The inclusion criteria were as follows: (1) age between 20 and 60 years; and (2) single-level PIVD with lack of significant response to conservative treatment, manifesting as persistent or recurrent pain with or without neurological deficit, despite adequate analgesic use, use of anti-inflammatory and muscle relaxant medication, and absolute bed rest for at least 3 months.
The exclusion criteria were as follows: (1) refusal for procedure; (2) multilevel lumbar canal stenosis, symptomatic lumbar canal stenosis, lumbar instability, arachnoiditis or deformity, and severe medical illnesses, including active infection, and other chronic conditions that interfered with clinical or radiological assessments; (3) history of allergy to contrast media, steroids, and local anesthetic agents; (4) previous lumbar spine surgeries; and (5) active cancer, history of substance abuse, current psychiatric comorbidity, pregnancy, diabetes mellitus, and congestive cardiac failure.
Diagnosis was clinically and radiologically confirmed, and posterior decompression and discectomy were performed. Clinical follow-up of patients was conducted at intervals of 6 weeks, 3 months, 6 months, and 12 months; pain and functional outcome were evaluated; and contrast-enhanced magnetic resonance imaging (MRI) was performed between 12 and 18 months. All patients underwent surgery under general anesthesia. Antibiotic prophylaxis with 1.5 g intravenous cefuroxime was administered, and the patient was placed in supine position on the table and then rolled over to prone position. Operative field was cleaned and draped. The level of the surgery was marked under fluoroscopy. Posterior midline incision was made, and posterior decompression was performed for the required level of PIVD. Gelfoam or free autologous fat graft obtained from incision site was placed over the dura mater after laminectomy (
Fig. 2). Hemostasis was achieved intraoperatively. The postoperative clinical follow-up was conducted at intervals of 6 weeks, 3 months, 6 months, and 12 months. Clinical assessment was conducted followed by evaluation through Oswestry Low Back Pain Disability Questionnaire (ODI; also known as Oswestry Disability Index), which is considered a “gold standard” tool to measure the patient’s permanent functional disability. For each section (10 sections), the statements were marked 0 to 5. The scores were marked as follows: 0%–20%, minimal disability; 21%–40%, moderate disability; 41%–60%, severe disability; 61%–80%, crippled; and 81%–100%, bed-bound or exaggerating symptoms. It indicates how patients’ back or leg pain is affecting patients’ ability to manage daily life [
9]. Clinically assessment for activity-related pain, backache, and radicular pain and Straight Leg Raising Test (SLRT) were performed. In SLRT, the patient is placed in supine position with one leg either straight or flexed at the knee and the other affected leg raised in a straight position, and the test is positive when the raised leg between 30° to 70° causes pain to occur and radiate down the leg to at least below the knee or up to the great toe (sensitivity=91%, specificity=26%). Visual Analog Scale (VAS) is a pain rating scale based on symptoms reported by the patient that is recorded with a mark placed at one point along the length of a 10-cm line from left to right “no pain,” 0 cm, and “worst pain,” 10 cm [
10]. Radiological assessment through the modified Ross grading using contrast-enhanced MRI performed between 12 and 18 months of follow-up [
11]. Quantification by MRI in a single slice at the level of laminectomy is performed by dividing the spinal canal into four quadrants by drawing perpendicular lines from the center of the dural sac. Quadrants a and b represent anterior epidural spaces to the right and left, respectively, and include the lateral recesses and spinal nerve roots. Quadrants c and d represent the posterior epidural spaces to the right and left, respectively. The posterior border of the evaluation area is demarcated by drawing the line between the most posterior bony remnants. Each quadrant is quantified separately using a scale of 0–4: 0, no/trace EF; 1, 1%–25%; 2, 26%–50%; 3, 51%–75%, and 4, 76%–100% of quadrant affected by EF. Therefore, for each operative level, including two to three imaging slices centered around the intervertebral disc, a minimum of 0 and a maximum of 16 scores can be obtained. According to the modified Ross grading, looking at the complete slice as a whole, each quarter of the quadrants actually represents sixteenth of the slice. Thus, the result, number 1, which in Ross’s model represents 1/4 of the quadrant affected by fibrosis, will correspond to 1/16 or 6.25% of fibrosis per level. Similarly, number 2, which in Ross’s model stands for 2/4 of the quadrant affected by fibrosis, will represent 2/16 or 12.5% of fibrosis per level, and number 3 will represent 3/16 or 18% of fibrosis per level, while number 4 would mean 4/16 or 25% of fibrosis per level. For example, if two slices are obtained, slice 1—a=1, b=2, c=3, and d=4. Therefore, the total is a+b+c+d=10/16=0.625×100=62.5% and slice 2—a=1, b=0, c=0, d=4. Therefore, the total is a+b+c+d=5/16=0.325×100=31.25%. Thus, the total amount of EF is (slice 1+slice 2)/2, i.e., 62.5+31.25/2=46.875 (
Fig. 3). The collected data were tabulated, coded, and then analyzed using SPSS software ver. 16.0 (SPSS Inc., Chicago, IL, USA). Continuous variables were presented as mean and standard deviation (unpaired Student
t-test), while categorical variables were presented as percent (chi-square test, analysis of variance, and Fisher’s exact test).