Applied anatomy of the arthrocentesis of lumbar facet joint

Objective:To investigate anatomic puncture approach of lumbar facet joints and provide references for clinical application. Methods:The joint types, joint angles,the distance between superior and inferior articular processes and the shape of articular surface of L1-2～L5-S1 were observed on 35 adult (22 men and 13 female) lumbar specimens by sectional anatomy method. Results:①The joints showed the type of concavity upwardly (82.6%) and the type of plane (17.4%), in which 51.4% of L5~S1 belonged to the former type, while 48.6% to the plane type. ② The joint angles increased gradually from L1~2 to L5~S1, formed as 26°, 30°, 35°, 40° and 45° (3°～5° higher in female) respectively. ③Joints located on lateral side of the posterior median line, between midpoints of the posterior edge of superior and inferior lumbar spines. The distance between joints and the posterior median line were 14.20 mm, 15.74 mm, 18.90 mm, 24.22 mm and 27.20 mm from upper to lower parts. ④Puncture needle passed through skin, superficial fascia, thoracolumber fascia, erector spinae and articular capsule respectively. Conclusions:According to the type and angle of joints, puncture position of lumbar facet joint should be laterally set on 14.20～27.20 mm (average 20.05mm) away from the midpoint of relevant lumbar intervertebral space.