Osteoporotic vertebral compression fractures are a common problem and cause much pain and disability. Traditional treatments have included bed rest, bracing, and narcotics; however, none of these measures is very effective. Major reconstructive surgery is poorly tolerated by patients, but balloon kyphoplasty has established itself as a useful, minimally invasive treatment for acute osteoporotic vertebral compression fracture. This article reviews the safety and effectiveness of kyphoplasty and explains how it can relieve pain and improve quality of life in patients with these fractures.

CASE

The patient is an 80-year-old female with mild, chronic, intermittent back ache who had an abrupt exacerbation of back pain 3 weeks ago as she was getting out of her bed. Since then, she has had severe back pain, rating the pain as 9 out of 10 in severity. She had no radicular or myelopathic symptoms. The pain worsened when she stood up or changed position. Her primary care physician treated her with acetaminophen/propoxyphene napsylate (Darvocet) and ordered plain films of the lumbar spine (see Figure 1). These showed an L1 compression fracture and osteopenia.

The patient was referred to neurosurgery with continued severe back pain and was considered for kyphoplasty. MRI confirmed the acute L1 vertebral compression fracture, and bone mineral density testing revealed a T score of –1.3 for the spine consistent with osteopenia. The neurologic examination elicited mild tenderness in the lower back. Otherwise, motor strength was completely intact. Balloon kyphoplasty at L1 was recommended.

Under general anesthesia, the patient was positioned on the operating table in the prone position on soft jellyrolls, which were positioned transversely. The skin of the back was prepared with Betadine and draped sterilely. Two image intensifiers were brought into position for anteroposterior (AP) and lateral fluoroscopy. The L1 pedicles were identified and marked on the skin with an indelible marker.

A small stab wound was made with a #11 blade, and an 11-gauge entry needle was placed into the junction of the pedicle and vertebral body at L1 on the left side. The stylet was removed. A guide pin was inserted through the needle into the mid-portion of the vertebral body. The needle was removed, leaving the guide pin in place. A blunt dissector and cannula were placed over the guide pin and advanced into the posterior aspect of the vertebral body. The guide pin was removed. The blunt dissector was removed. A drill was placed through the cannula and advanced into the vertebral body under fluoroscopic guidance. The drill was removed. A bone biopsy was performed. An inflatable bone tamp was placed through the cannula into the vertebral body and inflated to 0.5 cc and 50 psi. Expansion of the bone tamp was done sequentially in increments of 0.25 to 0.5 cc of contrast per injection, with careful attention to the inflation pressures and balloon position. The inflation was monitored with AP and lateral imaging. The final balloon volume was 4.5 cc on the left side. The maximum pressure was 150 psi. There was no breach of the walls of the vertebral body. The bone tamp was deflated and removed.

Under fluoroscopic guidance, internal fixation was achieved through a low-pressure injection of methyl methacrylate with a volume of 4.5 cc on the left. The cannula was removed. The same technique was then used on the right side. Final AP and lateral imaging showed a satisfactory fill pattern. The patient was bought to the recovery room in stable condition.

One month following the procedure, the patient reported that her severe back pain had completely resolved. Postoperative lumbar spine radiography showed an excellent appearance with cement deposition in the L1 vertebral body (see Figure 2). The patient was taking no pain medication and was able to resume normal activity and enjoy a good quality of life. Her primary care physician started her on risedronate (Actonel) for her primary osteoporosis.

Two years later, the patient experienced recurrent back pain after moving some plants. Her pain scale was 8/10. Again, she did not have any radicular or myelopathic symptoms. She had once again been taking acetaminophen/propoxyphene napsylate without relief. An imaging study showed a new T9 vertebral compression fracture. The patient underwent kyphoplasty at T9, and again achieved excellent pain relief.

DISCUSSION

Osteoporosis is a common disease that is characterized by low bone mass, resulting in an increased risk of fracture. In 2000, there were an estimated 9 million osteoporotic fractures worldwide, of which 1.4 million were clinical vertebral fractures.1 These injuries may result in limitation of ambulation, depression, loss of independence, chronic pain, and an increased mortality rate.

Clinical presentation About two-thirds of vertebral compression fractures are asymptomatic, diagnosed as an incidental finding on a chest or abdominal plain film.2 In some patients, vertebral fractures may become apparent because of height loss or kyphosis. Patients with symptomatic vertebral fracture typically present with acute severe back pain after sudden bending, coughing, or lifting.3 The pain often radiates bilaterally into the distribution of contiguous nerve routes. Most of the time, the pain never radiates into the legs, as may be seen with a herniated disk.

Approximately 19% of patients who have a vertebral compression fracture will have another fracture in the next year.4 Women with pre-existing vertebral fractures have greater risk of subsequent vertebral fractures than do women without prior fractures.5 The presence of vertebral fractures is also predictive of future nonvertebral fractures, such as hip fractures, and this risk increases with the number and severity of prior fractures.6

Diagnosis Advancing age, a history of fragility fracture, chronic glucocorticoid use, low body mass index, cigarette smoking, and excess alcohol intake are the risk factors that have been demonstrated to be most predictive of fracture. After a careful medical history, patients with a suspected acute compression fracture should be evaluated with plain radiography, AP and lateral views, to confirm the diagnosis. Then, MRI or CT is needed to further evaluate the severity of a fracture and to provide additional information on bone marrow architecture. A bone density study provides the quantitative assessment of bone density.

Treatment The patient should be informed that fractures may take up to 3 months to heal and that pain will diminish gradually. Traditional treatments have included bed rest, bracing, and narcotics to relieve pain. However, none of these measures has been very effective. Major reconstructive surgery is poorly tolerated by these patients. Balloon kyphoplasty has established itself as a useful, minimally invasive treatment for acute osteoporotic vertebral compression fracture.

The first kyphoplasty was performed in the United States in 1998, and the procedure is now recognized as a successful, low-risk procedure for vertebral compression fracture. Kyphoplasty is performed under general anesthesia or under local anesthesia with intravenous sedation. Under fluoroscopic guidance, cannulas are placed in the fractured vertebral body using a bilateral transpedicular approach (see Figure 3a). The bone is drilled (see Figure 3b), and an inflatable bone tamp is inserted on each side (see Figure 3c). The balloons are inflated with contrast medium until they expand to the desired height and then removed (see Figure 3d). The spaces created by the balloons are filled with polymethylmethacrylate using a low-pressure injection (see Figure 3e). The cement provides strength and stability to the vertebra, thereby restoring vertebral body height and relieving pain. Sometimes, the procedure can be accomplished with a single balloon using a unilateral approach.

Results Serious complications from kyphoplasty are uncommon. Spinal cord or nerve root injury, pulmonary embolus from cement, rib fractures from positioning, and medical problems related to anesthesia are some of the more common complications.7 Results from our institute show that patients with osteoporotic and osteolytic vertebral compression fractures tolerate kyphoplasty well. We have performed many kyphoplasties with a complication rate of less than 10%.

At the Mayo Clinic Jacksonville, we have studied the functional outcome in patients who have undergone kyphoplasty using data collected with the Short Form-36 (SF-36) and the Oswestry Disability Index (ODI) at baseline (perioperative visit) and at the 3-month and 1-year follow-up visits. Our results show that patients with osteoporotic and osteolytic vertebral compression fractures who underwent kyphoplasty have statistically significant improvement in pain and in physical and emotional function as assessed by these instruments. A decrease in the ODI is associated with an improvement in functional outcomes. The SF-36 scores include bodily pain, physical function, vitality, social function, mental health, role-emotional, role-physical, and general health.

Conclusion Kyphoplasty is a minimally invasive procedure that can restore vertebral body height and improve sagittal alignment. The procedure provides hope for patients with osteoporotic vertebral compression fractures who suffer from acute, intractable pain. Kyphoplasty has been proven to be safe and effective and has demonstrated its ability to relieve pain and improve physical and emotional function in affected patients. JAAPA

Steve Wilson, PA-C, department editor

REFERENCES

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Sheon RP, Rosen HN. Clinical manifestations and treatment of osteoporotic thoracolumbar vertebral compression fractures. UpToDate Online Web site. http://uptodateol.com. Updated November 21, 2007.

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4.

Lindsay R, Silverman SL, Cooper C, et al. Risk of new vertebral fracture in the year following a fracture. JAMA. 2001;285(3):320-323.

5.

Klotzbuecher CM, Ross PD, Landsman PB, et al. Patients with prior fractures have an increased risk of future fractures: a summary of the literature and statistical synthesis. J Bone Miner Res. 2000;15(4):721-739.

6.

Black DM, Arden NK, Palermo L, et al. Prevalent vertebral deformities predict hip fractures and new vertebral deformities but not wrist fractures. Study of Osteoporotic Fractures Research Group. J Bone Miner Res. 1999;14(5):821-828.

7.

Deen HG. Current status of percutaneous vertebral augmentation techniques for vertebral compression fractures. Neurol Neurochir Pol. 2006;40(4):320-326.


HoiKee Ng practices in the Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida. The author has indicated no relationships to disclose relating to the content of this article.