Table 1.
Reference data used for age-specific prevalence estimates (%) for degenerative features of the spinal column (Brinjikji et al. [3]) and paravertebral muscle fat (%; ± standard deviation; Crawford et al. [11] and Valentin et al. [12]) according to age. Sample sizes are in parentheses
| Study | Age (years) | |||||
|---|---|---|---|---|---|---|
| Brinjikji et al. 2015 [3] | Imaging Finding | 20 | 30 | 40 | 50 | n |
| Disk degeneration | 37 % (273) | 52 % (604) | 68 % (415) | 80 % (311) | (1603) | |
| Disk signal loss | 17 % (46) | 33 % (142) | 54 % (352) | 73 % (73) | (613) | |
| Disk height loss | 24 % (15) | 34 % (163) | 45 % (186) | 56 % (208) | (572) | |
| Disk bulge | 30 % (55) | 40 % (101) | 50 % (151) | 60 % (123) | (430) | |
| Disk protrusion | 29 % (87) | 31 % (468) | 33 % (490) | 36 % (363) | (1408) | |
| Annular fissure | 19 % (167) | 20 % (350) | 22 % (426) | 23 % (53) | (996) | |
| Facet degeneration | 4 % (0), (100)a | 9 % (0), (100)a | 18 % (596) | 32 % (53) | (849) | |
| Spondylolisthesis | 3 % (0), (100)a | 5 % (0), (100)a | 8 % (31) | 14 % (53) | (284) | |
| Crawford et al. 2015 [11] | Paravertebral muscles | 20–29 | 30–39 | 40–49 | 50–60 | |
| MF + ES | 12.4 ± 3.7(20) | 15.9 ± 5.0(20) | 15.7 ± 4.5 (20) | 18.1 ± 7.8 (20) | (80) | |
| Multifidus | 16.3 ± 5.3 (20) | 20.8 ± 6.4 (20) | 21.6 ± 6.1 (20) | 24.1 ± 8.7 (20) | (80) | |
| Erector spinae | 10.1 ± 4.7 (20) | 12.9 ± 4.3 (20) | 12.4 ± 3.4 (20) | 14.7 ± 7.3 (20) | (80) | |
| Valentin et al. 2015 [12] | Paravertebral muscles | 18–25 | 45–60 | |||
| Psoas | 35.7 ± 2.0 (12) | 37.1 ± 1.5 (12) | (24) | |||
| MF + ES | 40.2 ± 3.0 (12) | 42.8 ± 2.9 (12) | (24) | |||
| Multifidus | 40.7 ± 3.4 (12) | 43.9 ± 3.7 (12) | (24) | |||
| Erector spinae | 39.6 ± 2.8 (12) | 41.8 ± 2.3 (12) | (24) | |||
MF + ES multifidus and erector spinae combined, n total sample size
aSample size of 100 assumed in simulation