Fractured neck of femur in the mobile independent elderly patient: should we treat with total hip replacement?

Journal of Orthopaedic Surgery, Dec 2003 by Pai, V S, Arden, D, Wilson, N

ABSTRACT

Purpose. To report the outcome of displaced subcapital neck of femur fractures in the independent elderly (>70 years) managed with total hip arthroplasty through a modified Hardinge approach.

Methods. Between 1998 and 2000, a surgeon performed a cemented hip replacement using a modified lateral approach in 35 consecutive patients in the Hawke's Bay Regional Hospital, Hastings. Medical charts and out-patient follow-up clinic records were reviewed with respect to outcomes, with particular reference to complications. Independent review of functional outcome was completed at one year postsurgery using a questionnaire.

Results. At an average follow-up of 1.8 years (range, 1-3 years), no patient needed further surgery. One patient had died, giving a mortality rate at one year of 2.9%. All other medical complications were successfully treated. The overall prevalence of early medical complications was 43%. There were no dislocations, and 80%) of patients had a good clinical outcome at their latest follow-up.

Conclusion. The modified lateral approach of Hardinge minimises the incidence of postoperative dislocation. However, there was a high incidence of medical complications and aggressive treatment of such complications was necessary, both preoperatively and postoperatively. The number of pre-existing medical conditions was a significant factor influencing patient morbidity.

Key words: femoral neck fractures; Hardinge approach; total hip replacement

INTRODUCTION

The choice of surgical treatment for a displaced intracapsular fracture of the proximal femur in the previously independent elderly patient remains as controversial now as it was almost 50 years ago, and for this reason has been referred to as 'the unsolved fracture'. The goal of treatment of these fractures is the restoration of pre-injury function, without associated morbidity. The improved functional capacity and greater predictability of total joint replacement prostheses have broadened the indications for joint replacement surgery in displaced femoral neck fractures over recent years.

The reported mortality rate associated with this fracture is between 14% and 36%.1 A case fatality study in New Zealand reported a mortality rate of 8% within 35 days, and 24% within one year.2 However, the population of elderly patients with hip fractures is, by nature, a diverse group. Patient subgroups based on age, ambulatory capability, home living environment, and pre-injury co-morbidities (including diabetes, heart disease, dementia, and visual impairment) all differ markedly. Different mortality rates are evident among these subgroups.

The purpose of this review was to evaluate the functional outcome of fractures of the hip in a group of previously mobile, independent, elderly patients following a total hip replacement. There is lack of agreement among New Zealand orthopaedic surgeons regarding the optimum treatment of fracture in this subgroup.3 The study by Beadel et al.4 suggests that a good outcome is likely in this patient group. In that study, specific emphasis was placed on the 1-year mortality and morbidity rates, and the ability to return to pre-injury level with regard to independence, walking, and performing activities of daily living.

The current study reports a consecutive series of 35 patients treated with total hip replacement through a modified lateral approach.

METHODS

Between January 1998 and October 2000, a surgeon (VSP) performed total hip replacements for 35 consecutive patients with a fractured neck of femur at the Hawke's Bay Regional Hospital, Hastings. Inclusion criteria for patient selection were: mobile independent elderly (>70 years) patient; mentally competent (mental test5 score >7), displaced fractured neck of femur, and surgery performed through a modified lateral approach. There were 30 women and 5 men. The patients had a mean age of 85 years (range, 70-92 years), with 14 patients aged over 85 years.

The mean delay between admission and surgery was 2.5 days (range, 1-7 days). At the time of admission effort was made to schedule all patients for surgical stabilisation of the fractured hip as soon as possible. The only patients who were intentionally delayed were those who had an active medical condition that was not well controlled, such as diabetes or congestive heart failure. Associated medical conditions were seen in the majority (68.5%; n=24) of patients preoperatively. These included significant cardiovascular disease (34%; n=12); pulmonary disease (20%; n=7); metabolic conditions, including diabetes, alcoholism, chronic renal failure (30%; n=10); and neurological disorders including stroke, transient ischaemic attack, and Parkinson's disease (20%; n=7). The mean number of preoperative medical conditions was 1,7 per patient. 15 patients had no or minimal medical co-morbidities.

Each patient received 24 hours of prophylactic antibiotics beginning prior to the surgical incision. None of the patients received routine anticoagulant therapy. All of the procedures were performed using the Exeter hip system (Howmedica International Inc., Clare, Ireland) with a 28 mm modular head, and cemented acetabular and femoral components. The capsule-retaining modified lateral approach of Hardinge6 was used in all patients, under spinal anaesthesia, with or without general anaesthesia. This modified approach7 differed from the original approach described by Hardinge in several ways: