Selection of a surgical approach for total hip arthroplasty according to the depth to the surgical site.
BACKGROUND
The surgical depths of approaches for total hip arthroplasty (THA) have not been reported previously. In this study, we investigate the relationships between the distances to the centre of the femoral head in different approaches and body mass index (BMI).


METHODS
The study included patients with normal hip joints who presented to our hospital. We used the pelvic coordinate system relative to the anterior pelvic plane and the femur coordinate system relative to the posterior condylar plane. We assessed the anterior, anterolateral, lateral and posterior approaches, and defined each approach line. We evaluated each distance in terms of BMI and gender.


RESULTS
164 hips were assessed. The distance to the centre of the femoral head was the longest in the posterior approach, followed by the lateral, anterolateral, and anterior approaches (p<0.05). Additionally, the distance in each approach increased as patients' BMI increased. The approximated line tilts were almost the same. The correlation coefficients between BMI and the distance to the centre of the femoral head were high in all approaches. In the anterior and anterolateral approaches, men with low BMI had a short distance to the femoral head. The distance for each approach was measured according to the pelvic coordinate system and the femur coordinate system. The results showed no significant differences between them.


CONCLUSIONS
The distance to the centre of the femoral head is the shortest in the anterior approach, regardless of BMI and gender. The distance in each approach might increase with an increase in BMI. BMI has similar effects in all approaches.
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Takaaki
T
Ohmori
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Tamon
T
Kabata
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.|Department of Orthopaedic Surgery, Kanazawa Red Cross Hospital, Kanazawa - Japan.
Toru
T
Maeda
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Yoshitomo
Y
Kajino
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Tadashi
T
Taga
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Kazuhiro
K
Hasegawa
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Daisuke
D
Inoue
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Takashi
T
Yamamoto
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Tomoharu
T
Takagi
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa - Japan.
Hiroyuki
H
Tsuchiya
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D015992:Body Mass Index; D002922:Ciguatoxins; D005260:Female; D005270:Femur Head / Q000601:surgery*; D005500:Follow-Up Studies; D006617:Hip Dislocation / Q000601:surgery*; D006621:Hip Joint / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult
C454647:ciguatoxin 1B (CTX 1B); D002922:Ciguatoxins