Comparison of Direct Anterior Approach vs. Lateral Hemiarthroplasty for Femoral Neck Fracture Repair

Overview

Recent research has demonstrated that a hemiarthroplasty (replacement of half the joint) has lower rates of post-surgical complications than a total hip arthroplasty does. However, surgeons tend to vary in their approach to hemiarthroplasties. The lateral approach, which involves making an incision at the side of the patient's hip, requires surgeons to cut through the muscle to access the hip, which has been associated with greater muscle damage and slower rates of recovery. On the other hand, the direct anterior approach does not require the cutting of the patient's muscle and is therefore associated with minimal muscle damage and faster rates of recovery. This study will aim to assess the impact of the surgical approach (Direct Anterior Approach vs. Lateral approach) during hemiarthroplasty on patients' short-term mobility, quality of life, function, pain, and safety parameters.

Hip fractures continue to increase with the aging Canadian population. Overall clinical and functional outcomes following hip fractures are poor, with only a third of patients returning to their pre-injury functional status (1). The hemiarthroplasty, which involves replacing the femoral head with a prosthesis after femoral neck fracture, is the procedure of choice in most intra-capsular hip fractures (2). Similar to the total hip arthroplasty, the hemiarthroplasty has been shown to be a safe and effective surgical technique. A recent study found that the hemiarthroplasty was associated with lower incidence of serious adverse events when compared to total hip arthroplasty (3). Approaches to the hip used by surgeons to perform arthroplasty procedures may vary. The lateral approach has been advocated by National bodies to be the approach of choice in arthroplasties for hip fractures because it is associated with a smaller dislocation compared to the posterior approach. However, the lateral approach is associated with significant morbidity to the musculature about the hip, which is already weak and degenerate in this population. Thus, the lateral approach may further impede recovery of this frail population. An attractive alternative of a surgical approach for this population may be the Direct Anterior Approach to the hip. This is an inter-nervous and inter-muscular approach, associated with minimal muscle damage. Furthermore, stability (i.e. dislocation risk) has been reported to be at least equal to that reported with the lateral approach. However, the Direct Anterior Approach is an approach associated with a learning curve of at least 100 cases and a potential increased risk of infection and peri-prosthetic fracture. The Direct Anterior Approach has shown to have superior outcomes compared to the lateral approach in total hip arthroplasty studies, however, no study to-date has compared these approaches in the setting of hip fractures where the lateral approach is considered the gold standard. The investigators feel that this is an important question to answer and believe that The Ottawa Hospital has the appropriate expertise to conduct such study. This center has utilized the Direct Anterior Approach in total hip arthroplasty for the last 10 years and the team's extensive experienced has been published. At present, 5 arthroplasty surgeons routinely perform the Direct Anterior Approach for at least half of their hip arthroplasty patients. Furthermore, 3 of the staff surgeons are considered key opinion leaders on the Direct Anterior Approach having mentored many surgeons nationally and internationally in many teaching formats including courses and invited lectures. The primary objective of this study is to assess the impact of the surgical approach for a hemiarthroplasty on patients' short-term mobility. The secondary objectives are to assess the impact of approach on quality of life, function, pain and safety parameters. The hypothesis is that the Direct Anterior Approach will lead to superior function and mobility at short-term follow-up.