SpineUniverse Case Study Library

PMMA Extravasation Following Kyphoplasty


The patient is a 72-year-old female who underwent kyphoplasty to treat a T12 burst fracture two weeks ago at a different hospital. After the kyphoplasty procedure, her back pain increased and a new symptom of lower extremity weakness, right greater than left developed. She also lost bowel and bladder function. While postoperative imaging was performed, she was ultimately transferred to a rehabilitation center. While in rehab, her pain persisted, and she did not seem to be making any functional gains. Her daughters, therefore, requested she be transferred to our referral hospital.

She presents at our hospital with intractable back pain and dense R>L lower extremity weakness.  Her proximal limb girdle muscles, including her iliopsoas, quads and adductors are 1/5 on the right and 2/5 on the left.  Her distal extremity strength, including her hip abductors as well has her gastrosoleus and tibialis anterior are 3/5 on right and 4/5 on the left.  Her lower extremity sensation is preserved, including the perineum. She exhibits weak, voluntary anal sphincter contraction. Her vascular exam is intact.

The patient’s medical history includes osteoporosis, chronic obstructive pulmonary disease, coronary artery disease, and steroid-dependent rheumatoid arthritis.

Pretreatment Imaging

A lateral thoracic CT scan with contrast shows a T12 kyphoplasty with PMMA extravasation into the spinal canal (Figure 1).

Preoperative lateral CT scan with contrastFigure 1. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com.

Axial images demonstrate the extent of the extravasation of PMMA; Figures 2-4 below.

Axial CT scan of T12 with extravasation of PMMAFigure 2. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com.

Axial CT scan of T12 with extravasation of PMMAFigure 3. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com.

Axial CT scan of T12 with extravasation of PMMAFigure 4. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com.


T12 osteoporotic burst fracture, status post T12 kyphoplasty with PMMA extravasation into the spinal canal, incomplete spinal cord injury, spinal stenosis at T11-T12, T12-L1.

Suggest Treatment

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Selected Treatment

  • Open reduction and internal fixation of the T12 burst fracture
  • Pediculo-facetectomy; T12, right
  • Thoracolumbar laminectomies: T10-T11, T11-T12, T12-L1
  • Posterior thoracolumbar fusion: T9-L2
  • Posterior segmental thoracolumbar instrumentation: T9-L2
  • Vertebroplasties at T9, T10, and L2

Given the cranio-caudal extent of the PMMA extravasation, laminectomies to normal dura at the T10-T11 and T12-L1 interspaces was planned. Given the patient’s osteoporosis and the plan for resection of the right T12 pedicle and T11-T12 facet, an instrumented fusion from T9 to L2 was planned. We augmented the pedicle screw tracts at T9, T10 and L2 with PMMA. This was done by preparing the pedicle for screw placement using a Lenke probe. A ball tipped feeler was used to ensure cortical integrity. We placed pedicle markers and assessed their positions fluoroscopically.  Next, the markers were removed, and we tapped the screw tracts. Bone void fillers were placed into the vertebral bodies. PMMA was placed under live image intensification guidance. Immediately thereafter, the screws were placed.

Initially, placement of a short screw into the left T12 pedicle was considered but ultimately the cement mantle prevented a screw much longer than 15 mm, so this was abandoned.

Laminotomies were performed at T10-T11 and T12-L1.  Then an en bloc laminectomy was performed over the intervening laminae by creating bilateral troughs with a high speed burr. The troughs were completed with a micro Kerrison.

The right T11-T12 facet was removed in its entirety by extending the laminectomy through the lateral pars above and below the facet. The remaining, lateral portion of the right T12 pedicle was skeletonized and burred flush with the vertebral body. At this point, the PMMA was essentially free of the posterior elements and attached only anteriorly, just medial to the stump of the T12 pedicle.

Intraoperative picture of the thoacic spine with PMMA extravasationFigure 5. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com. With the pedicle removed laterally, it was possible to break the PMMA away from the dura in a lateral and right posterior direction. There was some adhesion of the PMMA to the dura laterally, but no frank durotomy was encountered. The dura was thin and was ultimately augmented with DuraSeal.

Intraoperative picture of the thoacic spine following removal of PMMAFigure 6. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com. Figure 7 pictures the pieces and fragments of PMMA removed.

PMMA fragments removed from the thoracic spinal cordFigure 7. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com.

Intraoperative screw placement, T9, T12, L2Figure 8: T9 is top left, L2 bottom left, and T12 on right top and bottom. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com. We had discussed bone grafting options with the patient preoperatively. Given her medical issues and poor bone quality, autogenous graft harvest from the iliac crest was not advised. We were concerned that she would be at heightened risk for screw loosening and implant failure. We therefore employed local bone from the decompression to which 1 gm of vancomycin powder had been added. This bone graft was augmented with rh-BMP2 and allograft (MagniFuse).

Intraoperative CT scans of screw and rod placementsFigure 9: Intraoperative imaging. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com.

Postoperative lateral and PA x-raysFigure 10: Postoperative lateral and posterolateral x-rays. Image courtesy of Eeric Truumees, MD, and SpineUniverse.com. Although the patient's lower extremity MEP responses were poor (as predicted by the patient's weakness), they (and the SSEPs) were stable during surgery.

The patient was in the operating room for 105 minutes. Blood loss was 50 cc. There were no complications.


Given her medical issues, the patient spent her first postoperative night in the ICU, but she recovered from anesthesia well. She spent an additional 4 nights in the hospital followed by transfer back to the rehab center. Interestingly, her pain was under better control compared with preop by the second postoperative day. Her left leg weakness also improved fairly quickly. We placed her in a limited contact brace, which we plan to continue for 8-12 weeks.

At the time of discharge, her proximal limb girdle muscles, including her iliopsoas, quads and adductors are 2/5 on the right and 4/5 on the left. Her distal extremity strength, including her hip abductors as well has her gastrosoleus and tibialis anterior are 3/5 on right and 5-/5 on the left.

She was seen in the office just over one month from the procedure. In the interval, she had continued to do well symptomatically with marked improvement in pain and function. Her bowel function normalized, but, as of this writing, she continues to experience daily (though not complete) bladder incontinence.

Her current proximal limb girdle muscles, including her iliopsoas, quads and adductors are 3-/5 on the right and 4+/5 on the left.  Her distal extremity strength, including her hip abductors as well has her gastrosoleus and tibialis anterior are 4+/5 on right and 5-/5 on the left. Her recovery has been challenged by a UTI and bouts of confusion, one of which led to a 2 day hospital readmission, at which time a postoperative thoracic spine CT was obtained.

Case Discussion

The case presented should be considered a "never event". This unfortunate individual with multiple medical comorbidities underwent a vertebral augmentation procedure with extensive cement extravasation into the spinal canal. The intraoperative extravasation of cement is directly related to the initial practitioner not recognizing the leak on fluoroscopic images while the cement was being deposited, or simply not using fluoroscopy during the placement of the cement.

In addition, one can surmise that the postoperative symptoms were either ignored or not recognized, which resulted in a substantial delay of treatment. Dr. Truumees immediately recognized and investigated the issues, and initiated the most appropriate and least invasive method of addressing all the surgical variables, which included an elderly individual with severe osteoporosis and neurological compromise. Even with a delayed decompression and reconstruction he reports that this patient is making a recovery.

The only additional question in this case would be a consideration of prophylactic cement augmentation of the levels above and below the instrumentation and fusion. I would maintain that this individual is at high risk for proximal and distal junctional kyphotic failure, and as such prophylactic adjacent level cement augmentation may provide added benefit.

The lessons from this case include; 1) the importance of intraoperative fluoroscopy during any vertebral augmentation procedure, 2) the importance of proper history, examination and investigation if the expected outcome is not be realized after an intervention, and 3) even with a delayed decompression, there is still an opportunity for neurological recovery.

Community Case Discussion (3 comments)

SpineUniverse invites spine professionals to share their thoughts on this case.

This is a catastrophic event that highlights the risk of using PAIN as a diagnosis. Pain is a symptom not a diagnosis. Unfortunately, many "pain specialists" appear to not be very curious as to etiology. I recently treated a lady who became paraplegic 3 months after a lumbar discectomy. She was referred for a baclofen pump, 5 years after the event. No one had studied her with any diagnostic over this 5 years. She harbored a thoracic disc herniation that occupied 70+% of her thoracic canal. Unfortunately she did not improve after its removal . Fortunately she in no longer being thrown out of her wheelchair by her spastic paraplegia after Baclofen pump.
I think it is imperative that spine surgeons open a dialog with our pain colleagues to help in establishing real diagnoses not just symptoms.

It is clear from figure 4, that the original surgeon did not establish appropriate transpedicular kyphoplasty port. One can clearly see the path of that port as it traversed the right lateral corner of the spinal canal. Even though, standard technique that was taught at Kyphon training many years ago was to establish transpedicular port, in the thoracic spine, given the small size of the pedicles and vertical orientation of the pedicles in the axial plane, establishing the correct oblique trajectory for the working port is both difficult and unsafe. Of more than 100 kyphoplasties that I have performed both in the thoracic and lumbar spine, establishing traditional (vertebroplasty) extrapedicular port is safer and much easier, especially in the thoracic spine. The surgeon who performed this case most likely did not have simultaneous presence of 2 C-Arms to have biplanar simultaneous flouroscopic visualization that would allow triangulation and establishment of appropriate trajectory for the working port.

Once the port has been established along the anterior midline portion of the vertebral body and the balloon is inflated to create the void, PMMA should only be injected once it has become fairly viscous, more so in burst fractures. Following injection of PMMA, the port, along with the bone filler device (BFD) should be left in place until the PMMA is nearly fully polymerized. Only then should the BFD be removed along with the port, to prevent any PMMA extravasation.

As unfortunate as the care was that this patient received from the original surgeon , it is equally impressive how proficiently and appropriately Dr. Truumees addressed this complication. I fully concur with his surgical treatment.

Thank you Dr Trummees for sharing this case. Not being a surgeon, I won't comment on the appropriateness of the decision to add multilevel fusion to a laminectomy with removal of PMMA. But I would very much appreciate hearing from the surgeons (both neuro- and orthopedic-), as the survey results suggest that 57% of orthopedic surgeons agreed with decision to include multilevel fusion and only 36% agreed with laminectomy/PMMA removal, while more than 53% of the neurosurgeons felt that laminectomy with PMMA removal would suffice, and only 33% agreeing with added multilevel fusion. I would ask the surgeons to help us non-surgeons with the evidence for and against each approach.


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