Sagittal Classification of Calcified Lumbar Disc Herniation and Therapeutic Analysis of Percutaneous Endoscopic Interlaminar Discectomy.

Background: Calcified lumbar disc herniation (CLDH) is one specific type of lumbar disc herniation (LDH). Currently, there are no uniform classification standards for different calcification degrees of herniated lumbar disc tissue. Percutaneous endoscopic interlaminar discectomy (PEID) has been proved to exhibit great efficacy in treating LDH, but whether it can achieve satisfactory results in treating CLDH with different calcification remains unclear.

Methods: A total of 271 patients who suffered from single CLDH (97 patients) or NCLDH (non-calcified lumbar disc herniation) who received PEID surgery between January 2016 and December 2018 in our hospital participated in this retrospective study. Moreover, CLDH was divided into four grades based on preoperative sagittal CT images, including 34 Grade I, 22 Grade II, 19 Grade III, and 22 Grade IV. Operative time was evaluated between the two groups. In addition, VAS (leg pain), ODI, and MacNab scale score were applied to assess the efficacy of PEID in treating CLDH with different calcification degrees by Student's t tests or χ² test.

Results: All the patients successfully underwent PEID surgery. According to the analysis, the operative time in the CLDH group was significantly longer than that in NCLDH group. Preoperative and postoperative VAS (leg pain) and ODI scores have no significant differences between the CLDH and NCLDH groups. Furthermore, postoperative modified MacNab scale scores and complication rates were almost the same in the two groups. However, there were some differences in terms of VAS (leg pain), ODI, and MacNab scores during LDH patients with different degrees of calcification. CLDH was divided into four grades in our study, and the analysis displayed that VAS (leg pain) and ODI scores after operation in the Grade IV CLDH group were both obviously higher than those in the control group. Moreover, the modified MacNab scale showed that excellent or good rates in the Grade IV CLDH group (73%) were lowest, and they were significantly lower than those in the control group (91%). The other statistical indexes such as recurrence and complication rates showed no significant difference in CLDH with different degrees of calcification.

Conclusion: CLDH was innovatively divided into four grades in our study. PEID is an effective and safe surgical method for treating CLDH; it can achieve a satisfactory outcome. However, it should be considered carefully in the treatment of lumbar disc herniation with severe calcification (Grade IV).