E_SURF

Clinical studies have shown that hip resurfacings provide improved patient function over total
hip replacements (THR) with reduced recovery times; however, since 2008 there has been a
large fall in the number of resurfacings performed. This is due to concern over ion release
from metal-on-metal (MoM) implants leading to ALVAL (aseptic lymphocytedominated
vasculitis associated lesion, also termed pseudotumors) and chromosomal changes.The aim of
this project is to develop a metal-on-polymer (MoP) bearing couple on a large diameter
resurfacing device. The MoP bearing couple consists of an acetabular component assembled
from an innovative metal shell and polymer liner, and a metal femoral head. ECiMa (vitamin
E cold irradiated mechanically annealed) is a next generation advanced bearing developed by
Corin and Massachusetts General Hospital, and is proven to be a low wearing polymer with
enhanced fatigue resistance. ECiMa is currently used as a bearing surface in THRs. This
project will combine the current technical advances in polymer bearings with the clinical
benefits of resurfacing to produce a next generation device suitable for young, active patients.
The innovative MoP hip resurfacing will have a direct positive impact, especially on younger
patients for the treatment of arthritis. Lower wear rates, improved function, increased range of
motion and a return to an active lifestyle, mean that a resurfacing procedure is preferential to
THR for sections of the patient demographic. Patients thought to benefit from hip resurfacing,
but not currently recommended for a MoM device as they are considered at high risk from
metal ion release, will be able to take advantage of the bone conserving treatment. The device
will help address the NHS drive for an eighteen week referral to a treatment admitted pathway
as hip resurfacings have a shorter recovery time and so can help reduce the current backlog of
orthopaedics waiting times.