Painful osteoporotic vertebral compression fractures are a common disorder in the elderly, seriously affecting their mobility and quality of life. Traditional treatment with prolonged bed rest, brace immobilization and medication is difficult to relieve persistent low back pain. The reduction in activity further leads to bone loss, resulting in re-fracture. Multi-system complications such as circulatory and respiratory problems caused by prolonged bed rest can also endanger the lives of elderly patients. Kyphoplasty is an emerging minimally invasive spinal technique for the treatment of osteoporotic vertebral compression fractures and vertebral tumors in recent years. It has a good pain relief effect, can restore the effective height of the vertebral body, correct the kyphosis deformity and stabilize the spine. It has achieved good clinical efficacy. Lu Qinglin, Department of Orthopedics, Shandong Qianfo Mountain Hospital
Surgical method
1.2 Surgical method: The patient was placed in a prone position with the abdomen suspended. The C-arm fluoroscopy was positioned so that the upper and lower endplates of the affected vertebrae were orthogonally displayed as “a line of shadow”, and the bilateral arch root shadow was equidistant from the spinous process. The puncture point was marked, and the orthogonal puncture point was located in the upper quadrant of the external arch shadow, at 10 o’clock on the left and 2 o’clock on the right. The skin was routinely disinfected and sterile towel sheets were laid. 1% lidocaine was used for local infiltration anesthesia to the subperiosteum. A longitudinal incision of about 5 mm in length was made, and the puncture catheter needle was taken to penetrate the vertebral body percutaneously under fluoroscopy, and the C-arm was adjusted to observe the frontal and lateral positions during the puncture process; the tip of the needle was stopped when it exceeded the posterior edge of the vertebral body by about 2-3 mm in the lateral position, and the inner core was removed to establish a working channel. The bone cone was pierced into the chase body through the working channel at about 2-3 mm from the anterior wall of the vertebral body, and the bone cone was withdrawn to probe the vertebral body with a guide needle to confirm that the anterior wall of the vertebral body was not penetrated. (1) SKY-PKP: The SKY bone expansion system was implanted, and the bone expansion system was tilted from posterior up to anterior down under lateral fluoroscopy. The bone expander is slowly expanded under continuous X-ray surveillance, and when the vertebral body height is restored satisfactorily or the expander reaches its maximum volume, the expansion is stopped and the expander is withdrawn. The bone cement is blended and pushed into the vertebral body at low pressure when the bone cement is in the form of toothpaste. Stop the injection when the bone cement fills satisfactorily or there is leakage and record the amount of bone cement. Rotate the bone cement injection catheter when the bone cement is about to solidify to separate it from the solidified bone cement, and then withdraw the injection device and working catheter. The skin puncture site is covered with sterile excipients. Observe for 10 minutes to ensure stable vital signs and return to the ward. (2) Inflatablebone Tamp-PKP: The surgical maneuver is the same as before, and the expansion balloon is placed through the working channel, the lateral position shows that the ideal position is the anterior 3/4 of the diseased vertebra, balloon pressurization is performed, and the pressure is gradually increased, the balloon expansion and fracture repositioning are monitored through the C-arm X-ray machine, and the pressurization is stopped when the vertebral body is satisfactorily repositioned or the balloon reaches the bone cortex around the vertebral body. The balloon was removed, the bone cement was prepared and injected into the vertebral body when the bone cement was in the shape of toothpaste, and the bone cement injection process must be monitored by the C-arm X-ray machine. In this group, an average of 4 ml of bone cement was injected into each vertebral body, and the patient was allowed to walk on the floor after 4 hours of postoperative lying down and 8 hours of postoperative walking.
Results
The group was followed up for 2-21 months, with an average of 4 months, and regular frontal and lateral spine radiographs were taken to measure the changes in height of the anterior and middle vertebral bodies; the VAS score was used to determine the changes in low back pain. All data were subjected to t-test, and P < 0.01 was considered a significant difference.
2.1 Postoperative functional changes
The VAS score decreased from 8.5±1.9 before surgery to 1.3±0.8 after surgery, which was a significant improvement compared with the preoperative period (P＜0.01), and there was one case of L1-5 vertebral compression fracture in this group, in which the pain disappeared immediately after surgery, but after one month, the pain in the low back was again found to be fractured in T10-12 vertebral body by radiography, and the pain in T10-12 disappeared after surgery. The pain disappeared after T10-12 surgery.
2.2 Change in vertebral body height
The average loss of anterior vertebral body height before surgery (18.6 ± 2.1) and the average loss of anterior vertebral body height after surgery (4.6 ± 16.0) were significant before and after surgery (P < 0.01). The mean loss of height at the middle of the diseased vertebral body before surgery (9.8 ± 1.2) and after surgery (3.3 ± 1.1), with a significant difference before and after surgery (P < 0.01). the Cobb angle was corrected from a mean of 24.3° ± 6.21° before surgery to 8.1° ± 4.6° after surgery, with a significant difference before and after surgery (P < 0.01).
Discussion
Vertebral compression fractures caused by osteoporosis not only affect the function of the spine, but also lead to dysfunction of the respiratory, digestive, urinary, and circulatory systems. Intractable pain in the low back and prolonged bed rest have a serious impact on patient care and life, and Kado [ 1 ] et al. reported a five-year morbidity and mortality rate of 23-34 in OVCF patients, which is significantly higher than that of the general population. The key to treating OVCF is immediate pain relief, early mobility, and stabilization of the spine. Percutaneous kyphoplasty is an effective method for minimally invasive treatment of osteoporotic vertebral compression fractures that has emerged in recent years [ 2.3 ], and the results of this group showed that percutaneous kyphoplasty has the ability to restore vertebral height to correct kyphotic deformity with a pain relief rate of 100 G. Lieberman et al [ 2 ] reported a significant reduction in pain intensity in all patients after percutaneous kyphoplasty, and the results of this group confirm this This was also confirmed by the results of this group. The mechanism of pain relief is thought to be the chemical and thermal effects of polymethylpropionic acid methyl ester resulting in the destruction of nerve endings that conduct pain signals and the mechanical stabilization of microfractures. Biomechanically, percutaneous kyphoplasty only fixes the diseased vertebra, preserves the motion segment, is more biomechanical, and achieves the same stabilization of the spine.
Indications for percutaneous kyphoplasty: elderly patients with painful osteoporotic vertebral compression fractures, vertebral hemangiomas and vertebral metastases who have undergone OVCF or have the potential to do so. It should be noted that low back pain is consistent with physical examination imaging; no spinal nerve injury manifestation; imaging shows the posterior wall of the vertebral body is intact; vertebral compression is less than 80 G. MRI should be performed for multivertebral and old vertebral fractures, painful vertebrae show low signal on T1-weighted image due to the presence of hemorrhage and edema, while T2-weighted image is high signal, and vertebral body shows high signal on both T1- and T2-weighted images, indicating that the vertebral body The fracture has healed and the vertebral body is in a stable state [4] . Serious complications of vertebral kyphoplasty are nerve injury due to cement extravasation, as well as pulmonary embolism and cerebral embolism. One of our 121 patients had a small amount of cement extravasation at the anterior edge of the vertebral body, and no obvious symptoms of nerve injury were observed. We believe that mastering the indications, the selection of the puncture point and puncture direction of the vertebral arch, and the puncture route, and grasping the timing of bone cement injection are the main measures to prevent complications.
There are three types of surgical approaches for vertebroplasty: the pedicle approach, the paravertebral approach, and the lateral approach to the vertebral body. The transforaminal approach is less traumatic and the bone cement is less likely to spill along the needle tract, so the transforaminal approach is mostly used. However, since the T5-T8 arch is small, the lateral approach will inevitably restrict the puncture needle to the lateral side of the vertebral body, and it is easy to penetrate the inner wall of the arch, so the cement cannot be well distributed in the middle. During the operation, under orthogonal and lateral C-arm fluoroscopic surveillance, the puncture needle should be adjusted in time to ensure the accuracy and safety of the puncture needle by adjusting the camber and sagittal angle of the puncture needle when puncturing from the outer upper edge to the inner lower edge of the vertebral arch, and choosing 9-11 points on the left side and 1-3 points on the right side according to the degree of compression of the vertebral body. Kim et al [5] concluded that with proper manipulation of the needle tip to the appropriate position, a satisfactory intravertebral distribution could be obtained by unilateral perfusion, and clinical application revealed that the pain relief effect of both There is no statistical difference between the two in terms of pain relief. We agree with this view, and all cases in this group used unilateral arch approach, and our experience is to adjust the height of the needle entry point according to the degree of compression of the vertebral body, increase the camber angle so that the needle tip is on the midline of the vertebral body, and perform unilateral arch kyphoplasty through instrumentation expansion and bone cement infiltration and anchoring to obtain satisfactory stabilization and pain relief, while having the advantages of short operation time and low risk. The SKY bone expansion system was used in 55 cases; percutaneous balloon expansion vertebroplasty was used in 66 cases. The principle of treatment for this group of cases is to choose SKY mechanical shaping for compression fractures over 4 weeks, and balloon shaping for fresh fractures. the front end of the SKY bone expansion system should reach the center of the anterior lower third of the vertebral body before expansion, so that the bone expander can expand the anterior and middle columns of the vertebral body to the maximum extent in the cancellous bone, reduce the posterior convexity deformity, and minimize the re-injury of the upper end plate. It is important to emphasize that the expandable portion of the SKY bone expansion system should be pushed all the way into the vertebral body to minimize the possibility of cortical fractures caused by the SKY bone expansion system. The amount of cement injected into each diseased vertebra during kyphoplasty is mainly related to the size of the vertebral body and the height recovery of the compressed vertebral body, but recent clinical and experimental data show that a smaller amount of cement is sufficient for spinal stabilization and pain relief, and increasing the amount of cement increases the compressive strength of the vertebral body, but also increases the chance of cement leakage. The amount of bone cement injected was not positively correlated with the degree of pain relief. Most scholars believe that the amount of bone cement injected and the filling rate are not proportional to the pain relief, but are related to the distribution of the injected material in the vertebral body, and that the amount of filling or complete filling of the vertebral body should not be pursued excessively, and the amount of bone cement should not be increased blindly [7]. The exact amount of bone cement that should be injected intraoperatively to achieve stable fracture healing and treat pain is unclear. The amount of bone cement injected per vertebral body in this study averaged 3.5 (2.5 to 5 ) ml. The timing of the bone cement injection is critical for this procedure. We chose to start the injection slowly during the drawing period, because if it is too early, the bone cement is not fully polymerized and the free monomer can spread with the venous return, which can damage monocytes, granulocytes, and vascular endothelial cells and promote the formation of thrombus, and if it is too late, the poor mobility of the bone cement will affect the cement injection and diffusion in the vertebral body.
In conclusion, PKP is less invasive, safe and easy to perform, can effectively restore the height of the compressed vertebral body, rapidly and effectively relieve pain, increase the strength of the vertebral body, improve the stability of the spine, and enable patients to move early, so it is worthy of clinical promotion and application.