of the treatment group and the control group at final follow-up were 14 and 12 years respectively. The mean duration of follow-up was 5.7 years in the treatment group and 8.3 years in the control group.
  
  
  RESULTS
  Preoperative articulotrochanteric distance, head-shaft angle, and functional outcome at the final follow-up assessment were similar in the 2 groups. However, preoperative and postoperative CE angles and physeal inclination angles differed significantly in the treatment group (p < 0.05). The final epiphyseal valgus angles were better in the treatment group than in the control group (p = 0.05). The treatment group improved after the operation.
  
  
  CONCLUSIONS
  Medial percutaneous epiphysiodesis performed through a mini-incision under fluoroscopic control is a worthwhile modality in terms of changing the valgus tilt of the femoral head.
authors.affiliation: Orthopedics and Traumatology , Izmir Tepecik Education and Research Hospital.
authors.forename: Haluk
authors.initials: H
authors.lastname: Agus
authors.forename: Burak
authors.initials: B
authors.lastname: Önvural
authors.forename: Cemal
authors.initials: C
authors.lastname: Kazimoglu
authors.forename: Ali
authors.initials: A
authors.lastname: Reisoglu
authors.forename: Onder
authors.initials: O
authors.lastname: Kalenderer
mesh_terms: D017760:Bone Malalignment / Q000601:surgery*; D002648:Child; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging / Q000601:surgery; D005271:Femur Head Necrosis / Q000601:surgery*; D006132:Growth Plate / Q000000981:diagnostic imaging / Q000601:surgery*; D006618:Hip Dislocation, Congenital / Q000145:classification / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D019637:Orthopedic Procedures / Q000379:methods*; D011859:Radiography; D012189:Retrospective Studies