ASRA Pain Medicine Update

Osteoporotic compression fractures affect 30–50% of people older than 50 years.^[1] Severe pain that limits basic activities of daily living (ADLs), despite a trial of conservative treatment, is a common reason for patients to be referred to an interventional pain medicine clinic. Vertebral augmentation, which includes both kyphoplasty and vertebroplasty, is an option for patients to help restore function, decrease pain, and decrease mortality.^[2]

The key difference between the two procedures is that kyphoplasty involves the use of a balloon to create a cavity and elevate the endplates to help restore vertebral height. The space allows for low pressure injection of viscous cement, which may lower the risk of periosteal leakage.^[3]

History

Vertebroplasty was first successfully used clinically in 1984 by Drs Deramond and Galibert, a radiologist and neurosurgeon, respectively, for the treatment of painful cervical hemangioma, and it has been performed in the United States since 1995. Kyphoplasty was approved by the US Food and Drug Administration in 1998 for the treatment of osteoporotic compression fractures.^[4] Both are minimally invasive percutaneous procedures that involve the injection of material, most commonly polymethylmethacrylate (PMMA), into the vertebral body. PMMA may offer analgesia via vertebral body solidification, mechanical body stabilization (ie, physical stabilization of the vertebral body fracture by the cement), or inhibition of osteoclastic activity. Temperature elevation may induce neuromodulatory effects on neural structures like the posterior annulus, sinuvertebral nerve, and segmental dorsal root ganglion, which also help to ameliorate pain.^[5]

Patient Selection

Appropriate patients typically experience acute or subacute painful vertebral compression fractures from T5–L5, limiting activities of daily living, despite trials of conservative treatment such as medications, rest, or back braces. Clinically, patients have pain on the spinous process without radicular pain. The gold standard imaging modality is magnetic resonance imaging with short tau inversion recovery sequence demonstrating bone edema at the affected level. Patients who are appropriate candidates for the procedure must be able to stop anticoagulation and be free of active infection.

Contraindications for proceeding with vertebral augmentation include radicular pain with associated retropulsed bone fragment into the spinal canal, an uncorrectable coagulation disorder, active site of infection or sepsis, burst fracture, pain unrelated to fracture, or allergies to PMMA or contrast. Complications are rare but include bleeding, infection, no pain relief, increase in pain, cement leakage, and pulmonary embolism.

Performing the Procedure

Vertebral augmentation may be performed with conscious sedation or general anesthesia in an outpatient office setting, surgical center, or hospital. Prep and drape the patient in a sterile fashion. After infiltrating with local anesthetic, use fluoroscopic guidance to advance a trocar via a transpedicular or extrapedicular approach into the vertebral body. Anteroposterior and lateral fluoroscopic images are routinely obtained to ensure proper trocar placement. Once in the vertebral body, take a bone biopsy to evaluate for potential malignancy if indicated. Then, if kyphoplasty is being performed, insert balloons through the trocars bilaterally and inflated to create a cavity to help restore vertebral height. Withdraw the balloons and use PMMA or another bone cement to fill the cavity under live fluoroscopy. Flush needles with local anesthetic and withdraw under live fluoroscopy to ensure cement does not spread posteriorly (Figures 1–11).

The patient is observed for an appropriate amount of time and then discharged. Follow-up visits are typically performed 1 and 4 weeks after the procedure.

Controversy and Evidence Support

Vertebral augmentation was widely accepted as the appropriate treatment for painful vertebral compression fractures unresponsive to conservative treatment prior to 2009.^[6],[7] That year, however, the New England Journal of Medicine published reports of two placebo-controlled, randomized trials that showed no beneficial effect of vertebroplasty compared with paraspinal injection of local anesthetics. Since then, the treatment option has been the subject of controversy. The studies have since been discredited and downgraded because of design flaws, but the controversy persists despite the publication of six prospective randomized controlled studies and two meta-analyses showing superior results with vertebral augmentation compared to conservative treatment.^[8]

Most significantly, vertebral augmentation can improve mobility in elderly and frail patient populations, thereby decreasing the risk of atelectasis, deep venous thrombosis, pneumonia, lack of independence, and loss of ability to perform ADLs.

In 2018, the EVOLVE trial, a large, prospective clinical study, demonstrated that kyphoplasty is a safe, effective, and durable procedure for the treatment of patients with painful vertebral compression fractures because of osteoporosis and cancer.^[9] In addition, researchers conducting another meta-analysis in 2018 endorsed kyphoplasty and vertebroplasty over vertebral augmentation with implant and nonsurgical management for the treatment of vertebral compression fractures. Furthermore, evidence validated the procedure’s safety.^[10]

Pros/Cons

Vertebral augmentation is not appropriate for all patients. As with any interventional procedure, appropriate patient selection is essential. Patients must fail conservative treatments and continue to have corresponding pain that adversely affects ADLs and quality of life. Patients may fail the use of a back brace because of discomfort or respiratory limitations. They may fail medical management because of side effects. Patients may also not be candidates for certain medications because of comorbid conditions.

Proceeding with a minimally invasive procedure instead of prescribing opioids or other pain medications may result in fewer complications such as dependency, tolerance, respiratory depression, and overdose. Furthermore, polypharmacy in elderly patients can result in additional side effects and increase the risk of subsequent falls. In addition, an increase in kyphosis because of vertebral compression fractures may worsen underlying pulmonary conditions. Most significantly, vertebral augmentation can improve mobility in elderly and frail patient populations, thereby decreasing the risk of atelectasis, deep venous thrombosis, pneumonia, lack of independence, and loss of ability to perform ADLs. As a result, vertebral augmentation has been shown to decrease morbidity and mortality when compared to conservative management in the Medicare population.^[2]

Disadvantages of vertebral augmentation include cost as well as complications from the procedure or PMMA. In addition, vertebral augmentation may increase the risk of adjacent level fractures because of biomechanical stress, although this has not been proven. Many patients with one or more vertebral compression fractures may experience additional fractures if the underlying condition, typically osteoporosis, has not been treated.^[11]

Summary

As the population continues to age, the number of patients with vertebral compression fractures increases concurrently. Options for treatment include medical management, rest, bracing, vertebral augmentation, and surgery. As with any interventional technique, vertebroplasty or kyphoplasty should be offered by an experienced practitioner only to appropriate patients. With appropriate patient selection, vertebral augmentation provides an effective and low-risk option for patients to resume ADLs and improve quality of life, thereby decreasing morbidity and mortality.

References

1. Ballane G, Cauley JA, Luckey MM, El-Jajj Fulihan G. Worldwide prevalence and incidence of osteoporotic vertebral fractures. Osteopor Int 2017;28(5):1531–1542.
2. Edidin, AA, Ong K, Lau E, Kurtz S. Morbidity and mortality after vertebral fractures: comparison of vertebral augmentation and nonoperative management in the Medicare population. Spine 2015;40:1228–1241.
3. Hargunai R, Le Corroller T, Khashogii K, Murphy KJ, Munk PL. Percutaneous vertebral augmentation: the status of vertebroplasty and current controversies. Semin Musculskelet Radiol 2011;15:117–124.
4. Garfin SR, Yan HA, Reiley MA. New technologies in spine: kyphoplasty and vertebroplasty for the treatment of painful osteoporotic compression fractures. Spine 2001;26:1511–1515.
5. Armsen N, Boszczyk B. Vertebro-/kypholasty history, development, results. Eur J Trauma 2005;31:433–441.
6. Kallmes DF, Comstock BA, Heagerty PJ, et al. A randomized trial of vertebroplasty for osteoporotic spinal fractures. N Engl J Med 2009;361:569–579.
7. Buchbinder R, Osborne RH, Ebeling PR, et al. A randomized trial of vertebroplasty for painful osteoporotic vertebral fractures. N Engl J Med 2009;361:557–568.
8. Beall D, Tutton SM, Murphy K, Olan W, Warner C, Test JB. Analysis of reporting bias in vertebral augmentation. Pain Physician 2017;20:E1081–E1090.
9. Beall D, Chambers MR, Thomas S, et al. Prospective and multicenter evaluation of outcomes for quality of life and activities of daily living for balloon kyphoplasty in the treatment of vertebral compression fractures: the EVOLVE trial. Neurosurgery 2019;84:169–178.
10. Beall D, Lorio MP, Yun BM, Runa MJ, Ong KL, Warner CB. Review of vertebral augmentation: an updated meta-analysis of the effectiveness. Intl J Spine Surg 2018;12(3):1–27.
11. Berleman U, Ferguson SJ, Nolte LP, et al. Adjacent vertebral failure after vertebroplasty: a biomechanical investigation. J Bone Joint Surg Br 2002;84:748–752.