[Clinical outcomes of spinal endoscopic surgery for tiny lumbar disc herniation with severe radiating pain of lower limb]

Objective: To study the clinical characteristics of the patients with tiny lumbar disc herniation and severe symptoms(tLDHSS) and the therapeutic effects of percutaneous endoscopic lumbar discectomy(PELD).

Methods: From January 2014 to February 2019, 34 patients with tLDHSS were reviewed retrospectively, including 20 males and 14 females, aged from 31 to 73 (48.8±10.1) years, with a follow up duration ranged from 8 to 48 (21.8±10.3) months. The clinical manifestations, imaging and surgical data were analyzed. The visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores were analyzed before operation, 1 month after operation and at the latest follow-up. The preoperative and postoperativescores were compared. At the latest follow up, the Macnab system was used to evaluate the effects of the operation.

Results: The main symptom of 34 cases was severe radiation pain on one side of lower limbs. The duration of preoperative symptoms ranged from 0.33 to 84 months. The disc herniation was found in 7 cases of L_{4, 5} and 27 cases of L₅S₁. According to the MSU division of lumbar disc herniation, 31 cases were located in area B. In all cases, it was confirmed that the protruding nucleus compressed the nerve root, and in 26 cases, the nerve root was obviously inflamed. The operation time ranged from 30 to 80 min, with a mean time of (43.5±9.5) min. The preoperative VAS score was 8.1±1.3 and ODI score was 31.8±6.7. And the VAS score was 1.1± 0.3, 0.7±0.4 on the first month after operation and the latest follow up, respectively. The ODI score was 5.3±2.1 and 0 to 10 (with a median score of 2) on the first month after operation and the latest follow-up respectively. The postoperative VAS and ODI scores were improved compared with preoperative scores.At the latest follow up, 28 cases got an excellent result and 6 cases good according to Macnab evaluation system. During the follow-up period, only one patient had recurrent disc herniation.

Conclusion: The main symptom of patients with tLDHSS is severe radiation pain on one side of lower limb. It manifests as sudden onset and shorter course of disease. Severe local inflammation was induced by local compression of the protruding nucleus pulposus on the nerve root out of the dura. For this kind of patients, thin layer CT scan has an important diagnostic value. In the treatment of this kind of patients, the symptoms are relieved rapidly, the curative effect is definite and the recurrence rate is low.