Accepted Manuscript Title: Assisted techniques for vertebral cementoplasty: Why should we do it? Author: M. Muto S. Marcia G. Guarnieri V. Pereira PII: DOI: Reference:
S0720-048X(14)00174-0 http://dx.doi.org/doi:10.1016/j.ejrad.2014.04.002 EURR 6738
To appear in:
European Journal of Radiology
Received date: Revised date: Accepted date:
12-3-2014 31-3-2014 2-4-2014
Please cite this article as: Muto M, Marcia S, Guarnieri G, Pereira V, Assisted techniques for vertebral cementoplasty: Why should we do it?, European Journal of Radiology (2014), http://dx.doi.org/10.1016/j.ejrad.2014.04.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Assisted techniques for vertebral cementoplasty: why should we do it? M. Muto 1, S. Marcia2 ,G. Guarnieri1, V. Pereira3. 1
Department of Diagnostic Imaging, Section of Neuroradiology - “A. Cardarelli” Hospital, Naples, Italy Section of Radiology - Santissima Trinità Hospital, Cagliari, Italy 3 Unit of Interventional Neuroradiology – HUG, Genève, Suisse
ip t
2
Abstract
d
M
an
us
cr
Assisted techniques (AT) for vertebral cementoplasty include multiple mini-invasive percutaneous systems in which vertebral augmentation is obtained through mechanical devices with the aim to reach the best vertebral height restoration. As an evolution of the vertebroplasty, the rationale of the AT-treatment is to combine the analgesic and stability effect of cement injection with the restoration of a physiological height for the collapsed vertebral body. Reduction of the vertebral body kyphotic deformity, considering the target of normal spine biomechanics, could improve all systemic potential complications evident in patient with vertebral compression fracture (VCF). Main indications for AT are related to fractures in fragile vertebral osseous matrix and nonosteoporotic vertebral lesions due to spine metastasis or trauma. Many companies developed different systems for AT having the same target but different working cannula, different vertebral height restoration system and costs. Aim of this review is to discuss about vertebral cementoplasty procedures and techniques, considering patient inclusion and exclusion criteria as well as all related minor and/or major interventional complications.
te
Key Words: Assisted technique Cementoplasty; Kyphoplasty, Spine jack, Vertebral Body Stenting,
Ac ce p
Vertebral compression fracture, Cerament.
Correspondence : Mario MUTO Neuroradiology Service Cardarelli Hospital Naples, Italy
Via cardarelli 7 80131 Naples,Italy Tel/fax:00390817473838
Email: [email protected]
Page 1 of 19
ip t cr
Abstract
te
d
M
an
us
Assisted techniques (AT) for vertebral cementoplasty include multiple mini-invasive percutaneous systems in which vertebral augmentation is obtained through mechanical devices with the aim to reach the best vertebral height restoration. As an evolution of the vertebroplasty, the rationale of the AT-treatment is to combine the analgesic and stability effect of cement injection with the restoration of a physiological height for the collapsed vertebral body. Reduction of the vertebral body kyphotic deformity, considering the target of normal spine biomechanics, could improve all systemic potential complications evident in patient with vertebral compression fracture (VCF). Main indications for AT are related to fractures in fragile vertebral osseous matrix and nonosteoporotic vertebral lesions due to spine metastasis or trauma. Many companies developed different systems for AT having the same target but different working cannula, different vertebral height restoration system and costs. Aim of this review is to discuss about vertebral cementoplasty procedures and techniques, considering patient inclusion and exclusion criteria as well as all related minor and/or major interventional complications.
Ac ce p
Key Words: Assisted technique Cementoplasty; Kyphoplasty, Spine jack, Vertebral Body Stenting, Vertebral compression fracture, Cerament, cementoplasty; spine,fluoroscopy; spine MRI; spine CT
Page 2 of 19
ip t
Introduction Assisted techniques (AT) for vertebral cementoplasty can be considered as an evolution of the
cr
simple cement injection in the vertebral body, the so-called “vertebroplasty” (VP): AT include multiple percutaneous systems in which a vertebral augmentation is obtained through mechanical
us
devices in order to reach the best vertebral height restoration. The first assisted technique to consider is certainly the balloon Kyphoplasty (KP) that was performed for the first time in in
1998
[1]:
this
procedure
consists
in
delivering
an
California
cement
–
PMMA
M
(Polymethylmethacrylate) into a fractured vertebral body under fluoroscopic guidance after creation of a cavity within the vertebral body by a dedicated expandable balloon [2].
d
Vertebral compression fractures (VCFs) are mostly related to osseous fragility due to porotic
stretching. [3]
te
metabolic deficiency, causing microfractures and spine pain due to periosteal nerve fibers
Ac ce p
Scope of the treatment is to combine the analgesic and stability effect of cement injection to restore a physiological height for the collapsed vertebral body and to reduce the kyphotic deformity: the target is to achive the normal spine biomechanics, improving all systemic potential complications that could be evident in patients with VCF, such as respiratory and gastro-intestinal dysfunctions.[1,2,4]
Main indications for ATs are related to fractures in fragile vertebral osseous matrix and nonosteoporotic vertebral lesions due to spine metastasis or trauma, such as primary and secondary vertebral tumors, as well as in selected primary vertebral traumatic fractures [2,4] Common indications for those techniques are certainly porotic VCF with spinal pain refractory to non-invasive medical and/or physical treatment and orthesis devices [6-12].
Page 3 of 19
The cost of ATs is much more expensive than simple VP: in terms of numbers of treated patients, 70% of patients with VCF are treated with VP and 30% with AT, but regarding to the cost and requested budget for these devices the situation is completely inverted with 70% related to AT and
ip t
only 30% to VP devices [6-12]. This condition created a competition and a benchmark between many companies developing new system for AT (up to 21 system at this moment available
cr
worldwide), having the same target but different working cannula, different vertebral height restoration system and cost, often less expensive.
us
How to select patients
Porotic VCF with pain represents main indication to AT, also in patients with acute thoracic or
an
lumbar spine pain refractory to bed rest and medical and/or physical therapies [2].Reduction of the
M
kyphotic deformity is the major target of all AT thanks to capacity of the system to recovery the vertebral height [3]. For this reason, AT should be recommended in case of lost of the vertebral
d
height of at least 30-40% or more of the normal anatomical morphology.[2,4,12] Preliminary
te
diagnostic approach includes MR examination with sagittal T2-STIR sequence (or any fat suppression if using a 3T MR equipment), that is mandatory to decide about the treatment and the
Ac ce p
number of vertebral bodies to treat: in fact, hyperintensity due to bone marrow oedema is a findings of not healing fracture. [14]
Absolute contraindications are similar to those related to VP, such as the presence of local or systemic infections, painless vertebral fracture and allergy to PMMA. The presence of a myelopathy and radicular compression in case of spine tumors represent an obvious and urgent indication to surgical decompression.[12] Multiple myeloma and spine metastases can also be treated with AT, especially in cases of loss of vertebral height. The presence of epidural soft tissue component with thecal sac compression represent a not absolute contraindication to AT, but it requests accurate clinical evaluation in order to decide between mini-invasive therapy or surgical treatment [6,8,12].
Page 4 of 19
Vertebral traumatic fractures can be defined as stable or unstable related to three- or four columns theory [13-15]; multiple classifications of vertebral trauma are available in literature [13-15]. Magerl’s classification [5] is the most commonly used and considers the trauma in compression,
ip t
rotation and distraction injuries with multiple subtypes. The management of spine traumatic patients is well known and defined by many protocols related to associated clinical neurological symptoms,
cr
especially in case of presence or absence of myelopathy or radicular deficit, using diagnostic
us
imaging resources such as X-ray, MRI, MDCT or both MRI/MDCT. [16]
Magerl A1 type traumatic vertebral fractures [6] represents main indication for AT , but this kind of
an
patients can also be treated with orthesis devices, bed rest as well as medical and /or physical therapy at least for 3-6 months. However this treatment could be not always able to exclude the
M
possibility of worsening of the VCF with an increase of the kyphotic deformity [17-18]; it should be considered also all the problems related to the orthesis such as cardio-respiratory diseases, sleep
d
disorders and gastro-intestinal motility reduction [17-18]. Thanks to the capacity of the AT to
te
restore the physiologic vertebral height and to obtain a more homogeneous distribution of the cement with a better axial resistance to load, this treatment certainly represents a good indication in
Ac ce p
patients affected by Magerl A1 fractures[5,12]. The patients having Magerl’s lesions A2 and A3 type [5] can also be considered for this treatment in selected cases, such as in polytrauma with comorbidities (long bones fractures, abdominal traumatic lesion, etc), in elderly people not suitable for surgical intervention and in all cases in which the surgical and anesthesiologist risk is too high [2,4]. There is no absolute rule about the timing of AT; the only difference is about timing of vertebral traumatic fracture that should be performed as soon as compared to older patients. Because the bone metabolism is much more active in young people than in elderly, it should be preferable to submit younger patients to the AT treatment as soon as possible [19]. How to approach the vertebral body
Page 5 of 19
A preliminary bilateral trans-peduncolar approach under fluoroscopic
guidance is always
mandatory in all AT procedures to obtain a good vertebral body height restoration and an homogeneous cement filling. High quality fluoroscopy is also very important to achieve a complete
ip t
anatomical control of the spine, in order to obtain a correct peduncolar approach avoiding complications even in case of patients affected by aged scoliosis [16,19,21,123-27] (Fig.1-3).
cr
Dimension of the peduncles is important to lead a correct anatomical approach and their size should be checked before to make a treatment decision. An oblique approach with the typical “scotty dog”
us
imaging appearance is also useful to reach the third anterior of the vertebral body.
AT can be performed in local anaesthesia, but in several cases a general anaesthesia could be
an
required (especially in case of more than one single level or in young traumatic patients): this
M
condition is related to the cannula calibres used in KP (10-11 G) compared to the ones used in VP (13 or 15 G). Moreover, the time procedure is certainly longer in AT respect to VP interventions
d
[23-27]. Traumatic fractures in young patients are often more painful than in elderly patients due to
te
the different bony structure: for this reason they need to be treated in general anaesthesia [19]. A VP intervention associated to AT could represent a potential solution to prevent fractures to above
Ac ce p
and below spine metamers especially at the level of thoraco-lumbar junction [20] Once local anaesthesia has been done, the needle is positioned in the vertebral body through a transpeduncolar approach reaching its posterior wall; in AP view the medial margin of the peduncle is an absolute anatomical landmark to check before to pass over the posterior wall of the vertebral body in LL view. A metallic drill can also be used to model the trabecular bone such as other osteotomy cannula to lead the insertion of the balloon tamp or metallic implant without problems. The drill is then removed and the balloons or the mechanical system can be inserted; the systems are connected and under fluoroscopic guidance the inflation of the balloon or the mechanical restoration can begin and be controlled.[12] After creation of a cavity or a mechanic implant deployment, it is then possible to prepare and inject the cement.[12] The amount of cement injected in the vertebral body is extremely variable: 2 to 4 ml by each peduncle depending from the spine metamer to treat Page 6 of 19
(thoracic or lumbar) and the grading of the collapsed vertebra; however, there is not absolute rule regarding the amount of cement to be injected [12] The cement can be injected through a slow injection system such as a bone filler or through 1 ml
ip t
syringe that lead to inject a quite high viscosity cement, with less either disk and venous leakage [23-27].
cr
The procedure and the technique are the same with all different types of vertebral body augmentation devices, however considering the size of the working cannula and dimension of the
us
device to deploy, AT can be performed at middle-lower thoracic level and lumbar level but there is
an
no reason to perform it at the cervical or upper thoracic level. Clinical evidence of treatment efficacy
M
All the AT are able to reduce a pathological kyphosis in 50-60% of patients, improving to restore the normal vertebral biomechanics, the early mobilization of the patient and a pain relief in 90% of
d
cases [23-25].
te
There is a general scientific consensus supported by many International Societies (CIRSE, ASNR, ACR, SFR) that percutaneous vertebral cementoplasty represents a successful, safe and effective
Ac ce p
minimally invasive procedure in selected patients [21-33]. Many publications demonstrate its efficacy with a clinical evidence level III; several recent randomized trials with clinical evidence level I reporting controversial results have been presented, however their scientific methodology could be opinable and controversial [24-28]. A recent randomized prospective study with clinical evidence level I, comparing percutaneous vertebroplasty with optimal conservative management of patients with osteoporotic VCF, showed that pain relief after VC is immediate, is sustained for at least a year, and is significantly greater than that achieved with conservative treatment, at an acceptable cost (the Vertos studies) [29-33] AT is more effective in the setting of osteoporotic compression fractures than a long-lasting conservative medical therapy[34]. As in VP, AT procedure requires a constant fluoroscopic monitoring (angiographic equipment or portable C-arm) to ensure correct needle position and Page 7 of 19
sometimes neurolepto-analgesia or even general anaesthesia. The scope of AT is to restore the vertebral height and to create a space into the vertebral body leading a safe injection of PMMA at low pressure with low rate of cement’s leakage. In fact, the risk of somatic or venous cement
ip t
leakage during AT with this methodology is lower than in VP due to the newly created space having a containing effect for the cement, that is highly viscous and it is pushed through the
cr
working cannula with a slow-flow cement injection system. With the injection of PMMA, the vertebral micro fractures that are responsible of the pain, are then immobilized, making the
us
vertebral body more compact and resistant. However, AT has been shown to restore vertebral
an
height in 40% of cases, with a reduction in wedge angle varying between 6° and 9° [26,27]. Many studies or trials have been performed to analyse the outcome of technique about the reduction
M
of pain as well as the kyphosis correction and complications, such as cement leakage, disk leakage, pulmonary embolism and new vertebral fractures at adjacent or distant vertebral body [27-29]. The
d
risk of cement leakage is certainly lower with AT respect to VP while the incidence of new
osteoporotic disease [28,34].
te
fractures to an adjacent or a distant vertebral body is almost the same, mostly related to the
Ac ce p
The Fracture Reduction Evaluation (FREE) [35],a multicentre randomized controlled trial, compared the efficacy and safety of balloon kyphoplasty (149 patients for BKP-group) to nonsurgical management (151 patients for NSM-group) over 24 months in patients with painful vertebral compression fractures (VCF). Compared to NSM, the BKP-group had greater improvements in SF-36 physical component summary (PCS) scores at 1 month (5.35 points; 95% CI, 3.41 − 7.30; P < 0.0001) and when averaged across the 24 months (overall treatment effect 2.71 points; 95% CI, 1.34–4.09; P = 0.0001) . The BKP-group also had greater functionality by assessing timed up and go (overall treatment effect − 2.49s; 95% CI, − 0.82 to − 4.15; P = 0.0036). At 24 months from the procedure, the change in the index fracture kyphotic angulation was statistically significantly improved in the kyphoplasty group (average 3.13° of correction for kyphoplasty compared with 0.82°in the control, P = 0.003). Number of baseline prevalent fractures ( P = 0.0003) Page 8 of 19
and treatment assignment (P = 0.004) are the most predictive variables for PCS improvement; however, in patients who underwent BKP, there may also be a link with kyphotic angulation. In BKP, the highest quart for kyphotic angulation correction had higher PCS improvement (13.4
ip t
points) than the quart having lowest correction of angulation (7.40 points, P = 0.0146 for difference). The most common adverse events temporally related to surgery ( i.e. , within 30 d)
4 NSM), as well as urinary tract infection (10 BKP, 3 NSM) [35].
cr
were back pain (20 BKP, 11 NSM) new VCF (11 BKP, 7 NSM), nausea and or vomiting (12 BKP,
us
The Cancer Patient Fracture Evaluation (CAFE) study [36], a multicenter randomised controlled trial, compared balloon kyphoplasty (70 patients) versus non-surgical fracture management (64
an
patients) for treatment of painful VCFs in patients with cancer and one to three painful VCFs. The
M
primary endpoint was a back-specific functional status measured by the Roland-Morris disability questionnaire (RDQ) score at 1 month .The mean RDQ score in the kyphoplasty group changed
d
from 17.6 at baseline to 9.1 at 1 month (mean change −8.3 points, 95% CI −6.4 to −10.2; p
S0720-048X(14)00174-0 http://dx.doi.org/doi:10.1016/j.ejrad.2014.04.002 EURR 6738
To appear in:
European Journal of Radiology
Received date: Revised date: Accepted date:
12-3-2014 31-3-2014 2-4-2014
Please cite this article as: Muto M, Marcia S, Guarnieri G, Pereira V, Assisted techniques for vertebral cementoplasty: Why should we do it?, European Journal of Radiology (2014), http://dx.doi.org/10.1016/j.ejrad.2014.04.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Assisted techniques for vertebral cementoplasty: why should we do it? M. Muto 1, S. Marcia2 ,G. Guarnieri1, V. Pereira3. 1
Department of Diagnostic Imaging, Section of Neuroradiology - “A. Cardarelli” Hospital, Naples, Italy Section of Radiology - Santissima Trinità Hospital, Cagliari, Italy 3 Unit of Interventional Neuroradiology – HUG, Genève, Suisse
ip t
2
Abstract
d
M
an
us
cr
Assisted techniques (AT) for vertebral cementoplasty include multiple mini-invasive percutaneous systems in which vertebral augmentation is obtained through mechanical devices with the aim to reach the best vertebral height restoration. As an evolution of the vertebroplasty, the rationale of the AT-treatment is to combine the analgesic and stability effect of cement injection with the restoration of a physiological height for the collapsed vertebral body. Reduction of the vertebral body kyphotic deformity, considering the target of normal spine biomechanics, could improve all systemic potential complications evident in patient with vertebral compression fracture (VCF). Main indications for AT are related to fractures in fragile vertebral osseous matrix and nonosteoporotic vertebral lesions due to spine metastasis or trauma. Many companies developed different systems for AT having the same target but different working cannula, different vertebral height restoration system and costs. Aim of this review is to discuss about vertebral cementoplasty procedures and techniques, considering patient inclusion and exclusion criteria as well as all related minor and/or major interventional complications.
te
Key Words: Assisted technique Cementoplasty; Kyphoplasty, Spine jack, Vertebral Body Stenting,
Ac ce p
Vertebral compression fracture, Cerament.
Correspondence : Mario MUTO Neuroradiology Service Cardarelli Hospital Naples, Italy
Via cardarelli 7 80131 Naples,Italy Tel/fax:00390817473838
Email: [email protected]
Page 1 of 19
ip t cr
Abstract
te
d
M
an
us
Assisted techniques (AT) for vertebral cementoplasty include multiple mini-invasive percutaneous systems in which vertebral augmentation is obtained through mechanical devices with the aim to reach the best vertebral height restoration. As an evolution of the vertebroplasty, the rationale of the AT-treatment is to combine the analgesic and stability effect of cement injection with the restoration of a physiological height for the collapsed vertebral body. Reduction of the vertebral body kyphotic deformity, considering the target of normal spine biomechanics, could improve all systemic potential complications evident in patient with vertebral compression fracture (VCF). Main indications for AT are related to fractures in fragile vertebral osseous matrix and nonosteoporotic vertebral lesions due to spine metastasis or trauma. Many companies developed different systems for AT having the same target but different working cannula, different vertebral height restoration system and costs. Aim of this review is to discuss about vertebral cementoplasty procedures and techniques, considering patient inclusion and exclusion criteria as well as all related minor and/or major interventional complications.
Ac ce p
Key Words: Assisted technique Cementoplasty; Kyphoplasty, Spine jack, Vertebral Body Stenting, Vertebral compression fracture, Cerament, cementoplasty; spine,fluoroscopy; spine MRI; spine CT
Page 2 of 19
ip t
Introduction Assisted techniques (AT) for vertebral cementoplasty can be considered as an evolution of the
cr
simple cement injection in the vertebral body, the so-called “vertebroplasty” (VP): AT include multiple percutaneous systems in which a vertebral augmentation is obtained through mechanical
us
devices in order to reach the best vertebral height restoration. The first assisted technique to consider is certainly the balloon Kyphoplasty (KP) that was performed for the first time in in
1998
[1]:
this
procedure
consists
in
delivering
an
California
cement
–
PMMA
M
(Polymethylmethacrylate) into a fractured vertebral body under fluoroscopic guidance after creation of a cavity within the vertebral body by a dedicated expandable balloon [2].
d
Vertebral compression fractures (VCFs) are mostly related to osseous fragility due to porotic
stretching. [3]
te
metabolic deficiency, causing microfractures and spine pain due to periosteal nerve fibers
Ac ce p
Scope of the treatment is to combine the analgesic and stability effect of cement injection to restore a physiological height for the collapsed vertebral body and to reduce the kyphotic deformity: the target is to achive the normal spine biomechanics, improving all systemic potential complications that could be evident in patients with VCF, such as respiratory and gastro-intestinal dysfunctions.[1,2,4]
Main indications for ATs are related to fractures in fragile vertebral osseous matrix and nonosteoporotic vertebral lesions due to spine metastasis or trauma, such as primary and secondary vertebral tumors, as well as in selected primary vertebral traumatic fractures [2,4] Common indications for those techniques are certainly porotic VCF with spinal pain refractory to non-invasive medical and/or physical treatment and orthesis devices [6-12].
Page 3 of 19
The cost of ATs is much more expensive than simple VP: in terms of numbers of treated patients, 70% of patients with VCF are treated with VP and 30% with AT, but regarding to the cost and requested budget for these devices the situation is completely inverted with 70% related to AT and
ip t
only 30% to VP devices [6-12]. This condition created a competition and a benchmark between many companies developing new system for AT (up to 21 system at this moment available
cr
worldwide), having the same target but different working cannula, different vertebral height restoration system and cost, often less expensive.
us
How to select patients
Porotic VCF with pain represents main indication to AT, also in patients with acute thoracic or
an
lumbar spine pain refractory to bed rest and medical and/or physical therapies [2].Reduction of the
M
kyphotic deformity is the major target of all AT thanks to capacity of the system to recovery the vertebral height [3]. For this reason, AT should be recommended in case of lost of the vertebral
d
height of at least 30-40% or more of the normal anatomical morphology.[2,4,12] Preliminary
te
diagnostic approach includes MR examination with sagittal T2-STIR sequence (or any fat suppression if using a 3T MR equipment), that is mandatory to decide about the treatment and the
Ac ce p
number of vertebral bodies to treat: in fact, hyperintensity due to bone marrow oedema is a findings of not healing fracture. [14]
Absolute contraindications are similar to those related to VP, such as the presence of local or systemic infections, painless vertebral fracture and allergy to PMMA. The presence of a myelopathy and radicular compression in case of spine tumors represent an obvious and urgent indication to surgical decompression.[12] Multiple myeloma and spine metastases can also be treated with AT, especially in cases of loss of vertebral height. The presence of epidural soft tissue component with thecal sac compression represent a not absolute contraindication to AT, but it requests accurate clinical evaluation in order to decide between mini-invasive therapy or surgical treatment [6,8,12].
Page 4 of 19
Vertebral traumatic fractures can be defined as stable or unstable related to three- or four columns theory [13-15]; multiple classifications of vertebral trauma are available in literature [13-15]. Magerl’s classification [5] is the most commonly used and considers the trauma in compression,
ip t
rotation and distraction injuries with multiple subtypes. The management of spine traumatic patients is well known and defined by many protocols related to associated clinical neurological symptoms,
cr
especially in case of presence or absence of myelopathy or radicular deficit, using diagnostic
us
imaging resources such as X-ray, MRI, MDCT or both MRI/MDCT. [16]
Magerl A1 type traumatic vertebral fractures [6] represents main indication for AT , but this kind of
an
patients can also be treated with orthesis devices, bed rest as well as medical and /or physical therapy at least for 3-6 months. However this treatment could be not always able to exclude the
M
possibility of worsening of the VCF with an increase of the kyphotic deformity [17-18]; it should be considered also all the problems related to the orthesis such as cardio-respiratory diseases, sleep
d
disorders and gastro-intestinal motility reduction [17-18]. Thanks to the capacity of the AT to
te
restore the physiologic vertebral height and to obtain a more homogeneous distribution of the cement with a better axial resistance to load, this treatment certainly represents a good indication in
Ac ce p
patients affected by Magerl A1 fractures[5,12]. The patients having Magerl’s lesions A2 and A3 type [5] can also be considered for this treatment in selected cases, such as in polytrauma with comorbidities (long bones fractures, abdominal traumatic lesion, etc), in elderly people not suitable for surgical intervention and in all cases in which the surgical and anesthesiologist risk is too high [2,4]. There is no absolute rule about the timing of AT; the only difference is about timing of vertebral traumatic fracture that should be performed as soon as compared to older patients. Because the bone metabolism is much more active in young people than in elderly, it should be preferable to submit younger patients to the AT treatment as soon as possible [19]. How to approach the vertebral body
Page 5 of 19
A preliminary bilateral trans-peduncolar approach under fluoroscopic
guidance is always
mandatory in all AT procedures to obtain a good vertebral body height restoration and an homogeneous cement filling. High quality fluoroscopy is also very important to achieve a complete
ip t
anatomical control of the spine, in order to obtain a correct peduncolar approach avoiding complications even in case of patients affected by aged scoliosis [16,19,21,123-27] (Fig.1-3).
cr
Dimension of the peduncles is important to lead a correct anatomical approach and their size should be checked before to make a treatment decision. An oblique approach with the typical “scotty dog”
us
imaging appearance is also useful to reach the third anterior of the vertebral body.
AT can be performed in local anaesthesia, but in several cases a general anaesthesia could be
an
required (especially in case of more than one single level or in young traumatic patients): this
M
condition is related to the cannula calibres used in KP (10-11 G) compared to the ones used in VP (13 or 15 G). Moreover, the time procedure is certainly longer in AT respect to VP interventions
d
[23-27]. Traumatic fractures in young patients are often more painful than in elderly patients due to
te
the different bony structure: for this reason they need to be treated in general anaesthesia [19]. A VP intervention associated to AT could represent a potential solution to prevent fractures to above
Ac ce p
and below spine metamers especially at the level of thoraco-lumbar junction [20] Once local anaesthesia has been done, the needle is positioned in the vertebral body through a transpeduncolar approach reaching its posterior wall; in AP view the medial margin of the peduncle is an absolute anatomical landmark to check before to pass over the posterior wall of the vertebral body in LL view. A metallic drill can also be used to model the trabecular bone such as other osteotomy cannula to lead the insertion of the balloon tamp or metallic implant without problems. The drill is then removed and the balloons or the mechanical system can be inserted; the systems are connected and under fluoroscopic guidance the inflation of the balloon or the mechanical restoration can begin and be controlled.[12] After creation of a cavity or a mechanic implant deployment, it is then possible to prepare and inject the cement.[12] The amount of cement injected in the vertebral body is extremely variable: 2 to 4 ml by each peduncle depending from the spine metamer to treat Page 6 of 19
(thoracic or lumbar) and the grading of the collapsed vertebra; however, there is not absolute rule regarding the amount of cement to be injected [12] The cement can be injected through a slow injection system such as a bone filler or through 1 ml
ip t
syringe that lead to inject a quite high viscosity cement, with less either disk and venous leakage [23-27].
cr
The procedure and the technique are the same with all different types of vertebral body augmentation devices, however considering the size of the working cannula and dimension of the
us
device to deploy, AT can be performed at middle-lower thoracic level and lumbar level but there is
an
no reason to perform it at the cervical or upper thoracic level. Clinical evidence of treatment efficacy
M
All the AT are able to reduce a pathological kyphosis in 50-60% of patients, improving to restore the normal vertebral biomechanics, the early mobilization of the patient and a pain relief in 90% of
d
cases [23-25].
te
There is a general scientific consensus supported by many International Societies (CIRSE, ASNR, ACR, SFR) that percutaneous vertebral cementoplasty represents a successful, safe and effective
Ac ce p
minimally invasive procedure in selected patients [21-33]. Many publications demonstrate its efficacy with a clinical evidence level III; several recent randomized trials with clinical evidence level I reporting controversial results have been presented, however their scientific methodology could be opinable and controversial [24-28]. A recent randomized prospective study with clinical evidence level I, comparing percutaneous vertebroplasty with optimal conservative management of patients with osteoporotic VCF, showed that pain relief after VC is immediate, is sustained for at least a year, and is significantly greater than that achieved with conservative treatment, at an acceptable cost (the Vertos studies) [29-33] AT is more effective in the setting of osteoporotic compression fractures than a long-lasting conservative medical therapy[34]. As in VP, AT procedure requires a constant fluoroscopic monitoring (angiographic equipment or portable C-arm) to ensure correct needle position and Page 7 of 19
sometimes neurolepto-analgesia or even general anaesthesia. The scope of AT is to restore the vertebral height and to create a space into the vertebral body leading a safe injection of PMMA at low pressure with low rate of cement’s leakage. In fact, the risk of somatic or venous cement
ip t
leakage during AT with this methodology is lower than in VP due to the newly created space having a containing effect for the cement, that is highly viscous and it is pushed through the
cr
working cannula with a slow-flow cement injection system. With the injection of PMMA, the vertebral micro fractures that are responsible of the pain, are then immobilized, making the
us
vertebral body more compact and resistant. However, AT has been shown to restore vertebral
an
height in 40% of cases, with a reduction in wedge angle varying between 6° and 9° [26,27]. Many studies or trials have been performed to analyse the outcome of technique about the reduction
M
of pain as well as the kyphosis correction and complications, such as cement leakage, disk leakage, pulmonary embolism and new vertebral fractures at adjacent or distant vertebral body [27-29]. The
d
risk of cement leakage is certainly lower with AT respect to VP while the incidence of new
osteoporotic disease [28,34].
te
fractures to an adjacent or a distant vertebral body is almost the same, mostly related to the
Ac ce p
The Fracture Reduction Evaluation (FREE) [35],a multicentre randomized controlled trial, compared the efficacy and safety of balloon kyphoplasty (149 patients for BKP-group) to nonsurgical management (151 patients for NSM-group) over 24 months in patients with painful vertebral compression fractures (VCF). Compared to NSM, the BKP-group had greater improvements in SF-36 physical component summary (PCS) scores at 1 month (5.35 points; 95% CI, 3.41 − 7.30; P < 0.0001) and when averaged across the 24 months (overall treatment effect 2.71 points; 95% CI, 1.34–4.09; P = 0.0001) . The BKP-group also had greater functionality by assessing timed up and go (overall treatment effect − 2.49s; 95% CI, − 0.82 to − 4.15; P = 0.0036). At 24 months from the procedure, the change in the index fracture kyphotic angulation was statistically significantly improved in the kyphoplasty group (average 3.13° of correction for kyphoplasty compared with 0.82°in the control, P = 0.003). Number of baseline prevalent fractures ( P = 0.0003) Page 8 of 19
and treatment assignment (P = 0.004) are the most predictive variables for PCS improvement; however, in patients who underwent BKP, there may also be a link with kyphotic angulation. In BKP, the highest quart for kyphotic angulation correction had higher PCS improvement (13.4
ip t
points) than the quart having lowest correction of angulation (7.40 points, P = 0.0146 for difference). The most common adverse events temporally related to surgery ( i.e. , within 30 d)
4 NSM), as well as urinary tract infection (10 BKP, 3 NSM) [35].
cr
were back pain (20 BKP, 11 NSM) new VCF (11 BKP, 7 NSM), nausea and or vomiting (12 BKP,
us
The Cancer Patient Fracture Evaluation (CAFE) study [36], a multicenter randomised controlled trial, compared balloon kyphoplasty (70 patients) versus non-surgical fracture management (64
an
patients) for treatment of painful VCFs in patients with cancer and one to three painful VCFs. The
M
primary endpoint was a back-specific functional status measured by the Roland-Morris disability questionnaire (RDQ) score at 1 month .The mean RDQ score in the kyphoplasty group changed
d
from 17.6 at baseline to 9.1 at 1 month (mean change −8.3 points, 95% CI −6.4 to −10.2; p
