Kyphoplasty is a surgical procedure used to treat painful vertebral body fractures. With the help of a cement injected into the vertebral body, it is stabilized and straightened again. The modern procedure is used to reduce pain, especially in people affected by osteoporosis.
What is kyphoplasty?
Kyphoplasty is a surgical procedure used to treat painful vertebral body fractures. A cement injected into the vertebral body is used to stabilize and realign it. Kyphoplasty is a modern minimally invasive surgical procedure for the treatment of extremely painful fractures of the vertebral bodies. By injecting a special (bio)cement with a high degree of hardness or a PMMA plastic (polymethylmetacrylate or plexiglass) into the fracture site, the vertebral body in question is stabilized and reconstructed. The primary goal is to reduce pain symptoms caused by periosteal irritation due to the progressive and continuous sintering (collapse) of the vertebral body. In general, a distinction is made between substance-destroying (including balloon kyphoplasty) and substance-preserving (radiofrequency kyphoplasty) procedures.
Function, effect, and goals
Kyphoplasty is primarily performed for the rapid and effective relief of pain symptoms that allow a clear relationship to a vertebral body fracture in the lower and middle thoracic spine and lumbar spine. Thus, kyphoplasty is used for acute or chronically painful vertebral body fractures due to osteoporosis, accidental or traumatic vertebral body fractures that do not represent comminuted or burst fractures, painful malignant or benign tumors (including myeloma, hemangioma) of the vertebral body, and bone-dissolving bone metastases that are associated with an impending loss of stability of the vertebral body. The procedure is not suitable for cosmetic correction of a spinal curvature. Various techniques are available for kyphoplasty, such as substance-destroying (balloon kyphoplasty) and substance-preserving (radiofrequency kyphoplasty). In balloon kyphoplasty, after a cannula is advanced into the affected vertebral body, a small balloon catheter filled with radiopaque fluid is inserted through it and deployed under fluoroscopic control. This allows the vertebral body to be corrected and a defined cavity to be created, which remains when the fluid and balloon are removed. A special bone cement is then injected into the cavity, which hardens in a very short time and stabilizes the vertebral body. In addition, if a fresh fracture is present, the vertebra can be realigned in some cases. While the injected biocement hardens at body temperature, a PMMA resin must be polymerized exothermically, i.e., releasing heat to the adjacent structures. In addition, the biocement can be substituted and resorbed by normal tissue in the long term as part of bone remodeling processes, which simultaneously stimulates the synthesis of new bone substance. A newer substance-preserving procedure is radiofrequency kyphoplasty, in which only small channels or cavities are created inside the affected vertebra, into which a rubbery cement is introduced. The tough cement flows around the vertebral body structures and interlocks with the vital cancellous bone (spongy bone substance) without destroying it. The cement is then hardened by the addition of radiofrequency energy and reaches a high viscosity. The vertebral body is stabilized and in some cases can be straightened. Postoperatively, there is no need to wear a brace, and patients are usually mobile again after 24 to 48 hours following kyphoplasty.
Risks, side effects and dangers
Although kyphoplasty is a minimally invasive procedure, it is not completely risk-free. For example, there is a very rare risk of small amounts of cement leaking out of the vertebra and into surrounding tissue structures. In this case, the leaked cement can compress the spinal nerves and the spinal cord and lead to painful complaints with nerve damage and failures such as paralysis or sensory disturbances in the lower extremities.In addition, in rare cases, there is the possibility that parts of the injected cement may be washed off into the lungs during the surgical procedure and cause a pulmonary embolism there. In the event of such cement leakage, the lungs should always be checked postoperatively as part of a radiological examination. In the case of kyphoplasty with plastic, neighboring structures may be damaged as a result of the exothermic polymerization due to heat generation. In most cases, this damage is minor and is compensated for by the body’s own regeneration of bone substance. Kyphoplasty is also ruled out if a coagulation disorder is present, as this could lead to nerve damage via spinal canal hemorrhage. Infections in the area of the affected section of the spine (e.g., spondylitis, osteomyelitis), posterior edge instability (increased risk of spinal cord injury), pronounced signs of wear on vertebral bodies, existing bone disintegration with invasion of the spinal cord cavity, deformed cervical vertebral bodies, intervertebral disc complaints, and pain symptoms in the back that cannot be clearly attributed to a vertebral body fracture are further exclusion criteria for kyphoplasty.
