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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6011_Библиотеки_им_академика_М_И_Перельмана.pdf
C H A P T E R 3 6 Vertebral Body Stenting
225
H
I
F IG UR E 3 6- 5, co n t’d I, Follow-up standing x-ray after 6 months.
226
P A R T V Osteoporotic Surgical Treatment Modalities: Thoracic Spine
A
B
F IG UR E 3 6 -6 A, A 72-year-old woman with pain history of 8 weeks. The first x-rays show a complete collapse of L1 with severe kyphosis. B, Combining the
closed reduction techniques of lordoplasty23 and VBS allows a nearly complete height restoration. (From Orler R, Frauchiger LH, Lange U, Heini PF. Lordoplasty: report
on early results with a new technique for the treatment of vertebral compression fractures to restore the lordosis. Eur Spine J, 15(2) 1769-1775, 2006.)
C H A P T E R 3 6 Vertebral Body Stenting
227
C
F IG UR E 3 6 -6 , c on t ’ d C, Comparison of preoperative standing film and follow-up x-ray after 6 months. The vertebral height is well
restored and maintained and the kyphosis nearly completely corrected (D and E).
D
E
A
F IG UR E 3 6- 7 A 78-year-old man with severe compression fractures of L1 after simple fall. Known osteoporosis due to steroid medication.
Refractory immobilizing pain despite 10 days of hospital stay. A, CT scans depict severe vertebral body compression with posterior wall displacement
and cleft formation.
228
P A R T V Osteoporotic Surgical Treatment Modalities: Thoracic Spine
B
C
D
F IG UR E 3 6 -7 , c on t ’d B, Based on the CT scan, preoperative planning of feasibility and possible stent dimension is performed. The mini-
mal height for stent placement is about 8 mm. C to E, Intraoperative pictures of the surgical procedure: stent placement, expansion, balloon removal.
Arrows in the image indicate the fractures.
C H A P T E R 3 6 Vertebral Body Stenting
229
E
F
F IG UR E 3 6 -7 , c on t ’ d F, Standing x-ray images at 4 months postoperative with well-maintained vertebral
height. The adjacent vertebrae were reinforced in a prophylactic sense.
230
P A R T V Osteoporotic Surgical Treatment Modalities: Thoracic Spine
A
B
F IG UR E 3 6 - 8 A, Male patient, 41 years old, presents after a skiing accident with a burst split fracture of L1 (AO 3.2). B, The stent restored L1
to its former height. Ligamentotaxis provides realignment of the fragments, the cement then provides stability that allows immediate weight bearing.
Reservations against using PMMA in young people are justified; however, alternative material is lacking and histologic workup of a postmortem specimen depicts no adverse effects around the cement, as demonstrated in the MRI taken 1 month after the intervention.24 (From Braunstein V, Sprecher
CM, Gisep A, Benneker L, Yen K, Schneider E, Heini P, Milz S. Long-term reaction to bone cement in osteoporotic bone: new bone formation in vertebral
bodies after vertebroplasty. J Anat 2008;212-5:697-701.)
C H A P T E R 3 6 Vertebral Body Stenting
231
ADVANTAGES AND DISADVANTAGES OF VBS
Advantages
Height restoration and maintenance possible
Controlled expansion with balloon/stent assembly
Safe filling of void/stent space
Disadvantages
Surgical procedure demanding; exact stent placement mandatory
More expensive
be more important than the overall kyphosis regarding balance problems of
the spine.
is related to an increase of the pressure on the anterior column on one hand,
and, more importantly, a massive increase on the muscle load posteriorly.
This may be the cause of a vicious circle that ends up in this so-called sagittal
plane decompensation.
19
Biomechanical calculations suggest that the increase of kyphosis
17
Therefore there is a rationale for height restoration
14,20
and maintenance of spinal alignment. Further clinical studies are needed to
demonstrate how vertebral body stenting is able to contribute to this.
References
1. Incidence of vertebral fracture in Europe: results from the European Prospective Osteoporosis Study (EPOS), J. Bone Miner. Res. 17–4 (2002) 716–724.
2. D. Bliuc, N.D. Nguyen, V.E. Milch, T.V. Nguyen, J.A. Eisman, J.R. Center, Mortality risk
associated with low-trauma osteoporotic fracture and subsequent fracture in men and
women, JAMA 301–5 (2009) 513–521.
3. L. Alvarez, M. Alcaraz, A. Perez-Higueras, J.J. Granizo, I. de Miguel, R .E. Rossi,
D. Quinones, Percutaneous vertebroplasty: functional improvement in patients with osteoporotic compression fractures, Spine 31–10 (2006) 1113–1118.
4. S.P. Muijs, M.J. Nieuwenhuijse, A.R. Van Erkel, P.D. Dijkstra, Percutaneous vertebroplasty
for the treatment of osteoporotic vertebral compression fractures: evaluation after 36 months,
J. Bone Joint Surg. Br. 91–3 (2009) 379–384.
5. P.F. Heini, B. Walchli, U. Berlemann, Percutaneous transpedicular vertebroplasty with
PMMA: operative technique and early results. A prospective study for the treatment of
osteoporotic compression fractures, Eur. Spine J. 9–5 (2000) 445–450.
6. D. Wardlaw, S.R. Cummings, J. Van Meirhaeghe, L. Bastian, J.B. Tillman, J. Ranstam,
R. Eastell, P. Shabe, K. Talmadge, S. Boonen, Efficacy and safety of balloon kyphoplasty
compared with non-surgical care for vertebral compression fracture (FREE): a randomised
controlled trial, Lancet 373–9668 (2009) 1016–1024.
7. P.A. Hulme, S.K. Boyd, P.F. Heini, S.J. Ferguson, Differences in endplate deformation of the
adjacent and augmented vertebra following cement augmentation, Eur. Spine J., 2009.
8. J.C. Eck, D. Nachtigall, S.C. Humphreys, S.D. Hodges, Comparison of vertebroplasty and
balloon kyphoplasty for treatment of vertebral compression fractures: a meta-analysis of the
literature, Spine J. 8–3 (2008) 488–497.
9. D.F. Kallmes, B.A. Comstock, P.J. Heagerty, J.A. Turner, D.J. Wilson, T.H. Diamond,
R. Edwards, L.A. Gray, L. Stout, S. Owen, W. Hollingworth, B. Ghdoke, D.J. AnnesleyWilliams, S.H. Ralston, J.G. Jarvik, A randomized trial of vertebroplasty for osteoporotic
spinal fractures, N. Engl. J. Med. 361–6 (2009) 569–579.
10. R . Buchbinder, R.H. Osborne, P.R. Ebeling, J.D. Wark, P. Mitchell, C. Wriedt, S. Graves,
M.P. Staples, B. Murphy, A randomized trial of vertebroplasty for painful osteoporotic vertebral fractures, N. Engl. J. Med. 361–6 (2009) 557–568.
11. G. Voggenreiter, Balloon kyphoplasty is effective in deformity correction of osteoporotic ver-
tebral compression fractures, Spine 30–24 (2005) 2806–2812.
12. P.J. Ryan, G. Blake, R. Herd, I. Fogelman, A clinical profile of back pain and disability in
patients with spinal osteoporosis, Bone 15–1 (1994) 27–30.
13. C. Cooper, E.J. Atkinson, W.M. O’Fallon, L.J. Melton 3rd, Incidence of clinically diagnosed
vertebral fractures: a population-based study in Rochester, Minnesota, 1985-1989, J. Bone
Miner. Res. 7-2 (1992) 221–227.
14. M.H. Huang, E. Barrett-Connor, G.A. Greendale, D.M. Kado, Hyperkyphotic posture and
risk of future osteoporotic fractures: the Rancho Bernardo study, J. Bone Miner. Res. 21–3
(2006) 419–423.
15. R .P. Heaney, T.M. Zizic, I. Fogelman, W.P. Olszynski, P. Geusens, C. Kasibhatla, N. Alsayed,
G. Isaia, M.W. Davie, C.H. Chesnut 3rd, Risedronate reduces the risk of first vertebral fracture in osteoporotic women, Osteoporos. Int. 13–6 (2002) 501–505.
16. A.M. Briggs, A.M. Greig, K.L. Bennell, P.W. Hodges, Paraspinal muscle control in people
with osteoporotic vertebral fracture, Eur. Spine J. 16–8 (2007) 1137–1144.
17. A.M. Briggs, A.M. Greig, J.D. Wark, The vertebral fracture cascade in osteoporosis: a review
of aetiopathogenesis, Osteoporos. Int. 18–5 (2007) 575–584.
18. R . Rotter, S. Fürderer, P. Heini, Vertebral stenting, a new device for vertebral height restora-
tion, Eur. Spine J. 17 (2008) 1551.
19. A.M. Greig, K.L. Bennell, A.M. Briggs, J.D. Wark, P.W. Hodges, Balance impairment is
related to vertebral fracture rather than thoracic kyphosis in individuals with osteoporosis,
Osteoporos. Int. 18–4 (2007) 543–551.
20. A.M. Briggs, J.H. van Dieen, T.V. Wrigley, A.M. Greig, B. Phillips, S.K. Lo, K.L. Bennell,
Thoracic kyphosis affects spinal loads and trunk muscle force, Phys. Ther. 87–5 (2007)
595–607.
21. H.J. Wilke, P. Neef, M. Caimi, T. Hoogland, L.E. Claes, New in vivo measurements of pres-
sures in the intervertebral disc in daily life, Spine 24–8 (1999) 755–762.
22. K. Sato, S. Kikuchi, T. Yonezawa, In vivo intradiscal pressure measurement in healthy indi-
viduals and in patients with ongoing back problems, Spine 24–23 (1999) 2468–2474.
23. R . Orler, L.H. Frauchiger, U. Lange, P.F. Heini, Lordoplasty: report on early results with a
new technique for the treatment of vertebral compression fractures to restore the lordosis,
Eur. Spine J. 15 (2), 2006 1769–1775.
24. V. Braunstein, C.M. Sprecher, A. Gisep, L. Benneker, K. Yen, E. Schneider, P. Heini, S. Milz,
Long-term reaction to bone cement in osteoporotic bone: new bone formation in vertebral
bodies after vertebroplasty, J. Anat. 212–5 (2008) 697–701.
Structural Osteoplasty: The
Treatment of Vertebral Body
Compression Fractures Using the
OsseoFix Device
James J. Yue, Hitesh Garg, and Rudolf Bertagnoli
37
k e y p o i n t s
Controlled and directional reduction of vertebral compression fractures are
not mutually exclusive.
e OsseoFix device permits directional reduction of fractures with less
cement application than in vertebroplasty or kyphoplasty.
In the laboratory setting, the OsseoFix device offers superior resistance to
re-displacement postapplication strength versus kyphoplasty.
Device is available in 4.5, 5.5, and 7.0 mm sizes.
In the laboratory setting, less cement is required to produce equivalent
strength as compared to kyphoplasty and vertebroplasty.
INTRODUCTION
The incidence of osteoporosis and osteoporotic vertebral compression frac-
tures (VCFs) increases with advancing age with an estimated incidence of
more than 50% in women over the age of 80 years.
and biomechanical consequences of osteoporotic VCFs contribute substantially to the chronic morbidity and economic impact of osteoporosis.
increasing demand for improved quality of life, immediate pain relief, early
mobilization, and preservation of function have become the goals for the
management of osteoporotic VCFs.
A single vertebral body compression fracture results in a sagittal plane
deformity and greater flexion bending moment around the fractured vertebral body, thereby decreasing the force required to cause further increase
in degree and number of additional VCFs with a corresponding increase in
kyphosis.
also leads to loss of pulmonary capacity, malnutrition, decreased mobility,
and depression.
fractures is associated with a two to three times greater incidence of death
due to pulmonary causes.
may be incapacitating and may become chronic in a significant number of
cases.
the fractured segment are presumed to improve spinal biomechanics and
thereby mitigate these consequences.
tives for osteoporotic VCFs. Disadvantages of vertebroplasty include
high injection pressures, inability to correct deformity, and cement
extrusion. Similarly, poor directional reduction control, propagation of
burst fractures, and cement extrusion are insufficiencies of kyphoplasty.
The OsseoFix (Alphtatec Spine, San Diego, CA USA) technique and
implant permit a hybrid technique that we term structural osteoplasty.
1
Spinal deformity resulting from the loss of vertebral body height
3
Kyphosis secondary to osteoporotic vertebral compression
3
Moreover, the pain associated with acute VCFs
4
Interventions that restore fractured vertebral height and stabilize
Vertebroplasty and kyphoplasty are effective treatment alterna-
2
5,6
1
Adverse anatomical
1
With
232
Structural osteoplasty is the controlled directional reduction and bone
augmentation of VCFs. OsseoFix is a stent-like titanium device that is
inserted percutaneously into the fractured vertebral body and is intended
to stabilize and restore the height of vertebral compression fractures
before the insertion of polymethylmethacrylate (PMMA) cement in a
controlled and predictable manner. This implant is designed to overcome
the disadvantages associated with vertebroplasty and kyphoplasty.
CLINICAL INDICATIONS AND CONTRAINDICATIONS
The clinical indications for the OsseoFix device include symptomatic and
unhealed osteoporotic VCFs in the thoracic and lumbar spine from T6 to
L5. Additional potential indications include its use in tumor and traumatic
fractures. Before proceeding with this procedure, it is important to clarify
whether the fracture is actually caused by the fractured vertebral body by
use of clinical examination and radiographic analysis, which should include
radiographs and magnetic resonance imaging (MRI) with short tau inversion recovery (STIR) images. MRI would also confirm any cord or cauda
compression necessitating a decompression procedure. It is prudent to
obtain a CT scan if a break in the posterior cortex of the involved vertebral
body is expected, especially when a traumatic genesis is suspected.
Contraindications to this procedure include titanium allergies, chronic
healed fractures, vertebra plana, unstable burst fractures, fractures in the cervical spine, local or systemic infections, elevated white blood cell count, fever,
obesity, pregnancy, mental illness, or any other medical condition that would
prohibit beneficial surgical outcome apart from general contraindications,
such as coagulation disorder, unsuitability for general or local anesthesia, or
the inability to lie prone.
DESCRIPTION OF THE OSSEOFIX DEVICE
The OsseoFix device is a titanium implant composed of surgical grade
titanium alloy (Ti-6Al-4V, ASTM F 136) and commercially pure titanium (Ti-CP2, ASTM F 67) with an electrolytic conversion coating. It is a
cylindrical -shaped capsule, which expands in the middle after deployment
and helps reduce the vertebral fracture and maintains the vertebral body
height. Cement is then injected into the deployed implant. The implant
is available in various sizes to provide versatility for individual anatomical
dimension needs (Figure 37-1; Table 1).
Biomechanical Studies
The OsseoFix implant has undergone intense in vitro biomechanical test-
ing in terms of stiffness, yield load, and ultimate load after insertion into a
fractured vertebral body.
7,8
These studies have evaluated the biomechanical
C H A P T E R 3 7 Structural Osteoplasty
UNDEPLOYED IMPLANTS
DEPLOYED IMPLANTS
233
4.5 mm
5.5 mm 5.5 mm
7 mm 7 mm
F IG UR E 3 7- 1 OsseoFix titanium implants.
stability of vertebral compression fractures repaired using kyphoplasty type
repair techniques compared to several methods of using the OsseoFix repair
technique.
7,8
In the first reported in vitro biomechanical study evaluating the OsseoFix implant, four male human cadaveric (age 68 ± 9 yrs) spines from T2 to
L5 were scanned for bone mineral density (BMD) using a 3-D computed
tomography (CT) BMD measurement system (average BMD across spines
and all levels = 119 ± 44 mg/ml). Individual vertebral bodies were sectioned
from each spine and measured for anterior vertebral body height. Once measured, the intact vertebral bodies were mechanically tested using established
techniques.
5,6
To summarize these techniques, the intact vertebral bodies were placed
within a test frame with custom fixtures and epoxy resin that conformed
to the upper and lower vertebral body endplates (Figure 37-2). Vertebral
bodies were then compressed by 25% of the measured intact anterior vertebral body height (30-mm height × 25% = 7.5 mm compression). Following
intact testing, data for stiffness (N/mm), yield load (N), and ultimate load
(N) were calculated.
Fractured vertebral bodies were then randomly assigned to one of two
repair groups: those using standard kyphoplasty or those using the smallest
possible OsseoFix device (4.5 mm) (Figures 37-3 and 37-4). Both groups
were injected with PMMA cement. Following repair, anterior column
heights were remeasured to once again compress the vertebral bodies by
25% of the anterior column heights. The same data were calculated for the
repair groups. Data between intact and repaired vertebral bodies as well as
data between types of repairs were evaluated using a two-way ANOVA (p
< .05). In addition, the volume of cement injected and the height maintained following testing of the repaired vertebral bodies were evaluated with
a one-way ANOVA (p < .05).
4.5 mm
TA BL E 37 -1 Im plant Deployme nt Comp arison Cha rt
Initial
Diameter (mm)
4.5 26.4 11.4 22.8
5.5 30.0 13.0 26.4
7 35.2 14.8 31.7
Initial Length
(mm)
Maximum
Deployment
Diameter (mm)
Final Length
(mm)
Results – Study 1
Data from this initial study found no differences in anterior column height
between repair techniques in the intact or repaired phases. However, there
was a statistically greater amount of height maintained following mechanical
compression of the repaired vertebral bodies for the OsseoFix group compared to the kyphoplasty group (Figure 37-5). In addition, it was found
that statistically less cement was injected (1 ml less) for the OsseoFix group
compared to the kyphoplasty group.
There were no differences found in any of the mechanical variables
between OsseoFix or kyphoplasty repair groups. These data were then normalized to the intact data to evaluate the ability of each repair technique to
restore the vertebral body to its intact mechanical strength (Figure 37-6).
F IG UR E 3 7- 2 Testing configuration setup to compress anterior
column by 25% of intact height.
The normalized data were not statistically different between repair groups.
The yield load and ultimate load were restored to intact values, but the
stiffness did not reach intact values. This result is similar to data previously
reported for vertebroplasty or kyphoplasty biomechanical restoration of
fractured vertebral bodies.
5,6
234
P A R T V Osteoporotic Surgical Treatment Modalitites: Thoracic Spine
A
C
B
F IG UR E 3 7 -3 OsseoFix implant inserted
(A, B) and following cement injection (C).
A
F IG UR E 3 7- 4 Kyphoplasty repair A, Coronal radiograph with a deployed Ossefix device with cement. B, Lateral radiograph with a deployed Ossefix device
with cement.
Results – Study 2
Because of the strength provided by the smallest possible implant with the
lower injected cement volumes, a second biomechanical study was conducted to evaluate the inherent strength provided by the implant alone
when compared to kyphoplasty and OsseoFix implants with cement.
This study followed identical specimen preparation as the previous
B
7
biomechanical study.
implant repairs were selected based on pedicle width and height and the
desired amount of repair height. In addition, the mechanical data were
normalized to the BMD of individual vertebral bodies to understand
8
how fractures may be stabilized by eliminating the effect of the inherent
bone density.
However, in the second study, the OsseoFix