Correlation between diameter of sciatic nerve and symptoms or prognosis in patients with lumbar disc herniation / 中华骨科杂志

ABSTRACT

Objective To explore the effect of single level lumbar disc herniation on the morphology and diameter of sciatic nerve,and to identify the correlation between the diameter change in sciatic nerve and severity of clinical symptoms,as well as the prognosis of surgical treatment in patients with lumbar disc herniation.Methods From January 1,2017 to December 31,2017,Seventy lumbar disc herniation (LDH) patients who underwent single-level posterior lumbar spine surgery were recruited in this retrospective analysis study.Specific data including age,gender,the level of a disc herniation,the type of disc herniation,symptomatic side,surgical procedure were recorded respectively.In addition the morphological changes and the diameter of bilateral sciatic nerve were recorded preoperatively and postoperatively by B-mode ultrasound.Furthermore,the pain in patients and neurological function were evaluated by visual analogue scale (VAS,back pain and leg pain),Japanese orthopaedic association scores-lumbar (JOA) and Oswestry disability index (ODI).The correlation between the diameter of sciatic nerve and clinical features,as well as clinical prognosis of patients were identified in the present study.Results For patients with acute lumbar disc herniation,the diameter of sciatic nerve in affected side was 5.19±1.03 ram,which is significantly higher than that in the unaffected side (4.57±0.64 mm,t=6.735,P=0.000).In addition,preoperative ratio of the affected side to the healthy side of the sciatic nerve showed strong correlation with the VAS of leg pain (r=0.838,P=0.001),JOA (r=-0.857,P=0.001),and ODI score(r=0.881,P=0.000),but not with the VAS of back pain (r=-0.061,P=0.614).Three months after surgery,the diameter of sciatic nerve in the affected side decreased to 4.58±0.63 mm (t=6.865,P=0.000),while the unaffected side showed no significant change(t=0.300,P=0.765).Clinical improvement was observed in all the patients postoperatively.The changes in the diameter of sciatic nerve postoperatively in affected side showed strong correlation to the rate of improvement in VAS of leg (r=0.624,P=0.003),JOA(r=0.615,P=0.003) and ODI scores (r=0.722,P=0.002),but not to the rate of improvement in VAS of back (r=-0.025,P=0.836).Conclusion Single root compression in patients with single level disc herniation might cause morphological changes such as thickening and edema in sciatic nerve,which were closely related to the severity of clinical symptoms and the prognosis of surgical treatment.