Case 5
Extreme Vertebral Collapse
John M. Mathis
267
Clinical Presentation
A 97-year-old woman presented with new, severe pain in her back around the T12 level. She had experienced compression fractures before but had never had vertebroplasty. She had mild age-related medical problems and was ambulatory with minimal assistance before this injury. Her pain was focal and without radicular symptoms. The pain was worse with standing and bending. She did not tolerate strong analgesics and therefore was made basically immobile by the new problem.
Imaging Findings
A magnetic resonance image (MRI) was obtained that revealed old compression fractures at L2 and L5. Acute compression fractures were present at T11 and L1 (Case Figure 5.1A). The T11 compression was about 25% and was typical. The L1 compression showed severe loss of height estimated at 75% to 80%. The central portion of the vertebra was almost completely collapsed, and the lateral aspects had some more residual space for needle and cement placement (Case Figure 5.1B). A small amount of central bright signal on T2 suggested that there was a small central cavity (Case Figure 5.1C).
Procedure
The patient received intravenous antibiotics and procedural sedation.
The T11 vertebra was treated in the usual fashion with a bipedicular approach and cement reinforcement.
The L1 vertebra was approached in the same manner, but here it was technically harder to get adequate needle positioning. The lower edge of the pedicle was positioned over the residual vertebral body (Case Figure 5.2; see also Figure 2.17C). The needle entry site was through
Case Figure 5.1 (A)A lateral T1-weighted MRI demonstrates old fractures of L2 and L5. The L1 vertebra is almost completely collapsed in the midline, with buckling of the posterior wall. (B) A more lateral MRI image demonstrates more residual height to the L1 vertebra (white arrows), which allows room for needle introduction. (C) A T2-weighted MRI image shows a small amount of bright signal in the central part of the vertebra (white arrows). This indicates a small cleft or cavity.
A
B C
Lateral Slight oblique AP projection
AP oblique Mild fracture
Severe compression fracture
A
A B
B
C
Case Figure 5.2. (A)An anteroposterior oblique image with the needle in place on the right. The left pedicle is highlighted (white oval). It is larger than the residual height of the vertebra. The inferior margin was positioned over the vertebra and the needle placed through the inferior pedicle (black arrow indicated the region of interest), but on the opposite side. (B) Artist’s sketch of the angle that must be maintained for proper needle positioning in a very collapsed vertebra. A more cephalad-to- caudad angle works with minimal compression. As compression increases, a needle angle parallel to the vertebral endplates is necessary to gain access to the anterior part of the body. (C) Lateral radi- ograph showing the needles in place. The black arrows mark the inferior and superior pedicle margins.
Note the flat or horizontal needle trajectory.
this inferior portion of the pedicle, with care taken to ensure that the trajectory of the needle would allow access to the anterior vertebra once inserted. This usually dictates that the needle trajectory be horizon- tal or parallel to the residual vertebral endplates. Two needles were placed. Polymethylmethacrylate was injected, and a small cavity in the center of the vertebra filled more than the lateral aspects (Case Figure 5.3). A very small amount of cement (approximately 1 cc) was needed for this fill. There were no complications.
Results
The patient tolerated the procedure well, and there was an uneventful recovery. Pain relief was near total within 6 hours, and the patient was able to ambulate in her room with assistance on the day of the proce- dure. She returned to her usual daily routine within 48 hours.
Discussion
This case deals with the technical difficulties faced when a vertebra is almost completely collapsed. Because of the extreme loss of height, it is usually not possible to perform kyphoplasty on such a vertebra. Just placing 13-gauge needles can be technically challenging, as it was here.
It is common to find some sparing of vertebral height laterally even when there is extreme and near total collapse centrally. That was the case here. The pedicle height may be larger than the residual height of the vertebral body. A high position on the pedicle will usually make the entry angle too steep to allow the tip of the needle to reach the ante- rior part of the vertebral body (Case Figure 5.2B; see also Figure 2.17C).
Cement would then have to be injected too far posterior in the verte- Case Figure 5.3. Anteroposterior (A) and lateral (B) radiographs show filling achieved postprocedure.
The majority of the cement went into the central cleft.
A B
bra to be safe (easy leak into the epidural space). Taking a low position through the pedicle (with this part of the pedicle first lined up over the residual portion of the vertebral body) provides the trajectory to allow the needle tip to reach the anterior vertebra, as it did in this case (Case Figure 5.2C). Two needles are usually needed because the extreme central collapse will often not allow cement to cross from side to side during filling. Only a small volume of cement is needed to adequately reinforce this type of fracture.
These cases are technically difficult, and the results from percu- taneous vertebroplasty may not be as good as for less compressed vertebra. However, very compressed vertebra can respond to percutaneous vertebroplasty, and they should be treated when possible.
