Variability in locations of hip neurovascular structures and their proximity to hip arthroscopic portals.

PURPOSE: To measure the distances of pertinent neurovascular structures from bony landmarks used during hip arthroscopy and compare them among different demographic groups.

METHODS

The distances from neurovascular structures to bony landmarks often used during hip arthroscopy were measured on magnetic resonance images of the hip in 100 patients. The structures studied include the lateral femoral cutaneous nerve (LFCN), sciatic nerve, femoral nerve, and femoral artery. These distances were then compared across different demographic groups, and statistical analysis was performed.

RESULTS

The mean anteroposterior (AP) distance from the tip of the greater trochanter to the sciatic nerve was 10.32 mm (range, 0 to 23.8 mm). At the level of the superior tip of the greater trochanter, the mean distances from the anterior superior iliac spine reference line to the LFCN, femoral nerve, and femoral artery were 6.37 mm (range, -9.8 to 35.9 mm) for medial-lateral, 23.24 mm (range, 3.4 to 67.0 mm) for AP, and 26.34 mm (range, 7.3 to 65.5 mm) for AP, respectively. We found significant differences in distances for the LFCN, femoral nerve, and femoral artery for weight (P = .003, P = .041, and P = .004, respectively) and body mass index (P = .003, P = .010, and P = .003, respectively), as well as for the LFCN between whites and Hispanics (P = .032). There were also significant differences for the femoral nerve vector between African Americans and whites (P = .04), as well as between African Americans and Hispanics (P = .04).

CONCLUSIONS

We found the LFCN to be the most at-risk neurovascular structure with hip arthroscopy portal placement. This study also showed that there is wide variability in the locations of pertinent neurovascular structures across different demographic groups, including weight, body mass index, and race or ethnicity.

CLINICAL RELEVANCE: Portal placement during hip arthroscopy carries a risk of neurovascular injury, particularly to the LFCN. The clinician should be aware of the variability in structure location with different patient demographic characteristics.