Percutaneous Vertebroplasty and Kyphoplasty: Current Status, New Developments and Old Controversies

[Minimally invasive spinal surgery: stages of development]

In recent decades, spinal surgery has changed significantly. The active use of modern knowledge of anatomy, various diagnostic modules, specialized surgical equipment and high-tech tools has made it possible to transform classical surgical techniques into a new area of spinal neurosurgery - minimally invasive spine surgery (MISS). Its main goals are to reduce damage to the skin and adjacent tissues, significantly reduce the level of pain, reduce the duration of inpatient treatment and fully restore functional status in the shortest possible time. This article reflects the main criteria for MISS compliance and types of surgical interventions, provides information on the advantages of minimally invasive surgical technologies and their possible disadvantages. Currently, the use of MISS is observed in all areas of vertebrology - for degenerative diseases, tumors, inflammatory and traumatic lesions of the spine. At the same time, minimizing surgical aggression while maximizing the achievement of goal becomes the main rule of modern spinal surgery.

Stent-Screw Assisted Internal Fixation of Osteoporotic Vertebrae: A Comparative Finite Element Analysis on SAIF Technique

Vertebral compression fractures are one of the most relevant clinical consequences caused by osteoporosis: one of the most common treatment for such fractures is vertebral augmentation through minimally invasive approaches (vertebroplasty or balloon-kyphoplasty). Unfortunately, these techniques still present drawbacks, such as re-fractures of the treated vertebral body with subsidence of the non-augmented portions or re-fracture of the non-augmented middle column at the junction with the augmented anterior column. A novel minimally-invasive augmentation technique, called Stent-Screw Assisted Internal Fixation, has been recently proposed for the treatment of severe osteoporotic and neoplastic fractures: this technique uses two vertebral body stents and percutaneous cannulated and fenestrated pedicular screws, through which cement is injected inside the expanded stents to achieve optimal stents' and vertebral body's filling. The role of the pedicle screws is to anchor the stents-cement complex to the posterior column, acting as a bridge across the middle column and preserving its integrity from possible collapse. In order to evaluate the potential of the new technique in restoring the load bearing capacity of the anterior and middle spinal columns and in reducing bone strains, a Finite Element model of an osteoporotic lumbar spine has been developed. Both standard vertebroplasty and Stent-Screw Assisted Internal Fixation have been simulated: simulations have been run taking into account everyday activities (standing and flexion) and comparison between the two techniques, in terms of strain distribution on vertebral endplates and posterior and anterior wall, was performed. Results show that Stent-Screw Assisted Internal Fixation significantly decrease the strain distribution on the superior EP and the cortical wall compared to vertebroplasty, possibly reducing the re-fracture risk of the middle-column at the treated level.

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-part I, shoulder

BACKGROUND

Image-guided interventional procedures around the shoulder are commonly performed in clinical practice, although evidence regarding their effectiveness is scarce. We report the results of a Delphi method review of evidence on literature published on image-guided interventional procedures around the shoulder with a list of clinical indications.

METHODS

Forty-five experts in image-guided musculoskeletal procedures from the ESSR participated in a consensus study using the Delphic method. Peer-reviewed papers regarding interventional procedures around the shoulder up to September 2018 were scored according to the Oxford Centre for Evidence-based Medicine levels of evidence. Statements on clinical indications were constructed. Consensus was considered as strong if more than 95% of experts agreed and as broad if more than 80% agreed.

RESULTS

A total of 20 statements were drafted, and 5 reached the highest level of evidence. There were 10 statements about tendon procedures, 6 about intra-articular procedures, and 4 about intrabursal injections. Strong consensus was obtained in 16 of them (80%), while 4 received broad consensus (20%).

CONCLUSIONS

Literature evidence on image-guided interventional procedures around the shoulder is limited. A strong consensus has been reached for 80% of statements. The ESSR recommends further research to potentially influence treatment options, patient outcomes, and social impact.

KEY POINTS

• Expert consensus produced a list of 20 evidence-based statements on clinical indications of image-guided interventional procedures around the shoulder. • The highest level of evidence was reached for five statements. • Strong consensus was obtained for 16 statements (80%), while 4 received broad consensus (20%).

Efficacy of unilateral transverse process-pedicle and bilateral puncture techniques in percutaneous kyphoplasty for Kummell disease

In the present study, the efficacy of unilateral transverse process-pedicle and bilateral puncture techniques in percutaneous kyphoplasty (PKP) for Kummell disease was compared. Between March 2015 and June 2017, 63 patients with Kummell disease were recruited and underwent PKP with two different puncture techniques: A total of 38 patients were treated by unilateral transverse process-pedicle PKP and 25 patients were treated by bilateral PKP. The operative time, intra-operative fluoroscopy time, volume of bone cement injection and bone cement leakage were recorded. Prior to surgery and 1 day post-surgery, the visual analogue scale (VAS) pain score and Oswestry disability index (ODI) were determined, and the vertebral body height and Cobb angle were measured. The results indicated that the incidence of bone cement leakage in the unilateral group was similar with the bilateral group (15.79% vs. 16.00%), with no statistically significant difference between the two groups. None of the patients in the two groups had any obvious damage of the spinal cord. The operative time, intra-operative fluoroscopy time and volume of bone cement injection in the unilateral group were lower than those in the bilateral group. A chest X-ray examination at 1 day post-surgery revealed no pulmonary embolism in the two groups. The VAS score, ODI, vertebral body height and Cobb angle were significantly improved in the unilateral and bilateral groups at 1 day post-surgery and at the last follow-up (12 months post-surgery) as compared with these parameters prior to surgery. In conclusion, the unilateral transverse process-pedicle and bilateral puncture techniques in PKP exhibited good efficacy as a treatment for Kummell disease. The operative time, intra-operative fluoroscopy time and volume of bone cement injection were lower in the unilateral group.

The many (sur)faces of B cells

This issue of the Biomedical Journal is dedicated to the latest findings concerning the complex development and functions of B lymphocytes, including their origins during embryogenesis, their meticulous control by the CD22 receptor and different types of T cells, as well as the immunosuppressive abilities of certain B cell subsets. Furthermore, we learn about the complicated genetic background of a rare cardiac disease, the surgical outcomes of pure conus medullaris syndrome and occurrences of tuberculous spondylitis after percutaneous vertebroplasty. Finally, we discover that brain waves could very well be used for biometric authentication and that diffusion imaging displays good reproducibility through a spectrum of spatial resolutions.

Retained Curved Needle After Balloon Kyphoplasty: A Complication with a Novel Device and Its Management

To date, no case studies specifically describing a curved kyphoplasty needle becoming lodged in the vertebral body with the inability to be withdrawn have been reported. We describe a case involving a single level balloon kyphoplasty with a curved coaxial needle during which the cement delivery device could not be removed after cavity filling. In this case, a board-certified interventional pain management specialist was performing balloon kyphoplasty for an L2 osteoporotic vertebral compression fracture. The tools utilized in this procedure included flexible curved instruments designed to traverse the vertebral body and achieve uniform cement distribution through a unipedicular approach. Cannulation and cavity formation were completed without issue. Upon conclusion of cement filling, the curved cement delivery device was unable to be removed. After several attempts to remove the needle and consultation with both the device company and local spine surgeons, it was agreed that the device should be cut at the level of entry into the pedicle and left as a retained foreign object. The involved area was surgically exposed, the retained instrument was cut flush to the pedicle, and the free portion was removed without further complication. The patient followed up in clinic several months later without evidence of neurologic complications. Considerations when using a curved kyphoplasty device and a method of resolution when faced with the inability to remove such an instrument are discussed.

Fatal cardiac perforation and pulmonary embolism of leaked cement after percutaneous vertebroplasty

Percutaneous vertebroplasty consists of percutaneous injection of polymethylmethacrylate (PMMA) via a transpedicular approach for the treatment of collapsed osteoporotic or metastatic vertebrae. Even if percutaneous vertebroplasty is considered to be minimally invasive, threatening complications can occur. Cement leakage is the most common complication of percutaneous vertebroplasty. Rigorous patient selection and individual therapeutic strategy may reduce the occurrence of leakage, in particular the risk of cement entry into the venous system and the spinal canal is the potent major hazard of this technique. Cement pulmonary and cardiac embolism are reported in literature as a cause of unexpected death after percutaneous vertebroplasty. Authors report a fatal case of pulmonary cement embolization occurred after vertebroplasty with haemopericardium, due to the perforation of the right atrium wall from a cement solidified fragment. A complete post mortem examination documented the presence of multiple cement fragments in the pulmonary arteries and transmural perforation of the wall of the right atrium by a whitish needle-like foreign body. Pulmonary microembolization was observed under polarized light.

Minimally invasive non-fusion vertebral body stabilization in severe benign and malignant fractures. Stent-screw Assisted Internal Fixation: the SAIF technique

This short review focuses on clinical and therapeutic issues posed by severe osteoporotic and neoplastic insufficiency vertebral fractures and on the potential use of a new technique to obtain minimally invasive vertebral body reconstruction, augmentation, and stabilization in such severe fractures, combining two preexisting procedures. The implant of vertebral body stents is followed by insertion of percutaneous, fenestrated, cement-augmented pedicular screws that act as anchors to the posterior elements for the cement–stent complex. This procedure results in a 360° nonfusion form of vertebral internal fixation that may empower vertebral augmentation and potentially avoid corpectomy in challenging osteoporotic and neoplastic fractures.

Integrated CT-Fluoroscopy Equipment: Improving the Interventional Radiology Approach and Patient Experience for Treatment of Musculoskeletal Malignancies

Integrated CT-fluoroscopy equipment augments the comprehensive approach to the treatment of musculoskeletal (MSK) malignancy by interventional radiology techniques. As the role of minimally invasive treatment expands to meet the highly variable presentation of MSK malignancy, creative solutions to treatment challenges are required to improve locoregional tumor control and durability of pain palliation. Challenges to effective treatment can often be attributed to a combination of aggressive tumor biology, large size, forbidding location, and adverse vascularity. In these cases, a tailored treatment approach may necessitate the application of multiple interventional radiology (IR) techniques that require different image guidance capabilities. Integrated CT-fluoroscopy equipment provides the means to leverage both imaging modalities within the same procedural setting to facilitate the simultaneous application of multiple synergistic treatments and protective measures. This article examines the potential role of hybrid units in the IR treatment of challenging MSK malignancies as a means to empower a paradigm transition for a more comprehensive and patient-tailored approach.

Analyses of the efficacy of percutaneous kyphoplasty and alendronate sodium on thoracolumbar vertebral fracture and the risk factors of fracture

The present study investigated the efficacy of percutaneous kyphoplasty and alendronate sodium on thoracolumbar vertebral fracture, and the risk factors leading to the recurrence of fracture. In the present study, a total of 80 patients with thoracolumbar vertebral fracture who were admitted to the Affiliated Jiangyin Hospital of Southeast University Medical College between January 2014 and March 2016 for combination treatment of percutaneous kyphoplasty and alendronate sodium were enrolled. According to the recurrence of fracture, the patients were divided into two groups, the observation group (patients with fracture recurrence, n=40) and control group (patients with no fracture recurrence, n=40). All patients participated in a 1-year follow-up. The recurrence of fracture and the site of fracture were identified through the clinical symptoms and examination of the spine using magnetic resonance imaging. In addition, comparisons of the time of alleviation in numbness of lower limb and that in pains in waist and legs were carried out. Furthermore, statistics on the adverse reactions during intervention in the two groups were also collected; changes in visual analogue scale (VAS) and Oswestry Disability Index (ODI) of pains at different time points in two groups were also observed. One-way analysis and multivariate analysis were performed to identify the relevant risk factors. Alleviation time in numbness of lower legs in patients of the control group was significantly earlier than that in the observation group (P<0.05) and the alleviation time in pains of the waist and legs of patients in the control group was also significantly earlier than that in the observation group (P<0.05). Furthermore, the incidence rates of abdominal pain, diarrhea, constipation and hypocalcemiain in the control group were also significantly lower compared with those in the observation group (P<0.05). One week, one month and one year after operation, the scores of VAS of pains and ODI in the control group were significantly lower compared with those in the observation group in the same period (P<0.05). Lower preoperative bone density and exosmosis of bone cement in treatment were the independent risk factors leading to the recurrence of fracture. For patients with thoracolumbar vertebral fracture who received the combination treatment of percutaneous kyphoplasty and alendronate sodium, there underlies an important correlation between the recurrence rate of fracture and the preoperative bone density as well as the exosmosis of bone cement in operation.

Comparative biomechanical study of a new transpedicular vertebral device and vertebroplasty for the treatment or prevention of vertebral compression fractures

BACKGROUND

A comparative study was performed between a novel transpedicular implant (V-STRUT©, Hyprevention, France) and vertebroplasty. This study aims to assess the biomechanical efficacy of this implant in resurrecting and fortifying the osteoporotic vertebra following a vertebral body fracture.

METHODS

A total of 17 vertebrae from 3 human osteoporotic spine segments (T9-L5) were selected. Vertebral compression fractures were generated by eccentric compressive loading until a height reduction of 25%. Then the vertebrae were either fixed using vertebroplasty technique (control group; n = 8) or implanted with V-STRUT© implant combined with bone cement (device group; n = 9). A new compressive loading was performed in the same conditions. Maximal load and stiffness, as well as total energy to fracture were measured.

FINDINGS

Fracture force and energy to fracture were both increased either after V-STRUT© implantation or vertebroplasty compared to when the initial fracture was generated. Mean increase percentage between the initial value and the post-treatment value for each parameter were +77% vs +39% regarding fracture load and +126% vs +99% for energy to fracture, for the device group vs vertebroplasty group respectively. No pedicle fractures were observed in both groups, nor implant breaking or bending in the device group.

INTERPRETATION

These results show the ability of V-STRUT© combined with bone cement to reinforce the vertebral body strength, with an at least equivalent biomechanical performance as vertebroplasty. Further clinical investigation needs to be undertaken to demonstrate any clinical superiority of V-STRUT© over vertebroplasty.