The effect of synthetic polymer lubricants on the friction between common arthroplasty bearing biomaterials for encapsulated spinal implants

•Friction coefficient has been tested for different biomaterial and bio-lubricants.•Range of materials (combinations of CoCr, UHMWPE and PEEK) have been used.•Polyvinyl alcohol (PVA) was compared with Ringer׳s solution and calf serum.•The PVA showed the lowest friction coefficient for all biomaterial combinations.•The lowest friction coefficient was measured for UHMWPE/CoCr with PVA C (20 grs/100 ml).

There are two major problems with ball and socket artificial joints; the migration of wear particles inducing an inflammatory response, causing toxicity, osteolysis and subsequent implant loosening; and the poor tribology between interstitial or synovial fluid and device׳s articulation surfaces. Experiments have been conducted to assess the potential of the promising bio-lubricant polyvinyl alcohol (PVA) at different concentrations with a range of materials (combinations of CoCr, UHMWPE and PEEK). Tests were conducted on a pin-on-disc tribometer and results were compared against Ringer׳s solution and bovine calf serum. The highest friction coefficient was for CoCr/CoCr for all lubricants. The lowest, and superlubricity was measured for UHMWPE/CoCr (a friction coefficient of 0.009) with 20 g/100 ml PVA (PVA-C).