Vertebroplasty: where do we go from here?

Percutaneous Vertebroplasty: A History of Procedure, Technology, Culture, Specialty, and Economics

Percutaneous vertebroplasty (VP) progressed from a virtually unknown procedure to one performed on hundreds of thousands of patients annually. The development of VP provides a historically exciting case study into a rapidly adopted procedure. VP was the synthesis of information gained from spinal biopsy developments, the inception of biomaterials used in medicine, and the unique health care climate in France during the 1980s. It was designed as a revolutionary technique to treat vertebral body fractures with minimal side effects and was rapidly adopted and marketed in the United States. The impact of percutaneous vertebroplasty on spine surgery was profound.

Percutaneous vertebroplasty for subacute and chronic painful osteoporotic vertebral compression fractures can safely be undertaken in the first year after the onset of symptoms

The optimal timing of percutaneous vertebroplasty as treatment for painful osteoporotic vertebral compression fractures (OVCFs) is still unclear. With the position of vertebroplasty having been challenged by recent placebo-controlled studies, appropriate timing gains importance. We investigated the relationship between the onset of symptoms - the time from fracture - and the efficacy of vertebroplasty in 115 patients with 216 painful subacute or chronic OVCFs (mean time from fracture 6.0 months (sd 2.9)). These patients were followed prospectively in the first post-operative year to assess the level of back pain and by means of health-related quality of life (HRQoL). We also investigated whether greater time from fracture resulted in a higher risk of complications or worse pre-operative condition, increased vertebral deformity or the development of nonunion of the fracture as demonstrated by the presence of an intravertebral cleft. It was found that there was an immediate and sustainable improvement in the level of back pain and HRQoL after vertebroplasty, which was independent of the time from fracture. Greater time from fracture was associated with neither worse pre-operative conditions nor increased vertebral deformity, nor with the presence of an intravertebral cleft. We conclude that vertebroplasty can be safely undertaken at an appropriate moment between two and 12 months following the onset of symptoms of an OVCF.

Signal-inducing bone cements for MRI-guided spinal cementoplasty: evaluation of contrast-agent-based polymethylmethacrylate cements

OBJECTIVE

The purpose of this work is to evaluate two signal-inducing bone cements for MRI-guided spinal cementoplasty.

MATERIALS AND METHODS

The bone cements were made of polymethylmethacrylate (PMMA, 5 ml monomeric, 12 g polymeric) and gadoterate meglumine as a contrast agent (CA, 0-40 μl) with either saline solution (NaCl, 2-4 ml) or hydroxyapatite bone substitute (HA, 2-4 ml). The cement's signal was assessed in an open 1-Tesla MR scanner, with T1W TSE and fast interventional T1W TSE pulse sequences, and the ideal amount of each component was determined. The compressive and bending strength for different amounts of NaCl and HA were evaluated.

RESULTS

The cement's MRI signal depended on the concentration of CA, the amount of NaCl or HA, and the pulse sequence. The signal peaks were recorded between 1 and 10 μl CA per ml NaCl or HA, and were higher in fast T1W TSE than in T1W TSE images. The NaCl-PMMA-CA cements had a greater MRI signal intensity and compressive strength; the HA-PMMA-CA cements had a superior bending strength.

CONCLUSIONS

Concerning the MR signal and biomechanical properties, these cements would permit MRI-guided cementoplasty. Due to its higher signal and greater compressive strength, the NaCl-PMMA-CA compound appears to be superior to the HA-PMMA-CA compound.