Table 7.
Anatomical reference points for the ilioinguinal nerve
| Reference point | Studies | N | PME (95% CI) | I2 (95% CI) | Q |
|---|---|---|---|---|---|
| Distance from the IIN emerged to | |||||
| Inferior to the anterior superior iliac spine | 1 | 200 | 2.8 cm (2.65–2.95) | NC | NC |
| Medially to the anterior superior iliac spine | 4 | 428 | 3.62 cm (3.04–4.19) | 92.8 (84.9–96.6) | 41.83*** |
| Variations in the emergence of the nerve | |||||
| Posterior to the inguinal ligament | 2 | 140 | 19.6% (12.7–27.5) | NC | 1.18 |
| Posterior to the anterior superior iliac spine | 2 | 140 | 4.5% (1.0–9.8) | NC | 1.37 |
| Aberrant origin of the IIN from the genital branch of GNF | 2 | 130 | 2.5% (0.4–6.0) | NC | 0.95 |
| Common trunk with the IHN | 5 | 365 | 10.0% (2.0–23.3) | 89.2 (77.5–94.8) | 36.99*** |
| Course of the IIN with regard to the spermatic cord | |||||
| Parallel | 4 | 188 | 87.8% (46.6–100.0) | 96.9 (94.5–98.3) | 97.31*** |
| Ventrally | 4 | 188 | 57.2% (3.1–100.0) | 97.6 (96.0–98.6) | 126.97*** |
| Type of exit of IIN from inguinal canal | |||||
| IIN exit through SIR | 5 | 276 | 64.5% (19.0–99.0) | 97.7 (96.3–98.5) | 170.86*** |
| Acute infero-lateral angulation of the IIN in close contact with and parallel to the SIR fibers at exit | 3 | 168 | 4.9% (0.0–20.5) | 89.7 (72.2–96.2) | 19.36*** |
| A plane superficial to the EOA having pierced it proximal to the SIR | 5 | 276 | 14.6% (7.0–24.1) | 70.5 (24.8–88.4) | 13.55*** |
| Mode of termination and branches | |||||
| Unique trunks | |||||
| Scrotal termination | 1 | 110 | 36.4% (27.6–45.6) | NC | NC |
| Pubic termination | 1 | 110 | 3.6% (0.8–8.1) | NC | NC |
| Femoral termination | 1 | 110 | 2.7% (0.3–6.8) | NC | NC |
| Two branches | – | – | – | – | – |
| Three branches | – | – | – | – | – |
| Four branches | – | – | – | – | – |
PME pooled mean estimate, NC not computable because there were two or fewer studies in this group, SIR superficial inguinal ring, EOA external oblique aponeurosis, IIN ilioinguinal nerve, IHN iliohypogastric nerve, GNF genital branch of the genitofemoral nerve
A random-effects model was used for all outcomes
*p < .05, **p < .01, ***p < .001