[An anatomical study and clinical evaluation of modified subinguinal approach for treatment of acetabular fractures]

To investigate the clinical results of modified subinguinal approach without iliac osteotomy for anterior surgical treatment of acetabular fractures which involve the anterior wall and medial wall or in combination with femoral neck fracture.

The subinguinal approach was modified after anatomical study on 12 adult cadavers. Between May 2010 and March 2012, 34 patients with acetabular fracture that involved the anterior wall and medial wall or in combination with femoral neck fracture were treated with open reduction and internal fixation through modified subinguinal approach in 15 cases and through modified subinguinal approach combined with Kocher-Langenbeck approach. There were 28 males and 6 females with an average age of 31.1 years (range, 20-64 years). According to the Letournel-Judet classification, there were 15 cases of anterior acetabular/column fractures, 8 cases of anterior acetabular/column fractures combined with trear half transverse fractures, 7 cases of double column fractures, and 4 cases of T shape fractures. The time between injury and operation was 5-16 days (mean, 7.4 days).

Anatomy results: the inguinal ligament was reflection and continuity from the aponeurosis of obliquus externus abdominis with a length of (11.09 +/- 0.24) cm, which form part of abdominal muscle. The conjugate of inguinal ligament and iliopsoas muscle on the anterosuperior iliac spine was (0.69 +/- 0.08) cm. The vertical distance from the saphenous vein to the inguinal ligament was (3.58 +/- 0.49) cm.

all the cases were followed up 4-24 months (mean, 14.6 months). No complication was observed, such as wound infection, internal fixation loosening, and iatrogenic injury to the sciatic or femoral nerve. The bone union time was 12-16 weeks (mean, 14 weeks). According to Matta reduction criteria for acetabular fractures, anatomic reduction were achieved in 21 cases, satisfactory reduction in 10 cases, and unsatisfactory reduction in 3 cases at 1 week after operation. According to D'Aubigne and Postel criteria for hip function, the results were excellent in 25 cases, good in 4 cases, fair in 3 cases, and poor in 2 cases at last follow-up. Heterotopic ossification (Brooker's grade I) occurred in 8 cases.

The modified subinguinal approach can keep the inguinal ligament intact, provide broad visualization of anterior and medial wall of acetabulum and anterior hip capsule, which is a better modification and supplement for classic ilioinguinal approach.