Abstract: To investigate the method and efficacy of percutaneous posterolateral kyphoplasty (PKP) for the treatment of thoracolumbar fractures. METHODS: A total of 110 vertebrae in 96 patients with geriatric thoracolumbar OVCFs admitted to our hospital from January 2004 to January 2012 were retrospectively analyzed and treated with either unilateral PKP via the pedicle or combined with PVP on the other side, and their postoperative height restoration values of the anterior vertebral margins, improvement of pain in VAS and Oswestry scores, and the mode of cement leakage and rate were analyzed. RESULTS: All 110 vertebrae were successfully punctured, all 96 patients had satisfactory surgical results, the distribution of vertebral bone cement was relatively satisfactory, the operative time was about 20-40 min/vertebrae, the amount of bone cement injected was about 5,4 ml/vertebrae, the postoperative VAS and Oswestry pain scores were significantly relieved compared with the preoperative ones (P0,01), and the height of the anterior vertebral margin was significantly improved (P0,01). The main complication of the procedure was cement leakage, most of which occurred at the anterior margin of the vertebral body and in the anterolateral venous plexus, with an overall incidence of 56,3%. Of the 40 vertebrae in 36 patients followed up, one case had a fracture of an adjacent vertebra and one patient had a different degree of collapse of the anterosuperior margin of the treated vertebra (uncemented site), but the patient had no discomfort. CONCLUSION: PKP or combined with PVP is a safe, convenient, and effective method for the treatment of osteoporotic vertebral compression fractures in the elderly.
KEY WORDS: thoracolumbar fracture; percutaneous kyphoplasty; vertebral body kyphoplasty; treatment.
Percutaneous Kyphoplasty (PKP) in the Treatment of osteoporotic vertebral compression fractures of the Thoracic and Lumbar, /Wang Xisan, Wang Min, Liu He, Liu Chen, et al.
Abstract Objective: To discuss the method and the effects of percutaneous kyphoplasty (PKP) in the Treatment of the osteoporotic vertebral compression fractures of the Thoracic and Lumbar fractures of the Thoracic and Lumbar, Method:Retrospective analysis of 110 vertebraes in 96 patients who had the osteoporotic vertebral compression fractures and treating with the method of PKP or PKP with PVP between January 2004 and January 2012, We analysed the change of the anterior heights of the vertebral body, and the clinical outcomes were evaluated using VAS and Oswestry before and after the treatment, We also observe the rate of the cement We also observe the rate of the cement leakage, Result: eighty-five vertebraes were treated with the PKP sucessfully, and twenty-five vertebraes were treated with both PKP and PVP The diffusion of the cement of all the patients was satisfied, The operation time of every vertebrae is about 20-40 minutes for one side, The volume of iniection of every vertebrae is about 20-40 minutes for one side. The volume of iniection of every vertebrae is about 5,4ml, From the VAS and Oswestry, the pain was allevited obversely, and we got a nice clinical outcomes, The leakage of the cement is the only complication. The leakage of the cement is the only complication in these patients, the rate of the cement leakage was 56,3%, and most of the leakage was happened at the The leakage of the cement is the only complication in these patients,the rate of the cement leakage was 56,3%, and most of the leakage was happened at the anterior of the vertebrae and the vein nearby, Conclusions:PKPand PVP was a safe, convenient and effective method in treating the osteoporotic The vertebral compression fractures.
Key words:
Percutaneous kyphoplasty PKP is a recent treatment for osteoporotic vertebral compression fractures (OVCFs) in the elderly. It is characterized by its ability to restore part or all of the height of the fractured vertebral body, correct the kyphosis of the spine, and enhance the strength of the diseased vertebral body, reduce the leakage rate of bone cement [1], reduce the risk of surgery and complications in a short period of time, and is accepted by most elderly patients due to its advantages of minimal trauma and precise pain relief [2-5]. The authors observed 96 elderly patients with osteoporotic vertebral compression fractures with 110 vertebrae treated with PKP during the period from January 2004 to November 2011.
1 Data and methods.
1. 1 General data
There were 96 cases of geriatric OVCFs of the thoracolumbar spine with a total of 110 vertebrae admitted to our hospital from January 2004 to November 2011. There were 21 cases of 25 diseased vertebrae in men and 75 cases of 85 diseased vertebrae in women; age ranged from 36 to 85 years, with a mean of 66, 5 years; 109 cases of fresh fracture and 1 case of old fracture. All patients underwent X-ray, CT and MRI examinations before treatment and were proven to have fresh or old OVCFs, excluding primary tumors of the vertebral body as well as metastatic tumors, no signs and symptoms of spinal cord and nerve injury, no local infectious diseases, no skin diseases and no abnormal coagulation mechanism diseases. Among them, 84 were single-segment, 10 were two-segment, two were three-segment, 95 were patients with primary OVCFs, and one was a patient with secondary OVCFs (a patient with systemic lupus erythematosus), and the distribution characteristics of the specific lesioned vertebrae are shown in Figure 1. all patients with fresh fractures had a disease duration of 1-14 days, with an average of 5,2+1,1 days, and one patient with an old fracture had a disease duration of six months. Preoperative X-ray, CT examination and MRI examination of all patients with fresh fractures showed that there were fractures in the anterior wall of 110 vertebral bodies in 96 cases and combined posterior wall fractures in 26 cases, among which the posterior superior edge of vertebral bodies protruded mildly into the spinal canal in 5 cases, but there were no neurological symptoms. There were 18 cases of compression fractures above Ⅲ° and 87 cases of compression fractures from Ⅰ° to Ⅱ°. All 96 patients were treated with PKP or PKP combined with PVP for 110 vertebral bodies (if the effect of unilateral PKP was unsatisfactory, PVP was taken on the other side).
1. 2 Materials and equipment
All surgical materials for PKP and PVP were vertebroplasty kits and balloon-expandable vertebral body kyphoplasty systems provided by Shanghai Kalitai Medical Technology Co.
1.3 Surgical method
Patients were placed under local anesthesia with respiratory and cardiac monitoring, in prone position with pillows on the neck, chest and hips, and abdomen suspended as much as possible, firstly, to use the position for repositioning, and secondly, because most of the patients were elderly, abdomen suspension could reduce abdominal pressure and avoid the effect on respiration and blood pressure. Preoperatively, iodine allergy test was performed, and according to the weight and age of the patients, 75-100 dulcolax was given intramuscularly before crossing the bed to reduce the pain during moving and during surgery, respectively. After disinfecting the sheet and positioning under DSA surveillance, the vertebral body of the lesion and the location of the puncture were determined, and then local anesthesia was performed with 2% lidocaine diluted twice as much, starting from the vertebral arch, injecting anesthetic while retracting the needle, and expanding the anesthetic range appropriately. After the anesthesia is effective, the position of the projection of the vertebral arch root on the skin surface of the lumbar back is determined on the orthopantomogram, and a point 3,0 mm lateral to the lateral edge of the upper 1/3 junction of the projection is selected as the entry point. The puncture needle is positioned under fluoroscopy again after reaching the surface of the vertebral arch. In the orthogonal position, the puncture needle is located in the middle and upper 1/3 of the vertebral arch and pressed against the lateral wall of the vertebral arch, and the puncture needle is gently inserted into the superficial layer of the vertebral arch. Then the handle of the puncture needle is gently struck with a hammer under continuous fluoroscopy until the tip of the puncture needle reaches 5,0 mm from the anterior edge of the vertebral body (the puncture process should be quick and gentle and slow until it reaches the anterior wall of the vertebral canal, and attention should be paid to the patient’s sensation and whether there are symptoms of nerve compression, and once it crosses the pedicle and reaches the posterior edge of the vertebral body, the puncture needle is quickly struck into place, and this process is generally within (within 1 minute), the orthopantomogram shows that the tip of the needle reaches the middle of the vertebral body as the optimal puncture angle (but sometimes it does not reach the projection of the spinous process or crosses the spinous process to the opposite side of the vertebral body). The needle core is withdrawn, the guide needle is placed, then the outer core of the puncture needle is withdrawn after fixing the guide needle, the working trocar and trocar core are placed under the guidance of the guide needle, and the trocar core is passed through the pedicle straight to 3,0 mm anterior to the posterior edge of the vertebral body, which is seen to be in good position under fluoroscopy, the trocar core is withdrawn, the guide needle is removed, and the working channel is established. A 3,0 mm diameter flat-ended ring drill is passed through the working sleeve for drilling until it reaches a distance of 5,0 mm from the anterior edge of the vertebral body. The annular drill is rotated repeatedly in the vertebral body from shallow to deep and then from deep to shallow again, and the front end of the annular drill is properly expanded in the vertebral body and the bone channel is ensured to be as smooth as possible so as not to puncture the balloon.
The annular drill is removed and the balloon is inserted into the vertebral body through the working channel with the front end as close to the anterior edge of the vertebral body as possible to avoid breaking through the anterior edge of the vertebral body during expansion. Fill the pressure syringe with diluted contrast agent, then evacuate the gas and connect it well with the balloon, slowly inject the contrast agent under fluoroscopy into the balloon under pressure to expand the compressed vertebral body, but try to avoid breaking through the anterior or superior edge (end plate), while observing the pressure gauge to control the pressure below 18-20 Kpa to avoid rupture of the balloon under too high pressure. If the dilatation is not effective, the contrast agent can be injected into the balloon repeatedly after the balloon pressure is reduced to achieve the best degree of dilatation.
After the dilation is finished, the bone cement is blended, and the blended bone cement is injected into several injection sleeves with a 2 ml or 5 ml syringe before the drawing state, the balloon is removed, the injection sleeve is inserted, and then the timing of the bone cement injection is decided according to the fracture, the degree of osteoporosis, and the puncture.
Fill the bone cement as far as possible to the anterior edge of the vertebral body, and a slight leakage from the anterior edge will not be significant. Posteriorly, the bone cement should be filled to no more than the posterior edge of the vertebral body, and orthogonal slices should ideally be filled to both sides of the vertebral body. If only one side is filled and the compression on the other side is not obvious and the degree of osteoporosis is mild, the procedure is finished; if the other side is also compressed and accompanied by a certain degree of osteoporosis, PVP treatment is performed on the other side in the same way, so that both can achieve satisfactory results. The general amount of bone cement injection is about 5-6ml, and the specific amount is related to the degree of osteoporosis.
1.4 Postoperative treatment
After the operation, the patient is instructed to rest in bed, lying flat and pressing the wound for 2 hours, and then can move freely in bed, and the patient is instructed to move on the ground on the second day after the operation. If the patient’s pain relief is not satisfactory, the bed rest time can be extended appropriately, and if there is no special discomfort, the patient can be discharged from the hospital 3-5 days after the operation, and is instructed to take out-of-hospital anti-osteoporosis treatment.
1, 5 Clinical effect analysis
1, 5, 1 VAS pain score The pain VAS score (VAS 0-10, with 0 being no pain and 10 being the most painful) and Oswestry score were performed by the competent physician preoperatively and postoperatively, respectively, and statistically analyzed to understand the degree of postoperative pain relief of patients. 0-3 in the VAS score is excellent, 4-5 is good, 6-7 is acceptable, and 8-10 is poor.
1, 5, 2 Distribution of fractured vertebrae The fractured vertebrae of all patients were counted separately, analyzed, and their incidence was understood.
1, 5, 3 the amount of bone cement filling Register the amount of bone cement injected in each patient and calculate the average amount
1, 5, 4 Leakage rate of bone cement The postoperative review x-ray of all patients was observed by the same doctor separately to understand whether there was leakage of bone cement outside the vertebral body and to calculate the leakage rate of bone cement.
2 Results
All 110 vertebrae in 96 patients were treated with unilateral PKP or PKP on one side plus PVP on the other side under DSA surveillance in our radiology department. Of these, 85 vertebrae were treated with unilateral PKP (see Figures 2 and 3), and 25 vertebrae were treated with PKP plus PVP. During treatment, when the puncture needle reached 5 mm from the anterior edge of the vertebral body on the lateral image, the anterior projection of the puncture needle could reach the midline of the vertebral body in only 40% of patients on the orthopantomograph, close to the midline in 50% of cases, and beyond the midline to the contralateral side in only 3 cases, with the rest being on one side of the vertebral body only. The procedure time was 20-40 minutes for unilateral vertebral PKP and 40-60 minutes for bilateral puncture of two vertebral bodies or a single vertebral body. The volume of bone cement injected was 4,0-9,0 ml, with only one vertebral body having 9,0 ml (for single vertebral body bilateral injection cases), and most patients had an injection volume between 5,0-6,0 ml, with an average of 5,4 ml. All patients had significant postoperative symptomatic relief, with most patients having immediate relief 5 minutes after the end of the procedure, generally showing that the patient could be in bed after the postoperative bed Only 3 patients had pain relief 3 days after surgery (see Table 1 for comparison of VAS and Oswestry scores and average height of the injured anterior column of the spine before and after surgery in all patients). All patients were ambulatory for 12 hours while bedridden, some under the protection of a lumbar collar. No case produced local hematoma at the puncture site, no hemopneumothorax, no vascular injury, and no spinal cord injury occurred. Only one patient had preoperative intercostal neuralgia that did not produce postoperative recovery, and the symptoms resolved about two weeks after surgery. There was no case of pulmonary embolism, but the incidence of extravertebral leakage of bone cement was high, with an incidence of about 56,3%, including 31 cases of leakage from the anterior margin of the vertebral body, 15 cases of leakage from the anterior vertebral vein, 5 cases of leakage from the posterior vertebral vein, 15 cases of leakage from the upper intervertebral disc, 3 cases of leakage from the posterior wall of the vertebral body, 3 cases of leakage from the posterior lamina, and two cases of extravertebral lamina trailing off, including one case of posterior posterior longitudinal ligament of the vertebral body anterior leakage, but there were no symptoms of neurospinal cord injury and the patient’s pain symptoms disappeared significantly (see Table 2 for the proportion of various leaks). Except for one patient with an old fracture whose vertebral body height did not change after surgery, the vertebral body heights of all patients increased to varying degrees after surgery compared with those before surgery, with a significant difference of P0,01 (see Table 1 for comparison of preoperative and postoperative vertebral body heights). 40 vertebrae of 36 patients were followed up for 3-12 months, and one case had a fracture of an adjacent vertebral body, and one patient had a fracture of the anterosuperior margin of the treated vertebra (the One patient had a fracture of an adjacent vertebral body and one patient had varying degrees of collapse of the anterosuperior edge of the treated vertebra (uncemented area), but the patient had no discomfort.
Figure 1 Distribution of affected vertebrae
Table 1 Comparison of preoperative and postoperative VAS, Oswestry score, and mean height of the anterior column of the injured vertebra
VAS score (points)
Oswestry score (points)
Average height of the injured anterior column (mm)
Preoperative
9,1±0,8
42,5±4,2
18,3±2,5
Postoperative
2,3±0,5①
23.6±2.7②
22.6±3.6
Comparison with preoperative period: ①P0,01 ②P0,01
Anterior leakage of vertebral body
Leakage from the posterior wall of the vertebral body
Upper endplate leakage
Venous leakage
Posterior vertebral plate leakage
Total
Number of cases (cases)
31
5
15
20
3
62
Percentage (%)
28
4, 5
13, 6
18, 2
2, 7
56, 3
Table 2 Incidence of bone cement leakage (Note: individual vertebrae may have multiple leaks in combination)
Figure 2, the bone cement is basically dispersed in the vertebral body in the orthogonal image Figure 3, the bone cement is almost dispersed in the vertebral body in the lateral image
The distribution is relatively uniform on both sides of the vertebral body.
The distribution is slightly more than that of the posterior edge of the contralateral vertebral body, but not to the spinal canal.
3 Discussion
Osteoporotic fractures are an increasingly serious health problem, in which osteoporotic fractures of the vertebral body in the elderly are due to a decrease in bone mass and degenerative changes in bone structure resulting in a decrease in the mechanical strength of the bone. The current global incidence is on a significant upward trend, with Asia most notably expected to account for half of the global annual incidence. Vertebral compression fractures (OVCFs) are a common complication in older adults with osteoporosis, with an overall incidence of approximately 1.23% and a female incidence of 1.53%. In the past, patients with OVCFs often refused surgical treatment because of their age and fear of high surgical risks, and most of them took bed rest for conservative treatment, thus making it difficult to recover vertebral height, and more than 1/3 of patients with vertebral compression fractures showed chronic intractable pain. The pain and spinal deformity caused by the disease can cause a decrease in lung capacity, loss of appetite, sleep disruption, and reduced activity, which leads to further bone loss, which in turn causes a further decrease in vertebral strength, making it more susceptible to fracture, resulting in a vicious circle. In addition to the physical and psychological pain caused by long-term bed rest, it also brings many social problems.
Balloon-expandable kyphoplasty (PKP) is a new technique in the field of spine surgery. The application of this technique in spine surgery can improve the safety of kyphoplasty and reduce the complications of the surgery, and it has become one of the important techniques in minimally invasive spine surgery. It is accepted by the majority of elderly patients because of its many advantages such as small trauma, relatively low risk, short operation time, exact treatment effect, few complications, and short hospital stay.
With the continuous improvement of treatment level, the indications for vertebroplasty are gradually expanding, and PKP is overwhelmingly used to treat vertebral compression fractures (vertebral cpmpression fractures, VCF) caused by various reasons, and common diseases are: 1. Osteoporosis: As more than half of the elderly people over 60 years old have different degrees of osteoporosis, in recent years PVP and PKP treatment is mainly applied to VCFs caused by osteoporosis; 2, metastatic tumors; 3, myeloma; 4, aggressive hemangioma; 5, traumatic VCFs. we are currently mainly used for the treatment of OVCFs.
It is generally believed that there are no absolute contraindications to PVP and PKP, while the relative contraindications are: 1, vertebral compression over 75%, but some scholars [5] have reported better results with Sky surgery for diseased vertebrae with compression over 75%; 2, burst fracture or involvement of the posterior edge of the vertebral body, Eyheremendy et al [6] reported a percutaneous pedicle angioplasty (percutaneous pediculoplasty (PP) for osteoporotic vertebral compression fractures with pedicle fractures, in which PMMA is injected into the pedicle to stabilize the pedicle; 3, vertebral fractures combined with neuromuscular injury; 4, osteogenic metastases; 5, those with coagulation dysfunction; 6, those with severe cardiovascular disease or too poor physical condition to tolerate the procedure; 7, those with contrast allergy.
Most of the complications of PKP require only conservative treatment, and serious complications are extremely rare. Strictly grasp the indications for surgery and precise surgical operation can effectively avoid complications; 1, rib fracture, rare, 2 cases reported in the literature, mostly caused by improper operation or severe osteoporosis, etc.; 2, puncture-related complications, puncture process causing damage or destruction of surrounding tissues, such as injury to nerve roots and spinal cord, arch fracture, pneumothorax, etc.; 3, bone cement leakage, occurs most frequently. Leakage of bone cement into the tissues around the vertebral body causes thermal and compression injuries to the nerve roots and spinal cord. The most serious ones are dural leakage and leakage near the intervertebral foramen, requiring emergency decompression of the vertebral plate. garfin reviewed the literature as 30%-67%, and Ryu et al. analyzed 347 PVP treated vertebrae with an incidence of 26,5%. becker et al [7] reviewed 100 cases of PKP with a bone cement leakage rate of 31%, with most leaks occurring in the anterior or upper and lower walls of the vertebral body and 2% leaks occurring in the posterior wall. Marden [8] reported a case of cerebral embolism in a 70-year-old woman and 56% leakage of bone cement in this group of cases, but no serious complications of bone cement leakage occurred; 4, adjacent vertebral fractures, and adjacent vertebral fractures are likely to occur after bone cement enhancement of diseased vertebrae. Although bone cement etc. restores the strength of the diseased vertebrae, it changes the stress distribution between the vertebrae and the adjacent vertebrae are prone to fracture. syed et al [9] found that 20% of patients had fracture again by a 1-year follow-up after osteoporotic vertebral compression fracture. Ahn [10] reported that after PVP, the fracture principle of adjacent vertebrae is different from that of non-adjacent vertebrae, and the former is mainly due to methacrylic resin Lin et al [11] reported that leakage of bone cement into the intervertebral disc could also increase the incidence of fractures in adjacent vertebrae. No fractures of adjacent vertebrae have been found in this group of cases; 5. Other complications, such as sudden death and infection, are rare.
4 CONCLUSION: Through the treatment of this group of cases, we believe that PKP is currently not a better treatment method for patients with OVCFs, with the advantages of short operation time, low risk, good treatment effect, short hospital stay, and easy acceptance by patients; the disadvantage is high cost. However, to achieve a better surgical effect, the operator must have rich treatment experience, be flexible and versatile in the treatment process, should take different methods according to different patients, master the treatment skills, and minimize complications. The leakage rate of bone cement occurred relatively high in this group of cases, which is considered to be due to the fact that we pay more attention to the amount of bone cement infused in the diseased vertebrae. Future work will further investigate the effect of the amount of bone cement infusion with the patient’s immediate and long-term treatment outcomes, as well as explore the optimal amount of infusion.
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