Self-anchored anterior lumbar discectomy and fusion for L 5 isthmic spondylolisthesis / 中华骨科杂志

ABSTRACT

Objective:To evaluate the value and efficacy of self-anchored anterior lumbar discectomy and fusion (SA-ALDF) for L 5 isthmic spondylolisthesis. Methods:From June 2018 to December 2019, a total of 11 cases of L 5 isthmic spondylolisthesis were treated with SA-ALDF, including 4 men and 7 women, aged 43.2±12.6 (range 29-63) years. All patients had intractable low back pain aggravating during standing activities and alleviating during rest, without lower extremity radicular symptoms. Imaging examination showed bilateral isthmus cleft of L 5 with spondylolisthesis of 1 degree in 10 cases and 2 degree in 1 case according to Meyerding grading system. Under general anesthesia and supine French position, transverse 6 cm incision was made. Then, the L 5S 1 intervertebral disc was exposed via extraperitoneal approach between the bifurcation of abdominal aorta and vena cava. The intervertebral disc was sufficiently removed. The intervertebral space was released and distracted followed by canal ventral decompression and sequential mold testing. Suitable self-anchoring cage filled with auto iliac cancellous bone was implanted to restore intervertebral height and lordosis as well as reduction of spondylolisthesis. Under fluoroscopic guidance, the distal anchoring plate was knocked into the sacrum followed by direct reduction and proximal anchoring plate locking in the L 5 vertebral body. The patients were followed up for 12.1±4.7 (range 6-18) months. The visual analogue score (VAS) and Oswestry dysfunction index (ODI) were evaluated. The reduction and fusion were evaluated on the X-ray films. Furthermore, the rate of spondylolisthesis, the height and the lordosis of intervertebral space were measured. Results:The operation was performed successfully in all the patients with operation duration 90±18 (range 70-120) min, intraoperative blood loss 30±16 (range 10-60) ml. No severe complication such as nerve and blood vessel injury occurred. All patients experienced alleviation of symptom during follow-up. X-rays confirmed that the spondylolisthesis and alignment were recovered obviously without obvious cage displacement. However, the loss of reduction was 63.2% for the grade 2 spondylolisthesis. At the final follow-up, VAS decreased from 6.1±2.1 to 0.9±0.5, ODI decreased from 43.6%±14.2% to 6.0%±3.4%. The spondylolisthesis recovered from 17.7%±10.3% to 8.0%±7.2% with reduction rate of 54.8%±21.6%. The interverbral height recovered from 6.4±2.1 mm to 9.8±3.9 mm and intervertebral lordosis recovered from 4.8°±2.9° to 9.6°±4.7°.Conclusion:SA-ALDF can provide satisfactory outcomes for selected L 5 isthmic spondylolisthesis of degree 1 without neurological compromise. However, its mechanical stability may be insufficient for isthmic spondylolisthesis of degree 2.