Patient Demographics: Food and Drug Administration Investigational Device Exemption Study of the Charité Artificial Disc
| Investigational Group (N = 205) | Control Group (N = 99) | P | |
|---|---|---|---|
| Gender, no. (%) | |||
| Men | 113 (55.1) | 44 (44.4) | .088 |
| Women | 92 (44.9) | 55 (55.6) | |
| Age, y | |||
| Mean (SD) | 39.6 (8.16) | 39.6 (9.07) | .946 |
| Median | 40.0 | 39.0 | |
| Range | 19-60 | 20-60 | |
| > 45, no. (%) | 47 (22.9) | 30 (30.3) | .205 |
| ≤ 45, no. (%) | 158 (77.1) | 69 (69.7) | |
| Race, no. (%) | |||
| White | 188 (91.7) | 87 (87.9) | .540 |
| African American | 8 (3.9) | 5 (5.0) | |
| Other | 9 (4.4) | 7 (7.1) | |
| Height, cm | |||
| Mean (SD) | 172.3 | 173.6 | .249 |
| Median | 170.2 | 172.7 | |
| Range | 150-201 | 155-196 | |
| Weight, kg | |||
| Mean (SD) | 77.5 (15.67) | 81.7 (16.46) | .035 |
| Median | 77.1 | 79.4 | |
| Range | 46-120 | 51-122 | |
| Body mass indexa | |||
| Mean (SD) | 26.0 (4.23) | 27.0 (4.76) | .056 |
| Median | 26.0 | 26.9 | |
| Range | 17-39 | 18-10 | |
| Previous spinal surgery, no. (%) | |||
| Yes | 70 (34.1) | 33 (33.3) | .999 |
| No | 135 (65.9) | 66 (66.7) | |
| Normal activity level before experiencing back pain, no. (%) | |||
| Active | 188 (91.7) | 86 (86.9) | .284 |
| Moderate | 15 (7.3) | 11 (11.1) | |
| Light | 1 (0.5) | 2 (2.0) | |
| Minimal | 1 (0.5) | 0 | |
| Activity level at enrollment, no. (%) | |||
| Active | 9 (4.4) | 1 (1.0) | .064 |
| Moderate | 26 (12.7) | 5 (5.0) | |
| Light | 54 (26.3) | 27 (27.3) | |
| Minimal | 116 (56.6) | 66 (66.7) | |
| Preoperative work status, no. (% working) | 109 (53.2) | 57 (57.6) | .470 |
Note. Fisher's exact test was used to test categorical variables. Student's t test was used to test means.
↵a Weight (in kg) divided by height (in m)2.