TITLE:
Morphology of Acetabulum and Femoral Head-Neck Junction in Hip Dysplasia Which Underwent Rotational Acetabular Osteotomy
AUTHORS:
Ryo Kanto, Hiroshi Nakayama, Shoji Nishio, Yuki Fujihara, Yu Takeda, Shigeo Fukunishi, Shinichi Yoshiya, Toshiya Tachibana
KEYWORDS:
Acetabular Hip Dysplasia, Acetabular Osteotomy, Femoroacetabular Impingement
JOURNAL NAME:
Open Journal of Orthopedics,
Vol.5 No.5,
May
21,
2015
ABSTRACT: The purpose of this study was to evaluate the preoperative radiographs
with cases of developmental dysplasia of the hip (DDH) leading to
rotational acetabular osteotomy (RAO) or curved peri-ace-tabular osteotomy
(CPO), and examine the frequency of femoroacetabular impingement (FAI) related
bone morphology in the acetabulum and femoral head-neck junction. Twenty-four
hips with hip dyaplasia who underwent CPO or RAO were included in this study.
Six hips had grade 0 and eighteen hips had grade 1 OA according to the Tönnis
classification. We excluded patients with moderate and severe hip osteoarthritis
and major femoral head deformities. Preoperative radiograph was evaluated on sharp angle, center-edge angle, alpha angle, crossover sign and posterior
wall sign. Crossover signs were revealed in 7 hips (29.2%); posterior wall signs
were revealed in 16 hips (66.7%); and cam-type deformities with an alpha angle
of ≥50.5° were observed in 19 hips (79.2%) in preoperative evaluation. As
determined using the Tönnis scale, no progression of osteoarthritis was found
in 16 of the 24 hips; there was a one-grade progression in 8 hips. Among the 8
hips, either positive cross-over sign or posterior sign in acetabulum, and an
alpha angle of ≥50.5° in femur were observed in six hips with progression of
osteoarthritis. The presence of cam-type deformity and acetabular retroversion
in patients who underwent RAO or CPO was relatively high in preoperative
radiographs, and caution should be employed during surgery in patients with
DDH. There is a possibility of secondary FAI due to excessive forward coverage
of the bone fragments after RAO and CPO.