Patient Workup and Selection

Some osteoporotic fractures may generate only mild pain, or there may be a rapid decrease in the initially severe pain after VCF. In either of these situations, PV is not usually indicated. However, persistent pain that limits the activities of daily living or requires narcotic analgesics (with or without hospitalization) may be rapidly diminished with the use of PV. The time between fracture and therapy may be prolonged by failed attempts at conservative management or delayed referral. Patients with severe disability that requires hospitalization and parenteral analgesics should be treated immediately. There is no definite medical requirement for delay of therapy with PV if significant benefit to the patient is to be gained by its use. Some patients may present later with chronic, persistent pain and limitation of normal activity. There are no absolute exclusion criteria based on the time between fracture and PV. However, old fractures (>3 months) are less likely to have beneficial

Herniated Disc 11mm
Figure 14.1. (A) Extreme vertebral compression with the patient in expiration. The vertebral height at the point measured is 8 mm. (B) In inspiration the vertebral height increases to 11 mm. This motion is consistent with nonunion and usually associated with severe pain.

results from PV unless one can show signs of nonunion or signs of recurrent fracture (Figure 14.1). Nonunion is indicated by persistent motion noted on fluoroscopy and can signify osteonecrosis (Kummell's disease). Also the finding of persistent marrow edema on magnetic resonance imaging (MRI) scans (which may indicate new or recurrent fracture) is a good indication for PV.

Preoperative augmentation of vertebra prior to instrumentation and routine prophylactic use of PV are not validated for benefit or safety at this time, and these measures should be used with extreme caution under investigational protocols.

On physical examination, the patient's pain location should be consistent with the anatomical location of the fracture considered for treatment with PV. The patient's pain should not be radicular, since this suggests nerve root compression. However, it is not uncommon to have referred pain, and this should not be considered to be a contraindica-

tion to treatment (i.e., referred intercostal pain associated with a thoracic vertebral fracture or referred hip pain associated with a lower lumbar fracture). It is often helpful to place a metallic marker at the site of maximal pain and to correlate fluoroscopically the anatomical location of the pain and the compression fracture. It should be remembered that pain localization is limited to no better than plus or minus one vertebral level in most patients.

Simple clinical situations in which physical findings are well correlated with recent radiographic exams may be treated without the addition of complex studies such as MRI, computed tomography (CT), or nuclear medicine (Figure 14.2).

Patients with multiple fractures or nonfocal pain often pose diagnostic dilemmas and require a more complex imaging evaluation. These patients should have magnetic resonance imaging in addition to a recent, standard radiographic evaluation. Acute fractures will be easily demonstrated on T1-weighted sagittal images as having loss of signal in the affected vertebral marrow space (Figure 14.3). Also offering

Kummell Disease
Figure 14.2. Lateral radiograph showing a typical osteoporotic compression fracture (arrow). Compression is typically more in the anterior two thirds of the vertebra, with sparing of posterior wall height.
Bank Like Osteoporotic CompressionMri Lower Lumbar

Figure 14.3. Three sagittal views. (A) The T1-weighted MRI shows an acute vertebral compression (arrow) with low signal in the marrow space. Chronic (healed) compressions have normal (bright) marrow signal (stars). (B) The STIR MRI reveals high signal in the marrow space of the acutely fractured vertebra (arrow). (C) The T2-weighted MRI demonstrates a high signal zone below the superior endplate in a recently fractured vertebra (arrow). This is believed to represent a fluid-filled cleft. Filling of the cleft with cement is essential for pain relief.

c

high sensitivity for recent fracture and marrow edema (represented by an abnormal bright signal in the involved region) are short-tau inversion recovery (STIR) images with fat suppression. Images made with T2 weighting occasionally give additional information as these sequences can show fluid-filled clefts that can result after fracture. These findings are important because the clefts or spaces should be filled with cement for dependable pain relief.

On T1-weighted MRI sequences, normal marrow will exhibit high (bright) signal, including any vertebra that were previously compressed and have undergone healing. One should be reluctant to perform PV for pain based on MRI unless an acute fracture or persistent marrow abnormality can be demonstrated.

If MRI cannot be performed or leaves doubt with respect to the need for therapy, a nuclear medicine (NM) bone scan may be utilized. However, NM may not be as useful as MRI for primary screening because the former has poorer anatomical resolution [even when single-photon-emission computed tomography (SPECT) is used] and does not give information about conditions such as spinal stenosis, disc herniation, or tumor extension into the epidural space. Also, abnormal activity on a bone scan may persist long after healing has been demonstrated on MRI. A low-level positive NM scan may indicate only normal, progressive healing, which in turn might mislead a physician about the possible benefit of PV.36 However, there is a definite place for NM in patient evaluation. Some patients cannot tolerate MRI, and NM becomes the next best alternative. Rarely, information from the MRI will be insufficient to accurately localize an acute fracture. This usually happens in a very heterogeneous marrow (which may be found as a normal variation in the elderly or with conditions such as myeloma). Then, NM will usually add sufficient information to identify an acute fracture or determine the need for treatment (Figure 14.4).

Computed tomography offers anatomical information (as do standard radiographs) but is unable to distinguish acute from chronic fractures under most circumstances. Therefore CT is not part of the routine initial patient workup. It may be very helpful to evaluate the cause of complications that are possible after PV, such as a cement leak outside the vertebral body. This mode of diagnosis should be used immediately if symptoms worsen or new symptoms present after PV.

The degree of compression does not correlate with the quantity of local pain. Minimal compressions, as measured radiographically, may cause incapacitating pain to some individuals. Even with minimal deformity, acute fractures are easily identified on MRI because they demonstrate local marrow edema. MRI may also show more than one acute compression injury (Figure 14.5). This finding will indicate a need for therapy at each of the involved and painful levels. As the amount of compression increases, the degree of technical difficulty of performing the PV may increase as well. This is particularily true when

Figure 14.4. Nuclear medicine bone scan showing increased uptake at T12 (arrow) resulting from an osteoporotic compression fracture.

Figure 14.4. Nuclear medicine bone scan showing increased uptake at T12 (arrow) resulting from an osteoporotic compression fracture.

T12 Fracture Vertebral BodyMicro Fractures Vertebral Body Mri

the compression exceeds 70%. With complete or nearly complete vertebral collapse, the likelihood of successful PV is reduced but not eliminated.37,38 Before one attempts PV in a nearly complete collapse, one should obtain an MRI indicating no additional cause of pain. The same MRI should be evaluated to identify residual vertebral marrow space laterally. Often, severe collapse is greatest centrally and will show residual marrow space laterally that can be successfully treated with PV (Figure 14.6). Patients with these lesions should be made aware that there may be a reduced chance of pain relief (in comparison to a modestly compressed vertebral fracture) and higher risk of complication.

Although PV has been shown to be very durable, on rare occasions one may see a refracture with progressive height loss after PV. This

Acute Vertebral Fracture The Mri
Figure 14.5. Sagittal T1-weighted MRI revealing two acute fractures (arrows) at different locations in the spine.
Mri Stir Osteoporotic Fracture Spine

Figure 14.6. (A) Sagittal T1-weighted MRI (midline) reveals extreme compression of the center of the L1 vertebral body (arrow). (B) Images along the lateral edge of L1 reveal less compression and more residual marrow space, which can accept bone cement (arrow).

Figure 14.6. (A) Sagittal T1-weighted MRI (midline) reveals extreme compression of the center of the L1 vertebral body (arrow). (B) Images along the lateral edge of L1 reveal less compression and more residual marrow space, which can accept bone cement (arrow).

usually occurs when the patient had had a less than optimum fill during an initial treatment (even with good initial pain relief) or in the situation of an extremely fragile vertebra. In either case, the amount of cement introduced probably was not sufficient to restore adequate strength to resist recurrent compression. Pain relief and cement filling are poorly correlated. Recurrence of pain, marrow edema, and additional vertebral collapse may indicate the rare need for repeat treatment.

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