Table IV.
Definition of pincer impingement across continents
| North America | South America | Europe | Asia | Australia | |
|---|---|---|---|---|---|
| Definition of pincer impingement | |||||
| Number of studies reporting (subjects) (% of studies reporting a definition) | 16 (949) (21%) | 0 | 8 (471) (22%) | 1 (21) (9%) | 0 |
| Crossover sign | 9 (535) | 7 (353) | 1 (21) | ||
| Coxa profunda | 7 (522) | 4 (182) | 1 (21) | ||
| Protrusio acetabulae | 7 (430) | 4 (182) | 0 | ||
| Acetabular retroversion | 3 (305) | 1 (118)a | 1 (21) | ||
| LCEA > 40° | 2 (150) | 0 | 1 (21) | ||
| ACEA > 35° | 1 (60) | 0 | 0 | ||
| Tönnis angle < 0° | 1 (60) | 0 | 0 | ||
| Ischial spine sign | 1 (36) | 1 (101) | 0 | ||
| Posterior wall sign | 0 | 1 (11) | 0 | ||
| Mean lateral center edge angle (degrees) | 31.2 ± 10.8 | nr | 31.7 ± 6.71 | nr | nr |
| Number of studies reported (subjects) | 12 (1747) | 3 (215) | |||
| Proportion of studies reporting (subjects) | 15% (30%) | 8.1% (6.0%) | |||
| Mean anterior center edge angle (degrees) | 28.5 ± 3.54 | nr | nr | nr | nr |
| Number of studies reported (subjects) | 2 (110) | ||||
| Proportion of studies reporting (subjects) | 2.6% (1.9%) | ||||
| Mean Tönnis angle | 7.0° | nr | 12.8° | nr | nr |
| Number of studies reported (subjects) | 4 (26) | 1 (86) | |||
| Proportion of studies reporting (subjects) | 5.1% (0.4%) | 2.7% (2.4%) | |||
| Number of studies assessing AIIS impingement (subspine impingement) | 4 (228) | nr | nr | nr | nr |
ACEA, anterior center edge angle; AIIS, anterior inferior iliac spine; LCEA, lateral center edge angle; nr, not recorded.
aRetroversion defined as anteversion less than 14 degrees.