Percutaneous kyphoplasty is a new minimally invasive spinal surgery technique for the treatment of painful vertebral lesions such as osteoporotic compression fractures and vertebral metastases in the thoracolumbar spine in recent years.
With the aging of the population, osteoporosis has become a common disease that seriously endangers the health of the elderly, especially elderly women, and fracture is the main serious complication of this disease, of which vertebral compression fracture is the most common. Patients are bedridden for a long time due to pain, losing their ability to work and take care of themselves, and their quality of life is significantly reduced. Since the symptoms cannot be relieved rapidly by anti-osteoporosis drugs, they often rely on pain medications, thus bringing a series of side effects; while open reduction internal fixation surgery is traumatic and difficult for patients to accept, and the internal fixator is prone to loosening causing internal fixation failure.
PKP is a new minimally invasive spine surgery technique developed in the late 1990s, which has many advantages such as excellent pain relief, small surgical trauma, correction of posterior convexity deformity and significant reduction of cement leakage rate, and has developed rapidly in recent years at home and abroad, becoming the main surgical procedure for the treatment of osteoporotic vertebral compression fractures [3,4]. Although PKP is a minimally invasive procedure, a thorough preoperative preparation is essential because the patients are mostly elderly and the fractured vertebrae are adjacent to important structures such as nerves. Preoperative coagulation, cardiopulmonary function and relevant biochemical indices should be routinely checked to evaluate the function of important organs. Because elderly patients have difficulty tolerating the prone position, and the patient is required to remain in the prone position for about 30-60 min and remain as still as possible, preoperative prone tolerance training is essential. Patients should be instructed to start training 2 to 3 d before surgery, several times a day, and gradually extend the training until the surgery is required; they should also be informed that they should actively cooperate with the surgeon during surgery, and that they should immediately tell the surgeon when there is radiating pain or numbness in the lower limbs to ensure the safety of the surgery. The patient’s vital signs should be closely observed during the surgical operation. During the puncture process and the pushing of the bone cement, the patient should be constantly asked whether there is pain and numbness in the lower limbs, and the movement of both lower limbs should be checked to detect possible spinal nerve injury in time. After the operation, the patient should rest flat on a hard bed for 12h to facilitate compression of the puncture site to reduce bleeding and also to maximize the strength of the bone cement in the vertebral body.
Complications of PKP mainly include bone cement leakage, thermal injury to nerve roots and surrounding tissues, pulmonary embolism and venous thrombosis, and infection, etc. Bone cement leakage is especially common, and the amount of bone cement leakage is positively correlated with the amount of injected bone cement. When leakage to the intervertebral space, most of them have no clinical symptoms; if leakage to the epidural space and intervertebral foramen, symptoms of nerve compression may appear and emergency surgery is needed to decompress; if leakage occurs in the soft tissues in front or side of the vertebral body, there are no clinical symptoms when the amount is small, but symptoms such as pain and stiffness of the spine may appear when the amount is large. The key point to avoid leakage of bone cement is to master the arch puncture technique and the timing and amount of bone cement injection. During puncture, special emphasis should be placed on the principle that when the puncture needle is placed in the arch, it is better to lean outward than inward and upward than downward, and in lateral fluoroscopy, the puncture needle can reach the posterior part of the vertebral body, while in orthogonal fluoroscopy, the tip of the puncture needle should never be in or above the midline of the vertebral body. The entire injection process should be performed under X-ray fluoroscopy, and the injection speed should be slowed down when the bone cement reaches the posterior 1/4 of the vertebral body to prevent leakage into the spinal canal.
PKP surgery method
The abdomen is suspended in the prone position with soft pillows on both sides of the anterior chest and under the iliac crest. In patients with fresher osteoporotic fractures, the operating table can be adjusted so that the lumbar region is in the hyperextended position to facilitate postural repositioning. After connecting cardiac monitoring to monitor vital signs, the patient is positioned under C-arm X-ray machine fluoroscopy so that the orthogonal position shows a linear shadow of the upper and lower endplates of the affected vertebrae, while the bilateral pedicle shadow is equidistant from the spinous process, and the puncture point is marked on the body surface, orthogonally located at the outer superior edge of the pedicle shadow. The puncture site was marked on the body surface and orthotopically located at the outer edge of the arch. An incision of approximately 3 mm in length is made, and the trocar needle (4.0 mm outer diameter) is punctured into the vertebral body using a balloon-expanded percutaneous vertebral body formation sleeve surgical system with fluoroscopic percutaneous transcatheter root puncture. During the puncture process, the C-arm should be adjusted to observe the position on the front and side images, and when the needle is inserted in the lateral position to reach the posterior edge of the vertebral body via the pedicle, the orthotropic position should be located at the inner edge of the pedicle shadow; after continuing to drill 2~3mm, the core of the puncture needle is withdrawn, the guide needle is implanted, and the expansion cannula and working cannula are placed along the guide needle so that the front end of the working cannula is located 2~3mm in front of the posterior edge of the vertebral body, and the fine bone drill is used to pierce into the vertebral body along the working channel to reach The tip of the needle should reach or cross the midline of the vertebral body on the orthostatic image. After confirming that the position is correct, the pressure injection device is connected and the balloon is placed. When the vertebral body height is satisfactorily restored or the balloon reaches the upper and lower endplates of the vertebral body, the pressure is stopped, the contrast agent is withdrawn and the balloon is withdrawn, and polymethylmethacrylate (PMMA) bone cement is deployed. After satisfactory fluoroscopic observation of PMMA distribution in the frontal and lateral views, the injection catheter was rotated several times before the cement set to separate it from the bone cement, and then the injection device was withdrawn. The wound was closed with 1 stitch, covered with sterile dressing, observed for 10 min, and the operation was finished with normal activities of both lower limbs and stable vital signs, and sent back to the ward. The patient was allowed to move on the ground after 1 d or 2 d postoperatively, and was given calcium and dense calcium rest routine treatment after the operation.
Typical case 1
Female, 85 years old, T11 compression fracture, treated conservatively
After 9 months of conservative treatment, the T11 fracture did not heal with intravertebral pseudarthrosis formation and progressively increasing back pain.
Intraoperative percutaneous puncture of the diseased vertebra under C-arm X-ray surveillance
Intraoperative balloon expansion
Immediate pain relief after vertebroplasty
Typical case 2
Male, 79 years old, sudden onset of low back pain, no abnormality detected by CT, MRI confirmed as lumbar 1 compression fracture
percutaneous puncture surgery
Intraoperative balloon expansion and bone cement injection
Surgery completed
Typical case 3
Female, 53 years old, multiple vertebral compression fracture
Multi-vertebral body cementoplasty