Minimally Displaced Femoral Neck Fracture Pilot Study

Nearly half of all elderly hip fractures are femoral neck fractures (FNFs) and approximately 20% are minimally displaced. Internal fixation has remained the treatment of choice for these injuries because these fractures can be fixed in situ and the surgical implants can be inserted with little surgical dissection. Patients treated with internal fixation experience high complication rates, with the pooled risk of reoperation and mortality each above 14%. Preliminary data have suggested arthroplasty for minimally displaced fractures may lead to better patient outcomes, including improved ambulation, fewer reoperations, and a lower risk of death compared to internal fixation. While the preliminary data supporting the use of arthroplasty for minimally displaced fractures is promising, the necessary evidence to make this significant practice change remains lacking.

The eventual definitive trial has significant potential to change clinical practice and optimize patient outcomes for individuals that experience a minimally displaced FNF. Treating minimally displaced FNFs with arthroplasty, instead of internal fixation, would be a paradigm shift in clinical care. This pilot study will demonstrate feasibility of the definitive trial and be used to refine aspects of the study protocol as necessary. If feasibility is successfully demonstrated, the pilot activities will be considered a vanguard phase for the definitive clinical trial.

Adult patients ages 60 years or older with a low-energy minimally displaced femoral neck fracture treated with surgery will be eligible to participate in the study. Patients will be randomized to receive either hip arthroplasty or internal fixation. Patients will be followed for 1 year, with visits occurring at 6 weeks, 4 months, 8 months, and 1 year after fracture. At each follow-up, mortality, ambulation, days at home, and health status will be collected.

The primary objective is to assess feasibility of the trial and to collect information to inform the design of the definitive trial. The feasibility outcomes will include participant enrollment, adherence to treatment allocation, data collection methods, and compliance with key aspects of the protocol.

Inclusion criteria

• Patients 60 years of age or older.
• Complete fracture of the femoral neck (AO/OTA 31B) confirmed with anteroposterior and lateral hip radiographs, computed tomography, or magnetic resonance imaging (MRI).
• Minimally displaced fracture that could be, in the judgment of the attending surgeon, optimally managed with either arthroplasty or in situ internal fixation without reduction.
• Low energy injury mechanism defined as a fall from standing height.
• Informed consent obtained from patient or proxy.
• Surgeons with expertise in total hip arthroplasty, hemiarthroplasty, and internal fixation are available to perform surgery. Note: Surgeons do not need to be experts in all techniques.

Exclusion criteria

• Unable to ambulate 10 feet pre-injury with any assistance.
• Associated lower extremity injury that prevents post-operative weightbearing.
• Retained hardware around the hip that precludes either study treatment.
• Infection around the hip (soft tissue or bone).
• Pathologic fracture with a lytic lesion in the femoral neck that precludes internal fixation.
• Patient is too ill, in the judgement of the attending surgeon, for internal fixation.
• Patient is too ill, in the judgement of the attending surgeon, for arthroplasty.
• Unable to obtain informed consent due to language barriers.
• Problems, in the judgment of study personnel, with maintaining follow-up with the patient.
• Currently enrolled in a study that does not permit co-enrollment.
• Prior enrollment in the trial.
• Other reason to exclude the patient, as approved by the Methods Centre.