External Validity of a Randomized Controlled Trial in Patients With a Femoral Neck Fracture

The aim of this study is to evaluate the external validity of a randomized controlled trial comparing choice of hip arthroplasty for elderly patients (>80 years) with a displaced femoral neck fracture.

The hypotheses are that patient reported hip function, quality of life are better and healthier in those included in the randomized controlled trial than those excluded. The external validity of the randomized controlled trial is acceptable.

A prospective randomized controlled trial is planned and patients with a displaced femoral neck fracture will be included and randomized between either a hemiarthroplasty or total hip arthroplasty. All patients screened will be included in a prospective cohort study for evaluation of the external validity of the randomized controlled trial. The prospective cohort study will consist of 3 different groups.

Patients included in the randomized controlled trial will form group 1. Patients eligible for the randomized controlled trial but did not give their informed consent and therefore excluded, form group 2.

Patients with a femoral neck fracture which by any reason were excluded form group 3.

Primary endpoint is patient-reported hip function (Harris hip score) and pain on the operated extremity evaluated with VAS (Visual Analogue Scale) and patient reported quality of life evaluated with EuroQol (EQ-5D). Secondary outcome measurement are the frequency of the complications, periprosthetic fracture, dislocation, revision surgery due to wound infection (deep and superficial) and loosening of the components. Baseline data, age, sex, comorbidity, cognitive status, weight, height, motor function, complications and reoperations. Follow up is performed 1-2 years after surgery.

Group 1 is followed up in the ongoing randomized controlled trial by visits to the orthopedic department at Danderyd Hospital. Group 2 and 3 are followed up by telephone interview 1-2 year after surgery.