| ObjectiveTo evaluate the clinical efficacy of bone cement-injectable perforated pedicle screw system in the treatment of osteoporotic degenerative disease of the lumbar spine.MethodsA retrospective analysis was conducted on 27 patients with osteoporosis and lumbar degenerative diseases who underwent posterior lumbar laminectomy and decompression,nucleus pulposus exploration,internal fixation by pedicle system,pedicle screw augmented with Polymethylmethacrylate(PMMA)and intertransverse bone graft fusion in orthopedics departmen 3 of Dongzhimen Hospital,Beijing University of Chinese Medicine from October 2016 to October 2017.All included patients were preoperatively diagnosed with osteoporosis(BMD T<-2.5).Basic information and complications of operation were recorded.VAS and ODI were used for preoperative assessment of lumbar and leg pain.The positive and lateral lumbar X-ray films were re-examined I week after the surgery.The positive and lateral,flexion and extension,dual-oblique X-ray films,lumbar CT+3D reconstruction were re-examined 3 months or more after the surgery for imaging evaluation.The height of adjacent vertebrae,the height of proximal intervertebral space,the height of distal intervertebral space and lordosis angle of lumbar fixation segment were measured.The cross-sectional regional distribution,morphological types(concentration and dispersion)of bone cement in vertebral body,trend of flow direction of vertebral bone cement in coronal position(up,down,inside,outside and no trend)was observed.Meanwhile,VAS score of lumbar and leg pain,lumbar ODI score were performed.Preoperative,postoperative one week and the last follow-up were conducted for comparative analysis of some indexesResultsAmong the 84 vertebral bodies of the 27 patients,168 bone cement-injectable perforated pedicle screws were used,among which 163 screws were enhanced by PMMA and 5 screws were not enhanced.The operative time was(162.2±25.9)min,the intraoperative blood transfusion volume was(233.9±197.2)ml,and the injection dose of PMMA for each screw was(1.09±0.81)ml.RBC,HGB and HCT were decreased(0.58±0.27)1012/L,(18.63±6.84)g/L,(5.7%±2.0%),respectively,on the first day after surgery.The mean follow-up time was 7.96 months.The scores of lumbar spine ODI,LBP VAS and leg pain VAS decreased from preoperative(48.38%±5.74%),(5.78±1.42)and(5.67±1.21)to the last follow-up(12.18%±6.95%),(0.59±0.57)and(0.37±0.49),respectively.At the last follow-up,the scores were statistically significant(P<0.05),and the improvement rates were 74.36%,90.12%and 93.93%,respectively.During the postoperative review and follow-up,8(29.63%)patients were found to have spot-like and filamentous bone cement leakage in the anterolateral side of 11(6.75%)vertebral bodies,but none of them caused any clinical symptoms.At the last follow-up,the height of adjacent vertebrae,the height of proximal intervertebral space,the height of distal intervertebral space were all reduced(0.54±0.84)mm,(1.56±1.46)mm,and(1.36±1.03)mm,respectively,compared with the week after surgery,and the differences were statistically significant(P<0.05).Lordosis angle of lumbar fixation segment of postoperative a week more preoperative increased to different extent,but at the time of the last follow-up angle have different degree of loss,the loss angle for(3.13±2.46)°,there was no significant difference(P<0.05)among lordosis angle of lumbar fixation segment at the preoperative,postoperative a week and the time of the last follow-up.There were 54(33.13%)pedicle screws in only zone 2 bone cement of cross-section in the vertebral body,6(3.68%)pedicle screws were found in only zone 3,8(4.91%)pedicle screws in zone 1 and 2 at the same time,71(43.56%)pedicle screws in zone 2,and 3 at the same time,24(14.72%)pedicle screws in zone 1,2 and 3 at the same time.Bone cement was mainly distributed in zone 2 and 3 in the vertebral body,followed by only zone 2.The total number of pedicle screws was 125(76.69%).In the term of morphological types of bone cement,there are concentration and dispersion in the vertebral body,among which 107(65.64%)pedicle screws were concentrated and 56(34.36%)were diffused.The flow direction of vertebral bone cement in the coronal position was upward,downward,inward,outward and non-trend,and the number of pedicle screws was 9(5.52%),45(27.61%),50(30.67%),2(1.23%)and 57(34.97%),respectively.No screw loosening,displacement,cutting or even fracture were found,and the positions were well fixed,without any revision case.ConclusionsThe clinical efficacy of bone cement-injectable perforated pedicle screw system in the treatment of osteoporotic degenerative disease of the lumbar spine is satisfactory.This strong internal fixation method can restore and improve the holding force of the pedicle screw under the condition of osteoporsis,increase the pullout strenght of the screw;significantly reduce the screw loosening,and maintain the stability of the degenerative lumbar spine.For patients with osteoporosis and lumbar degenerative diseases,PMMA-augmented perforated pedicle screws surgery is safe and effective. |
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