Anatomical Study Of Pararectus Approach For Acetabular Fractures

Objective:Compare the exposure provided by pararectus approach with by the Stoppa approach,define the factors at risk in the surgical field and adjacent relationship of important neurovascular structures, provide anatomical basis for clinical application by anatomical study of pararectus approach.Methods:Dissections were conducted on six human cadaver specimens,one side with pararectus approach,the other side with the Stoppa approach.The pararectus approach was divided into5windows,we observed neurovascular structures in each window,such as lateral femoral cutaneous nerve, genitofemoral nerve, iliolumbar vessels, corona mortis vessels, obturator nerve,obturator vessels; measured the distance from lateral femoral cutaneous nerve to anterior superior spine,the distance from obturator nerve and obturator vessels to linea iliopectinea and the distance from corona mortis vessels to symphysis.Calculated and compared the exposure area of pararectus approach and Stoppa approach.Results:The incision length of pararectus approach was10.4±0.9cm.The approach described facilitated the exposure from the pubic symphysis to the sacroiliac joint, quadrilateral plate posterior column, iliac fossa and the iliac crest. The exposure area provided by paraectus approach is101.0±5.6cm2,the exposure area provided by stoppa approcch is61.0±4.2cm2.There were many neuro vascular structures in the surgical field,however they were clearly visualised in all specimens.Obturator vessels and nerve were the most important structures at risk.Measurements Regarding obturator nerve:The distance from the obturator canal entrance to linea terminalis left18.2±2.2mm, right18.0±1.7mm,the distance from the intersection point of linea terminalis to sacroiliac joint left21.9±2.6mm, right17.1±1.9mm, maximum distance to linea terminalis by retraction (at the intersection point)left12.8±1.8mm,right13.2±1.8mm.Measurements regarding obturator artery:The distance to linea terminalis at the obturator canal entrance left22.0±2.6mm, right22.9±3.0mm,the distance from the midpoint to linea terminalis left20.3±1.5mm, right15.9±1.3mm, the distance from the midpoint to linea terminalis by retraction left29.4±2.5mm, right28.2±1.5mm.Measurement regarding obturator vein:The distance from the obturator canal entrance to linea terminal left20.9±2.1mm,right20.2±2.6mm, the distance from the midpoint to linea terminalis left28.7±1.7mm, right21.7±1.5mm, the distance from the midpoint to linea terminalis by retraction left36.6±1.7mm, right33.3±1.6mm. The lateral femoral cutaneous nerve was most commonly found at1cm lateral to the anterior superior iliac spine and2cm medial to the anterior superior iliac spine,as far medially as6cm.Corona mortis vessels were found in41.7%of specimens,the distance from vascular to the pubic symphysis was57.0±10.5mm.Conclusion:The Pararectus approach requires a single incision with good exposure of pelvic brim from pubic symphysis to anterior sacroiliac joint,quadrilateral plate,media posterior column,fossa iliaca, iliac crest. The pararectus approach allows direct visualisation of neurovascular structures. The exposure field provided by the pararectus approach is prior to by the Stoppa approach when addresses hemiacetabular fracture.