Introduction
Methods
Study population
The pain catastrophizing scale
Questionnaires
Statistical analysis
Study population n = 615 | TKA n = 442 | UKA n = 173 | |
---|---|---|---|
Female (%) | 320 (52.0) | 240 (54.3) | 80 (46.3) |
Age (SD) | 67.3 (9.7) | 67.9 (9.5) | 65.6 (9.9) |
BMIa (SD) | 29.0 (4.5) | 29.1 (4.5) | 28.9 (4.2) |
Alcohol > 24 g/daya | 36 (6.3) | 26 (6.2) | 10 (6.2) |
Smoking (%)a | 82 (14.5) | 64 (15.3) | 18 (11.1) |
Co-morbidity (%)a | 436 (72.2) | 320 (73.7) | 116 (69.0) |
Operated bilateral (%)c | 61 (9.9) | 42 (9.5) | 19 (11.0) |
SF-36 (PF)a(SD) | 19.0 (4.1) | 18.5 (4.1) | 20.1 (3.8) |
EQ 5D (IQR)b | 0.723 (0.144) | 0.723 (0.129) | 0.723 (0.121) |
OKS (SD) | 25 (6.3) | 24.4 (6.4) | 26.6 (6.7) |
PCS (IQR) | 16 (17) | 17 (17) | 13 (14) |
Results
OKS total score | |||
---|---|---|---|
Variable | Change in OKS a | (95% CI) | P value |
TKA (n = 419) | |||
PCS < 11 | ref | ||
PCS =11–21 | 0.9 | (−1.5, 3.2) | 0.47 |
PCS > 21 | 3.2 | (1.0, 5.4) | 0.005 |
UKA (n = 162) | |||
PCS < 11 | ref | ||
PCS = 11–21 | 4.3 | (1.5, 7.1) | 0.003 |
PCS > 21 | 5.4 | (2.2, 8.6) | 0.001 |
Moderate/severe pain vs mild/very mild/no pain | |||
---|---|---|---|
Variable | Odds ratioa | (95% CI) | P-value |
TKA (n = 419) | |||
PCS < 11 | ref | ||
PCS 11–21 | 2.2 | (1.1, 4.4) | 0.03 |
PCS > 21 | 2.7 | (1.4, 5.2) | 0.003 |
UKA (n = 159) | |||
PCS < 11 | ref | ||
PCS 11–21 | 0.4 | (0.1, 2.8) | 0.44 |
PCS > 21 | 4.8 | (1.1, 21.7) | 0.04 |
All patients | TKA | UKA | |||||
---|---|---|---|---|---|---|---|
PCS < 11 | PCS > 21 | P-value | PCS < 11 | PCS > 21 | PCS < 11 | PCS > 21 | |
n = 205 | n = 207 | n = 138 | n = 165 | n = 67 | n = 42 | ||
Female (%) | 106 (51.7) | 112 (54.1) | 0.63 | 73 (52.9) | 92 (55.8) | 33 (49.3) | 20 (47.6) |
Age years (SD) | 67.7 (9.2) | 66.7 (10.0) | 0.37 | 68.1 (9.0) | 67.0 (9.9) | 66.7 (9.5) | 65.9 (10.4) |
BMI kg/m2 (SD) | 28.2 (4.3) | 29.7 (4.4) | < 0.001 | 28.0 (4.2) | 29.8 (4.5) | 28.7 (4.4) | 29.3 (4.1) |
Alcohol > 24 g/Day (%) | 11 (5.6) | 9 (4.6) | 0.70 | 7 (5.2) | 8 (5.1) | 4 (6.5) | 1 (2.3) |
Smoking (%) | 25 (12.6) | 33 (16.9) | 0.22 | 21 (15.4) | 27 (17.2) | 4 (6.5) | 6 (15.8) |
Co-morbiditya (%) | 139 (67.8) | 153 (73.9) | 0.24 | 100 (72.5) | 124 (75.2) | 39 (58.2) | 29 (69.0) |
Walking aid (%) | 24 (12.1) | 38 (19.5) | 0.03 | 21 (15.4) | 30 (19.1) | 3 (4.8) | 8 (21.1) |
Living alone (%) | 53 (26.8) | 42 (21.5) | 0.23 | 37 (27.2) | 33 (21.7) | 16 (25.8) | 9 (23.7) |
Operated bilateralb (%) | 20 (9.7) | 16 (7.7) | 0.52 | 13 (9.4) | 13 (7.9) | 7 (10.5) | 7 (7.1) |
Outcome | |||||||
Preoperatively | |||||||
OKS (IQR) (n = 412) | 29 (9) | 21 (8) | < 0.001 | 28 (10) | 21 (8) | 31 (8) | 22 (8) |
Pain (%) (n = 412) | 127 (61.2) | 187 (90.3) | < 0.001 | 89 (64.5) | 152 (92.1) | 38 (56.7) | 35 (83.3) |
SF-36 (PF) (IQR) (n = 404) | 50 (35) | 35 (25) | < 0.001 | 50 (35) | 35 (25) | 57.5 (30) | 35 (20) |
EQ 5D (IQR) (n = 376) | 0.72 (0.08) | 0.66 (0.33) | < 0.001 | 0.72 (0.05) | 0.66 (0.33) | 0.77 (0.10) | 0.59 (0.40) |
4 months | |||||||
OKS (IQR) (n = 336) | 39 (10) | 36 (12) | 0.001 | 37 (11) | 35 (11) | 41 (8) | 37 (12) |
Pain (%) (n = 412) | 32 (17.7) | 56 (33.9) | 0.001 | 25 (20.8) | 47 (36.2) | 7 (11.5) | 9 (25.7) |
SF-36 (PF) (IQR) (n = 346) | 80 (25) | 75 (30) | 0.004 | 75 (30) | 75 (30) | 85 (15) | 80 (30) |
EQ 5D (IQR) (n = 331) | 0.82 (0.23) | 0.82 (0.28) | 0.023 | 0.82 (0.28) | 0.82 (0.28) | 0.84 (0.18) | 0.82 (0.23) |
12 months | |||||||
OKS (IQR) (n = 412) | 42 (10) | 38 (13) | < 0.001 | 41 (11) | 37 (14) | 44 (8) | 41 (8) |
Pain (%) (n = 412) | 21 (10.2) | 49 (23.7) | < 0.001 | 16 (11.6) | 42 (25.5) | 5 (7.5) | 7 (16.7) |
SF-36 (PF) (IQR) (n = 401) | 85 (25) | 75 (30) | 0.001 | 80 (30) | 75 (32.5) | 85 (20) | 80 (20) |
EQ 5D (IQR) (n = 397) | 0.84 (0.22) | 0.82 (0.28) | 0.002 | 0.84 (0.22) | 0.82 (0.28) | 1 (0.28) | 0.82 (0.23) |
Low (n = 205) vs high (n = 207) PCS | ||||||
---|---|---|---|---|---|---|
Time | OKS | 95% CI | P value | SF36 (PF) | 95% CI | P value |
Preoperative | 7.5 | (6.4, 8.7) | 0.000 | 16.7 | (12.7, 20.6) | 0.000 |
4 months | 2.8 | (1.2, 4.3) | 0.001 | 6.2 | (2.0, 10.5) | 0.004 |
12 months | 3.9 | (2.2, 5.5) | 0.000 | 7.0 | (2.4, 11.7) | 0.003 |