SGER: Separation of Polyethylene Wear Debris Found in Synovial Fluid Generated from Total Joint Prostheses Using Bio-Ferrography

University Of Rhode Island, Kingston RI

Investigators

Abstract

0092944 Meyer The orthopedic community would benefit from knowing the ratio of the various constituents contained in the synovial fluid of patients with total hip and knee replacements before the onset of complications leading to revision surgery. Aspirating the joints of patients with indications is recommended most specifically prior to revision surgery. It is the aspirate from these patients that will be used as the basis for the proposed set of experiments. The ratios of the constituents to each other may be used by physicians as one of several tools in the decision whether to perform revision surgery. There may also be instances in which surgery will not be recommended based in part on the particulate ratios, in which case benefits to both the patient and the economy may be realized. The clinical relevance would be that the surgeon now has a quasi-inside look at the prosthesis before surgery, offering some information about what area(s) of the implant may require revision. This is not information that can be readily seen in x-rays or by other visual means. An SGER award supports research to examine the feasibility of using a technique called Bio-Ferrography to separate the various types of wear particles which form in total hip and knee replacements as they wear. The PI has access to a unique collection of over one hundred well-documented samples of synovial fluid aspirate which has been obtained from total hip and knee replacements prior to revision surgery. The primary wear particles are ultra high molecular weight polyethylene (UHMWPE) from the acetabular cup, metal particles such as stainless steel or cobalt-cromium-molybdenum from the femoral head, particles of bone cement used for fixation of the prostheses at the bone/implant interface, and bone particulate itself. The particles will be tagged with magnetic tagging molecules which make it possible to sort them by the magnetic field in the bio-ferrograph. Identification of suitable tagging molecules, sorting of the particles by material and size, and relating the nature and amount of wear particles to observations made of the worn joint during and after surgery will be the main components of the study. ***