An Application Anatomic Study Of The Inferior Gluteal Nerve

Objective:By systematic study of the position, length and way of reaching out from pelvic cavity of inferior gluteal nerve, and intensive study of number and position at inferior gluteal nerve reaching out from pelvic cavity, we can understand better about the anatomical structure of inferior gluteal nerve and round about. It would offer guidance to clinical at exploring and treating diseases relating to inferior gluteal nerve's variation.Materials and Methods:Prepare 50 anticorrosive fixed Chinese adult cadavers poured into 20% formaldehyde and being unfreaky ,consisting of 40 males and 10 famales. Observe the position and length of inferior gluteal nerve reaching out from pelvic cavity. Observe the number and position of inferior gluteal nerve reaching out from pelvic cavity. Observe the situation and surface positioning of inferior gluteal nerve and piriformis.Result:1,inferior gluteal nerve reaches out from pelvic cavity as 1 to 4 branches. It including 40 sides of type of 1 branch(43%), inferior gluteal nerve divides into 2 to 4 branches when it running at gluteus maximus's deep layer after reaching out of pelvic cavity, then the latter devides into couple branches and enter gluteus maximus partly; 47 sides of type of 2 branches (inside branch and outside branch)(47%); 11 sides of type of 3 branches (inside branch, intermediate branch and outside branch)(11%). Type of 2 or 3 devide into 2 to 4 branches and enter gluteus maximus. 2 sides of type of 4 branches (2%).2,54 sides of inferior gluteal nerve reach out of pelvic cavity at the middle one-third of the ligature of posterior superior iliac spine and tuberischiadicum(52%); 46 sides reach out of pelvic cavity at the up one-third of the ligature of posterior superior iliac spine and tuberischiadicum(46%);2 sides of below. Among them , the distense between inferior gluteal nerve of type of 1 branch and posterior superior iliac spine is (79.32±10.74)mm,distense between it and posterior midline is (75.82±6.93)mm,distense between it and where pudendal nerve reaches out of pelvic cavity is (20.57±5.08)mm; the distense between inferior gluteal nerve's inside branch of type of 2 branch and posterior superior iliac spine is (85.67±10.85) mm,distense between it and posterior midline is (75.01±7.97)mm,distense between it and where pudendal nerve reaches out of pelvic cavity is (17.61±6.45)mm; the distense between inferior gluteal nerve's outside of type of 2 branch and posterior superior iliac spine is (85.39±10.02)mm,distense between it and posterior midline is (75.88±9.21)mm,distense between it and where pudendal nerve reaches out of pelvic cavity is (18.41±8.47)mm.3,inferior gluteal nerve reaches out from pelvic cavity by 4 ways: 83 sides (83%) from infrapiriformis foramen; 11 sides (11%) from piriformis; 4 sides (4%) from suprapiriformis foramen ;2 sides (2%) inferior gluteal nerve devide into 2 branches and reaches out from infrapiriformis foramen and suprapiriformis foramen partly.4,as to the range from where inferior gluteal nerve reaches out from pelvic cavity to where inferior gluteal nerve devides apart, the length of type 1 is(9.87±5.68)mm,width is(4.76±1.32)mm,thickness is(0.76±0.31)mm,the number of nerves is(3.86±1,23)mm. the length of inside branch of type 2 is(14.78±6.13)mm,width is(4.11±1.46)mm,thickness is(0.46±0.11)mm,the number of nerves is((2.27±0.89)mm; the length of outside branch of type 2 is(14.50±5.88)mm,width is(4.03±1.57)mm,thickness is(0.51±0.12)mm,the number of nerves is(2.33±0.95)mm.5,Absolute value of inferior gluteal nerve reaching out from piriformis: The length outside of mdline is (6.23±0.89)cm, upside is (5.02±0.94)cm, so, the place of inferior gluteal nerve reaching out from piriformis is focused within 2C. The average of the asolute value is focused within the bottom of 2C.Conclusions:1,Through this study we know inferior gluteal nerve have an anatomical feature that it has multi-branch into the muscle. And part of the fiber plays a functional role. Thus, in clinic we can use inferior gluteal nerve to transfer pudendal nerve as the treatment of Conus medullaris and pudendal nerve damage, in order to reconstruct the perineum function.2,The place of inferior gluteal nerve reaching out from piriformis is focused within 2C.so we can make a better surface orientation. A smaller wound will be operated in clinic treatments to avoid adverse effects.