MINIMIZING OSTEOTOMY RELATED COMPLICATIONS FOR THE BERNESE PERIACETABULAR OSTEOTOMY

Abstract

We utilized a dry-bone model of the pelvis and proximal femur, set upon transparent Lucite plates with four mounting screws and adjustable struts, allowing measurable and reproducible pelvic tilt and rotation. Our protocol for osteotome placement at each of the osteotomy sites strictly followed the technique described by Ganz. A 30°, 15 mm bifid osteotome was used for imaging at the initial ischial osteotomy at the infracotyloid groove. A 30°, 2 cm straightedge osteotome was placed 4 cm below the pelvic brim to image the retroacetabular osteotomy on the quadrilateral plate. Various osteotome placements were imaged with the C-arm image intensifier to better define the risks of inferior and posterosuperior intraarticular osteotomies at each of these sites, respectively. A 600 osteotome oriented at 500 to the quadrilateral plate was also utilized.

In addition, violation of the inferior quadrant of the joint as well as posterolateral slipping of the osteotome blade along the posterior column, were appreciated on all images of pelvic flexion and rotation. The false-profile view always confirmed the perpendicular orientation of the osteotome blade. The false-profile view allowed for accurate evaluation of the positioning of the 30°, 2-cm straightedge osteotome along the retro-acetabular osteotomy site. In the views obtained, the blade could be seen aligned parallel to the posterior surface of the acetabulum, while respecting the posterosuperior joint space with optimal step-off from the posterior column. False-profile and posterior judet views provided optimal visualization of the 60° osteotome on the quadrilateral plate. In addition, pelvic flexion and rotation did not impact the ability to visualize the inferior margin of the acetabulum in evaluating the potential for creating an inferior intraarticular osteotomy. The results of our study indicate that awareness of the appearance of ideal osteotome placements at each osteotomy site on AP and false profile C-arm image intensification will decrease the incidence of iatrogenic osseous and therefore neurovascular complications reported in the literature and reduce post-operative patient morbidity.