Ultrasound measurement of sciatic nerve cross-sectional area in early outcome assessment after endoscopic surgery for unilateral lumbar disc herniation
Objective To investigate the correlation between early clinical outcomes following endoscopic surgery for unilateral lumbar disc herniation and variations in the cross-sectional area of the sciatic nerve.Methods Fifty-two patients(n=52)with unilateral lumbar disc herniation were recruited from June 2023 to June 2024 at the Pain Department of the First Affiliated Hospital of Nanchang University.The cross-sectional area(CSA)values of bilateral sciatic nerves were measured at the gluteal sciatic tuberosity-great femoral rotor level using ultrasound before and on the 4th day after surgery.The change in nerve cross-sectional area ΔCSA and sciatic nerve swelling rate(SR-SN)were calculated.Patient BMI(Body Mass Index),visual analog scale(VAS),Japanese Orthopaedic Association score(JOA),Oswestry Disability Index(ODI),and Treatment Improvement Rate(TIR)were collected preoperatively and on postoperative day 4.Changes in sciatic nerve cross-sectional area in unilateral lumbar disc herniation and its relationship to clinical outcomes were analyzed using the scoring scales as controls.Results Compared to the preoperative period,there was a significant decrease in VAS and ODI scores,as well as an increase in JOA score on the 4th postoperative day(P<0.01).Furthermore,surgical intervention led to substantial improve-ment in clinical outcomes for the patients.Prior to surgery,the CSA value of the affected side of the sciatic nerve was greater than that of the healthy side(P<0.01).Although CSA value decreased on the affected side after surgery,it remained higher than that of the healthy side(P<0.01).Additionally,there was a significant difference between SR-SN values on both sides with higher values observed on the affected side(P<0.01).Notably,△CSA on the affected side exhibited a negative correlation with postoperative VAS score,JOA score,and treatment improvement rate(P<0.05);The SR-SN on the affected side exhibited a positive correlation with BMI and negative correlations with postoperative VAS score,JOA score,and treatment improvement rate(P<0.05).However,no significant correlations were observed between △CSA,SR-SN,and ODI score on the affected side.(P>0.05).Conclusions In patients undergoing endoscopic surgery for lumbar disc herniation,a greater change in the cross-sectional area of the affected sciatic nerve before and after the operation is associated with more pronounced improvement in early symptoms.However,further investigation is required to explore the relationship between this change and recovery of both lumbar spine and lower limb function.