Clinical Effect of Treatment of Lumbar Disc Herniation with Osteoporosis through Augmentation of Pedicle Screw Fixation with Optimized Volume of PMMA

Abstract：Objective To evaluate the clinical effect of augmentation of pedicle screw fixation with optimized volume of bone cement in treatment of lumbar disc herniation with osteoporosis. Methods 27 patients with lumbar disc herniation and osteoporosis between June 2013 and June 2014 were treated with pedicle screw fixation and bone cement augmentation,lami-nectomy,discectomy and interbody fusion. All patients underwent pre-operative examination of bone mineral density with T-score ﹤ - 2. 5 and were diagnosed with osteoporosis. All patients underwent augmentation of pedicle screw fixation with injec-tion of 1. 5 mL bone cement and all patients were treated with anti-osteoporosis therapy pre- and post-operation. All patients were observed and recorded with basic conditions and complications. At pre-operation,6-month post-operation and last follow-up,pain visual analogue scale(VAS)and Japanese Orthopedic Association low back pain score(JOA)and Oswestry disability index(ODI)of all patients were recorded and the screw stability and interbody fusion of all patients were evaluated in X-ray and CT examination. Results 27 patients were successfully underwent operation with operation time about 130 ~ 200 min and blood loss about 200 ~ 500 mL. There were no spinal cord or nerve injury,no dural tear and no obviously bone cement leakage and screw loosening during operation. All patients were followed up for 18 to 30 months. X-ray and CT examination at last fol-low-up showed no leakage of bone cement,non-loosening of pedicle screw and non-sinking of cage. Good interbody fusion was found and fusion rate was 88. 9% . At 6-month post-operation and last follow-up,VAS,JOA and ODI were significantly im-proved than those at pre-operation(P ﹤ 0. 05),but there were no significantly differences on these parameters between 6-month post-operation and last follow-up(P ﹥ 0. 05). Conclusion During operation for lumbar disc herniation with osteoporosis,aug-mentation of pedicle screw fixation with 1. 5 mL bone cement can effectively enhance initial stability of pedicle screw in osteo-porosis. This method can well maintain long-term stability of internal fixation in osteoporosis,improve interbody fusion rate and significantly reduce risks of long-term screw loosening and interbody non-fusion.