Direct anterior compared to posterior approach for hip hemiarthroplasty following femoral neck fractures

Abstract

The differences in complication rates between the direct anterior and posterior approaches for hemiarthroplasty in elderly patients with femoral neck fractures are not yet fully understood. Dislocation, a severe complication associated with increased mortality and often requiring additional surgery, may occur less frequently with the direct anterior approach compared to the posterior approach. Careful consideration of patient demographics is essential when planning the surgical approach. Future research in this area should focus on robust randomized controlled trials involving elderly patients recovering from femoral neck fractures.

Key Words: Direct anterior approach, Posterior approach, Hemiarthroplasty, Femoral neck fractures, Arthroplasty, Dislocation, Surgical technique

Core Tip: The current literature base is contradictory regarding the optimal surgical approach for hip hemiarthroplasty in the management of femoral neck fractures. This topic should be explored further in future randomized control trials.

TO THE EDITOR

We read with great interest the retrospective study by Charles et al[1], assessing the impact of surgical approach on postoperative outcomes following hip hemiarthroplasty in elderly individuals with femoral neck fractures. We commend the authors on their recent manuscript as it is both timely and informative.

The authors offer a critical comparison of hip hemiarthroplasty performed using the posterior vs the direct anterior approaches in the management of femoral neck fractures, evaluating 171 and 108 cases, respectively. The study addresses an important clinical question with implications for surgical practice and found that the direct anterior approach was significantly associated with lower dislocation rates. This finding warrants further attention, as it could influence surgical decision-making for elderly patients sustaining a femoral neck fracture. The study’s methodology appears robust, with a large sample size and appropriate statistical analyses. The authors’ efforts to control for potential confounding factors such as patient demographics, standardized procedural positioning, and protocols, as well as femoral head size add to the strength of their conclusions.

However, we would have liked to see further discussion on the potential reasons behind the observed differences in complication rates between the two approaches beyond surgical technique alone. While the average age of the cohort was above 80 years, comorbidities including impaired cognitive function or neuromuscular disease were not recorded. All direct anterior approaches utilized a traction table and the adherence to rehabilitation protocols following the posterior approach was not assessed. Factors such as patient positioning, postoperative care protocols, and comorbidities may have contributed to these outcomes and merit exploration in future studies.

While the authors explored the comparison between medical trainees, residents, and senior surgeons, they did not account for the variation in years of operating experience among surgeons, which could be a significant factor influencing outcomes. They do acknowledge the role of experienced hip surgeons in performing some of the procedures using the posterior approach, which may introduce a bias towards surgical experience rather than the approach itself. However, this bias could be better understood by including surgeon experience as a variable in a regression analysis. By conducting a linear regression controlling for surgeon experience, the authors could assess whether differences in complication rates are due to the surgeon's experience rather than the surgical approach. This is particularly relevant as the direct anterior approach requires a higher learning curve, as demonstrated by increased dislocation rates in the first 100 hips managed with the direct anterior approach (2 hips) compared with a cohort of 300 hips managed with the posterior approach (1 hip)[2].

Additionally, it would be valuable for the authors to consider the short-term benefits of the direct anterior approach in mobility. Rodriguez et al[3] demonstrated consistent benefits of the direct anterior approach with respect to early mobility, specifically the timed up-and-go test, motor component of functional independence, and Harris hip score, suggesting its potential advantages. However, most findings were equalized after 2 weeks postoperatively, and at the 6-week postoperative period, there were no measurable differences between the groups, indicating the importance of considering both short-term and long-term outcomes in the analysis. A metanalysis of randomized control trials found that the anterior approach demonstrated potential advantages in terms of faster short-term rehabilitation, higher functional scores, shorter hospital stays, and quicker discontinuation of walking aids like crutches and walkers[4]. Conversely, the posterior approach showed potential benefits in terms of shorter operative times, without an increase in complication rates, and similar long-term functional outcomes.

Although the direct anterior approach is soft tissue preserving, the impact of the surgical approach on instability remains contentious in the literature, with no definitive superior method identified. Maratt et al[5] had found no differences in dislocation rate in a retrospective study of 2147 undergoing total hip arthroplasty. However, the variance in findings observed in the present study may be attributed to differences in the patient population. Additionally, there has been some discussion in the literature about using a modified posterior approach that preserves the short external rotator muscles as an alternative to decrease the dislocation rate[6]. This current study makes a valuable contribution to the literature regarding hip hemiarthroplasty in elderly patients with femoral neck fractures, as it suggests an increased dislocation risk associated with the surgical approach in these patients. These findings underscore the importance of careful consideration when selecting a surgical approach and highlight the need for further research in this area. In the future, randomized control trials could be undertaken to provide definitive answers on the optimal approach for hemiarthroplasty in elderly patients following femoral neck fracture. We look forward to seeing more work from these authors in the future.