Kyphoplasty and Vertebroplasty

In 1984, a surgical technique designed to reduce the pain and loss of function called Percutaneous Vertebroplasty was developed in France. In 1998, the Food and Drug Administration cleared a special balloon, the KyphX Inflatable Bone Tamp, for use in reducing (setting) fragility fractures to help them heal and creating a cavity in the soft inner bone in the vertebral body.

What is an Osteoporotic Fracture?

Osteoporosis, the loss of calcium from bones resulting in weakened bone structure, increases the risk of fracture of vertebral body (the thick block of bone at the front of the vertebrae).
In this type of fracture, the top of the vertebral body collapses down with more collapse in front thus producing the “wedged” vertebrae, the “dowagers” hump and shortened height.
The resulting change in height and spinal alignment can lead to serious health problems, including:

  • Chronic or severe pain
  • Limited function and reduced mobility
  • Loss of independence in daily activities
  • Decreased lung capacity
  • Difficulty sleeping

Also, studies show that a first osteoporotic fracture makes it five times more likely further fractures will occur. That is why it is important that patients seek medical treatment for osteoporosis before it reaches the fracture stage.

Kyphoplasty Compared with Vertebroplasty

Vertebroplasty and kyphoplasty are both minimally invasive surgical procedures for treating osteoporotic fractures where a cement-like material is injected directly into the fractured bone. This stabilizes the fracture and provides immediate pain relief in many cases.
Kyphoplasty includes an additional step. Prior to injecting the cement-like material, a special balloon is inserted and gently inflated inside the fractured vertebrae. The goal of this step is to restore height to the bone thus reducing deformity of the spine. Most patients return to their normal daily activities after either procedure.

Indications

  • Vertebroplasty and kyphoplasty are radiologic procedures for the treatment of the intense pain caused by vertebral compression fractures that is refractory to conventional therapies such as analgesic use, bed rest, and bracing.
  • Vertebroplasty may also be applied prophylactically to an at-risk vertebra between 2 other abnormal vertebrae.
  • Kyphoplasty is a refinement of the vertebroplasty procedure. In addition to the reduction of fracture-related pain, some or all of the height is restored to the compressed vertebral body.
  • Kyphoplasty is most effective with acute compression fractures secondary to either trauma or osteoporosis (vs fractures secondary to infection, solid tumors, or vascular lesions).

Contraindications

  • Because the injection of acrylic under pressure is likely to pass through the fracture into the spinal canal, a posterior cortical defect is considered a relative contraindication for vertebroplasty.
  • Vertebroplasty also is contraindicated in cases involving a bone infection such as diskitis with osteomyelitis.
  • Kyphoplasty is not recommended for the treatment of fractures secondary to infection, most solid tumors, and vascular lesions.
  • The presence of a burst fracture with loss of integrity of the posterior vertebral cortex and retropulsion of a fracture fragment into the spinal canal is considered exclusionary.
  • Kyphoplasty is not indicated for the treatment of degenerative disk or joint disease.

Anesthesia

  • Vertebroplasty is not painful and requires only mild sedation and analgesia.
  • Local, deep, periosteal and endosteal anesthesia is provided at the outset.
  • In selected patients, a preprocedural epidural block can further reduce procedural pain.
  • Occasionally, patients report pain when the trocar reaches the fracture fragments and when the injection of acrylic cement is initiated. Endosteal anesthesia appears to reduce the intensity of the pain, it but does not eliminate the pain entirely.

Complications

The risks of the procedure are low, but they potentially include infection, worsening of pain, and neurologic problems such as weakness or pain in the legs.
Occasionally, the acrylic may extend into the epidural or paraspinous veins. Cement in the epidural venous plexus may lead to an ascending venous thrombosis or contribute to a spinal stenosis or cord or nerve root compression. Acrylic may extend from the paraspinous veins into the vena cava and may result in a pulmonary embolus. The risk of venous embolization increases if the operator cannot adequately identify when the cement begins to pass into the venous system.
Patients with osteoporosis should be aware that new fractures can occur in vertebra adjacent to previously treated vertebra. This, however, is not the result of the vertebroplasty procedure; rather, it is a consequence of the wedge deformity of the original fracture exerting additional stresses on the adjacent weakened osteoporotic vertebra (see image below). These patients are at risk of a second fracture of an adjacent vertebral body from this deformity, regardless of whether a vertebroplasty procedure was performed on the first fracture.

Results

Approximately 85-90% of patients have rapid pain relief.

  • This procedure is associated with a low morbidity rate. Less than 1% of patients with nonneoplastic lesions and only 5-8% of patients with neoplastic lesions have morbidity. Morbidity may include local pain, rib pain, spinal stenosis, nerve root compression, and intravascular extension of acrylic.
  • Pain improves in all patients who have undergone vertebroplasty; approximately 90% of patients note a complete resolution of pain. Incisional and muscular pain may persist for the first few days after the procedure. Point tenderness that is noted before the procedure has not been noted in any of the patients after the procedure.
  • Although pain is reduced or eliminated after the procedure, patients must exercise caution in subsequent activities because other osteoporotic vertebral bodies may also be prone to fracture. Medical management of the underlying disorder that weakens the vertebral bodies should be initiated. This procedure does not eliminate the need for aggressive treatment of osteoporosis, without which other fractures may ensue. Ideally, treatment should include Actonel; Fosamax; Miacalcin; calcium supplements; and multivitamins, including vitamins C and D. Hormonal replacement therapy should also be considered in female patients. Alterations in the medications and dosage of drugs that predispose the patients to osteoporosis (eg, steroids) should also be evaluated. Progress should be monitored with serial dual-energy x-ray absorptiometric (DEXA) scans. For complete medical treatment details, see Medscape Reference article Osteoporosis.