Table 2.
Patient demographics and pre-operative functional scores according to symptoms of stiffness 1 year after surgery
| Demographic | Descriptive | Increased Stiffness | Odds ratio/difference | 95% CI | p value | ||
|---|---|---|---|---|---|---|---|
| Yes (n = 129) | No (n = 2460) | Lower | Upper | ||||
| Gender (n, % of group) | Male | 78 (60.4) | 1109 (45.1) | 1.86 | 1.30 | 2.68 | 0.001 |
| Female | 51 (39.5) | 1351 (54.9) | |||||
| Mean age (years: mean, SD) | 69.7 (9.6) | 68.8 (9.7) | 0.9 | − 2.6 | 8.7 | n.s | |
| BMI (kg/m2: mean, SD) | 29.1 (5.0) | 29.8 (6.9) | 0.7 | − 0.6 | 1.9 | n.s | |
| Comorbidity (n, % of group) | Heart disease | 21 (16.3) | 414 (16.8) | 0.96 | 0.60 | 1.55 | n.s |
| Hypertension | 66 (51.2) | 1346 (54.7) | 0.87 | 0.61 | 1.24 | n.s | |
| Lung disease | 33 (25.6) | 366 (14.9) | 1.97 | 1.30 | 2.97 | 0.001 | |
| Cancer | 8 (6.2) | 117 (4.8) | 1.32 | 0.63 | 2.77 | n.s | |
| Neurological disease | 14 (10.9) | 139 (5.7) | 2.03 | 1.14 | 3.63 | 0.02 | |
| Diabetes mellitus | 27 (20.9) | 338 (13.7) | 1.66 | 1.07 | 2.58 | 0.02 | |
| Gastric ulceration | 18 (14.0) | 309 (12.6) | 1.13 | 0.68 | 1.88 | n.s | |
| Kidney disease | 8 (6.2) | 71 (2.9) | 2.23 | 1.05 | 4.73 | 0.03 | |
| Liver disease | 5 (3.9) | 39 (1.6) | 2.50 | 1.0 | 6.46 | 0.05 | |
| Anaemia | 9 (7.0) | 237 (9.6) | 0.70 | 0.35 | 1.40 | n.s | |
| Depression | 28 (21.7) | 348 (14.1) | 1.68 | 1.09 | 2.60 | 0.02 | |
| Back pain | 76 (58.9) | 1233 (50.1) | 1.43 | 1.0 | 2.0 | n.s | |
| Functional measures (mean, SD) | |||||||
| WOMAC | Total | 46.0 (16.1) | 36.0 (16.2) | 10.0 | 7.1 | 12.8 | < 0.001 |
| Pain | 42.4 (15.9) | 35.1 (17.7) | 7.3 | 4.2 | 10.4 | < 0.001 | |
| Function | 45.3 (16.9) | 36.3 (16.9) | 9.0 | 6.0 | 12.0 | < 0.001 | |
| Stiffness | 61.0 (22.4) | 36.0 (19.6) | 25.0 | 21.5 | 28.5 | < 0.001 | |
| SF-12 | PCS | 28.4 (7.6) | 27.5 (7.4) | 0.8 | − 0.5 | 2.2 | n.s |
| MCS | 46.3 (13.3) | 47.1 (13.6) | 0.8 | −1.6 | 3.2 | n.s | |
n.s. non-significant
*Unpaired t test unless otherwise stated
**Chi-square