Percutaneous Vertebroplasty And Kyphoplasty

Article Author:
Avik Patel
Article Editor:
Kevin Carter
Updated:
12/17/2018 9:17:12 AM
PubMed Link:
Percutaneous Vertebroplasty And Kyphoplasty

Introduction

Compression fractures are prone to progression over time and may facilitate the compression of adjacent vertebrae due to compensatory increases in axial load. Vertebroplasty and kyphoplasty are 2 percutaneous interventional procedures that can help alleviate pain and fortify structural integrity after sustaining a vertebral compression fracture.

Vertebral compression fractures are most commonly a result of fragile, osteoporotic bone. Osteoporotic individuals may suffer a vertebral compression fracture as a result of seemingly insignificant trauma, for example, sitting down abruptly. In younger individuals, a higher-energy, axial loading force would be needed to compress the cancellous bone of the vertebral body. Non-osteoporotic lumbar compression fractures are typically seen in car accidents and falls or jumps from a height. Infectious and malignant processes that weaken vertebrae can also lead to an eventual compression fracture.[1]

Anatomy

Vertebral compression fractures are the result of axial force overcoming bony integrity. Compression fractures characteristically involve the anterior column of the spine which is comprised of the anterior two-thirds of the vertebral body, the anterior two-thirds of the intervertebral disc, and the anterior longitudinal ligament. Unlike vertebral burst or Chance fractures, a compression fracture does not compromise the posterior tension band.[2] (III) The posterior tension band is characterized by muscles, ligaments, processes, and pedicles that maintain spinal stability. Therefore, compression fractures are deemed stable fractures.

Posterior tension band components include:

  • Posterior ligamentous complex: Supraspinous and interspinous ligaments, ligamentum flavum
  • Musculature: Longissimus, iliocostalis, spinalis, semispinalis, rotatores, intertransversarii, multifidus
  • Bone: Transverse and spinous processes, pedicles, facets[3]

Indications

Vertebroplasty and kyphoplasty are indicated most commonly to treat painful, acute, and subacute vertebral compression fractures refractory to medical therapy. Medical therapy is limited to pain medicine, bracing, and rest.[1]

Contraindications

An absolute contraindication to vertebroplasty and kyphoplasty is an asymptomatic compression fracture. Often found incidentally on chest x-rays, healed compression fractures will not benefit from intervention. The procedure should not be performed if there are ongoing local or systemic infectious processes such as osteomyelitis or discitis. Vertebroplasty and kyphoplasty are not considered a prophylactic intervention in patients with known osteoporosis.[1]

Equipment

  • Fluoroscopy
  • Spinal needle
  • Spinal needle stylets, with diamond-shaped multi-bevel and single-bevel
  • Polymethacrylate (PMMA) cement
  • +/- Kyphoplasty balloon catheter See Technique for details.[1]

Personnel

Vertebroplasty and kyphoplasty are performed primarily by interventional radiologists, interventional pain management physicians, and spine specialists. Intraoperative personnel may also include a fluoroscopy technician and nurse. If general sedation is implemented, an anesthesiologist is also present.

Preparation

Prior to any spinal procedure, a thorough physical exam with a complete neurological evaluation should be completed.

Imaging is crucial for initial diagnoses of a vertebral compression fracture and evaluating chronicity. Conventional radiographs of the thoracic and/or lumbar spine are most often used to diagnose the fracture. On lateral radiographic projections of the spine, a compression fracture will demonstrate a prototypical wedge-shaped deformity of the vertebral body with accentuated vertebral body height loss anteriorly. MRI is the preferred modality for evaluating chronicity of compression fractures. On MRI, the presence of bone marrow edema suggests acute, subacute, or nonhealing fractures. Bone marrow edema will be hypointense (dark) on T1W sequences and hyperintense (bright) on T2W and STIR sequences. If a patient is unable to have an MRI, a bone scan may be used to determine chronicity. Acute fractures have increased bone perfusion and turnover. On bone scans, compression fractures will demonstrate increased radiotracer uptake at the fractured vertebral segment.[1]

Vertebroplasty and kyphoplasty are considered a procedure with moderate bleeding risk (Category 2) according to the SIR Standards of Practice Consensus Guidelines. INR and complete blood count (CBC) should be attained pre-procedure. Recommendations are as follows:

  • INR correct to less than 1.5
  • Transfuse for platelets less than 50,000
  • ASA: No need to hold
  • Clopidogrel: Hold 5 days pre-procedure  
  • LMWH: Hold one dose pre-procedure

Antibiotic prophylaxis is achieved with the administration of 1 gram of intravenous (IV) cefazolin, 1 hour pre-procedure (first-line).

Technique

The most common approach for vertebroplasty and kyphoplasty in the thoracic and lumbar spine is transpedicular. The patient is placed in the prone position and draped and prepped in a sterile fashion. Conscious sedation is achieved commonly with a combination of midazolam and fentanyl. Throughout the procedure, the patient’s vitals are monitored. The C arm is positioned directly over the vertebral body such that the anterior and posterior vertebral walls eclipse one another. 

The following steps can be carried out unilaterally or bilaterally:

Local anesthetic, typically lidocaine, is injected into the skin, subcutaneous tissues, and periosteum overlying the procedure site. The C arm is positioned 20 to 30 degrees ipsilateral oblique such that the pedicle is straight-on. Under intermittent fluoroscopy, a spinal needle with a multi-bevel stylet is placed near the upper and lateral half of the pedicle face and subsequently advanced longitudinally through the pedicle using a mallet. Intermittent lateral views can ensure adequate craniocaudal positioning. Once the needle enters the posterior vertebral body, a single-bevel stylet may be introduced to steer the needle into proper position: the junction of the anterior and middle thirds of the vertebral body in the midline. At this point, vertebroplasty can be accomplished by injecting PMMA cement[4]; whereas, kyphoplasty will require inflation of a balloon inside the vertebral body, creating a more defined space before cement injection. Cement injection should be continuously monitored in the lateral view. The amount of injected cement varies significantly and is interventionalist-dependent.

Complications

  • Infection and bleeding: Universally recognized risks of any interventional procedure.
  • Radiculopathy or neurological deficit: If the spinal needle violates the inferior or medial wall of the pedicle during entry, there is a significant risk of damage to a nerve root or the spinal cord.
  • Extra-vertebral cement migration:
    • Pulmonary embolization: Cement particles introduced into a vein have the potential to embolize to the lungs.
    • Spinal stenosis: Cement leakage into the epidural space can essentially cause iatrogenic spinal stenosis.[5]

Clinical Significance

Acute compression fractures are often painful, immobilizing conditions of elderly individuals. Studies have demonstrated significant pain relief, improved quality of life, decreased dependence on narcotics, and increased mobility in patients who undergo such interventions. In summation, vertebroplasty and kyphoplasty have proven to be an effective treatment modality in patients with painful, acute compression fractures refractory to medical management. A risk/benefit analysis should always be completed before intervening, and an understanding of SIR consensus guidelines assures a higher standard of care.

Enhancing Healthcare Team Outcomes

Only patients with acute compression fractures should be considered for vertebroplasty and kyphoplasty. It is the responsibility of the primary care physician and interventionalist to verify the acuity of the fracture using diagnostic imaging. Careful consideration of bleeding risk helps prevent potentially life-threatening spinal hematoma or hemorrhage. Careful, post-procedure, clinician and nursing follow up are recommended to ensure that the desired analgesic effect has been achieved. Interventionalists, rehabilitation specialists, and physical therapists all play an integral role in helping patients return to their daily activities and previous quality of life. Nursing must evaluate for postoperative infection and other complications.



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      contributed by Mohamad Jaber, MD

References

[1] Jay B,Ahn SH, Vertebroplasty. Seminars in interventional radiology. 2013 Sep     [PubMed PMID: 24436552]
[2] CHANCE GQ, Note on a type of flexion fracture of the spine. The British journal of radiology. 1948 Sep     [PubMed PMID: 18878306]
[3] Pizones J,Zúñiga L,Sánchez-Mariscal F,Alvarez P,Gómez-Rice A,Izquierdo E, MRI study of post-traumatic incompetence of posterior ligamentous complex: importance of the supraspinous ligament. Prospective study of 74 traumatic fractures. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2012 Nov     [PubMed PMID: 22722921]
[4] Chiras J,Depriester C,Weill A,Sola-Martinez MT,Deramond H, [Percutaneous vertebral surgery. Technics and indications]. Journal of neuroradiology. Journal de neuroradiologie. 1997 Jun     [PubMed PMID: 9303944]
[5] McGraw JK,Cardella J,Barr JD,Mathis JM,Sanchez O,Schwartzberg MS,Swan TL,Sacks D, Society of Interventional Radiology quality improvement guidelines for percutaneous vertebroplasty. Journal of vascular and interventional radiology : JVIR. 2003 Sep     [PubMed PMID: 14514838]