Short summary

The study concerns hip fracture patients, that are operated with an total hip arthroplasty(THA). One group of patients is operated primarily with a THA after fracture, the other group gets a THA, secondarily, as a salvage procedure after failed primary treatment.

We want to establish, if the secondary THA group is at higher risk of revision, which would be result of a major complication. This would help to improve the quality of the information, the patients get preoperatively, as well as  to help improve treatment modalities.

Rationale

Introduction

Hip fractures are the most common osteoporotic fractures and intracapsular fractures of the hip comprise about 50 % of the above. World population, as well as life expectancy is increasing, leading to aging populations that contribute to growing numbers of hip fractures. Treatment of the osteoporotic fractures, as well as complications to the treatment is  well recognised as a growing burden on the health systems.  

In Denmark the intracapsular fractures of the hip are treated according to recommendations based on the types of fractures, age of the patients and their daily function. The treatment algorithm for displaced fractures recommends internal fixation for patients younger than 70 years old, total hip arthroplasty (THA) for patients between 70 and 80 years old and hemialloplasty for patients over 80. Patients with severely impaired cognitive functions or without ability to walk can be treated with Girdlestone procedure. 

Treatment of intracapsular hip fractures has been a subject of vigorous discussion for almost a century. Numerous studies compare THA with hemiarthroplasties and internal fixation and find it just as safe in regard to mortality and medical postoperative complications.

  Problems with the treatment include dislocations, postoperative deep infection, aseptic loosening, periprosthetic fracture and reoperations. 

There are only few studies describing outcomes after a secondary THA, performed when primary procedure fails. The earlier studies compare the patients receiving secondary THA with a primary THA performed as a treatment for arthritis. Reported complications include deep infection, permanent dislocation and aseptic loosening of the femoral component.

Existing studies are not sufficient to compare the clinical data of patients treated with a THA as a primary procedure after a hip fracture with those who received a THA as a result of a salvage procedure after failed IF or HA. 

Motivation

Modern clinical practice requires that both the patients and physicians are aware of the advantages and risks when choosing a treatment. Hip fractures are treated surgically. There are different surgical procedures available to choose from. Failed primary procedures are treated with a secondary THA in majority of patients. At present we lack the knowledge about complications of the treatment in patients previously sustaining a hip fracture. The study aims at presenting the risks and complications associated with a secondary THA. Other aim of the study is comparing the patients with a secondary THA with those treated with a primary THA after a hip fracture. This will help the clinicians to make an informed decision while choosing the treatment option. It will provide information for both surgeons and patients facing salvage procedures about the risks of surgery, as well as the rate of complications in the postoperative phase. The study will also give information about longer term complications and the risk of revision in the salvage procedure patients as well as primary THA patents.

Aim

Primary aim of the study is to calculate the overall risk of revision in patients, receiving a secondary THA as a salvage procedure after failure of the initial fracture treatment. Then compare it to the risk of revision in patients, receiving a primary THA as a hip fracture treatment.

Secondary aim of the study is to identify reasons for revision and assess mortality in the two groups. 

Description of the cohort

The study will be conducted on a retrospective cohort of Danish hip fracture patients. In Denmark all the data about every contact to national hospital health care system is recorded in Danish National Patient Registry - Landspatientregistret (LPR). Patients undergoing THA surgery, both primary and secondary, are reported to the Danish Hip Arthroplasty Register (DHR). 

Danish hip fracture patients, aged 65 and over, receiving THA as a primary or secondary procedure. The subjects will be chosen from DHR with the exposure: "patients receiving primary THA after a hip fracture" and "patients previously operated on the same hip with internal osteosynthesis or hemialloplasty, receiving a THA". Those are the terms used to report the surgeries to DHR.

Participants will be identified by the national ID number. This will allow the follow up and cross-matching between databases. 

Exclusion criteria: pathologic fracture

The inclusion period will be 2009 - 2014, set arbitrarily. 

The patients will be followed for at two years until the first revision, death or loss to follow up. 

Data and biological material

Retrospective cohort study based on data from the Danish Hip Arthroplasty Register (DHR). National cohort. Study protocol written in accordance with The Reporting of studies Conducted using Observational Routinely-collected health Data (RECORD) guidelines.

Collaborating researchers and departments

Department of Orthopedic Surgery, Esbjerg Hospital

• Dominika Butowska, MD

Department of Orthopedic Surgery, Kolding Hospital

• Bjarke Viberg, PhD

Department of Orthopedic Surgery, Esbjerg Hospital

• Professor Niels Wedderkopp

Department of Orthopedic Surgery, Odense University Hospital

• Professor Søren Overgaard, dr. med.