The ultrasonographic appearance of the femoral nerve and cases of iatrogenic impairment.
OBJECTIVE
To assess the feasibility of ultrasonography of femoral nerves in a cadaveric specimen, healthy volunteers, and patients.


METHODS
In 1 unembalmed cadaveric specimen (female, 90 years) and 20 healthy volunteers (9 male and 11 female, 18-50 years; n = 40 scans), the topographic features, cross-sectional shapes (oval or triangular), and cross-sectional areas of the femoral nerves were evaluated by ultrasonography (5- to 12-MHz broadband linear array). In a subsequent study, 7 consecutive patients with postoperative findings assigned to the femoral nerve were evaluated and assessed by a neurologist.


RESULTS
The mean +/- SD anteroposterior and mediolateral diameters of the femoral nerves in the volunteers were 3.1 +/- 0.8 and 9.8 +/- 2.1 mm, respectively, at an average cross-sectional area of 21.7 +/- 5.2 mm2. The cross-sectional shape was oval in 67.5% superior to the inguinal ligament and in 95% inferior to the ligament. The infrainguinal femoral nerve showed variable distances to the femoral artery. In the subsequent patient study, 5 patients had swelling of the femoral nerve in the affected side. In 1 patient, the nerve had a blurred echo structure due to a hematoma. In 1 patient, major damage of the femoral nerve was ruled out clearly.


CONCLUSIONS
Ultrasonography allows the depiction and assessment of the femoral nerve from about 10 cm superior to 5 cm inferior to the inguinal ligament. In this region, ultrasonography is helpful in detection of impairments and, therefore, in decisions about planning and even acceleration of further treatment.
Gruber
Hannes
H
Department of Radiology, University Hospital Innsbruck, Innsbruck, Austria.
Peer
Siegfried
S
Kovacs
Peter
P
Marth
Roland
R
Bodner
Gerd
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005240:Feasibility Studies; D005260:Female; D005267:Femoral Nerve / Q000000981:diagnostic imaging* / Q000293:injuries*; D020428:Femoral Neuropathy / Q000000981:diagnostic imaging / Q000209:etiology; D006801:Humans; D007049:Iatrogenic Disease; D008297:Male; D010243:Paralysis / Q000000981:diagnostic imaging / Q000209:etiology; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D014463:Ultrasonography