title: Using the transverse acetabular ligament as a landmark for acetabular anteversion: an intra-operative measurement.
abstract: PURPOSE. To measure the transverse acetabular ligament (TAL) anteversion in hips with severe deformity, using fluoroscopy-computed tomographic navigation. METHODS. 31 hips in 10 men and 19 women aged 40 to 78 (mean, 58.7) years who underwent total hip arthroplasty for primary osteoarthritis (n=6) or osteoarthritis secondary to developmental hip dysplasia (n=19) or congenital hip dislocation (n=6) were included. The severity of hip dislocation was classified according to the Crowe classification; 15 hips were grade 1, 7 were grade 2, 3 were grade 3, and 6 were grade 4. The TAL anteversion was measured using fluoroscopy-computed tomographic navigation. The difference in TAL anteversion between non-dislocated hips (Crowe grade 1, n=15) and dislocated hips (Crowe grades 2-4, n=16) was compared. RESULTS. In all 31 hips, the TAL could be visualised intra-operatively. No patient reported severe pain, early wear, loosening, or dislocation after 2 years. The mean TAL anteversion and inclination angles measured by the navigation system were 26.5 (SD, 8.9; range, 8-42) degrees and 41.5 (SD, 4.6; range, 32-49) degrees, respectively. 22 of the 31 hips were in the safe zone. TAL anteversion in non-dislocated and dislocated hips was not significantly different. Inter- and intra-observer mean absolute differences in TAL anteversion were 0.3 and 0.4 degree, respectively. CONCLUSION. The TAL is a useful anatomic landmark for total hip arthroplasty in dislocated hips.
authors.affiliation: Department of Orthopaedic Surgery, Wajo Eniwa Hospital, Eniwa, Hokkaido, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Inoue
authors.forename: Tokifumi
authors.initials: T
authors.lastname: Majima
authors.forename: Satomi
authors.initials: S
authors.lastname: Abe
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakamura
authors.forename: Taiki
authors.initials: T
authors.lastname: Kanno
authors.forename: Takeshi
authors.initials: T
authors.lastname: Masuda
authors.forename: Akio
authors.initials: A
authors.lastname: Minami
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D060750:Bone Anteversion / Q000000981:diagnostic imaging*; D016025:Bone Transplantation; D005260:Female; D006618:Hip Dislocation, Congenital / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D008022:Ligaments / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging* / Q000601:surgery; D011859:Radiography
keywords: anatomic landmarks; arthroplasty,
  replacement, hip; bone anteversion