Wear Assessment of Tibial Inserts Made of Highly Cross-Linked Polyethylene Supplemented with Dodecyl Gallate in the Total Knee Arthroplasty.

BACKGROUND: the wear of tibial insert is still one of primary factors leading to failure of total knee arthroplasty (TKA). Dodecyl gallate (DG) has shown improvements in the oxidation stability of highly cross-linked polyethylene (HXLPE). This study aimed to assess the application of HXLPE supplemented with DG (HXLPE-DG) on the tibial insert in TKA concerning the wear resistance and the potential impact on implant fixation; Methods: tibial inserts made of HXLPE-DG were subjected to a 3 million loading-cycle wear test following ISO 14243-1:2009. The loss of mass and wear rate of the tibial inserts were calculated. The quantity, size,- and shape of wear particles were recorded; Results: the test specimens lost an average mass of 16.00 mg ± 0.94 mg, and were on an average wear rate of 3.92 mg/million cycles ± 0.19 mg/million cycles. The content of wear particles in the calf serum medium was 3.94 × 108 particles/mL ± 3.93 × 107 particles/mL, 96.66% ± 0.77% of the particles had an equivalent circular diameter less than 0.5 µm. The aspect ratio of wear particles was 1.40 (min: 1.01; max: 6.42). CONCLUSIONS: HXLPE-DG displayed advantages over the commonly used materials for tibial inserts and presented the potential of application in TKA.

In Vitro Analysis of Wearing of Hip Joint Prostheses Composed of Different Contact Materials.

Cobalt-chromium-molybdenum alloy (CoCrMo) and ceramic are the two most common materials for the femoral head in hip joint prostheses, and the acetabular liner is typically made from ultra-high molecular weight polyethylene (UHMWPE), highly cross-linked polyethylene (XLPE), or highly cross-linked polyethylene blended with Vitamin E (VEXLPE). The selection of suitable materials should consider both wear performance and cost-effectiveness. This study compared the wear rate between different friction pairs using a hip joint simulator and then recommended a suitable prosthesis based on the corresponding processing technology and cost. All wear simulations were performed in accordance with ISO 14242, using the same hip joint simulator and same test conditions. This study found that when using the same material for the femoral head, the XLPE and VEXLPE liners had a lower wear rate than the UHMWPE liners, and the wear rate of the XLPE liners increased after blending with Vitamin E (VEXLPE). There was no significant difference in the wear rate of XLPE when using a CoCrMo or ceramic head. Considering the wear rate and cost-effectiveness, a CoCrMo femoral head with an accompanying XLPE liner is recommended as the more suitable combination for hip prostheses.