Minimally invasive anterior muscle-sparing versus a transgluteal approach for hemiarthroplasty in femoral neck fractures-a prospective randomised controlled trial including 190 elderly patients

Abstract

Background: The relevance of femoral neck fractures (FNFs) increases with the ageing of numerous societies, injury-related decline is observed in many patients. Treatment strategies have evolved towards primary joint replacement, but the impact of different approaches remains a matter of debate. The aim of this trial was to evaluate the benefit of an anterior minimally-invasive (AMIS) compared to a lateral Hardinge (LAT) approach for hemiarthroplasty in these oftentimes frail patients.

Methods: Four hundred thirty-nine patients were screened during the 44-months trial, aiming at the evaluation of 150 patients > 60 yrs. of age. Eligible patients were randomised using an online-tool with completely random assignment. As primary endpoint, early mobility, a predictor for long-term outcomes, was evaluated at 3 weeks via the "Timed up and go" test (TUG). Secondary endpoints included the Functional Independence Measure (FIM), pain, complications, one-year mobility and mortality.

Results: A total of 190 patients were randomised; both groups were comparable at baseline, with a predominance for frailty-associated factors in the AMIS-group. At 3 weeks, 146 patients were assessed for the primary outcome. There was a reduction in the median duration of TUG performance of 21.5% (CI [- 41.2,4.7], p = 0.104) in the AMIS-arm (i.e., improved mobility). This reduction was more pronounced in patients with signs of frailty or cognitive impairment. FIM scores increased on average by 6.7 points (CI [0.5-12.8], p = 0.037), pain measured on a 10-point visual analogue scale decreased on average by 0.7 points (CI: [- 1.4,0.0], p = 0.064). The requirement for blood transfusion was lower in the AMIS- group, the rate of complications comparable, with a higher rate of soft tissue complications in the LAT-group. The mortality was higher in the AMIS-group.

Conclusion: These results, similar to previous reports, support the concept that in elderly patients at risk of frailty, the AMIS approach for hemiarthroplasty can be beneficial, since early mobilisation and pain reduction potentially reduce deconditioning, morbidity and loss of independence. The results are, however, influenced by a plethora of factors. Only improvements in every aspect of the therapeutic chain can lead to optimisation of treatment and improve outcomes in this growing patient population.

Trial registration: www.clinicaltrials.gov : NCT01408693 (registered August 3rd 2011).

Keywords: Femoral neck fracture; Fracture hemiarthroplasty; Gerontotraumatology; Minimal invasive hemiarthroplasty; Orthogeriatrics; Randomized controlled trial in the elderly; Trauma surgery in geriatric patients.

Fig. 1

Institutional treatment algorithm for femoral neck fractures. Algorithm for the treatment of FNF with a high degree of personalizability according to the specific patient characteristics, with a focus is on early pain free and fully weight-bearing mobilization

Fig. 2

Flow of patients in the two trial arms. Flowchart documenting the reasons for unavailability for analysis after randomization

Fig. 3

The distribution of duration of TUG performance (DTP) at the 3 weeks follow up visit in relation to treatment arm and pfFIM. Visualisation of the duration of TUG performance in the context of its clinical relevance. The green background signifies independence, while the yellow and red imply an increasing degree of dependence for mobilisation (yellow) and basic activities of daily living (red)

Fig. 4

Distribution of duration of TUG performance (DTP) at day 5 and at all follow up visits in relation to treatment and pfFIM. Individual values for patients’ TUG performance in relation to their pfFIM and treatment. The running median curves are based on the next 25 neighbours on both sides of an observation and illustrate larger differences in patients with lower pfFIM. Note that the y-axis uses a logarithmic scale

Fig. 5

The distribution of duration of TUG performance (DTP) at day 5 and at all follow-up visits stratified by treatment arm and by normal and abnormal MSQ-values (upper panel) or by frailty index (lower panel). The figure illustrates larger differences in TUG duration for patients with low abnormal MSQ values or with high frailty index, respectively, especially at early time-points. Note that the y-axis uses a logarithmic scale