Radiographic Evaluation of Acetabular Component Position in Dogs

Abstract

Computer-aided image analysis can be used to calculate angles of lateral opening to within 10 degrees throughout the range of acetabular positions seen in practice and is appropriate for postoperative documentation of cup position. The angles of inclination and version should be interpreted with caution.

Management of total hip replacement luxation with triple pelvic osteotomy

“…The inclusion of both cemented and cementless THR in this study implies the use of different techniques to measure ALO. The ellipse and Renwick methods for ALO measurement have a reported accuracy of 5 °‐10 °; however, their accuracy decreases with increasing IA, pelvic rotation, and decreasing ALO . The accuracy of VA measurement is affected by declining ALO, cup size, and IA .…”

“…For cemented THR cases, the ALO was calculated by using the ellipse of best‐fit method (Figure ) . For uncemented THR cases, the ALO for size 24‐, 28‐, and 32‐mm cups was measured by using a system described by Renwick et al If a size 20‐, 26‐, or 30‐mm cup was used, the ALO was estimated from the available data .…”

“… Examples of the ellipse ( A ) and Renwick ( B ) methods for determining ALO in cemented and cementless THR systems on a ventrodorsal pelvic radiograph. For the ellipse method, ALO is calculated by using the equation ALO = cos −1 (a/b) . By using the Renwick method, the distance between the center of the femoral head and the truncated surface of the cup is measured, and that distance correlates to a known ALO for the cup size .…”

Evaluation of the effect of pelvic tilt in the coronal plane on the Norberg angle measured in ventrodorsal radiographic views of a canine hip joint bone model

“…12 In each radiographic image, the NA of the hip joint was measured 3 times by each of 2 operators (designated as OP-A and OP-B), who were unaware of the extent and direction of pelvic tilt. 12 In each radiographic image, the NA of the hip joint was measured 3 times by each of 2 operators (designated as OP-A and OP-B), who were unaware of the extent and direction of pelvic tilt.…”

Total hip replacement for the treatment of atraumatic slipped femoral capital epiphysis in dogs

“…In one smaller patient and two where remodelling of the acetabulum had occurred, acetabular bone stock was felt to be insufficient to support a cementless cup and cemented fixation was employed. Assessment of implant orientation has been previously described in detail (Dyce and others , Renwick and others ). Postoperative radiographs showed satisfactory implant orientation in all cases in this study.…”