Table 3 Intraoperative and radiographic measurements for the two different cup orientation aids with the Stulberg positioner (an inclinometer was used in all patients with the Capello positioner) and for the two different positioners accounting for visual aid (inclinometer)
Parameter | Inclinometer (n = 50) | Mechanical alignment guide (n = 50) | p-value | Stulberg positioner (n = 50) | Capello positioner (n = 50) | p-value |
|---|---|---|---|---|---|---|
Radiographic inclination | 42° ± 6 | 42° ± 6 | 0.63 | 42° ± 6 | 39° ± 6 | 0.02 |
Radiographic anteversion | 22° ± 5 | 23° ± 5 | 0.32 | 22° ± 6 | 22° ± 7 | 0.98 |
Optimum inclination (30°-50°) (n) | 46 (92%) | 46 (92%) | 1.0 | 46 (92%) | 46 (92%) | 1.00 |
Optimum inclination and anteversion (n) | 42 (84%) | 44 (88%) | 0.57 | 42 (84%) | 40 (80%) | 0.60 |
Intra-operative inclination (IOI) | 37° ± 3 | – | – | 37° ± 3 | 32° ± 3 | < 0.001 |
True operative cup inclination (TOI) | 37° ± 5 | 38° ± 5 | 0.9 | 37° ± 5 | 36° ± 6 | 0.015 |
ΔPelvicPosition (= TOI – IOI) | 0° ± 5 | – | – | 0° ± 5 | 3° ± 6 | 0.011 |
ΔDefinition (= RI – TOI) | 4° ± 2 | – | – | 4° ± 2 | 4° ± 2 | 0.355 |