PRESENTED BY

 

AHMED SAEEDASSISSTANT LECTURER AT NEUROSURGICAL DEPARTEMENTALEXANDRIA UNIVERSITY

PERCUTANEOUS VERTEBROPLASTY IN CASES

OF OSTEOPOROTIC VERTEBRAL COMPRESSION

FRACTURES 

• Osteoporosis is defined by the World Health Organization (WHO) as a BMD of 2.5 standard deviations or more below the mean peak bone mass as measured by dual-energy X-ray absorptiometry

• Osteoporosis itself has no symptoms; its main consequence and most dangerous aspects is the increased risk of fragility fractures.

Mechanism of VCFs

Acute fractures occur when the weight of the upper body exceeds the ability of the bone within the vertebral body to support the load.

Up to 30 percent of compression fractures occur while the patient is in bed. In cases of moderate osteoporosis, more force or trauma is required to create fracture, such as falling off a chair, or attempting to lift a heavy object.

The applied force usually causes the anterior part of the vertebral body to crush, forming an anterior wedge fracture.

Because the majority of damage is limited to the anterior vertebral column, the fracture is usually stable and rarely associated with neurologic compromise.

Wedge fracture of a lumbar vertebra

Wedge fracture of a lumbar vertebra

Clinical picture of VCFs

Spinal compression fractures can be insidious and may produce only modest back pain early in the course of progressive disease.

Over time, multiple fractures may result in significant loss of height. Progressive loss of stature results in shortening of paraspinal musculature requiring prolonged active contraction for maintenance of posture, resulting in pain from muscle fatigue.

This pain may continue long after the acute fracture has healed. Patients develop thoracic kyphosis and lumbar lordosis as vertebral height is lost.

Most patients will remember a specific injury as a cause; however, fractures may occur without any history of increased force on the spine. Lying in the supine position generally relieves some of the discomfort. Standing or walking exacerbates the pain

Physical examination will reveal:

• tenderness directly over the area of acute fracture,

• increased kyphosis may be noted.• In uncomplicated cases, straight leg

raising test will be negative and neurologic examination will be normal.

Radiological and laboratory investigations of VCFs

1) Plain radiographs: (AP/lat) show the classic wedge deformity. A decrease in vertebral height of 20 percent or more, or a decrease of at least 4 mm compared with baseline height is considered positive for compression fracture

2) Computed tomography (CT) and magnetic resonance imaging (MRI): CT can be helpful for identifying a fracture that is not well visualized on plain films. The MRI is recommended when patients have suspected spinal cord compression or other neurologic symptoms. The bone marrow signal on MRI can help identify an acute fracture and distinguish ages of compression fractures.

3) Bone density studies: Dual-energy X-ray absorptiometry (DEXA) scan is considered the gold standard for measuring the bone mineral density (BMD). Osteoporosis is diagnosed when the BMD is less than or equal to 2.5 standard deviations below the normal range of the age. The normal BMD is ≥ −1.0. Osteopenia is diagnosed when BMD is between −1.0 to −2.5.

Differential diagnosis of VCFs 1) VCFs due to osteoporosis, most common.(54) 2) Cancer-related fracture (e.g, myeloma). 3) Traumatic fracture. 4) Scheuermann’s disease. 5) Congenital abnormalities (e.g, scoliosis). 6) Spondylosis. 7) Tuberculous spondylitis. 8) Schmorl's nodes. 9) Degenerative disc disease. 10) Lumbar facet arthropathy. 11) Lumbar spondylolysis and spondylolisthesis.

Treatment of osteoporotic VCFs

1) Traditional treatment is nonoperative and conservative. Oral or parenteral analgesics may be administered. Calcitonin-salmon (Miacalcin) nasal spray can be used for treatment of osteoporotic VCFs.

2) Surgical treatment: Patients who do not respond to conservative treatment or who continue to have severe pain may be candidates for vertebroplasty, either open or percutaneous. Vertebroplasty is a procedure for reducing pain caused by a VCF that involves injection of an acrylic cement through a trocar into the body of the fractured vertebra for stabilization.

Open vertebroplasty including surgical wound and injection of the cement mixture (acrylic cement; polymethylmethacrylate, PMMA) was previously done for the treatment of osteoporotic VCFs

Percutaneous vertebroplasty (PV) is a minimally invasive technique which results in early appreciable pain relief and low complication rates and achieves the benefits of surgical vertebroplasty without the morbidity associated with such open procedure.

• The procedure was first performed in 1984 by Galibert and Deramond in the Department of Radiology of the University Hospital of Amiens, France. In the early 1990s, PV was introduced into the clinical practice in the United States at the University of Virginia. Since that time, PV has become a more commonly used method for treating vertebral lesions. Nowadays, PV is used for the treatment of painful vertebral lesions caused mainly by osteoporotic VCFs or due to metastatic vertebral deposits causing compression fractures.

MECHANISM OF PAIN RELIEF

The mechanism of pain relief is still unknown but it may be due to stabilization of the fractured bone fragments by PMMA or by the analgesic result from local chemical, vascular, or thermal effect of PMMA on nerve endings of surrounding tissues.

Contraindications of PV

Absolute contraindications: 1. Asymptomatic VCFs. 2. Patient improving on medical therapy. 3. Prophylaxis in osteoporotic patients. 4. Ongoing local or systemic infection. 5. Retropulsed bone fragment. 6. Spinal canal compromise secondary to

tumor. 7. Uncorrectable coagulopathy. 8. Previous known allergy to bone cement or

opacification agent

Relative contraindications:

1. Radiculopathy in excess of vertebral pain, caused by a compressive syndrome unrelated to vertebral collapse. Occasionally, preoperative PV can be performed before a spinal decompressive procedure.

2. Asymptomatic retropulsion of a fracture fragment causing significant spinal canal compromise.

3. Asymptomatic tumor extension into the epidural space.

Complications of PV

Mild complications:1. Temporary increase in pain following vertebroplasty is infrequently encountered.

2. Cement leakage into the disc during vertebroplasty although of no definite clinical consequence, has a theoretical increase in the risk of subsequent fractures of adjacent vertebral bodies. Therefore, it is advised to place the needle laterally and far from the center of the vertebra in a centrally located fracture.

3. A substantial number of patients with osteoporosis develop new fractures after the procedure; two-thirds of these new fractures occur in a vertebra adjacent to those previously treated.

Moderate complications

1. Infection is a risk in any percutaneous procedure. It is a complication that can be eliminated or minimized.

2. Extravasation of cement into the epidural or foraminal space is a rare complication. Most cases are clinically silent. Paraplegia may occur, due to cement-related spinal cord compression in only 0.4% of patients.

3. Needle traversing of the lamina instead of the pedicle can occur, especially in the thoracic vertebra, where the pedicle is smaller, and can lead to catastrophic complications

Severe complications

Severe complications are usually related to cement leakage into the paravertebral veins leading to pulmonary embolism, cardiac perforation, cerebral embolism, and even death. Paravertebral venous leak can be due to a combination of highly vascular lesions and liquid consistency of the cement.

Disc space leakage

CT showing a new fracture of T11 (arrow) in osteoporotic woman who had undergone percutaneous vertebroplasty

of T9 and T10, presenting with new severe back pain

Lateral fluoroscopic image during placement of an osteoplasty needle for vertebroplasty of T11 in osteoporotic man. Arrow shows an epidural leak

Post-procedural CT scan of the thoracic spine in old woman who underwent

vertebroplasty of T11. Arrow points to lamina puncture instead of pedicle

Candidates for PV1. Adult patients (30-85 years) with osteoporotic vertebral compression fractures with no neurological or radiological signs of spinal cord compression.2. Subacute or acute fractures less than one year old.3. The fracture is the prime generator responsible for the refractory pain.4. Pain resistant to any medical treatment.5. Focal tenderness at the fractured site.6. Patients with decreased bone mineral density (BMD) and T-score <-2.5.7. Collapsed vertebral body height from 30% up to 80%.8. Bone marrow edema on MRI.9. Patient with low serum calcium (< 9mg/dl).

MATERIALS

1) Collection of demographic data: age, sex….

2) Complete history-taking; Onset, duration and course of illness

3) Complete neurological examination: motor, sensory, reflexes…

4) Visual analogue scale (VAS): preoperatively, clinical assessment of pain severity using the Visual Analogue Scale (VAS) IS IMPORTANT. For. Postoperatively, the VAS must be measured measured at regular monthly interval for a total of 6 months.

Investigations for assessment of osteoporotic VCFs

1. Bone mineral density (BMD).

2. Plain X-ray of the spine.

3. Computed tomographic (CT) scan of the spine.

4. Magnetic resonance imaging (MRI) of the spine.

The percutaneous kit of vertebroplasty

Acrylic bone cement powder with the solvent

A high pressure torque needle with the stylet injecting bone cement mixture to

the spinal needles.

The spinal needles

How was PV accomplished

The procedure is performed using local anaethetic (Xylocaine). Several approaches and techniques are used to reach the body of the

vertebra in PV as transpedicular approach, intercostovertebral approach, and the parapedicular approach. The transpedicular approach is used for the thoracic and lumbar spine.

The transpedicular needle must be introduced up to the anterior third of the vertebral body. The cement mixture is then injected . Every turning motion delivers 0.5ml of the mixture.

The adequate consistency of the mixture for injection resembles toothpaste. The mixture must fill up to the posterior third of the vertebral body as seen on the lateral radioscopic projection. This represent 3-5ml.

Methylmetacrylate injection volumes as low as 2ml resulted in pain remission, bringing up the possibility that the exothermic reaction during polymerization may silence the free nerve endings.

How is the entry point determined for the transpedicular approach?

A simple method which is named the Curitiba method is used based on the study of reconstructed homographic images of the spine. In this method, the entry points are chosen under anteroposterior radiological guidance. The initial step is to draw, on the skin, a line corresponding to the sequence of spinal processes, so midline. A second line, passing through the centre of the pedicles, is drawn, parallel to the midline. The distance between the midline and the pedicular line is replicated laterally to find the horizontal coordinate of the entry point for the vertebroplasty. The vertical coordinate of the entry point is found under lateral radiological guidance.

Entry point detection

A diagram showing decreased VAS at each monthly interval compared to the previous one.

A diagram showing decreased VAS at each monthly interval compared to the

previous one.

ILLUSTRATED CASES

CASE 1: 70 years old lady patient complaining of back pain due to fracture L1 with BMD -4.2 (least encountered BMD) which indicates severe osteoporotic condition.

 

CASE 2: 65 years female patient complaining of back pain due to osteoporotic fracture of D12 with BMD -1.9 (osteopenic).

CASE 3: 61 years old lady patient complaining of back pain due to

osteoporotic fracture of D12 with BMD was -3.1.

CASE 4: 54 years male patient complaining of back pian due to fracture L2 with BMD -2.6.

CASE 5: 51 years female patient complaining of back pain due fracture L2 with BMD -2.9. Disc space leakage was encountered in this patient which was of no significance.

CASE 6: 72 years old female patient complaining ofback pain due to osteoporotic fracture of L2 with BMD -2.9. Disc space leakage was encountered in this case which was of no significance

CONCLUSION

• Percutaneous vertebroplasty is a safe and effective method for controlling pain associated with osteoporotic spine fractures when the conservative treatment fails.

• Percutaneous vertebroplasty does not treat the underlying cause of the fracture, an etiological investigation and causal treatments must be executed concomitantly.

RECOMMENDATIONS

• Percutaneous vertebroplasty (PV) is a minimally invasive technique which results in early appreciable pain relief and low complication rates and achieves the benefits of surgical vertebroplasty without the morbidity associated with such open procedure.

• The ideal amount for cement injected is 3-8 cc from the mixture. As low as 2 cc is enough to give strength to the fractured vertebra and alleviate pain.

• Osseuss venography is a new radiological investication that may be needed in order to avoid backward leakage of the cement to the spinal canal and to prevent pulmonary embolism.

 

Thank you