The ilio-inguinal approach is used to achieve internal fixation of acetabular fractures. Although the outcomes of this procedure have been extensively reported, information is lacking on potential complications. More specifically, the effect on the ilio-psoas muscle, whose iliac attachments are almost completely released, has not been accurately evaluated.

Endopelvic dissection does not alter the ultrasound structure of the ilio-psoas muscle compared to the normal side at a distance from acetabular internal fixation via the ilio-inguinal approach.

We retrospectively evaluated 26 patients who underwent internal fixation of acetabular fractures via the ilio-inguinal approach between 2006 and 2010. Two patients with multiple injuries died shortly after the procedure, leaving 24 patients with unilateral fractures for the study. In 2012, an observer who was not involved in the surgical treatment of these patients conducted an assessment (Oxford score except in the 8 patients who required revision surgery for arthroplasty and evaluation for a deficit of the lateral femoral cutaneous nerve in the full cohort). At the same time point, ultrasonography was performed to compare ilio-psoas muscle morphology on the two sides. Any other complications (vascular, nervous, or parietal) were recorded.

Of the 24 patients, 11 (45%) experienced complications, of whom only 3 required further surgery, 2 with infections that recovered fully after lavage and 1 with a haematoma responsible for compression of the urinary bladder. The lateral femoral cutaneous nerve was injured in 8 (33%) patients, including 4 who had achieved a full recovery at last follow-up. At last follow-up, none of the 24 patients had ultrasound evidence of a significant difference in ilio-psoas muscle size at the lateral window: mean transverse diameter was 51.8±0.8mm (range, 44–58mm) on the operated side versus 51.7±0.79mm (range, 44–59mm) on the other side (P=0.9). After a mean follow-up of 49months (range, 31–70months), the mean Oxford score in the 16 patients who had not required further surgery was 20.5/60 (range, 12–44).

Our results show that, despite extensive endopelvic dissection, the ilio-inguinal approach has no effect on the ultrasound morphology of the ilio-psoas muscle. There is a high risk of injury to the lateral femoral cutaneous nerve that should be disclosed to the patient before the procedure. In contrast, no parietal complications were recorded. In selected patients, the Cole-Stoppa approach is an alternative that spares the lateral femoral cutaneous nerve.

Level IV, retrospective study.