Due to the increase of age, the physical quality of the elderly population continues to decline, osteoporosis is more serious, and the response flexibility is reduced. Therefore, it is more likely to have fracture injury when suffering from slip, fall from height, car accidents, etc. Although most of them are compression fractures, they can often lead to burst fractures if caused by traffic injuries or other serious violence. Denis B type accounted for 49.2% of thoracolumbar burst fractures, mainly including anterior and middle column injury and upper endplate rupture . For elderly patients with osteoporotic Denis B thoracolumbar burst fracture with intact nerve function, conservative treatment is often used . Conservative treatment requires long-time bed rest and braking, which increases the risk of accumulation pneumonia, urinary system infection, lower extremity deep venous thrombosis and bedsore. In addition, some patients have fracture nonunion and further collapse of vertebral body, resulting in kyphosis, and develop into chronic pain, even delayed nerve damage, which seriously affects the quality of life of elderly patients , and may even endanger their lives due to complications. However, for the majority of AO Spine type A3/A4 elderly osteoporotic thoracolumbar burst fractures are often complicated with basic diseases such as chronic bronchitis, emphysema, coronary atherosclerotic heart disease, or severe trauma and combined injury, and cannot tolerate open surgery under general anesthesia. Their own osteoporosis is easy to be treated by internal fixation, which may lead to nail removal or loosening and falling off, and the need for second-stage removal and internal fixation surgery, which not only increases the trauma, prolongs the operation time, but also increases medical costs [11–15].
For the treatment of OTLBF, because of the posterior wall rupture and a small amount of fracture mass encroaching on the spinal canal, percutaneous kyphoplasty (PKP) is easily caused by implanting an expandable balloon in the collapsed vertebral body, so that the expansion balloon can reposition the end plate of the fractured vertebral body, and the bone mass of the middle column of the vertebral body is further displaced into the spinal canal. The risk of cement leakage is increased in the case of broken vertebral periosteal wall, especially in those with fracture in the posterior wall, and cement may enter the spinal canal along the fissure and even cause spinal nerve injury, so the risk is greater.
Pain reliefs as well as stabilization of the fracture and early ambulation are the primary goals of treatment of burst fractures. For the elderly and frail patients with compound injuries, it is not strong to demand PVP without complete recovery of vertebral height and kyphosis to minimize the operation time. Our case gave PVP treatment to 13 elderly patients with osteoporotic thoracolumbar burst fractures in our hospital, with an overall response rate of 92.30%.
The results showed that the scores of ODI and VAS after PVP combined with body reduction were significantly lower than those before operation, which indicated that the operation had a significant effect on the relief of pain and the improvement of dysfunction, PVP combined with body reduction can effectively restore the height and shape of the compressed vertebral body, correct kyphosis, restore the stability of the vertebral body, and reduce the compression and stimulation of the nerve, so it can effectively relieve the pain.
According to our experience, the technical points are as follows:
1) After admission, while treating the composite injury, the flat hard bed was used during the perfect examination, and the fracture site was added with supine back pitch, which can assist the reduction. Preoperative hyperextension facilitates the return of a burst vertebral posterior border bony mass to the spinal canal under the influence of the posterior longitudinal ligament. Intraoperatively, it was found that most of these patients could obviously relieve the kyphosis angulation and relax the compressed vertebral body by positional reduction.
2) Staged continuous bone cement filling technique: under continuous monitoring by dynamic C-arm X-ray machine, first irrigate with cement at the end of a small amount of drawing, push back of cement into the tube by 2-3mm wait for 40-50s after closing the defect, and push back of cement remaining in the pushed in tube can effectively prevent the leakage of cement.
3) Cement leakage is the main complication. The most common sites of cement leakage were paravertebral venous plexus, intervertebral space, paravertebral soft tissue and intraspinal canal. The leakage was related to the amount, viscosity, pressure and velocity of the bone cement injection. The indication for stopping cement injection is that the cement has exceeded the posterior 1/3 of the vertebral body, but has not reached the posterior wall to prevent cement from leaking into the vertebral canal. The senile burst fracture is different from the young and middle-aged fracture. The pathological basis is osteoporosis, so the degree of comminution of the fracture is light, the fissure of the fracture block is small, and the leakage is relatively small. Moreover, the enlarged space between the trabecular bone is beneficial to the diffusion of bone cement, to increase the effect of vertebral body strengthening. External forces cause burst fractures in most older adults, but the posterior longitudinal ligament is generally intact, enabling partial bone block reduction due to the pressure on the posterior longitudinal ligament.
4) During the operation, the appropriate hyperextension posture was adjusted to reduce the patient's kyphosis and reduce the vertebral body. The x-ray film and CT SCAN should be observed before operation in the elderly patients with thoracolumbar burst fracture to grasp the fracture line, the position and condition of vertebral body rupture, and make the operation plan. At the same time, the puncture path should be parallel to the vertebral endplate.
5) Unilateral paracentesis is easy result in leakage of bone cement because of the need to increase the inclination angle and too fine injection of bone cement to increase the diffusion effect. Bilateral puncture with less cement injected into each side with less pressure can achieve satisfactory clinical results, thus reducing cement leakage .
6) At the time of puncture, the needle should be as far as possible as 4 ~ 5 mm from the anterior edge of the vertebral body, at least 1/3 of the anterior column should be filled with bone cement. The Cement Push Rod should be placed in front of the vertebral body first. According to the images during the operation, after the anterior column of the Vertebral Body is diffused satisfactorily, the position of the push rod should be reversed, Once cement is found to cross the posterior 1/3 of the vertebral body, the injection should be stopped to prevent entering the spinal canal to burn the spinal cord or compress the nerve root and spinal cord;
7) Timing and dosage of bone cement injection: for burst fractures, we do not seek to inject too much bone cement, a single vertebral body can be 4 ~ 5 ml, bone cement thick stage of injection, to reduce leakage. Because of more vertebral fractures, the cement should be thicker than a simple compression fracture to reduce the rate of leakage. During the course of injection, a small amount of bone cement was slowly injected, then the bone cement was pushed back 2 ~ 3mm and waited for 40 ~ 50s, and then continued to push into the bone cement after the broken edge of the bone cement hardened to form a hard shell.
About half a year follow-up, we found no serious complications, pain relief and vertebral height recovery rate remained good. Osteoporosis is the underlying cause of this condition,PVP is only to solve the problem of fracture and pain. Normal anti-osteoporosis treatment is still needed after PVP. Otherwise, it is easy to refracture and adjacent vertebral fracture.
This study evaluated the quality of life of patients through six items: Social Function, emotional function, physiological function, physical pain, physiological function and mental health, the quality of life of the patients after the operation was significantly higher than that before the operation. Because the combination of PVP and the reduction of the body position during the operation had a better ability to correct kyphosis and promote the reduction of the vertebral body, the utility model can significantly relieve the pain of patients, improve the clinical symptoms of patients, thereby improving the quality of life.
The results of this study support the growing interest in minimally invasive techniques in the management of spinal injuries with no neurological deficit. In addition, advances in surgical techniques have made it possible to treat vertebral compression fractures in full compliance with traditional PVP procedures, including reduction maneuvers, while limiting muscle injury by using a purely percutaneous approach. Rigorous patient selection is necessary and the time to learn the procedure must be taken into account. Studies with a longer follow-up are required to confirm the stability of the correction over time.