Outcomes between older adults with atypical and typical femoral fractures are comparable.

Introduction: Atypical femoral fractures (AFFs) are rare but a serious complication associated with prolonged use of bisphosphonates. However little is known about clinical outcomes of AFFs. The aim of this study is to compare the characteristics and postoperative outcomes between older patients with AFFs and typical femoral fractures (TFFs).

Methods: A retrospective matched cohort study (each AFF was age- and sex-matched with three TFFs) of patients aged 65 years or older who were admitted to The Queen Elizabeth Hospital, South Australia between January 2011 and December 2013 was undertaken. Baseline characteristics of both groups were compared. The primary outcomes evaluated were level of independence in mobility at discharge and 3 months after surgery. Secondary outcomes included length of hospital stay, post-operative complications, rate of surgical revision, discharge destination (after acute hospital stay or rehabilitation), 28-day hospital readmission and 12-month mortality.

Results: Ten patients (mean age: 78.1 years) with AFFs were compared with 30 matched TFFs. Patients with AFFs were predominantly female (90%) and 80% had been taking oral bisphosphonate. Nine of the AFFs had their fractures fixed with an intramedullary (IM) nail. The level of independent mobility at discharge (OR 0.31; 95%CI: 0.06-1.71; p=0.26) and at 3 months (OR 0.51; 95%CI: 0.10-2.53; p=0.47) were comparable between the two groups. Only one AFF patient treated with plate and screws required surgical revision, compared with none in the TFF group. Secondary outcomes were not significantly different between the two groups.

Conclusion: Recovery of mobility and reoperation rates after surgery of patients with AFFs were favourable and did not differ significantly from TFFs. Further consideration should be given to using IM fixation in the management of AFFs in older people.