Treatment of displaced femoral neck fractures in the elderly

Abstract: Femoral neck fracture (FNF) in elderly patients is a common cause of suffering and premature death in individuals with osteoporotic bones. This fracture type is more common in women after menopause, and the associated patients are often osteoporotic, which contributes to a higher incidence of fractures. FNFs can be undisplaced or displaced, with the latter representing 70-75% of cases. The treatment of displaced FNF in the elderly is still controversial. Optimizing the treatment for improved outcomes and reducing the need for secondary surgery are mandatory for humanitarian and economic reasons. Various options for the surgical treatment of patients with FNF are available, including internal fixation (IF), hemiarthroplasty (HA) and total hip arthroplasty (THA). Each treatment has its advantages and disadvantages. IF is not controversial for the treatment of undisplaced FNF and represents the method of choice for displaced FNF in young patients (less than 65-70 years old) and the frailest elderly patients who are not medically fit for prosthesis surgery. HA is the most common surgical procedure in elderly patients with low functional demands, whereas THA is the preferred method for healthy, active and lucid elderly patients. HA is still the dominant procedure for the treatment of displaced FNF. In Sweden, 64% of all patients with displaced FNF are treated with HA, 22% are treated with THA and 14% are treated with internal fixation. The most common method of performing prosthesis fixation in elderly patients is with bone cement, although concerns over performing this method in older frail patients with multiple comorbidities have been noted. Bone cement implantation syndrome (BCIS) is more prevalent in cemented stems than uncemented stems in patients with FNF. Severe BCIS has a substantial impact on early and late mortality. Thus, the use of uncemented hydroxyapatite stems for this patient group may be justified. Recent reports on modern hydroxyapatite-coated femoral stems used in FNF patients have shown promising early results. However, a more direct comparison between uncemented and cemented stems is required because recent register data suggest a significant increased risk of reoperation with uncemented stems. The functional outcome and the rate of complications and reoperation after modern HA in patients with displaced FNF in combination with cognitive dysfunction are relatively unknown. This patient group has not been sufficiently analysed, and a few studies have recommended IF for this patient group. Moreover, some studies have reported improved post-operative functional outcomes and a lower rate of complications and reoperation after cemented HA compared to IF, even in the presence of severe cognitive dysfunction. The aim of this thesis was to define the optimal treatment for elderly patients with a displaced FNF with respect to their age, functional demands and cognitive function. Study I: This study is a randomized controlled trial (RCT) of 100 patients ≥65 years of age with a displaced FNF, and it was designed to compare THA and IF. Follow-up evaluations were performed at three months and at one, two, four, eleven, and seventeen years. We found a higher Harris hip score and a lower rate of reoperations for patients who were treated with THA. Study II: This study is a RCT of 69 patients aged 65-79 years with a displaced FNF, and it was designed to compare uncemented and cemented stems in patients treated with THA. The patients were followed up at three months and one and two years. Patients who were treated with the uncemented stems showed more complications than patients who were treated with the cemented stems without affecting the functional outcome. Study III: This study is a RCT of 120 patients ≥80 years of age with a displaced FNF, and it was designed to compare THA and HA. The one-year results showed that THA did not present superior outcomes to those of HA. Study IV: This study is a prospective observational cohort study of 160 patients with displaced FNFs, and it was designed to compare the results after HA in 100 patients aged ≥65 years with cognitive dysfunction with that of 60 patients aged ≥80 years without cognitive dysfunction. The patients were followed up at three months and one year. HA in patients with cognitive dysfunction was associated with higher mortality and a higher prevalence of the inability to walk. Patients with cognitive dysfunction who did not receive geriatric rehabilitation had worse patient-reported outcomes and were almost 9-times more likely to be confined to a wheelchair or bedridden. The main conclusions of this thesis are as follows: • THA is the treatment of choice for a displaced FNF in healthy and lucid elderly patients with good hip function preoperatively. • Uncemented femoral stems should be avoided in patients older than 65 years with a displaced FNF. • THA yields no benefits over HA in octa- and nonagenarians treated for a displaced FNF. • HA is a safe option as a treatment for displaced FNF in patients with dementia or cognitive dysfunction.