Three-dimensional morphology and bony range of movement in hip joints in patients with hip dysplasia.
To confirm whether developmental dysplasia of the hip has a risk of hip impingement, we analysed maximum ranges of movement to the point of bony impingement, and impingement location using three-dimensional (3D) surface models of the pelvis and femur in combination with 3D morphology of the hip joint using computer-assisted methods. Results of computed tomography were examined for 52 hip joints with DDH and 73 normal healthy hip joints. DDH shows larger maximum extension (p = 0.001) and internal rotation at 90° flexion (p < 0.001). Similar maximum flexion (p = 0.835) and external rotation (p = 0.713) were observed between groups, while high rates of extra-articular impingement were noticed in these directions in DDH (p < 0.001). Smaller cranial acetabular anteversion (p = 0.048), centre-edge angles (p < 0.001), a circumferentially shallower acetabulum, larger femoral neck anteversion (p < 0.001), and larger alpha angle were identified in DDH. Risk of anterior impingement in retroverted DDH hips is similar to that in retroverted normal hips in excessive adduction but minimal in less adduction. These findings might be borne in mind when considering the possibility of extra-articular posterior impingement in DDH being a source of pain, particularly for patients with a highly anteverted femoral neck.
Osaka National Hospital, Department of Orthopaedic Surgery, 2-1-14 Hoenzaka Chuo-ku, Osaka, 540-0006, Japan.
I
I
Nakahara
M
M
Takao
T
T
Sakai
H
H
Miki
T
T
Nishii
N
N
Sugano
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D016208:Databases, Factual; D057925:Femoracetabular Impingement / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000473:pathology; D006618:Hip Dislocation, Congenital / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
Computer assisted; Dysplasia; Hip; Impingement; Morphology; Range of movement