Abstract: BACKGROUND: Traditional surgery for lumbar disc herniation involves extensive excision of tissue surrounding the nerve for decompression and removal of protruding lumbar intervertebral discs, which poses various risks and complications such as nerve damage causing paralysis, lumbar instability, herniation recurrence, intervertebral space infection, and adjacent vertebral diseases.
OBJECTIVE: To propose the symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous technique for lumbar spine symmetrically decompression, showing the induced resorption of herniated nucleus pulpous phenomenon and early clinical efficacy, and then analyze its decompression mechanism.
METHODS: 214 patients with lumbar disc herniation at Department of Orthopedics, First Affiliated Hospital of Zhengzhou University from March 2021 to May 2023 were enrolled in this study. Among them, 81 patients received conservative treatment as the control group, and 133 patients received symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous treatment as the trial group. Before surgery, immediately after surgery (7-14 days), and early after surgery (over 1 year), MRI images were used to measure the volume changes of lumbar disc herniation. CT images were used to measure the posterior displacement distance of the lumbar spinous process ligament complex, as well as the width and height of the lateral recess. Japanese Orthopaedic Association scores were used to evaluate the patient’s neurological function recovery.

RESULTS AND CONCLUSION: (1) Control group: 81 patients with lumbar disc herniation were treated conservatively, with a total of 171 herniated lumbar discs. The average follow-up time was (22.7±23.1) months. The first and second MRI measurements of 171 herniated lumbar discs showed herniated lumbar disc volumes of (551.6±257.9) mm3 and (792.2±330.4) mm3, respectively, with an average volume increase rate of (53.2±44.4)%, showing statistically significant differences (P < 0.001). Out of 171 herniated lumbar discs, 4 experienced natural shrinkage, with an absorption ratio of 2.3% (4/171) and an absorption rate of (24.5±9.9)%. (2) Trial group: 133 patients with lumbar disc herniation had a total of 285 herniated lumbar discs. (1) Immediately after surgery: All patients were followed up immediately after surgery. 229 out of 285 herniated lumbar discs experienced retraction, with an absorption ratio of 80.3% (229/285) and an average absorption rate of (21.5±20.9)%, with significant and complete absorption accounting for 6.5%. There were a total of 70 herniated lumbar discs in the upper lumbar spine, with an absorption ratio of 85.7% (60/70), an average absorption rate of (23.1±19.5)%, and a maximum absorption rate of 86.6%. There were 215 herniated lumbar discs in the lower lumbar spine, with an absorption ratio of 78.6% (169/215), an average absorption rate of (21.0±21.3)%, and a maximum absorption rate of 83.2%. Significant and complete absorption of the upper and lower lumbar vertebrae accounted for 5.7% and 6.5%, respectively, with no statistically significant difference (P > 0.05). The average distance of posterior displacement of the spinous process ligament complex immediately after surgery was (5.2±2.8) mm. There were no significant differences in the width and height of the left and right lateral recess before and immediately after surgery (P > 0.05). The Japanese Orthopaedic Association score immediately after surgery increased from (10.1±3.4) before surgery to (17.0±4.8), and the immediate effective rate after surgery reached 95.6%. (2) Early postoperative period: Among them, 46 patients completed the early postoperative follow-up. There were 101 herniated lumbar discs, with an absorption ratio of 94% (95/101) and an average absorption rate of (36.9±23.7)%. Significant and complete absorption accounted for 30.6%, with a maximum absorption rate of 100%. Out of 101 herniated lumbar discs, 3 remained unchanged in volume, with a volume invariance rate of 2.97% (3/101). Out of 101 herniated lumbar discs, 3 had an increased volume of herniated lumbar discs, with an increase ratio of 2.97% (3/101) and an increase rate of (18.5±18.4)%. The Japanese Orthopaedic Association score increased from preoperative (9.3±5.1) to (23.5±4.0), with an excellent and good rate of 93.4%. (3) The early postoperative lumbar disc herniation absorption ratios of the control group and trial group were 2.3% and 85.9%, respectively, with statistically significant differences (P < 0.001). (4) Complications: There were two cases of incision exudation and delayed healing in the trial group. After conservative treatment such as dressing change, no nerve injury or death occurred in the incision healing, and no cases underwent a second surgery. (5) It is concluded that symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous is a new method for treating lumbar disc herniation that can avoid extensive excision of the “ring” nerve and achieve satisfactory early clinical efficacy. It does not damage the lumbar facet joints or alter the basic anatomical structure of the lateral recess, fully preserves the herniated lumbar discs, and can induce significant or even complete induced resorption of herniated nucleus pulpous. Symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous provides a new basis and method for the clinical treatment of lumbar disc herniation. 

中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程

Key words: lumbar disc herniation, induced resorption of herniated nucleus pulpous, symmetric decompression, lateral recess, natural absorption