Particle size and morphology of UHMWPE wear debris in failed total knee arthroplasties—a comparison between mobile bearing and fixed bearing knees

Abstract

Osteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long-term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (1 3%). We postulated that mobile bearing knee implants tend to produce smaller sized particles. In our current study, we compared the particle size and morphology of polyethylene wear debris between failed mobile bearing and fixed bearing knees. Tissue specimens from interfacial and lytic regions were extracted during revision surgery of 10 mobile bearing knees (all of the low contact stress (LCS) design) and 17 fixed bearing knees (10 of the porous-coated anatomic (PCA) and 7 of the Miller/Galante design). Polyethylene particles were isolated from the tissue specimens and examined using both scanning electron microscopy and light-scattering analyses. The LCS mobile bearing knees produced smaller particulate debris (mean equivalent spherical diameter: 0.58 tiin in LCS, 1.17 pm in PCA and 5.23 pm in MIG) and inore granular debris (mean value: 93% in LCS, 77%) in PCA and 15%) in MIG).

Wear Tests of a Potential Biolubricant for Orthopedic Biopolymers

“…These nanoparticles are of a similar size range to wear debris found in failed total knee arthroplasties (low contact stress mobile bearing prostheses) [29]. There were a number of limitations.…”

Staged bilateral mobile-bearing and fixed-bearing total knee arthroplasty in the same patients: a prospective comparison of a posterior-stabilized prosthesis

“…In one knee with a mobile-bearing prosthesis, the preoperative femorotibial alignment was 11°o f valgus. The preoperative femorotibial alignment averaged 8.9°of varus (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) in all knees with a fixed-bearing prosthesis. The postoperative femorotibial alignment Fig.…”

Highly Crosslinked Polyethylene is Safe for Use in Total Knee Arthroplasty

“…There are data [43] suggesting particles generated by the highly crosslinked polyethylene are smaller when compared with traditional UHMWPE. These smaller particles are more biologically active and theoretically could create more osteolysis [11,14,21,22,33,43]. Patients can show signs of osteolysis while being asymptomatic and the rate of progression of osteolysis is variable.…”

“…The cellular response, including release of proinflammatory cytokines, results in the stimulation of osteoclasts and suppression of osteoblasts. The smallest particles induce the largest response secondary to the phagocytosis by macrophages [13,14,21,22]. In the face of major osteolysis, considerable bone loss may occur.…”