Total Hip Arthroplasty and Hemiarthroplasty in Mobile, Independent Patients with a Displaced Intracapsular Fracture of the Femoral Neck

To The Editor: On reading the Level-I study by Baker et al. entitled “Total Hip Arthroplasty and Hemiarthroplasty in Mobile, Independent Patients with a Displaced Intracapsular Fracture of the Femoral Neck. A Randomized, Controlled Trial,” (2006;88:2583-9), in which hemiarthroplasty was compared with total hip arthroplasty for the treatment of displaced femoral neck fractures in active elderly patients, I wanted to write to congratulate the authors for an excellent study regarding an important topic. Coincidentally, a consortium of United States surgeons (DFACTO [Displaced Femoral neck fracture Arthroplasty Consortium for Treatment and Outcomes]) has performed a similar study with strikingly similar results, which, in November 2006, was submitted for publication in the Journal of Orthopaedic Trauma.

I have some thoughts and questions that perhaps the authors can comment on.

First, with regard to the 7.5% dislocation rate reported in the study, it would appear from the Materials and Methods section that for the total hip replacements, a 28-mm prosthetic head was placed with use of a transgluteal approach to the hip, without a capsular repair, in all cases. Do the authors think that the use of larger prosthetic femoral heads (≥32 mm) with a capsular repair on closure would have decreased this dislocation rate?

Second, the finding that 66% of the hemiarthroplasty patients demonstrated some degree of acetabular erosion during the follow-up period was impressive, but I cannot help but to wonder if the use of modular unipolar heads in 1-mm size increments would have reduced the prevalence of acetabular erosion. During the performance of hemiarthroplasty of the hip for my patients, I prefer to implant the largest unipolar femoral head possible in order for the intact labrum to bear some of the stress during walking and hip movement.

Third, the results from our DFACTO trial also indicated that patients who were randomized to total hip arthroplasty had a higher likelihood of increased ability to walk when compared with those who were randomized to hemiarthroplasty. However, we preferred the use of the objective (non-patient-reported) measure known as the Timed Up and Go (TUG) test. One of the potential criticisms of all of these trials is that it is very difficult to blind the patient to the treatment; thus, self-reported outcomes must, therefore, be looked at skeptically because of higher potential bias.

The magnitude of the importance of this kind of work cannot be overstated. While I am less familiar with the demographics of the elderly population of the United Kingdom, we currently care for >350,000 hip fractures each year in the United States. This number is expected to double by 2040. The surgical outcome of each procedure must be optimized to keep our respective health care systems from being excessively burdened with complications and reoperations. Baker et al. correctly pointed out that the outcomes in an older, less independent population of patients remain more in question (although the application of capsular repair and enhanced head-to-neck ratio for total hip arthroplasty may allow for a more widespread application of total hip arthroplasty for the treatment of femoral neck fractures).

I challenge our colleagues who treat displaced femoral neck fractures throughout the world to also consider more the optimal treatment of similar patients below the age of sixty years, particularly those with a two-day interval from trauma to treatment, comminution of the femoral neck, a high degree of displacement, and poor bone quality.