Cementless Hip Implants: An Expanding Choice

Abstract

Introduction Total hip replacement is a successful procedure with long survival records compared to other joint arthroplasties. Cemented implants have been available for many years, however the complications associated with loosening and, ultimately, failure over time has led to the development of cementless stems and implants. The ideal prosthesis should recreate a biomechanically normal hip joint, allow pain-free function and last the patient's life span without requiring revision. Optimal results with uncemented femoral stems rely on obtaining initial stability, osseointegration, biological fixation, and uniform stress transfer to the proximal bone. There are a multitude of factors that can affect the integration, stability and fixation of these stems into bone, and understanding these factors is the key to choosing the appropriate implant for a specific femur. Methods This article aims to discuss cementless prostheses based on evidence-based practice. Geometry, roughness, stem coating, technique and bone quality are among the factors discussed. This was achieved through a review of the current literature. Conclusions Uncemented femoral stems have shown good, long-term survivorship and functional outcome, with promising results in younger patients. Limitations in the current literature make it difficult to assess and compare different designs to determine optimal indications for each type. Biological fixation, in which the prosthesis is directly fixed to the bone, is the preferred fixation method. Future studies of cementless implants should consistently address patient age, activity level, bone type, and deformities so that more definitive conclusions can be drawn about when to use each design.