Session V - Geriatrics

*Internal Fixation vs. Primary Total Hip Arthroplasty for Dislocated Femoral Neck Fractures: A Prospective Randomized Study

Jan Tidermark, MD; Sari Ponzer, MD; Olle Svensson, MD; Hans Törnkvist, MD, Department of Orthopaedics, Stockholm Söder Hospital, The Karolinska Institute, Stockholm, Sweden

Purpose: Although healing complications are common, the traditional treatment in Sweden for dislocated femoral neck fractures in the elderly is internal fixation with cannulated screws. The rationale for this concept is to salvage the hip of patients in whom the fracture heals. In North America, the current treatment for these patients is a hip arthroplasty, usually a hemi-prosthesis. Total hip replacement (THR) offers a better functional outcome but even here the literature presents high complication rates among these patients, particularly dislocations. The aim of this study is to analyze the differences in outcome after dislocated femoral neck fractures in elderly randomized to either internal fixation (IF) or THR.

Methods: Patients (>70 years) with an acute dislocated femoral neck fractureand normal walking capability, without severe cognitive dysfunction and living independently were randomized to internal fixation (IF) with 2 cannulated screws or to a primary modular THR using a Hardinge approach. Only 2 surgeons were involved. The patients were summoned at 4 and 12 months for clinical and radiographical examination. Two formulas for assessing quality of life were also presented to the patients (SF-36 and EuroQol). Pain at rest and pain while walking (VAS) were estimated. Changes in activity of daily living (ADL) were recorded. All patients were able to participate in the interviews.

In the THR group (n=23), 6 patients were excluded (2 refused, 2 had aortic valve stenosis contra-indicating major surgery, 1 developed sepsis prior to surgery, and 1 was diagnosed with rheumatoid arthritis (RA) during the follow-up). One patient was excluded in the IF group (n=23)(RA diagnosis during follow-up). Thirty-nine remained in the study group (5 males), mean age 81 (70­96). The 2 groups had similar background data.

Results: One IF patient had a myocardial infarction at 2 weeks after surgery. One THR patient had a suspected superficial infection that healed with antibiotics. In the IF group, 7 patients received a secondary hip arthroplasty (6 redislocations/ pseudarthrosis and 1 AVN), a 32% reoperation rate. One THR patient died (not related to surgery) at 10 months. There were no other complications. No dislocations occurred in the THR group. The mean total hospital stay during the first postoperative year was 36 days in the IF group and 26 days in the THR group.

At 12 months, even when excluding the patients with healing complications, the IF group fared worse than the THR group. VAS (0-100) for pain at rest: IF 13, THR 5; pain while walking: 25, 10. Walking aids were utilized by 67% in the IF group and 31% in the THR group. ADL (Katz), independent: 73%, 75%. Quality of life estimated by SF-36 and EuroQol was more than 10% higher in the THR group than in the IF group at 4 and 12 months.

Discussion: The complication rate after IF in dislocated femoral neck fractures is high. It is often claimed that many patients do not need further surgery because of their poor general condition. This was not our experience, perhaps because the cognitive state of the patient was one inclusion criteria. By using an anterior approach and modern modular THRs preserving an adequate offset, the dislocation rate can be decreased, and here the mental state of the patients also is of importance. The encouraging preliminary results with primary THR in elderly healthy patients with dislocated femoral neck fractures may be due to the surgical technique, selection of a modular prosthesis and strict indications.

Conclusion: Primary THR for dislocated femoral neck fractures in elderly patients seems to produce a better outcome than IF, even when compared to the IF patients without healing complications.