General Information
All patients gave their informed consent to participate in this study, which was endorsed by our hospital's ethics committee. Between June 2018 and April 2021, we used PEID and PETD to treat 45 consecutive patients with L4-L5 and L5-S1 CLDH at our facility. These patients were divided into two groups based on the surgical methods: PEID (n = 24) and PETD (n = 21). Each patient came in with a leg-lengthening low back discomfort. Despite taking conservative therapies for at least three months, such as acupuncture, physiotherapy, and medication, the discomfort persisted or recurred and interfered with everyday activities. The preoperative diagnosis of CLDH was validated using computed tomography and/or magnetic resonance imaging. The study did not include any participants with multi-segmented CLDH or lacking CLDH. Surgeons with at least five years of experience performed every operation. We retrieved and reviewed follow-up results, clinical data, and demographic information.
Surgical Procedure
All had general anesthesia and either PETD or PEID neurophysiological monitoring. On a radiolucent table, the patient was positioned prone. Under the supervision of a C-arm fluoroscope, the endoscopy is carried out.
PEID
A guide rod is placed medially into the inferior articular eminence after using fluoroscopy to identify the operative disc space. The working trocar is then inserted through the guide rod adjacent to the inferior articular eminence with an oblique surface facing the ligamentum flavum. A medial osteotomy of the inferior vertebral plate and articular eminence is carried out after inserting the endoscope into the trocar. After cutting a hole in the ligamentum flavum, the working trocar is moved into the epidural space. The region around the nerves and calcified foci is freed once the soft tissue around them has been removed. Following the removal of the soft disc, the nerve is dragged medially, the calcification is removed by grinding the drill, the nerve is tested for relaxation, and finally, the working channel is pushed out and the incision is sutured. All patients underwent CT and MRI scans before (Fig. 1A-D) and after (Fig. 1E-H) operation.
PETD
Once the surgical disc space has been located by fluoroscopy, an 18G puncture needle is inserted into the lateral side of the superior articular process. Cephalad to caudal should be the needle's route. The guide wire, guide rod, and soft tissue dilator are implanted one after the other along the route of the penetration needle. The guide wire, guide rod, and soft tissue dilator are implanted one after the other along the route of the penetration needle. A working cannula is introduced into the spinal canal through each dilator and guide rod. An articular eminence osteotomy was performed while under visualization to show the calcified lesion. After allowing the nerve to pulse, the working channel is removed, the disc and calcified foci are eliminated, and the incision is sutured. Prior to (Fig. 2A-D) and following (Fig. 2E-H) surgery, all patients obtained CT and MRI scans.
Outcome assessment
The demographic variables that were examined between the PEID and PETD groups were age, sex, body mass index (BMI), and follow-up time. In terms of surgical outcomes, including operation time, intraoperative blood loss, intraoperative fluoroscopy times, postoperative hospital stay, and complications, the two groups were compared. Clinical outcome indicators such the Oswestry Disability Index (ODI), the Visual Analog Scale (VAS) for Leg Pain, and modified MacNab criteria at the last follow-up were compared between the two groups. In the meantime, VAS and ODI scores were gathered at each follow-up appointment following PELD in comparison to the preoperative period.
Postoperative Treatment and Follow-Up
Straight leg raising exercises were advised at least on the first postoperative day, and mannitol and dexamethasone were administered for one day after surgery. It is advised to stay in bed for a week. Patients were evaluated one week, one month, three months, and twelve months after surgery. The VAS score and ODI were collected at each follow-up, however only the last follow-up included a Macnab criteria outcome evaluation.
Statistical analysis
All data were statistically analyzed using the SPSS 23.0 software (IBM Corporation, USA). The data's normality was evaluated using the Shapiro-Wilk test. Mean±standard deviation are used to represent parametric data, while median is used to show nonparametric data (interquartile range). Wilcoxon test was used for intragroup comparisons while Mann-Whitney test was utilized to compare the two groups. Chi-square tests were used to compare the modified MacNab criteria, sex and comorbidities. P<0.05 indicates a statistically signifcant diference.