Group A was comprised of 64 patients (males, 24; females, 40), and group B was comprised of 57 patients (males, 28; females, 29). The mean age in group A was 73.8±4.5 years (range, 65–93 years) and in group B was 47.3±12.7 years (range, 25–65 years). There was no significant difference (
p=0.09) in BMI between the groups (
Table 1). All patients in group A had neurogenic claudication as the presenting symptom, with a mean symptom duration of 9.5±8.6 months (range, 3–24 months) before surgery. In addition to neurogenic symptoms, 46 patients also complained of mechanical low back pain, with radiologically evident instability of varying degrees, with mean VAS score of 7.9±1.52 (range, 6–10). The preoperative mean ODI score in group A was 78.35±6.46 (range, 66–87) (
Table 4). In group B, 26 patients were in the 25–45-year age range, and 31 were in the 45–65-year age range. The mean preoperative VAS score was 7.8±1.13 (range, 4–9) and preoperative ODI score was 76.11±6.52 (range, 56–84). There was little significant difference in postoperative VAS score between the two groups, and the overall improvement in functional outcome at final follow-up was insignificant in the two groups. The mean duration of preoperative symptoms was 7.8±8.1 months (range, 3–24 months) in group B (
Table 4). The incidence of medical co-morbidities was greater among group A patients (single, 23 cases; multiple, 17 cases). In group B, 19 patients had a single co-morbidity, and 12 patients had two or more co-morbidities (
Table 1). The chi-square test revealed no significant difference in outcome at final follow-up between the two groups with reference to the presence of co-morbidities (
p=0.37 for group A and
p=0.17 for group B). The mean operative time was 154±29 minutes (range, 75–215 minutes) in group B and 158±35 minutes (range, 75–230 minutes) in group A. The mean operative blood loss was 220±15 mL in group A and 190±31 mL in group B (
p=0.01) (
Table 1). The reason for this statistical significance might be that one patient in group A had a blood loss of around 1,600 mL, for no obvious reason, and required multiple blood transfusions with prolonged hospital stay. In each group, there was a single, minor intraoperative dural tear that was managed with fibrin glue, Gelfoam, and watertight fascia closure, with no postoperative dural tear-related complications. In group A, 11 patients had complications in the postoperative period (
Table 3). Three patients, who had superficial infections (due to uncontrolled diabetes) and delayed wound healing, were managed conservatively with antibiotics and daily dressings, prolonging their hospital stays. Two patients had deep infection, requiring debridement on the seventh postoperative day. One patient had wound dehiscence on the ninth day postoperatively, requiring secondary re-suturing, and another patient developed transfusion related problems after multiple blood transfusions (acute respiratory distress syndrome [ARDS]). Additionally, three patients had urinary tract infections (UTI) with related fever and were managed with oral antibiotics postoperatively without additional hospital stay (
Table 3). The mean duration of hospital stay in group A was 3.5±1.67 days (
Table 1). Three patients had persistent paresthesia related to diabetic neuropathy, and none of the patients had any neurological complications in group A in the postoperative period. Seven patients developed syndrome of inappropriate antidiuretic hormone secretion due to electrolyte imbalance, and five patients needed prolonged catheterization in group A. Six patients in group B had postoperative complications. Two patients developed superficial wound infections, requiring minor debridement and re-suturing. One patient had a screw malposition with persistent paresthesia, requiring screw revision on the third postoperative day, and another patient had UTI with fever that required prolonged oral antibiotics (
Table 3). The mean duration of hospital stay in group B was 2.45±1.76 days. The mean ODI and VAS scores showed significant improvement (
p<0.05) in both the groups at final follow-up, with considerable improvement in clinical parameters (
Table 4). Per Wang’s criteria, 54 patients in group A had excellent-to-good outcomes. Ten patients had fair-to-poor outcomes, two had only partial symptom relief, and one patient had worsened symptoms after surgery. In group B, 51 patients had excellent-to-good outcomes, and six patients had fair-to-poor outcomes, with persistent or recurrent symptoms at final follow-up (
Table 4). There was no significant difference in mean time to return to mobilization between the two groups, although group A took a little longer (average, 3.4 weeks) to reach pain-free status than group B (average, 2.6 weeks). Radiological data analysis showed a 90.6% fusion rate, two cases of screw loosening, three pseudoarthrosis, and one case each of implant failure (due to trivial fall and low bone mineral density), adjacent segment disease (ASD), and cage migration in group A (
Table 5). Five patients, including two cases of screw loosening and three cases of pseudoarthrosis, underwent revision surgeries at the same level while a case of asymptomatic ASD was managed conservatively. The fusion rate was 92.9% in group B, with two cases of pseudoarthrosis and two cases of ASD (
Table 5). Revision surgeries were done in four patients, two cases each of pseudoarthrosis and symptomatic ASD in group B (
Table 3).