Posterior vertebral arch cement augmentation (spinoplasty) to prevent fracture of spinous processes after interspinous spacer implant

Augmentation in fragility fractures, bone of contention: a systematic review

BACKGROUND

Osteoporosis is a complex multifactorial disease characterized by reduced bone mass and microarchitectural deterioration of bone tissue linked to an increase of fracture risk. Fragility fractures occur in osteoporotic subjects due to low-energy trauma. Osteoporotic patients are a challenge regarding the correct surgical planning, as it can include fixation augmentation techniques to reach a more stable anchorage of the implant, possibly lowering re-intervention rate and in-hospital stay.

METHODS

The PubMed database and the Google Scholar search engine were used to identify articles on all augmentation techniques and their association with fragility fractures until January 2022. In total, we selected 40 articles that included studies focusing on humerus, hip, spine, and tibia.

RESULTS

Literature review showed a quantity of materials that can be used for reconstruction of bone defects in fragility fractures in different anatomic locations, with good results over the stability and strength of the implant anchorage, when compared to non-augmented fractures.

CONCLUSION

Nowadays there are no recommendations and no consensus about the use of augmentation techniques in osteoporotic fractures. Our literature review points at implementing the use of bone augmentation techniques with a specific indication for elderly patients with comminuted fractures and poor bone quality.

Clinical and radiological outcomes following insertion of a novel removable percutaneous interspinous process spacer: an initial experience

PURPOSE

To evaluate clinical and radiological outcomes of a series of patients treated with a removable percutaneous interspinous process spacer (IPS) (LobsterProject® Techlamed®) for symptomatic degenerative lumbar spinal stenosis (DLSS).

METHODS

All patients treated in two centres with this IPS during 2019 were retrospectively reviewed. Procedures were performed under deep sedation or general anaesthesia by two interventional radiologists. Patients were clinically evaluated before intervention and at 3-month follow-up with Visual Analog Scales for pain (VAS), Oswestry Disability Index (ODI) and radiologically with MRI or CT scans. Neural foramina were independently measured for each patient on pre- and post-procedural CT scans by two radiologists.

RESULTS

Fifty-nine patients were treated in the selected period of which fifty-eight had complete documentation (mean age 71.2 ± 9.2 years [55-92], 32 males, 26 females). Forty-eight interventions were performed under deep sedation and ten under general anaesthesia, without procedural complications. Clinical follow-up at 3 months showed a significant reduction of pain (VAS from 83 ± 9 to 29 ± 19, - 65%; p < 0.001) and an improvement in functional outcomes (ODI from 31 ± 12 to 13 ± 10%, - 58%; p < 0.001). There was one case of unsatisfactory positioning post procedure, two cases of posterior migration at 3-month follow-up and one case of spinous process fracture. Mean neural foramina area increased from 77 ± 23 to 95 ± 27 mm² (+ 26%; p < 0.001) with very good inter-observer reliability (Cronbach's alpha = 0.899).

CONCLUSION

Percutaneous minimally invasive insertion of a removable IPS device demonstrates a favourable safety profile, good clinical outcomes at 3 months, and apparent anatomical increase in foraminal dimensions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05203666-Release Date: 21^st January 2022, retrospectively registered.

The use of minimally invasive interspinous process devices for the treatment of lumbar canal stenosis: a narrative literature review

Minimally invasive interspinous process devices (IPD), including interspinous distraction devices (IDD) and interspinous stabilizers (ISS), are increasingly utilized for treating symptomatic lumbar canal stenosis (LCS). There is ongoing debate around their efficacy and safety over traditional decompression techniques with and without interbody fusion (IF). This study presents a comprehensive review of IPD and investigates if: (I) minimally invasive IDD can effectively substitute direct neural decompression and (II) ISS are appropriate substitutes for fusion after decompression. Articles published up to 22^nd January 2020 were obtained from PubMed search. Relevant articles published in the English language were selected and critically reviewed. Observational studies across different IPD brands consistently show significant improvements in clinical outcomes and patient satisfaction at short-term follow-up. Compared to non-operative treatment, mini-open IDD was had significantly greater quality of life and clinical outcome improvements at 2-year follow-up. Compared to open decompression, mini-open IDD had similar clinical outcomes, but associated with higher complications, reoperation risks and costs. Compared to open decompression with concurrent IF, ISS had comparable clinical outcomes with reduced operative time, blood loss, length of stay and adjacent segment mobility. Mini-open IDD had better outcomes over non-operative treatment in mild-moderate LCS at 2-year follow-up, but had similar outcomes with higher risk of re-operations than open decompression. ISS with open decompression may be a suitable alternative to decompression and IF for stable grade 1 spondylolisthesis and central stenosis. To further characterize this procedure, future studies should focus on examining enhanced new generation IPD devices, longer-term follow-up and careful patient selection.

Doughnut vertebroplasty for circumferential aggressive vertebral hemangiomas

BACKGROUND

To assess the feasibility, safety and efficacy of a percutaneous doughnut vertebroplasty of circumferential aggressive vertebral hemangiomas (VHs).

METHODS

We retrospectively reviewed our prospectively collected database of patients with VHs treated with vertebroplasty between January 2009 and January 2018. Patient demographics, clinical presentations and procedural details were recorded. All patients underwent preoperative computed tomography (CT) and magnetic resonance imaging (MRI). All vertebroplasties were performed under conscious sedation in the prone position, predominantly using biplane fluoroscopic guidance. A clinical and imaging evaluation (early CT scan and MRI) as well as a final follow-up clinical assessment was performed.

RESULTS

Twenty-two patients with aggressive VHs who underwent circumferential vertebroplasty with cementation of the entire vertebral body and at least one posterior hemi-arch were included (six males, mean age 53 years). At 3 months follow-up, nine patients (41%) had complete, 11 (50%) had partial and two (9%) had no resolution of pain. Nine of 14 patients had a decrease in venous swelling on MRI. No complications were observed. Five patients (23%) underwent adjunctive surgery within 1 year for persistence or worsening of neurological symptoms. Clinical and radiographic improvements were maintained to final follow-up.

CONCLUSIONS

Doughnut vertebroplasty offers a mini-invasive, safe and effective treatment of aggressive circumferential VHs. This technique improves pain in over 90% of patients as well as a reduction in radicular and neurological symptoms associated with a tendency to regression of the compressive epidural venous component of these lesions.

Successful use of percutaneous interspinous spacers and adjunctive spinoplasty in a 9 year cohort of patients

Purpose

Lumbar spinal canal stenosis and lumbar spinal foraminal stenosis are common, degenerative pathologies which can result in neurogenic claudication and have a negative impact on function and quality of life. Percutaneous interspinous devices (PIDs) are a recently-developed, minimally-invasive, alternative treatment option. This study details a 9 year single-centre experience with PIDs and examines the complementary use of spinous process augmentation (spinoplasty) to reduce failure rates.

Methods

A retrospective cohort assessment of 800 consecutive patients who presented to a specialized spine hospital was performed with 688 receiving treatment. Inclusion was based on high-grade stenosis, failure of conservative management and electromyography. 256 had a PID alone while 432 had concurrent polymethyl methacrylate (PMMA) augmentation of the adjacent spinous processes. The patients were followed up at 3 and 12 months using the Zurich Claudication Questionnaire (ZCQ) and Oswestry Disability Index (ODI).

Results

Both groups showed marked improvement in the patients’ ZCQ scores (3.2 to 1.3) and ODI scores (32 to 21), with strong satisfaction results (1.7). The symptom recurrence rate from complications for the group which received concurrent spinous process augmentation was reduced when compared with the PID alone cohort (<1% vs 11.3%).

Conclusion

This study demonstrates the efficacy of percutaneous interspinous devices in treating lumbar spinal stenosis. It also provides evidence that concurrent spinous process augmentation reduces the rate of symptom recurrence.

Image-Guided Percutaneous Treatment of Lumbar Stenosis and Disc Degeneration

Low back pain, radicular leg pain, and lumbar spinal stenosis are the most common of all chronic pain disorders. Discogenic pain is related to distress of annular fibers and tears, whereas spinal stenosis is related to reduction of the spinal canal dimensions and compression of the neural elements; radicular pain is mainly related to disc herniation and is initially managed conservatively. The percutaneous minimally invasive approach in discogenic and radicular pain is designed to reduce the volume of the nucleus pulposus in patients with failure of medical and physical treatment prolonged for at least 6 weeks.

Percutaneous Interspinous Spacer in Spinal-Canal-Stenosis Treatment: Pros and Cons

A comprehensive description of the literature regarding interspinous process devices (IPD) mainly focused on comparison with conservative treatment and surgical decompression for the treatment of degenerative lumbar spinal stenosis. Recent meta-analysis and articles are listed in the present article in order to establish IPD pros and cons.

Radioisotopic assessment of bone metabolism of the operated vertebra after inter-process stabilizer implantation in the lumbar segment of the spine

INTRODUCTION

Lack of efficacy of pharmacotherapy and physiotherapy in spinal pain syndrome is an indication for intervertebral stabilizer implantation between the processes in the lumbar segment of the spine.

MATERIAL AND METHODS

The group consisted of 32 patients qualified after radioisotopic single-photon emission computed tomography/computed tomography (SPECT/CT) examinations with assessment of bone metabolism and mineral density. For comparative purposes, the L2 vertebra was defined as normal. Parameters defined in the area of operated vertebrae were comparable to L2. Imaging examinations and a pain intensity test were performed before and 12 months after the procedure.

RESULTS

In SPECT, osteotropic isotope (OI) activity in spinous bodies and processes was close to L2 values. Density assessed in CT of analysed vertebrae was close to L2. In the control examination, activity of OI in spinous bodies and processes was higher in the procedure area. Under the stabilizer, there was a strong positive correlation with the L2 parameters. The differences were statistically significant (p = 0.0002). The increase of OI activity in the elements above the stabilizer was variable. In the control examination, there was higher density of spinous processes and bodies above and under the stabilizer. The difference, compared to the L2 density, was statistically significant.

CONCLUSIONS

The radioisotopic method with SPECT/CT allows for the precise assessment of bone metabolism in the spine. After the procedure, a negative correlation was observed between bone metabolism changes and pain intensity test results.

Posterior Arch Augmentation (Spinoplasty) before and after Single and Double Interspinous Spacer Introduction at the Same Level: Preventing and Treating the Failure?

Lumbar spinal canal stenosis (LSCS) is one of the most common degenerative diseases in elderly patients. Failure of he treatment can occur, generally related to bone remodelling/fracture of spinous processes. PMMA augmentation of the posterior arch (spinoplasty, SP) has recently been proposed in case of neoplastic involvement. This study evaluated the efficacy of SP as a prophylactic treatment before introducing an interspinous spacer (IS). Moreover, we consider the possibility to treat patients who previously underwent IS implants with subsequent failure of the device, by introducing a second spacer at the same level, performing accessory SP. From January 2009 to September 2011, 174 patients with LSCS underwent CT-guided percutaneous IS implant in our department. From January 2011, all patients with osteoporosis underwent prophylactic SP before introducing the spacer. Moreover, in patients with re-stenosis related to bone remodelling and/or fracture, after strengthening the spinous processes with PMMA introduction, a second similar device was introduced to re-open the stenotic spinal canal. In patients with prophylactic treatment before spacer introduction, no restenosis occurred at three to 12 month follow-up. Patients who underwent second spacer implant at the same level after posterior arch augmentation again obtained a resolution of symptoms, and no further bone remodelling had occurred at follow-up controls. In conclusion, prophylactic SP prevents single spacer failure for bone remodelling/fracture, and allows failure repair by introducing a second spacer at the same level.

Minimally-invasive posterior lumbar stabilization for degenerative low back pain and sciatica. A review

The most diffused surgical techniques for stabilization of the painful degenerated and instable lumbar spine, represented by transpedicular screws and rods instrumentation with or without interbody cages or disk replacements, require widely open and/or difficult and poorly anatomical accesses. However, such surgical techniques and approaches, although still considered "standard of care", are burdened by high costs, long recovery times and several potential complications. Hence the effort to open new minimally-invasive surgical approaches to eliminate painful abnormal motion. The surgical and radiological communities are exploring, since more than a decade, alternative, minimally-invasive or even percutaneous techniques to fuse and lock an instable lumbar segment. Another promising line of research is represented by the so-called dynamic stabilization (non-fusion or motion preservation back surgery), which aims to provide stabilization to the lumbar spinal units (SUs), while maintaining their mobility and function. Risk of potential complications of traditional fusion methods (infection, CSF leaks, harvest site pain, instrumentation failure) are reduced, particularly transitional disease (i.e., the biomechanical stresses imposed on the adjacent segments, resulting in delayed degenerative changes in adjacent facet joints and discs). Dynamic stabilization modifies the distribution of loads within the SU, moving them away from sensitive (painful) areas of the SU. Basic biomechanics of the SU will be discussed, to clarify the mode of action of the different posterior stabilization devices. Most devices are minimally invasive or percutaneous, thus accessible to radiologists' interventional practice. Devices will be described, together with indications for patient selection, surgical approaches and possible complications.

Percutaneous treatment of lumbar compression fracture with canal stenosis and neurogenic intermittent claudication: combining kyphoplasty and interspinous spacer

Vertebral compression fractures (VCFs) can cause symptomatic spinal canal stenosis secondary to posterior wall retropulsion. This report describes four patients with VCF and lumbar stenosis secondary to posterior wall retropulsion who were treated with combined kyphoplasty and percutaneous interspinous spacer (IS) placement. Clinical and imaging follow-up ranged from 12-36 months. Outcomes were favorable. Combined kyphoplasty and percutaneous IS implant represents a minimally invasive, safe, and efficient option to treat VCF with symptomatic spinal stenosis.

Finite element analysis of the biomechanical effect of coflex™ on the lumbar spine

Objective

The biomechanical properties of the Coflex™ (Paradigm Spine, NY, USA), a device designed to provide dynamic stabilization without lumbar fusion, have not been clearly defined. The purpose of this study was to determine the efficacy and biomechanical effect of Coflex™ using finite element model (FEM).

Methods

A 3D geometric model of the L3-L5 was created by integrating computerized tomography (CT) images. Based on the geometric model, a 3D FEM was created and the Coflex™ model was incorporated into the base model. Mechanical load dependent on the postural changes and boundary conditions, were imposed to simulate various 3D physiological states. The simulation analysis included stress and strain distributions, intervertebral disc deformation, and the range of motion of the facet joint and lumbar spinous process.

Results

Coflex™ significantly restrained displacement in extension, lateral bending and compression of joint between the L4-5 as one in the experimental group was observed -1.3% of flexion, -24.5% of extension, -44.5% of lateral bending and -37.2%. The average intradiscal pressure of the L4-5 decreased by 63% and the average facet contract force of the L4-5 decreased markedly by 34% in the experimental group. A load of 120 MPa from extension was observed at the base of spinous process in the experimental group.

Conclusion

The Coflex™ can be safely used for achieving functional dynamic stabilization of the lumbar vertebral column while preserving the intactness of the other components. However, the fatigue fracture of the L4 spinous process should be carefully monitored.