Table 1.
Baseline characteristics of the dual-mobility and unipolar cup THAsa
| Dual-mobility (n = 150) | Unipolar (n = 166) | Mean/Risk differenceb(95% CI) | p-value | |
|---|---|---|---|---|
| Mean age (SD) | 73 (11.1) | 65 (15.2) | −7.9 (−11 to −4.9) | < 0.001 |
| Mean BMI (SD) | 26 (5.8) | 26 (5.2) | −0.2 (−1.4 to 1.0) | 0.8 |
| Mean operating time (SD), min | 152 (60) | 185 (69) | 33 (19 to 48) | < 0.001 |
| Women (%) | 84 (56) | 76 (46) | 10 (−0.7 to 21) | 0.07 |
| BMI ≥30 (%) | 38 (25) | 39 (24) | 1.8 (−7.7 to 11) | 0.7 |
| Smoking statusc(%) | ||||
| Ever-smoker | 58 (46) | 59 (52) | −6.5 (−19 to 6.1) | 0.3 |
| Never-smoker | 69 (54) | 54 (48) | ||
| ASA score (%) | ||||
| 1–2 | 96 (64) | 116 (70) | −5.9 (−16 to 4.5) | 0.3 |
| 3–4 | 54 (36) | 50 (30) | ||
| Diabetes (%) | 26 (17) | 19 (11) | 5.9 (−1.9 to 14) | 0.1 |
| Previous THA revision (%) | 38 (25) | 36 (22) | 6.7 (−5.7 to 13) | 0.4 |
| Surgical approach (%) | ||||
| With osteotomy | 33 (22) | 48 (29) | −6.9 (−17 to 2.7) | 0.2 |
| Without osteotomy | 117 (78) | 118 (71) | ||
| Posterior | 68 (46) | 43 (26) | ||
| Anterior Hueter | 15 (10) | 14 (8.4) | ||
| Antero-lateral | 34 (23) | 61 (37) | ||
| Indication for revision (%) | ||||
| Aseptic loosening | 51 (34) | 76 (46) | −12 (−23 to −1.1) | 0.03 |
| Dislocation | 41 (27) | 17 (10) | 17 (8.6 to 26) | < 0.001 |
| Infection | 22 (15) | 26 (16) | −1.0 (−8.9 to 6.9) | 0.8 |
| Pain/impingement | 4 (2.7) | 19 (11) | −8.8 (−14 to −3.3) | 0.003 |
| Polyethylene wear | 5 (3.3) | 5 (3.0) | 0.3 (−3.6 to 4.2) | 0.9 |
| Adverse local tissue reaction | 7 (4.7) | 7 (4.2) | 0.5 (−4.1 to 5) | 0.9 |
| Periprosthetic fracture | 17 (11) | 11 (6.6) | 4.7 (−1.6 to 11) | 0.1 |
| Other | 3 (2.0) | 5 (3.0) | −1.0 (−4.4 to 2.4) | 0.6 |
| Head size (%) | ||||
| ≤ 32 mm | 150 (100) | 114 (69) | 31 (24 to 38) | < 0.001 |
| > 32 mm | – | 52 (31.3) | ||
| Acetabular reinforce-ment ring (%) | 53 (35) | 77 (46) | −11 (−22 to −0.3) | 0.05 |
a
Percentages calculated on total no. of patients with information available.
b
Age, BMI, and operating time is Mean difference, the rest is Risk difference
c
Information on smoking status missing for 23 patients in group 1 and for 53 patients in group 2.