Displaced femoral neck fractures in the elderly : treatment with arthroplasties

Treatment of displaced femoral neck fractures in the elderly with arthroplasties has become standard practice during the last decade and results in good and predictable outcomes regarding hip function and health-related quality of life (HRQoL). There is, however, a lack of evidence concerning certain types of arthroplasties and different subgroups of patients. Patients with severe cognitive dysfunction have a very limited life expectancy after a hip fracture and low functional demands, as well a low HRQoL before the injury. Many surgeons have concerns regarding arthroplasties in these patients. The bipolar hemiarthroplasty (HA) is designed to reduce stress and erosion on the patient`s natural acetabulum and should, in theory, render a better functional outcome and HRQoL than the unipolar HA. Patients with arthroplasties after displaced femoral neck fractures are at higher risk of sustaining a late periprosthetic fracture (PPF) compared to patients treated due to degenerative joint disease. In addition, some prosthetic designs have been pointed out as being a risk factor for PFF. Uncemented arthroplasties are widely used for various indications and show excellent clinical results. In addition, there are concerns about cementing in older frail patients with multiple comorbidities. All patients in Studies I to IV have been treated with arthroplasties because of a displaced femoral neck fracture.

Study I is a randomised controlled trial (RCT) comparing treatment with internal fixation (IF) and treatment with HA in patients with severe cognitive dysfunction. Compared to treatment with IF, HAs appear to result in a better HRQoL and fewer reoperations.

Study II is an RCT with a 48-month follow-up comparing bipolar and unipolar HAs. Treatment with a bipolar HA resulted in a better HRQoL after four years.

In Study III a cohort of 2757 patients with primary or secondary arthroplasties after femoral neck fractures were investigated. A single cemented femoral implant was used. The incidence of PPFs was high (2.3%) in the cohort, but the surgical outcome after reoperation for a PFF was better compared to previous reports.

Study IV is an RCT with a 12-month follow-up comparing uncemented arthroplasties with cemented arthroplasties. The uncemented arthroplasties showed inferior results regarding functional outcome and HRQoL.

The main conclusions of this thesis are: Treatment of displaced femoral neck fractures with arthroplasties is safe, even for patients with severe cognitive dysfunction; the use of uncemented arthroplasties should be avoided and there are still controversies regarding the use of bipolar Has.

List of scientific papers

I. Internal fixation versus cemented hemiarthroplasty for displaced femoral neck fractures in patients with severe cognitive dysfunction: a randomized controlled trial. Hedbeck CJ, Inngul C, Blomfeldt R, Ponzer S, Törnkvist H, Enocson A. J Orthop Trauma. 2013 Dec;27(12):690-5.
https://doi.org/10.1097/BOT.0b013e318291f544

II. Unipolar hemiarthroplasty versus bipolar hemiarthroplasty in patients with displaced femoral neck fractures: a four-year follow-up of a randomised controlled trial. Inngul C, Hedbeck CJ, Blomfeldt R, Lapidus G, Ponzer S, Enocson A. Int Orthop. 2013 Dec;37(12):2457-64.
https://doi.org/10.1007/s00264-013-2117-9

III. Postoperative periprosthetic fractures in patients with an Exeter stem due to a femoral neck fracture: cumulative incidence and surgical outcome. Inngul C, Enocson A. Int Orthop. 2014 Oct 24. [Epub ahead of print]
https://doi.org/10.1007/s00264-014-2570-0

IV. Cemented versus uncemented arthroplasty in patients with displaced femoral neck fractures: a randomised controlled trial. Inngul C, Blomfeldt R, Ponzer S, Enocson A. [Submitted]