Cemented Hemiarthroplasty Versus Uncemented Furlong Hemiarthroplasty

In England each year over 9,000 people fracture their hip. Most of these are elderly females with the fracture occurring after a fall. Approximately half of these fractures are classified as intracapsular fractures because of their close proximity to the hip joint. The majority of these fractures are treated surgically by excising the broken femoral neck and removing the femoral head (ball part of the hip joint) and replacing it with an artificial hip joint. This hip replacement has traditionally been a hemiarthroplasty or sometimes termed a 'half hip replacement' in which only the ball part of the hip joint is replaced. There are a number of different designs of hemiarthroplasty that may be used. Some of the implants are fixed in place with bone cement whilst the rest are inserted as a press fit without the bone cement. The early designs of implant were all press fit but these designs have now been shown to be inferior to those implants that are fixed in place with bone cement. There are however a number of newer designs of implant that are coated with a substance (hydroxyapatite) that encourage the bone to grow onto the implant to fix it into place. To date these implants have only been compared to the cement fit implants in only one previous study. This study found no notable difference between the two types of hemiarthroplasty. This study aims to add to the research studies by comparing standard cement fit implant with a hydroxyapatite coated press fit implant to assist in determining the optimum surgical treatment for this common and disabling condition. Both implants to be used in this study are still being used extensively within the United Kingdom and worldwide to treat this fracture. The study is therefore using two different implants within their recommended area of use, but in which there is uncertainty as to which is the best implant.

As a follow-on from our current randomised trials of different types of treatment for hip fractures, we wish to undertake a prospective randomised trial to compare a modern cemented hemiarthroplasty prosthesis with a modern hydroxyapatite coated uncemented arthroplasty. Cemented Exeter monoblock hemiarthroplasty The Exeter stemmed total hip replacement is considered one of foremost performing hip replacements in the world. The ETS (Exeter trauma stem) is one such implant and costs around £200. The implant has modern instrumentation and the stem has proven long term survival rates when used for total hip replacement. Hyroxyapatite coated prosthesis Coating a hip prosthesis with hydroxyapatite is common practice for an uncemented hip replacement arthroplasty. The hydroxyapatite stimulates bone ingrowth around the prosthesis and is this is thought to reduce loosening of the implant, residual pain and the long-term revision rate. The aim of the study is to assist in defining the optimum choice of arthroplasty for an acute hip fracture.

The cemented monoblock hemiarthroplasty is a double tapered polished stem with a hemiarthroplasty head cemented in place (Zimmer incorporated, UK)

the Furlong Hyroxyapatite coated prosthesis (JRI orthopaedics limited UK) is a hydroxyapatite coating uncemented a hip prosthesis with a hemiarthroplasty head. The implant is uncemented.

A furlong uncemeneted hyroxyapatite coated prosthesis.The hydroxyapatite stimulates bone ingrowth around the prosthesis and is this is thought to reduce loosening of the implant, residual pain and the long-term revision rate.

measurement with a mobility score - Kristensen MT, Bandholm T, Foss NB, Ekdahl C, Kehlet H. High inter-tester reliability of the new mobility score in patients with hip fracture. J Rehabil Med 2008;40:589-91.

Inclusion Criteria: All patients admitted to Peterborough City Hospital with a displaced intracapsular fracture will be considered for inclusion in the study. Exclusion Criteria: • Younger patients in which internal fixation is felt to be the choice of treatment to preserve the femoral head. This is generally those aged less than 60 years in which these patient have an expected good long term survival and are all treated by reduction and internal fixation. All other patients in whom the injury is to be treated by reduction and internal fixation for a specific indication. Those patients who are able to walk independently out of doors with no more than the use of a stick and are not cognitively impaired. These patients will first be considered for the ongoing randomised trial of Hemiarthroplasty or Total hip replacement (R&D reference - R&D/2012/30, REC reference - 12/LO/15490) Patients who decline to participate. Patients admitted when MJP is not available to supervise treatment.

Parker MJ, Cawley S. Cemented or uncemented hemiarthroplasty for displaced intracapsular fractures of the hip: a randomized trial of 400 patients. Bone Joint J. 2020 Jan;102-B(1):11-16. doi: 10.1302/0301-620X.102B1.BJJ-2019-1041.R1.