the vertebral fractures is the most common complications of osteoporosis.13 ) these fractures result in significant mortality and morbidity including prolonged and intractable pain.4,13 ) percutaneous vertebroplasty , a therapeutic procedure for filling the collapsed vertebral body with polymethylmethacrylate , provides pain relief.2,4 ) in general , percutaneous vertebroplasty is simple and safe if performed under continuing fluoroscopic control and technical precautions .
vertebroplasty has the potential risk of serious complications such as leakages of bone cement , cardiopulmonary complications , infection and the new fractures of the adjacent vertebrae.6,7 ) we present a case of extraspinal leakage after vertebroplasty at our hospital .
a 73-year - old male was admitted to our hospital for low back pain after slip down at one day earlier .
the patient had experienced l1 vertebroplasty and t12-l2 screw fixation for l1 compression fracture at another hospital before 2 years ago .
after incision of the skin , an 11-guage vertebroplasty needle was placed percutaneously on the posterior part of the vertebral body via bilateral transpedicular approach .
the needle was pushed through the cortex , situated the center of the pedicle as possible , and then directed into the vertebral body .
the contrast medium ( iohexol ) was injected to estimate bone cement distribution and minimize bone cement leakage and intraoperative complication such as pulmonary thromboembolism .
when a thin toothpaste consistency was achieved , the bone cement was injected into the vertebral body under continuous fluoroscopic control .
the filling process was stopped immediately when leakage of bone cement was observed into lateral space of body .
lumbar simple x - rays after procedure showed leakage of bone cement to right lateral side of the l4 vertebral body ( figure 1 ) .
lumbar computed tomography ( ct ) scanning revealed extraforaminal leakage of bone cement to outside of right l4 pedicle and it caused significant compression of l4 nerve root ( figure 2 ) .
the leaked bone cement along the l4 nerve root was removed carefully via paraspinal muscle - splitting approach . during surgery , two pieces of bone cements were removed carefully .
two whitish bone cements were located in the right lateral space of l4 - 5 body and the intervertebral foramen ( figure 3 ) .
postoperative lumbar spine plain images show that the leaked bone cement along right l4 nerve root was disappeared ( figure 4 ) .
complications related with vertebroplasty are not uncommon such as cement extravasation , pulmonary embolism , infection , epidural hematoma , systemic toxicity , and vertebral body fractures.1,7,8 ) among the commonest complications , cement extravasation has been estimated in 70% cases for vertebroplasty procedures.3,5 ) most of the cement extravasation is asymptomatic but , disastrous complications causing paraparesis have been also reported in the literature.5,7,12 ) the biplanar fluoroscopy is the best way to monitor the leakage of cement in procedure of vertebroplasty , but sometimes it is difficult to judge the leakage of cement after injection of the contrast medium .
yeom et al.14 ) described three different types of leakages of cement after vertebroplasty such as type b ( via basivertebral vein ) , type s ( via segmental vein ) , and type c ( via cortical defect ) .
nieuwenhuijse et al.9 ) recommended that the high viscosity of bone cement should decrease the rate of cement leakage during vertebroplasty .
due to high risk of pedicle fracture during vertebroplasty , cement leakage via pedicle violation can cause significant morbidity.11 ) park and kim10 ) mentioned technical tips while taking entry into the pedicle and the vertebral body .
the bone access needle can be advanced through the center of pedicle with use of a tunnel vision technique ( turn the c - arm obliquely until pedicle can be visualized at its widest and roundest ) and verification of needle trajectory at midpedicular level and posterior surface of vertebral body on lateral view .
on anterior - posterior view , if the tip is located too medially , the medial cortical wall of pedicle may be damage and leading to spinal canal violation .
if the tip is located too far laterally , lateral cortical bone damage and lateral violation could occurred . in our case , the reason of cement leakage might be presumed .
the tip of needle located more laterally when needle tip is located in the pedicle and vertebral body .
we experienced a case of lumbar nerve root compression by leaked bone cement after vertebroplasty .
proper entry point of trocar , keeping trocar within pedicle and proper position of trocar between the pedicle and spinous process under biplanar fluoroscopy view would be help to prevent leakage of bone cement after vertebroplasty .
 we experienced a 73-year - old male with lumbar nerve root compression due to leakage of bone cement after vertebroplasty . 
 he was underwent vertebroplasty for acute osteoporotic l4 compression fracture at our hospital . 
 after vertebroplasty , his back pain was improved but right leg pain was newly developed . 
 lumbar computed tomography scanning showed that bone cements were leaked along the l4 nerve root . 
 the leaked cements around l4 nerve root were removed carefully via paraspinal muscle - splitting approach . 
 after operation , severe right leg radiating pain was improved . 
 we recommend proper entry point , high viscosity of polymethylmethacrylate and constant monitoring can reduce complication . 
Introduction
Case Report
Discussion
Conclusion