FormalPara Introduction and Core Messages

Vertebroplasty and kyphoplasty are described including indications, contraindications, surgical technique, and complications. Both vertebroplasty and kyphoplasty achieve good pain relief in appropriately selected patients with osteoporotic compression fractures and those with spinal metastases, multiple myeloma, and some traumatic fractures as discussed further in the chapter. The main technical point to remember is never to cross the projection of medial pedicle cortex in AP view before posterior vertebral wall has been reached in the lateral view.

1 Indications

  • Painful osteoporotic vertebral compression fractures (VCFs), which have failed conservative treatment or show unacceptable progressive collapse. Patients most likely to benefit have fractures that demonstrate bone marrow edema on MRI or radiotracer uptake on a nuclear medicine bone scintigram. Two recent randomized trials have concluded that they found no beneficial effect of vertebroplasty as compared with a sham procedure in patients with painful osteoporotic vertebral fractures [1, 2].

  • Vertebral metastases with painful pathological fractures unsuitable for curative resection. Patients with spinal metastases and multiple myeloma can be treated with vertebral augmentation, and a biopsy can be obtained at the same time [3].

  • Traumatic fractures

    Balloon kyphoplasty is principally suitable for treatment of vertebral fractures that have a localized fragmented zone within the spongiosa and a kyphotic deformity or for treatment of endplate impression fractures. These criteria are met by fractures of type A1.1 (endplate impression fracture), A1.2 (wedge fracture), and A3.1 (incomplete burst fracture) [1, 3,4,5,6,7] (see Fig. 62.1a–d). According to current knowledge, split fractures (A2), burst fractures (A3.2), and complete burst fractures (A3.3) are not suitable for balloon kyphoplasty, as the splitting component of these fractures cannot be stabilized by the augmentation. However, a complete burst fracture type A3.3 must be distinguished from an osteoporotic collapse of a vertebral body type A1.3 as the latter is suitable for balloon kyphoplasty, as the endplates are hardly fragmented or not fragmented at all, unlike in a complete burst fracture.

  • Vertebral hemangiomas

    VP is an effective treatment option in this category if the pain is the main presenting feature. It is not suitable for cases with neurological deficit [8]. VP can achieve pain relief as well as stabilization, reducing the risk of secondary vertebral collapse. This treatment must be reserved only in vertebral hemangiomas, which are symptomatic and resistant to common conservative treatments, with radiological evidence of aggressiveness and/or epidural extension [6].

Fig. 62.1
figure 1

Schematic drawing of various fracture types and the appropriate needle trajectories. (a) Endplate impression fracture A1.1. (b) Superior wedge fracture A1.2.1. (c) Inferior wedge fracture A1.2.3. (d) Vertebral body collapse A1.3. (e) Axial views of an incomplete burst fracture below the level of the pedicles (upper image) and at the level of the pedicles (lower image) demonstrating disruption of the posterior wall only at the level of the pedicles

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Balloon kyphoplasty (KP) is indicated if vertebral height restoration or cavity formation is the aim, for example, in correcting the kyphotic deformity associated with osteoporotic VCFs, or traumatic vertebral fractures as mentioned before in the indications section or for situations where cavity formation might help, for example, in difficult indications for tumourous lesions. In order to achieve this aim, procedure should be performed relatively early on after the fracture (literature recommending periods of under 3 weeks to under 3 months).

2 Contraindications

  • Coagulation disorders.

  • Patient unfit for general anesthetic or local anesthetic with sedation or unable to lie prone on the operating table for the duration of the procedure.

  • Pregnancy (relative contraindication).

  • Hypersensitivity to cement components.

  • Local infection.

  • Relative: pulmonary hypertension (exacerbation through fat embolism).

  • Neurological compromise through posterior wall fracture or tumor mass extension.

  • Precaution: posterior wall disruption (increased leakage rate).

  • Adequate preoperative imaging is also an essential prerequisite to do the procedure and if for some reason, the relevant landmarks cannot be visualized on AP and lateral imaging, then it is not possible to proceed.

3 Technical Prerequisites Planning, Preparation, and Positioning

Preoperative workup should include MR scan with STIR sequences (fat suppression sequences that identify edema) for proper identification of the painful vertebral level, and clinical and radiological correlation is required as the collapsed vertebra may not always be the source of the pain and the pathology may reside in another noncollapsed vertebra. A chest X-ray is essential as well to count the ribs when dealing with thoracic spine. Adequate imaging quality and proper positioning of the patient on the table is essential, and before draping the patient, one must ensure that appropriate landmarks can be seen on AP and lateral fluoroscopy. On AP image, pedicles should be seen to lie in the upper lateral quadrant of the vertebral body; spinous processes should lie midway between the pedicles, and both the endplates and the posterior wall must come to lie parallel (superimposed so that double image is eliminated) on the AP and lateral images. The procedure can be performed either under general anesthetic or with local anesthetic and sedation depending on patient’s/anesthetist’s/surgeon’s preference and anticipated duration of procedure. The patient is positioned prone on pillows on a radiolucent operating table. A single C-arm fluoroscopy is usually used, which can be easily switched between AP and lateral orientation, although some surgeons prefer biplanar imaging with two image intensifiers.

4 Surgical Technique

4.1 Vertebroplasty

  • After prepping and draping, under image intensifier in AP view, and after local anesthetic infiltration, transverse 1–2-cm stab incisions are made over the entry points, which, in the lumbar spine, is over the tip of the transverse process and, in the thoracic spine, for the extrapedicular approach, is immediately superior to the costal angle of the relevant rib [4] (see Fig. 62.2).

  • The entry point can be adjusted also based on the fact whether unilateral or bilateral approach is being done and how much convergence is required (in unilateral approach, more convergence is required and hence more lateral starting point on the skin).

  • Central placement of the needle usually results in sufficient cement distribution in the smaller vertebrae of the thoracic spine.

  • The vertebral body can be either directly penetrated by the Jamshidi needle or first Kirschner (K)-wires are placed into the relevant vertebral bodies and then Jamshidi needle can be passed over the K-wires.

  • The vertebrae can be accessed through transpedicular approach in lumbar spine and transcostovertebral approach in the thoracic spine [4].

  • Once K-wire is advanced 2–2.5 cm into the pedicle without breaching the medial cortex on the AP view, switch to lateral view to see if the posterior vertebral cortex has been penetrated.

  • If the needle/K-wire is in the vertebral body, then this can be advanced further and converged more at this stage. One must never breach the medial pedicle cortex on AP view without penetrating the posterior vertebral cortex on the lateral view. Jamshidi needles are then passed over the K-wires.

  • Once the surgeon is satisfied with the position of the Jamshidi needles, that lateral image is saved on the screen as a reference image (this helps identify leakages through comparing the current image with the reference image without cement).

  • Cement is mixed and, when of appropriate consistency, injected under live screening, (lateral view) watching for any leak either posteriorly into the spinal canal or anteriorly into the veins.

  • Note: We try not to exceed 20–30 mL of cement injection in one sitting because of the risk of fat embolism resulting in pulmonary hypertension. Close collaboration with the anesthetist is essential, and if the cardiorespiratory state is compromised, injection should stop. Also, if there is any leakage of cement into canal or vessels, injection should be aborted.

Fig. 62.2
figure 2

Drawing of the transcostovertebral placement of the bone biopsy needle with the tip just penetrating the lateral pedicle at its base. In the view from posterior (a), the needle passes above the transverse process and meets the pedicle at the craniolateral circumference. The lateral view (b) confirms the placement of the tip of the needle close to the base of the pedicle. In an axial view (c), the needle is seen to pass through the costovertebral gap, between the neck of the rib and the lateral pedicle circumference, toward the base of the pedicle (d) balloon inflated within the vertebral body

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4.2 Balloon Kyphoplasty

  • The relevant anatomy (pedicles, posterior vertebral wall, endplates, spinous processes, etc.) should be clearly identifiable on image intensifier before proceeding.

  • In KP, it is essential to place the balloon in an optimum position in the middle of the vertebral body to achieve best possible reduction of the fracture without injuring the lateral margins of the vertebral body.

  • The principles and tool introduction are similar to the technique for PV described earlier.

  • The K-wire is inserted first on AP view so that the needle tip appears to lie just outside the pedicle ring on AP view when bone contact is made. It is then advanced so that it does not breach the medial pedicle cortex on AP view until it penetrates the posterior vertebral wall on the lateral view.

  • On AP view, tip of the needle should not cross the midline. On lateral view, K-wire is advanced to the anterior third of the vertebral body.

  • Jamshidi needle is passed over the K-wire.

  • Bone biopsy can be taken with the biopsy bone filler, and a hand drill bit can be used to drill the area where the balloon is going to lie and smoothen the bone edges.

  • A special curette can be used as well; the angle at the tip can be changed to 30°, 60°, and 90°. Then, Jamshidi needle is withdrawn and working cannula passed over the K-wire, the tip of the cannula lying only about 3 mm ventral to the posterior wall of the vertebra (to give space for the balloon) (see Fig. 62.3).

  • Bilateral approach is used and balloons are then passed bilaterally so that they lie in the middle next to each other, making sure that both markings of the balloons should lie outside the working cannula (Fig. 62.3).

  • The balloons are then simultaneously inflated keeping an eye on the pressure and the volume of the balloon and also frequently checking with imaging.

  • The inflation of the balloons is continued until the maximum volume or maximum pressure is reached or the pressure keeps dropping indicating that further elevation of the endplate is not possible.

  • Cement is then mixed, and once of appropriate viscosity, balloons are deflated and removed and the cavity in the bone filled with bone cement using bone fillers through the working cannulae under live fluoroscopy.

  • The bone fillers and the working cannulae are removed once the cement is fully hardened and stab incisions are sutured.

  • Final AP and lateral images are obtained.

Fig. 62.3
figure 3

Lateral view of balloon kyphoplasty (a). The tip of the working cannula lying just within the posterior vertebral cortex (b), the K-wire and then the drill passed to the anterior third of the vertebral body where balloon is going to be sited (c). Balloon seen inflated and see the height restoration (d) cement being injected into the cavity created by the balloon

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5 Complications and Their Avoidance

Listing all the possible complications is beyond the scope of this chapter; however, few salient learning points are mentioned: Both PV and KP are deceptively “easy” techniques and should only be performed by properly trained surgeons who can also deal with complications, for example, able to do open surgery (decompression/stabilization), if needed.

Cement leakage: Cement should be viscous enough before injecting. Good-quality imaging is essential to recognize the leaks at the very early stage. In difficult cases where fluoroscopy is suboptimal, CT-guided procedure combined with fluoroscopy can be done. Cement with an adequate radiopacity must be used.

Pulmonary emboli: Both VP and KP procedures will expel a volume of marrow equal to that of the cement injected. Although this is asymptomatic in most patients, those with pre-existing pulmonary disease, for example, COPD, are particularly at risk and should be monitored accordingly. They should be informed of the high risk preoperatively and amount of cement injected in one sitting should be limited in such patients.

Disk space leaks: In case of large leaks into the disk space, consideration should be given to augmenting the adjacent vertebra or careful follow-up of this, as there has been some speculation that this leads to higher incidence of adjacent vertebral fracture.