Commentary & Perspective

Commentary & Perspective on
"Comparison of Internal Fixation with Total Hip Replacement for Displaced Femoral Neck Fractures"
by Richard Blomfeldt, MD, et al.

Commentary & Perspective by
Daniel J. Berry, MD*,
Mayo Clinic, Rochester, Minnesota

In this issue of The Journal, Blomfeldt et al. report the four-year results of a prospective, randomized trial in which they compared reduction and internal fixation to cemented total hip arthroplasty in older patients who had a displaced femoral neck fracture. The same study cohort had been reported on previously at a shorter follow-up interval.

Inclusion criteria of the study are important to note: Patients were all seventy years or older, had no preexistent hip arthritis, lived independently before the fracture, and lacked severe cognitive dysfunction. The treating surgeons were experienced with both treatment methods.

The study results are striking and demonstrate a notable and significantly different complication rate and reoperation rate between the two groups; a difference which has become even larger since the initial study report. Patients treated with internal fixation had a 42% complication rate compared with 4% for the arthroplasty group. Similarly, the internal fixation group had a 47% reoperation rate compared with 4% in the arthroplasty group. Even when screw removal was excluded as a reason for reoperation, the frequency of reoperations in the internal fixation group (34%) was much greater than in the total hip arthroplasty group (4%). The most common reoperation in the internal fixation group was conversion to total hip arthroplasty for femoral neck nonunion or osteonecrosis.

These data are consistent with a growing body of information demonstrating that, with current methods, arthroplasty provides advantages over internal fixation in most elderly patients with displaced femoral neck fractures. There was no significant difference in mortality rate between the two groups, although the power to detect differences in a study with 102 patients probably was limited.

An interesting finding of the study was that those treated with total hip arthroplasty collectively had at least as good a functional level and health-related quality-of-life index as those treated with internal fixation over the first four years after fracture. This finding appears to challenge the dictum that preserving a patient’s own femoral head should result in better function than replacement would. However, the reader should recognize that the authors do not subanalyze the functional results of those patients treated with internal fixation who had no further operations and retained their own femoral head compared with those treated with an arthroplasty. The study design correctly analyzes patients according to "intent to treat." Therefore, all patients initially treated with internal fixation were analyzed together, even if they subsequently underwent conversion to total hip arthroplasty. For most of the time during the first four years after arthroplasty, the internal fixation group contained patients with poorer function and quality of life due to nonunited fractures, osteonecrosis of the femoral head, or painful internal fixation screws. By four years, at which time many patients in the internal fixation group had undergone another operation (either conversion to total hip arthroplasty or hardware removal) to resolve problems, the differences in function and quality of life between the groups narrowed.

All patients in the arthroplasty cohort were treated with total hip arthroplasty rather than hemiarthroplasty. In North America, hemiarthroplasty is the most common treatment method in older patients with this diagnosis. The low complication rate demonstrated in the arthroplasty cohort probably also would apply to patients treated with hemiarthroplasty. However, whether the excellent average functional level that the arthroplasty patients attained in this study can be extrapolated to hemiarthroplasty is less certain: hemiarthroplasty likely is associated with a higher risk of groin pain and possibly limp than total hip arthroplasty, although the magnitude of this difference is uncertain, particularly in an older, lower-activity patient population.

The low complication rate in arthroplasty patients in this study can be attributed in part to a low dislocation rate (2%), which is much lower than most previous series of total hip arthroplasties for this diagnosis. One important reason for a low dislocation rate in this series is the selection criteria of the study: prior to fracture, the patients lived independently and were cognitively intact. Further reasons for the low dislocation rate include an anterolateral operative approach and an experienced group of treating surgeons.

The results of this study should not be extrapolated to cognitively disabled or more physically disabled patients who represent a higher risk group for complications of total hip arthroplasty.

*The author did not receive grants or outside funding in support of his research or preparation of this manuscript. The author received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity (DePuy). In addition, a commercial entity (DePuy, Zimmer, and Stryker) paid or directed, or agreed to pay or direct, benefits to a research fund, foundation, educational institution, or other charitable or nonprofit organization with which the author is affiliated or associated.

Copyright © 2005 by the The Journal of Bone and Joint Surgery, Inc.