(119 days)
The system is indicated for primary or revision surgery in skeletally mature individuals for rehabilitating hips damaged as a result of noninflammatory degenerative joint disease (NIDJD) or its composite diagnoses of osteoarthritis, avascular necrosis, protrusio acetabuli, traumatic arthritis, slipped capital epiphysis, fused hip, fracture of the pelvis, and diastrophic variant.
The system is intended for use either with or without bone cement in total hip arthroplasty.
The Vivacit-E Vitamin E Highly Crosslinked Polyethylene Liners are neutral and elevated acetabular liners which are intended to mate with either the Continuum or Trilogy IT acetabular shells in total hip arthroplasty.
The Vivacit-E Vitamin E Highly Crosslinked Polyethylene Liners are designed for total hip arthroplasty. The acceptance criteria and performance of the device are detailed in a series of non-clinical laboratory tests and animal studies.
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Claim | Description of Test/Experiment | Acceptance Criteria | Reported Device Performance |
|---|---|---|---|
| Claim 1: Antioxidant protection prevents oxidation degradation | Tensile (ASTM D638), Izod Impact (ASTM F648, Annex A1), and Oxidation Index (ASTM F2102) samples of Vivacit-E Vitamin E HXPE were tested in non-aged condition and up to 24 weeks of accelerated aging (ASTM F2003: 100% oxygen, 73 psi, 70°C). Additionally, cyclic loading in oxidative environment (0.5 Hz, 10 MPa bending stress at 80°C in air for 5 weeks) was performed. | No significant change in tensile or Izod properties, no detectable oxidation (oxidation indices 8.0 minutes. | Vivacit-E Vitamin E HXPE showed no detectable oxidation (oxidation indices 8.0 minutes after 24 weeks of aging. Conventional GUR 1050 samples showed oxidation indices > 0.5 and OIT 3 with immeasurable OIT after 4 weeks. |
| Claim 3: Retains mechanical strength after accelerated aging | Vivacit-E Vitamin E HXPE tensile (ASTM D638) and Izod impact (ASTM F648, Annex A1) specimens were tested non-aged and up to 24 weeks of accelerated aging (ASTM F2003: 100% oxygen, 73 psi, 70°C). | No statistically significant difference in mechanical properties, with greater than 96% retention. | No statistically significant difference in ultimate tensile strength (p=0.63), elongation (p=0.61), and Izod impact (p=0.47) after 12 times the standard accelerated aging method. Greater than 96% retention of mechanical properties. |
| Claim 4: Vitamin E does not elute | Exhaustive solvent extractions (boiling hexane, isopropanol) were performed. Vivacit-E Vitamin E HXPE liners were immersed in 40°C de-ionized water for up to 24 weeks. Pressure-induced leaching study (150 N and 1500 N for 1 minute) was conducted. | Residue quantities comparable to non-Vitamin E predicate material; Vitamin E levels in aqueous solution below detectable limits; no change in Vitamin E Index or Oxidation Index; Vitamin E levels under pressure-induced leaching below detection limits. | FTIR analysis showed residues comparable to predicate; UV-Vis showed Vitamin E levels in water below detectable limits; no change in Vitamin E Index or Oxidation Index for liners; fluorescence spectroscopy showed Vitamin E levels under pressure-induced leaching below detection limits. |
| Claim 5: Resists cracking and oxidation under environmental stress | Cyclic loading (0.5 Hz, 10 MPa bending stress at 80°C in air for 5 weeks) in an oxidative environment. | No evidence of cracking and negligible oxidation (oxidation indices |
§ 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.
(a)
Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across the joint. This generic type of device has a femoral component made of a cobalt-chromium-molybdenum (Co-Cr-Mo) alloy or a titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high molecular weight polyethylene articulating bearing surface fixed in a metal shell made of Co-Cr-Mo or Ti-6Al-4V. The femoral stem and acetabular shell have a porous coating made of, in the case of Co-Cr-Mo substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average pore size between 100 and 1,000 microns, interconnecting porosity, and a porous coating thickness between 500 and 1,500 microns. The generic type of device has a design to achieve biological fixation to bone without the use of bone cement.(b)
Classification. Class II.