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

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). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12877-018-0898-9) contains supplementary material, which is available to authorized users.