Short-term clinical outcomes of single-level full-endoscopic lumbar interbody fusion for degenerative lumbar spine disorders combined with osteoporosis

English Keywords:Endoscopic fusion  Osteoporosis  Degenerative spine disorders  Minimally invasive spine surgery  Clinical outcomes

English Abstract:

  【Abstract】 Objectives: To explore the clinical outcomes of single-level full-endoscopic lumbar interbody fusion for degenerative lumbar spine disorders combined with osteoporosis. Methods: 24 consecutive patients with degenerative lumbar spine disorders who underwent single-level full-endoscopic lumbar interbody fusion and were detected by dual-energy X-ray absorptiometry(DXA) during hospitalization for bone mineral density(BMD) from June 2018 to February 2022 were enrolled, including 7 males and 17 females with an average age of 66.0±9.9 years old(range 44-80 years). The follow-up period was 21.6±12.6（3-47） months after operation. And the patients were divided into two groups of osteoporosis group(containing 8 osteoporotic cases) and control group(containing 16 non-osteoporotic cases). Anti-osteoporosis therapy was initiated on the diagnosis of osteoporosis. The surgery was performed using a 7.1mm inner-diameter full-endoscope. The general data and perioperative parameters were compared between the two groups. Before operation, on 3d after operation and at final follow-up, visual analogue scale(VAS) score for back and leg pain, Japanese Orthopaedic Association(JOA) score and Oswestry disability index(ODI) were used for evaluating clinical outcomes. Digital radiography(DR) and computed tomography(CT) were performed on postoperative 3d for neural decompression and implant position assessment. For patients who received DR examination, cage subsidence and screw loosening were recorded at the final follow-up; For patients who were followed-up for 6 months and more and examined with CT, fusion rate was evaluated. The complications were recorded and compared between the two groups. Results: No significant differences were found in age, gender, diagnosis, preoperative intervertebral height, surgical segment, preoperative VAS scores, JOA scores and ODI between the two groups. The average of the lowest T value was -3.2±0.6 for osteoporosis group, lower than the -1.4±0.8 for control group(P=0.000). The mean operative time was 429.9±135.2min for osteoporosis group, more than the 327.4±68.2min for the controls(P=0.020). There was no significant difference in intraoperative imaging assistance, bleeding, number of cases received unilateral laminotomy for bilateral decompression(ULBD), postoperative intervertebral height and length of hospital stay between groups. The VAS scores for back and leg pain, JOA scores and ODI improved postoperatively and at the final follow-up in both groups comparing with those values before operation(P<0.05), and there was no significant difference between groups, respectively. The postoperative 3d intervertebral height in both groups increased after surgery(P<0.01), and none significant difference was found between groups. In the osteoporosis group, asymptomatic cage subsidence happened in 1 case with severe osteoporosis(T=-4.4) due to intraoperative endplate damage during cage implantation, but no symptoms were observed, therefore no special treatment was given; And dural tear and subsequent incomplete nerve root injury happened to another case in the osetoporosis group, whose symptoms were relieved after symptomatic treatment such as neurotrophy. 18 patients received lumbar DR at final follow-up, and 10 patients received CT evaluation at more than 6 months′ follow-up, no significant difference was found in cage subsidence and screw loosening rate and fusion conditions between groups(P=1.000). Conclusions: Single-level full-endoscopic lumbar interbody fusion is safe and effective in the short-term for the treatment of degenerative lumbar spine disorder combined with osteoporosis.