Acetabular screws placement in primary and revision total hip arthroplasty: a narrative review

Abstract

Introduction: Total Hip Arthroplasty (THA) is one of the most successful procedures in orthopedic surgery. Today, arthroplasties are performed using minimally invasive techniques, with excellent long-term outcomes. However, complex cases, such as dysplastic hips, acetabular fractures, or revision surgeries involving bone loss, continue to represent significant challenges for surgeons in achieving primary stability. In such situations, acetabular screws can be used to improve stability, although this increases technical difficulties and the risk of neurovascular complications. This review aims to describe the optimal techniques for acetabular screw placement in THA, focusing on ensuring primary stability while minimizing risks. It also discusses the safe zones for screw placement based on acetabular anatomy and evaluates different acetabular component designs. A narrative review of the literature was conducted, addressing acetabular screw placement in the ilium, ischium, and pubic bone. A clock-face method and graphics are used to illustrate the optimal entry points for screws. The risk associated with various zones (e.g., the "death zone" and "caution zone") is highlighted. The iliac bone offers the best tolerance for screw placement, with a wide range of safe angles, whereas the ischium and pubis present narrower safety angles due to proximity to vital structures. Progressively more invasive types of prostheses are also discussed for severe cases of bone loss and reduced stability. The review emphasizes the importance of surgeon expertise and anatomical knowledge, particularly in high-complexity cases where bone stock is severely compromised.

Conclusions: Proper acetabular component selection and placement and screw fixation techniques are crucial for the success of both difficult primary and revision THA. Surgeons must be aware of the technical difficulties and the anatomical variations that can occur in difficult cases, to avoid complications, namely neurovascular injuries.

Keywords: Acetabular screws; Complications; Revision surgery; Screw placement zones; Total hip arthroplasty.