Clinical Application And Key Techniques Of Bone Cementinjectable Cannulated Pedicle Screw(CICPS)

As entering an aging society,the incidence of Osteoporosis(OP)is increasing year by year.With the improvement of China's economic and medical conditions,the average life expectancy of residents is significantly longer than before,the number of patients with diseases of the spine is increasing gradually,spinal disorders with osteoporosis are not uncommon.Pedicle screws fixation is standard operation,spine surgery due to osteoporosis in patients with vertebral body bone mineral density and the decrease in the number of bone trabecular,the strength of pedicle screw fixation will be directly affected,it's easy to have a screw loose,shift,fall off,causing spinal instability of structure,and even surgery failure.Currently,the use of polymethylmethacrylate(PMMA)to strengthen bone cement-injectable cannulated pedicle screw(CICPS)in such patients is considered to be safe and effective.However,there is still a lack of medium and long-term follow-up of large samples of such patients to confirm the medium and long-term efficacy.More importantly,there is still a lack of a unified standard and technical summary on the clinical timing,strategy and prevention of complications caused by the use of bone cement screws.At the same time,during the intervertebral fusion of osteoporosis patients,the current PEEK intervertebral fusion device has stress occlusion,postoperative vertebral space height loss and fusion device sinking are common.So our research group has independently developed a new type of allograft intervertebral fusion device(BioCage),which has passed relevant biomechanical tests in the early stage and obtained relevant national patent.How is its clinical efficacy compared with the traditional PEEK intervertebral fusion device,this study has carried out a preliminary exploration here together.Objective: To further evaluate the medium and long-term efficacy of CICPS;to summarize the key techniques of CICPS in the treatment of spinal disorders and osteoporosis,and make a systematic and scientific standard;To preliminarily explore the clinical efficacy of CICPS combined with BioCage in the treatment of spinal disorders with osteoporosis.Methods: In this study,276 patients with spinal degenerative disease complicated with osteoporosis who were strengthened with bone cement for CICPS from May 2011 to June 2018 were enrolled,111 cases of lumbar spondylolisthesis,91 cases of lumbar disc herniation with spinal stenosis,11 cases of degenerative scoliosis,37 cases of spinal fractures,22 cases of ankylost spondylitis with kyphosis,and 4 cases of revision surgery.There were 62 males and 214 females,with an average age of 61.74±9.83(24 ? 83)years and an average BMD of-3.18±0.68(-2.5 ?-5.4)SD.During the operation,the principle of "must be effective,use as little as possible,strengthen with small dose(1-2ml bone cement/screw)" was adopted for the application of CICPS.Individual application principle is: lumbar spondylolisthesis,?-? ° unilateral application,? ° above bilateral applications;Lumbar disc herniation with lumbar spinal stenosis,unilateral application;Ankylost spondylitis with kyphotic deformity: proximal and distal use;Spinal fractures,unilateral,bilateral if necessary;Degenerative scoliosis,the proximal fused vertebra is recommended,the remaining vertebra is applied according to the actual conditions during surgery.Regular follow-up was conducted immediately after the operation,1 month,3 months,6 months,12 months and every other year thereafter.The Visual Analogue Scale(VAS)and Oswestry Disability Index(ODI)were used to assess the clinical efficacy.The clinical safety assessment mainly collected whether the bone cement leakage and related clinical complications.X-ray and CT were used to assess the recovery and loss of intervertebral space height,the correction and loss of spinal deformity,the screw displacement of CICPS,and the fusion rate of fusion segments.Results: A total of 835 CICPS,254 PEEK intervertebral fusion devices and 47 BioCage were implanted in 276 patients.The follow-up time was 26.37±13.93(6-80)months.During intraoperative revision surgery on the vertebra previously strengthened with PMMA,one CICPS failed to strengthen.At the last follow-up,VAS score and ODI of the patients were significantly reduced compared with those before surgery(P < 0.05),and the kyphosis Angle and Cobb Angle were significantly improved compared with those before surgery(P < 0.05),and there was no significant loss compared with those after surgery(P < 0.05).Postoperative intervertebral space height was significantly improved in all patients(P < 0.05),but at the last follow-up,the intervertebral space was lost to a certain extent,the fusion sink rate of BioCage group(18.4%)was higher than that of the traditional PEEK group(13.8%)(P < 0.05).Leakage occurred in 74 CICPS(8.9%)of 64 patients(23.2%)during the operation,among which 55(15.96%)were thoracic vertebra leakage,15(8.63%)were lumbar vertebra leakage,4(3.85%)were sacral vertebra leakage,and 2 were intraspinal leakage.No clinically relevant symptoms were observed in all patients with leakage.The fusion rate was 100% in the BioCage group and 77.3%(P < 0.05)in the PEEK group at the first year after the surgery.By the end of the last follow-up,all fusion segments had achieved osseous fusion.No screw is broken,loose and pulled out.Conclusions: Although there are certain risks in PMMA enhanced CICPS,it is still safe and effective for patients with degenerative spinal diseases combined with osteoporosis.However,when CICPS is used in special segments(thoracic vertebra)and special indications(fracture,ankylospondylitis with kyphotic deformity),the leakage rate is higher,which should be paid more attention during the operation;The medium and long term clinical results show that the application principle of CICPS and individualized application strategy we proposed are scientific and are expected to be the unified standard for the application of bone cement screws;CICPS combined with BioCage is effective in the treatment of patients with spinal disorders complicated with osteoporosis.Compared with PEEK type intervertebral fusion,CICPS can achieve earlier intervertebral fusion,but it is more likely to show a reduction in intervertebral space unrelated to clinical effect.