TY - JOUR
T1 - Acetabular component positioning using anatomic landmarks of the acetabulum
AU - Ha, Yong Chan
AU - Yoo, Jeong Joon
AU - Lee, Young Kyun
AU - Kim, Jin Young
AU - Koo, Kyung Hoi
PY - 2012/12
Y1 - 2012/12
N2 - Background: The acetabular cup should be properly oriented to prevent dislocation and to reduce wear. However, achieving proper cup placement is challenging with potentially large variations of cup position. We propose a new technique to position the acetabular cup. Questions/Purposes: We used this technique, then determined actual cup position and subsequent dislocation rate. Methods: We measured acetabular abduction (α°) and anteversion (β°) on preoperative CT scans in 46 patients (50 hips) scheduled for THA. During the operation, we identified the transverse acetabular notch (TAN) and anterior acetabular notch (AAN), a notch at the anterior acetabular margin. We then marked two reference points for 40° abduction at the acetabular rim: the superior point, which is opposite the TAN, and the inferior point at |α - 40| mm inside (when a was[40°) or outside the TAN (when α was <40°). We also marked two reference points for 15° anteversion: the posterior point opposite the AAN and the anterior point at |β - 15| mm inside (when b was<15°) or outside the AAN (when β was>15°). During cup insertion, we aligned cup abduction to the line between the superior and inferior points and cup anteversion to the line between the anterior and posterior points. We measured cup abduction and anteversion and evaluated the dislocation rate. One patient was lost to followup before 60 months; the minimum followup for the other 45 patients was 60 months (mean, 62.8 months; range, 60-65 months). Results: The mean cup abduction was 40° (range, 32°-47°) and the mean cup anteversion was 17° (range, 8°-25°). No dislocation occurred postoperatively in 49 hips (45 patients) for a minimum of 5 years followup.
AB - Background: The acetabular cup should be properly oriented to prevent dislocation and to reduce wear. However, achieving proper cup placement is challenging with potentially large variations of cup position. We propose a new technique to position the acetabular cup. Questions/Purposes: We used this technique, then determined actual cup position and subsequent dislocation rate. Methods: We measured acetabular abduction (α°) and anteversion (β°) on preoperative CT scans in 46 patients (50 hips) scheduled for THA. During the operation, we identified the transverse acetabular notch (TAN) and anterior acetabular notch (AAN), a notch at the anterior acetabular margin. We then marked two reference points for 40° abduction at the acetabular rim: the superior point, which is opposite the TAN, and the inferior point at |α - 40| mm inside (when a was[40°) or outside the TAN (when α was <40°). We also marked two reference points for 15° anteversion: the posterior point opposite the AAN and the anterior point at |β - 15| mm inside (when b was<15°) or outside the AAN (when β was>15°). During cup insertion, we aligned cup abduction to the line between the superior and inferior points and cup anteversion to the line between the anterior and posterior points. We measured cup abduction and anteversion and evaluated the dislocation rate. One patient was lost to followup before 60 months; the minimum followup for the other 45 patients was 60 months (mean, 62.8 months; range, 60-65 months). Results: The mean cup abduction was 40° (range, 32°-47°) and the mean cup anteversion was 17° (range, 8°-25°). No dislocation occurred postoperatively in 49 hips (45 patients) for a minimum of 5 years followup.
UR - http://www.scopus.com/inward/record.url?scp=84871611744&partnerID=8YFLogxK
U2 - 10.1007/s11999-012-2460-y
DO - 10.1007/s11999-012-2460-y
M3 - Article
C2 - 22777589
AN - SCOPUS:84871611744
SN - 0009-921X
VL - 470
SP - 3515
EP - 3523
JO - Clinical Orthopaedics and Related Research
JF - Clinical Orthopaedics and Related Research
IS - 12
ER -