Upload
dinhtruc
View
223
Download
0
Embed Size (px)
Citation preview
Posterior Spinal Fusion
Robert Liss MD Orthopaedic Institute
Allegheny Health Network
Posterior Spinal Fusion
Definition Evolution Indications Techniques Complications/results Cases
Normal Function of the Spine
Conduit for spinal cord and nerves Support the body weight and external load
– Stability Allow efficient motion of the body for
various activities – Flexibility – BALANCE in sagittal and coronal plane
Spinal Disorders
Trauma
Tumor
Infection & Inflammatory Disease
Deformity
Degenerative
Treatment of Spinal Disorders
Conservative Treatment – Degenerative disease – Stable fracture – Mild deformity
Surgical Treatment – Failed conservative treatment – Unstable fracture (dislocation) – Progressive deformity – Neurologic deficit
Spinal Fusion
Restore stability Elimination of movement across a motion
segment by bone union
Spinal instability
A state in which normal loads result in (painful) abnormal motion or deformity with the potential for damage to neurologic structures
Clues to instability
>4mm translation on flexion/extension views
Excess angular motion Spondylolisthesis or retrolisthesis Traction spurs Abnormal flexion rhythm Radiographic progression of deformity
Natural spine fusions
Congenital failure of segmentation Spontaneous ankylosis
– Post traumatic – Inflammatory, AS – Post infectious – Degenerative (DISH)
DISH
Post infection
Ankylosing spondylitis
Ankylosing spondylitis
Posterior Spinal Fusion Posterior incision Joins together one or more vertebrae to
reduce pain and impart stability Requires bone graft or substitute Various techniques
– Posterolateral or intertransverse – Posterior interbody – Transforaminal interbody
+/- instrumentation Open or MIS
Spinal fusion: History
Fred Albee 1911 bone grafting from tibia Russell Hibbs 1911 feathered lamina,
overlapping bone, later added iliac bone
Posterior spinal instrumentation: History
Hadra 1891 wiring spinous processes Harrington-rod/hook 1960’s Cotrel-Dubousset segmental fixation Luque- sublaminar wires Roy-Camille 1970 pedicle screws Steffee 1980’s plate-screw Rod-screw constructs
Harrington
Flat back
Luque
Cotrel Dubousset Instrumentation
Spinal Instrumentation
Adjunct to fusion May correct deformity Increases the chance of successful fusion
for multilevel procedures Anchor point: pedicle screw, laminar hook,
wire Rod or plate connecting points of fixation
Spinal instrumentation today
Segmental fixation multiple pedicle screws Pelvic Dual contoured rods +/- interbody fusion/implant MIS option Image or robotic guidance
Bone graft
Ideal graft provides both: – Osteoinduction- biological stimulus to bone
formation – Osteoconduction- scaffolding for bone
formation – Osteogenesis-cells forming bone
Properties of Graft Materials Graft Osteogenic Osteo- Osteo- Materials Potential induction conduction Autogenous bone + + + Bone marrow cells + ? Allograft Bone ? + DBM + + BMPs + ? Ceramics + DBM = Demineralized bone matrix; BMP = Bone morphogenetic proteins
Posterior approach fusion options
Posterolateral—graft over transverse processes and lateral to facets
Posterior—graft over laminae Facet—graft in facet joints Interbody—graft in disc space, can be
accessed directly posterior or transforaminal
Posterior spine fusion
Facet fusion
Posterior approach interbody fusion
interbody fusion
Non fusion options
Robotic guidance
Jackson Spinal Surgery Table
Posterior spinal fusion: Complications
acute – infection – neurologic – Dural injury – Medical complication – Dvt
chronic – adjacent segment
problems – Nonunion – imbalance
JAMA. 2010;303(13):1259-1265. doi:10.1001/jama.2010.338
Complications: fusion
Complications: PLIF
S. Okuda, et. al, J. Neurosurg:Spine/Volume 4/April, 2006
Infection: incidence by technique
PLF vs PLIF 0.3 vs 1.37% – Ahn, DK et AL., J Spinal Disord Tech. 2012
Dec;25(8):E230-4 MIS vs open 0.24 vs 1.1%
– Gerard, E et al., SMISS 2011
Neurologic complications: instrumentation injury
Pedicle screw – Use landmarks for starting point – Laminotomy to palpate pedicle – Probe, sound, tap, sound – EMG stimulation – Fluoroscopy – Image guidance – WOF pedicle fracture
Postop deficits: CT and remove errant hardware
Figure 11a. Medial deviation of a pedicle screw.
Young P M et al. Radiographics 2007;27:775-789
©2007 by Radiological Society of North America
Figure 11b. Medial deviation of a pedicle screw.
Young P M et al. Radiographics 2007;27:775-789
©2007 by Radiological Society of North America
Neurologic: Instrumentation injury
Complications: late
Recurrent herniation Arachnoiditis Adjacent segment degeneration Pseudarthrosis Instability
Figure 21a. Symptomatic disk herniation at a level adjacent to instrumentation.
Young P M et al. Radiographics 2007;27:775-789
©2007 by Radiological Society of North America
Young P M et al. Radiographics 2007;27:775-789
©2007 by Radiological Society of North America
Adjacent segment degeneration
Case 1
49 y female with RA on steroids, methotrexate and Humira
Prior ACDF C5-6, TKR Unable to walk or stand > 20 minutes due to
back and bilateral leg pain PT, NSAIDs and LESI ineffective
Degenerative spondylolisthesis, stenosis
Degenerative Spondylolisthesis, stenosis
Cervical stenosis, spondylolisthesis C7-T1
Cervical stenosis
Case 2, Trauma
24-year-old male with unfortunate dismount from trampoline
severe back pain neurologically intact
24 y m L 4 burst fracture
L4 burst
L4 burst
L4 burst
L4 burst
Case 3, Trauma
67-year-old male fell while constructing his tree stand
presented with upper back pain and no motor or sensory function below nipples.
T4 burst
T4 burst
T4 burst
pre post
Case 4 Isthmic Spondylolisthesis
Isthmic Spondylolisthesis
6y po
Case 5
26 year old female with 2 prior L5-S1 discectomies, chronic LBP
Back and bilateral leg pain No weakness in legs Perineal numbness Unable to void
Recurrent HNP
Recurrent HNP
Spinal Fusion: Guiding principles
Primum non nocere “The goal of the OR should be to have a good
office” Fulfill your patient’s expectations
– Create realistic expectations – Don’t try to solve psychosocial problems with an
operation – Address the offending pathology at surgery
No role for exploratory surgery
Goals of Spinal Surgery
Relieve pain by eliminating the source of problems (decompression)
Stabilize the spinal segments after decompression when necessary – pay attention to sagittal and coronal alignment – Prevent the progression of deformity of the spine
Call in by AM. Fused by PM. Same-day fixes are available now.
Thank You!