Adverse prognostic factors and optimal intervention time for kyphoplasty/vertebroplasty in osteoporotic fractures

Effect of cement volume on biomechanical response of a spine segment treated with a PEEK polymer implant: a finite element comparative study with vertebroplasty

In the current study, a 3D finite element study was performed to investigate the biomechanical response of an osteoporotic spine segment treated with a novel transpedicular implant (V-STRUT©, Hyprevention, France) made of PEEK (polyetheretherketone) material combined with either injections of 2, 3, 4, 5 and 6 cc of cement. The objective was to assess numerically the biomechanical performance of the implant in combination with different doses of the injected bone cement and to compare its performance with the gold standard vertebroplasty (VP) technique. A female (69 yo) was selected and a 3D finite element model of an osteoporotic spine segment was built based on a Computed Tomography (CT) scan performed from T12 to L2 with corresponding intervertebral discs and ligaments. A heterogeneous distribution of bone material properties was assigned to the bone using grey scale levels. Bilateral ellipsoid geometries of the inserted cement were retained for the V-STRUT and VP models based on experimental observation performed on different patients treated with the V-STRUT device. The current study demonstrated an optimal dose of 4 cc of bilaterally injected cement for the V-STRUT and VP techniques to restore the treated segment and confirmed that the V-STRUT device in combination with bone cement is superior to VP alone in establishing the normal stiffness and in reducing the applied stress to the immediately adjacent vertebral levels.

The role of Vertebral Augmentation Procedures in the management of vertebral compression fractures secondary to multiple myeloma

Multiple myeloma (MM) is a systemic disorder characterised by proliferation of B-lymphocytes and plasma cells in the bone marrow. The primary aims of the management of spinal lesions in MM are pain control and fracture stabilisation. Vertebral augmentation procedures (VAP) can be subdivided into percutaneous vertebroplasty (VP) and balloon kyphoplasty (BKP). BKP involves the placement of orthopaedic balloons into the fractured vertebral body, creating a void into which polymethylmethacrylate bone cement is injected. This review outlines the management of spinal lesions in patients with MM, with a focus on the comparative risks and efficacy of vertebroplasty (VP) and balloon kyphoplasty (BKP). Soft tissue masses in MM are highly radiosensitive. Bisphosphonates and newer oncological therapies have decreased the indications for palliative radiotherapy, while spinal bracing can be utilised in selected cases to provide stability. BKP and VP provide equivalent long term pain control after MM vertebral compression fractures (VCF). BKP is superior to non-operative management and VP for restoration of vertebral body height and prevention of segmental kyphosis. Current evidence suggests a greater degree of correction of kyphotic deformity and restoration of mid vertebral height (MVH) with BKP when compared with VP. The literature supports the use of BKP even in the presence of posterior vertebral body wall (PVBW) fractures, a group previously considered a contraindication to VAP. Superior functional outcomes have been reported in patients undergoing early versus delayed BKP (<6-8 weeks). Current evidence supports a lower risk of cement extrusion with BKP than with VP, but serious complications following VAP are rare. MM spinal pathology should be managed in a multidisciplinary setting. Surgical decompression and instrumentation are rarely indicated, due to the radio-sensitivity of soft tissue lesions in MM. BKP is a safe and effective procedure for VCF secondary to MM.

Early cement augmentation may be a good treatment option for pain relief for osteoporotic compression fractures: a systematic review and meta-analysis

PURPOSE

The incidence of osteoporotic compression fractures (VCFs) have been rising over the past decades. Presently, vertebral cement augmentation procedures such as balloon kyphoplasty and vertebroplasty are common treatments allowing pain relief and functional recovery. However, there is controversy on whether different timeframes for cement augmentation affects clinical outcomes. Hence, this study aimed to compare pain relief and complication rates between early versus late cement augmentation.

METHODS

A comprehensive systematic review of PubMed, EMBASE, Scopus and Cochrane Library was conducted, identifying studies that compared early versus late cement augmentation for VCFs. As the definitions of "early" and "late" phases across studies are heterogenous, we established the cut-off between early and late phase as intervals to accommodate as many studies as possible for analysis. We conducted two separate analyses with different cut-off intervals and included studies that reported interventions within these respective time intervals. In analysis 1, we included studies which grouped patients into "early" and "late" group based on a cut-off time frame of 2-4 weeks. On the other hand, in analysis 2, we included studies which grouped patients into "early" and "late" groups based on a cut-off time frame of 6-8 weeks. Meta-analysis was conducted via random-effect models, comparing outcomes of interest between early and late groups.

RESULTS

Eleven studies were included. The total cohort size was 712 and 775 patients in analysis 1 and 2 respectively. Mean follow-up was 12.9 ± 3.7 months and 11 ± 0.6 months respectively. VAS change at final follow-up was significantly greater in the early group for both analyses. (MD = - 0.66, p = 0.01; and MD = - 1.18, p < 0.005 respectively). There was no significant difference in post-operative absolute VAS score, number of cement leakage, number of adjacent compression fractures and local kyphotic angle, for both analyses. Patients in both groups experienced reductions in VAS score that exceeded the minimum clinically important difference.

CONCLUSION

Both early and late timeframes for cement augmentation offered significant improvement in pain relief, with similar post-operative absolute pain score, kyphotic angle, cement leakage and adjacent vertebral fractures. Early surgery may offer substantial pain relief in patients presenting with pain as early as < 2-4 weeks of VCFs.

Effect of a new transpedicular vertebral device for the treatment or prevention of vertebral compression fractures: A finite element study

BACKGROUND

A finite element study was performed to investigate the biomechanical performance of a novel transpedicular implant (V-STRUT©, Hyprevention, France) made of PEEK (polyetheretherketone) material in terms of strengthening the osteoporotic vertebra and the thoraco-lumbar spine. The objective was to assess numerically the efficacy of the implant to reduce the stress distribution within bone and absorb part of the stress by the implant thanks to its optimized material selection close to that of normal bone.

METHODS

A numerical model was generated based on a scan of an osteoporotic patient. The model is composed of three consecutive vertebrae and intervertebral discs. A heterogeneous distribution of bone material properties was assigned to the bone. In order to investigate the rationale of the device material selection, three FE models were developed (i) without the device to serve a reference model, (ii) with device made in Titanium material and (iii) with device made in PEEK material. Stiffness and stress distribution within the spine segment were computed and compared in order to assess the implants' performances.

FINDINGS

The results obtained by the simulations indicated that the novel transpedicular implant made of PEEK material provided support to the superior vertebral endplate, restored the thoraco-lumbar spine segment stiffness and reduced the stress applied to the vertebrae under the compressive load.

INTERPRETATION

Implant geometry in combination with its material properties are very important factors to restore vertebral strength and stiffness and limiting the risk of fracture at the same vertebra or adjacent ones.

The role of cement augmentation with percutaneous vertebroplasty and balloon kyphoplasty for the treatment of vertebral compression fractures in multiple myeloma: a consensus statement from the International Myeloma Working Group (IMWG)

Multiple myeloma (MM) represents approximately 15% of haematological malignancies and most of the patients present with bone involvement. Focal or diffuse spinal osteolysis may result in significant morbidity by causing painful progressive vertebral compression fractures (VCFs) and deformities. Advances in the systemic treatment of myeloma have achieved high response rates and prolonged the survival significantly. Early diagnosis and management of skeletal events contribute to improving the prognosis and quality of life of MM patients. The management of patients with significant pain due to VCFs in the acute phase is not standardised. While some patients are successfully treated conservatively, and pain relief is achieved within a few weeks, a large percentage has disabling pain and morbidity and hence they are considered for surgical intervention. Balloon kyphoplasty and percutaneous vertebroplasty are minimally invasive procedures which have been shown to relieve pain and restore function. Despite increasing positive evidence for the use of these procedures, the indications, timing, efficacy, safety and their role in the treatment algorithm of myeloma spinal disease are yet to be elucidated. This paper reports an update of the consensus statement from the International Myeloma Working Group on the role of cement augmentation in myeloma patients with VCFs.

Is early vertebroplasty/kyphoplasty justified in multiple myeloma given the rapid vertebral fracture progression?

Xiao R, Miller JA, Margetis K, et al. Radiographic progression of vertebral fractures in patients with multiple myeloma. Spine J 2016:16:822-32 (in this issue).

Controversial issues in kyphoplasty and vertebroplasty in osteoporotic vertebral fractures

Kyphoplasty (KP) and vertebroplasty (VP) have been successfully employed for many years for the treatment of osteoporotic vertebral fractures. The purpose of this review is to resolve the controversial issues raised by the two randomized trials that claimed no difference between VP and SHAM procedure. In particular we compare nonsurgical management (NSM) and KP and VP, in terms of clinical parameters (pain, disability, quality of life, and new fractures), cost-effectiveness, radiological variables (kyphosis correction and vertebral height restoration), and VP versus KP for cement extravasation and complications profile. Cement types and optimal filling are analyzed and technological innovations are presented. Finally unipedicular/bipedicular techniques are compared. Conclusion. VP and KP are superior to NSM in clinical and radiological parameters and probably more cost-effective. KP is superior to VP in sagittal balance improvement and cement leaking. Complications are rare but serious adverse events have been described, so caution should be exerted. Unilateral procedures should be pursued whenever feasible. Upcoming randomized trials (CEEP, OSTEO-6, STIC-2, and VERTOS IV) will provide the missing link.