Paramedian Approach with Unilateral Pedicle Screw Fixation for Lumbar Disc Herniation Combined with Lumbar Instability

Objective:To discuss the clinical effects of the paramedian approach with unilateral pedicle screw fixation on the lumbar disc herniation combined with lumbar instability.Methods:From February 2007 to March 2009,a total of 33 cases(20 males,13 females, 35-52 years of age,average 40.5 years) of lumbar disc herniation combined with lumbar instability were treated with unilateral pedicle screw fixation by the paramedian approach.The Japanese Orthopaedic Association(JOA) and visual analogue scale(VAS) scores before and after surgery and the fusion rate were analyzed during the follow-up period.The improvement in the lumbar spine function and clinical effects of the surgery on the patients were also evaluated.Results:The average operation time and blood loss were (11(1±16.8)min and(206±40.1 )mL respectively.The average follow-up period of the patients was 26.7 months.The average preoperative JOA score was(8.1±0.9) and the average JOA score at the last follow-up was(14.2±0.5).The average postoperative improvement rate was 88.4%with 31 cases of excellent improvement rate(93.9%),1 case of good improvement rate(3.0%) and 1 case of fair improvement rate(3.0%).The excellent and good improvement rate was 96.9%.The preoperative VAS score was(7.9±0.4) and the VAS score at the last follow-up was(1.9±0.5) with a 75.9 precent decrease.No cage displacement or settlement and implant loosening or breakage in this group were found by the radiological examination during the follow-up period,and bony fusion was achieved in all patients with a 100 percent fusion rate.Statistical analysis revealed significant differences(P0.05) between the preoperative JOA or VAS scores and the JOA or VAS scores at the last follow-up.Conclusions:Good clinical outcomes in the treatment of the lumbar disc herniation combined with lumbar instability are achieved using the paramedian approach with unilateral pedicle screw fixation.This technique has advantages of less trauma and easy manipulation,can effectively alleviate the patients' symptoms and advance the neural functional recovery.