Table 2.
Summary of available wear testing data for cervical disc replacements under idealized (Mode I) conditions
| Reference | Design | Bearing couple | Standard referenced | Relevant test inputs | Wear rate | Particle size |
|---|---|---|---|---|---|---|
| SSED for PMA Number: P060023 (Bryan® Cervical Disc) [21] | Bryan® (Medtronic Sofamor Danek, Memphis, TN, USA) | Polycarbonate urethane on titanium | N/A | FE: ± 4.9° LB: N/A AR: ± 3.8° AL: 130 N and 300 N F: 2, 4, and 6 Hz |
As published: 0.4–1.4 mg/ MC Converted (density = 1.2 mg/mm3): 0.3–1.2 mm3/MC |
Greater than 90% of particles were less than 1 µm |
| SSED for PMA Number: P070001 (ProDisc™-C Total Disc Replacement) [20] | ProDisc™-C (Synthes Spine, West Chester, PA, USA) | UHMWPE on CoCr | N/A | FE: ± 7.5° LB: ± 6.0° AR: ± 4.0° AL: 150 N F: 1.0 Hz |
As published: 2.59 ± 0.36 mg/MC Converted (density = 0.94 mg/mm3): 2.8 ± 0.36 mm3/MC |
Average size 0.17–0.35 µm |
| Nectow et al., 2008 [43] | ProDisc™-C (Synthes Spine) | UHMWPE on CoCr | ISO 18192-1 | FE: ± 7.5° LB: ± 6.0° AR: ± 4.0° AL: 50-150 N F: 1.0 Hz |
As published: 1.99 ± 0.15 mg/MC Converted (density = 0.94 mg/mm3): 2.12 ± 0.15 mm3/MC |
Greater than 90% of particles were less than 1 µm |
| Bushelow et al., 2008 [12] | ProDisc™-C (Synthes Spine) | UHMWPE on CoCr | N/A | FE: ± 5° LB: ± 5.0° AR: ± 3.5° AL: 15-150 N F: 1.0 Hz |
As published: 0.88 ± 0.07 mg/MC Converted (density = 0.94 mg/mm3): 0.94 ± 0.07 mm3/MC |
Greater than 90% of particles were less than 1 µm; average diameter between 0.22 and 0.37 µm |
| N/A | FE: ± 10° LB: ± 5.0° AR: ± 4.0° AL:150 N F: 1.0 Hz |
As published: 2.59 ± 0.36 mg/MC Converted (density = 0.94 mg/mm3): 2.75 ± 0.38 mm3/MC |
||||
| ISO 18192-1 | FE: ± 7.5° LB: ± 4.0° AR: ± 6.0° AL: 15-150 N F: 1.0 Hz |
As published: 1.82 ± 0.11 mg/MC Converted (density = 0.94 mg/ mm3): 1.94 ± 0.12 mm3/MC |
||||
| SSED for PMA Number: P110002 (Mobi-C® Cervical Disc Prosthesis) [24] | Mobi-C® (LDR Spine, Austin, TX, USA) | UHMWPE on CoCr | ISO 18192-1 | FE: ± 7.5° LB: ± 6.0° AR: ± 4.0° AL: 50-150 N F: 1.0 Hz |
As published: 1.55 ± 0.08 mg/MC Converted (density = 0.94 mg/mm3): 1.64 ± 0.09 mm3/MC |
Average size 0.77 µm |
| SSED for PMA Number: P100003 (SECURE®-C Cervical Artificial Disc) [23] | SECURE®-C (Globus Medical, Audubon, PA, USA) | UHMWPE on CoCr | N/A | FE: ± 7.0° LB: ± 7.0° AR: ± 1.5° (Test I) and ± 6.0° (Test II) AL: 150 N F: 2.0 Hz |
As published: Test I: 2.57 ± 1.21 mg/MC Test II: 0.89 ± 0.3 mg/MC Converted (density = 0.94 mg/mm3): Test I: 2.73 ± 1.29 mm3/MC Test I: 0.95 ± 0.32 mm3/MC |
N/A |
| SSED for PMA Number: P100012 (PCM® Cervical Disc) [22] | PCM® (NuVasive, San Diego, CA, USA) | UHMWPE on CoCr | ISO 18192-1 | FE: ± 7.5° LB: ± 6.0° AR: ± 4.0° AL: 50-150 N F: 1.0 Hz |
As published: 6.33 mg/MC Converted (density = 0.94 mg/mm3): 6.73 mm3/MC |
Average size: 0.43 ± 0.04 µm and 0.53 ± 0.15 µm for two samples, respectively |
| Grupp et al., 2015 [28] | activ® C (Aesculap AG, Tuttlingen, Germany) | UHMWPE on CoCr | ISO 18192-1 | FE: ± 7.5° LB: ± 6.0° AR: ± 4.0° AL: 50-150 N F: 1.0 Hz |
As published: 1.0 ± 0.1 mg/MC Converted (1.29 mg/mm3): 0.78 ± 0.08 mm3/MC |
99% of particles were less than 1 µm |
| PEEK on PEEK | As published: 1.4 ± 0.4 mg/MC Converted (1.29 mg/mm3): 1.1 ± 0.3 mm3/MC |
99% of particles were less than 1 µm | ||||
| CFR-PEEK on CFR-PEEK | As published: 0.02 ± 0.02 mg/MC Converted (1.29 mg/mm3): 0.02 ± 0.02 mm3/MC |
99% of particles were less than 1 µm | ||||
| PEK on PEK | As published: 0.8 ± 0.1 mg/MC Converted (1.29 mg/mm3): 0.6 ± 0.1 mm3/MC |
90% of particles were less than 1 µm | ||||
| Brown et al., 2010 [11] | NuNec (Pioneer Surgical, Marquette, MI, USA) | PEEK on PEEK | ASTM F2423 | FE: ± 7.5° LB: ± 6.0° AR: ± 4.0° AL: 50-150 N F: 2.0 Hz |
As published: 0.26 ± 0.01 mg/MC Converted (1.29 mg/mm3): 0.20 ± 0.01 mm3/MC |
N/A |
| ISO 18192-1 | FE: ± 7.5° LB: ± 6.0° AR: ± 6.0° AL: 100 N F: 2.0 Hz |
As published: 0.32 ± 0.02 mg/MC Converted (1.29 mg/mm3): 0.25 ± 0.02 mm3/MC |
N/A | |||
| Xin et al., 2013 [51] | NuNec (Pioneer Surgical) | PEEK on PEEK | ISO 18192-1 | FE: ± 7.5° LB: ± 6.0° AR: ± 6.0° AL: 50-150 N F: 1.0 Hz |
As published: 2.5 ± 0.1 mg/MC As published: 1.9 ± 0.1 mm3/MC |
N/A |
| Design History File Report for the Kineflex|C | Kineflex|C (SpinalMotion, Mountain View, CA) | CoCr on CoCr | ISO 18192-1 | FE: ± 7.5° LB: ± 6.0° AR: ± 6.0° AL: 100 N F: 5.0 Hz |
As published: 3.2 mg/ MC Converted (Density = 8.5 mg/mm3): 0.4 mm3/MC |
Average size: 0.4–0.55 µm |
| Kurtz et al., 2012 [35] | Prestige ST (Medtronic Sofamor Danek) | Stainless steel on stainless steel | ASTM F2423 | FE: ± 9.7° (Phase II) LB: ± 4.7° (Phase I) AR: ± 3.8° (Phase I) AL: 49 N (Phase I)/149 N (Phase II) F: 1.0 Hz |
As published: Phase I: 0.72-0.76 mm3/MC Phase II: 0.004-0.059 mm3/MC |
Average size: 0.3–0.6 µm |
| SSED for PMA Number: P090029 (Prestige® LP Cervical Disc) [25] | Prestige® LP (Medtronic Sofamor Danek) | Titanium carbide on Titanium carbide | ASTM F2423* | FE: ± 7.5° (Phase II) LB: ± 6.0° (Phase I) AR: ± 6.0° (Phase I) AL: 100 N (Phase I/II) F: 1.0 Hz |
As published: Phase I then Phase II: 0.35 ± 0.3 mm3/MC* |
Average size less than 0.2 µm |
* Four wear tests were described in the SSED for the Prestige® LP Cervical Disc; the maximum standard wear rate has been reported; ASTM = American Society for Testing and Materials; ISO = International Standards Organization; FE = flexion/extension; LB = lateral bending; AR = axial rotation; AL = axial load; F = frequency; SSED = Summary of Safety and Effectiveness Data; N/A = not available.