In Reply:

Abstract

Thank you for your comments regarding the article “Safe Screw Placement In Acetabular Revision Surgery” (Volume 16, Number 8) [ 1 Meldrum R Johansen R Safe Screw Placement in Acetabular Revision Surgery. Arthroplasty. 2001; 16: 953 Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar ]. We agree that in acetabular revision surgery the bone that will achieve maximal screw purchase and fixation may dictate the screw's orientation and placement. Often in my own revision surgery practice, I find screws that achieve the greatest purchase and bony fixation enter the acetabulum in what would be an “unsafe zone” by the quadrant systems and exit safely in a posterior and superior direction through the back table of the ilium [ 2 Wasielewski RC Cooperstein L Kruger MP Rubash HE Acetabular anatomy and the transacetabular fixation of screws in total hip arthroplasty. J Bone Joint Surg Am. 1990; 72: 501 PubMed Google Scholar ]. The purpose of this article was not to show the path and safety of obliquely placed acetabular screws, but to provide a safety guideline for medial screw placement in the extremes of acetabular revision surgery with the uncemented acetabular componenet (Jumbo and High Hip Center) and each of the design styles of acetabular reconstruction rings or cages (Müller, Ganz, and Burch-Schneider; all Sulzer Medica, Austin, TX). Also, for this paper to expand on previous reports endorsing primary acetabular screw placements in safe quadrants, their orientation had to be placed perpendicular to the ilium, or radially inside of the acetabulum in and placed 15 mm longer than the depth measured [ 3 Keating EM Ritter MA Faris PM Structures at risk from medially placed acetabular screws. J Bone Joint Surg Am. 1990; 72: 509 PubMed Google Scholar , 4 Rubash HE Wasielewski RC Britton C Donaldson R Acetabular anatomy and transacetabular screw fixation in acetabular arthroplasty at the high hip center. 1998 Google Scholar ]. Safe screw placement in acetabular revision surgeryThe Journal of ArthroplastyVol. 16Issue 8PreviewRevision of an acetabular component with extensive bone loss is a procedure that sometimes includes allografting or the placement of an unusually sized or positioned uncemented acetabular component. We evaluated the quadrant system used to guide screw placement in primary uncemented total hip surgery in the high hip center, jumbo component, and 3 designs of reinforcement rings. We used 14 pairs of cadaver hemipelves, which were prepared by removing all soft tissues except the medial neurovascular structures. Full-Text PDF