Table 1.
Property | Disc Grade | Property Range | Reference | |
---|---|---|---|---|
Organ Level/ Motion Segment (in situ testing) | Disc height | Healthy | 11.1 ±2.5 mm 11.3 ±0.3 mm |
(Chen and Wei, 2009) (O’Connell et al., 2007) |
Degenerative | 9.2 ±2.9 mm (spondylolisthetic disc height) |
(Chen and Wei, 2009) | ||
Intradiscal pressure | Healthy | 0.5 MPa (leakage pressure) 1.9 MPa (300 N load pressure) Single patient 0.1–2.3 MPa |
(Panjabi et al., 1988) (Adams et al., 1996) (Wilke et al., 1999) |
|
Degenerative | 0.2 MPa (leakage pressure) 1.3 MPa (300 N load pressure) |
(Panjabi et al., 1988) (Adams et al., 1996) |
||
Torsional mechanics | Healthy | 0.7° – 0.8° (with 8° pelvic rotation) 3°max axial rotation 3.18 ±0.89 Nm/° |
(Blankenbaker et al., 2006) (Haughton et al., 2002) (Costi et al., 2007) (Showalter et al., 2012) |
|
Degenerative | 1.8° – 3.2° (with 8° pelvic rotation) | (Blankenbaker et al., 2006) (Haughton et al., 2002) |
||
Tissue Level (in vitro testing) | Compressive (confined compression) |
Healthy | 0.56 ±0.21 MPa (HA, aggregate modulus) |
(Iatridis et al., 1998) |
Degenerative | 1.10 ±0.53 MPa (HA, aggregate modulus) |
(Iatridis Et Al., 1998) | ||
Tensile (circumferential samples) |
Healthy | 12.7 MPa (E, tensile modulus) | (Acaroglu et al., 1995) | |
Degenerative | 9.4 MPa (E, tensile modulus) | (Acaroglu et al., 1995) | ||
Shear | Healthy | 25 <Geq (kPa)<110 | (Iatridis et al., 1999) | |
Degenerative | 25 <Geq (kPa)<140 | (Iatridis et al., 1999) |