We encourage the reader to take the opportunity to review the
ANATOMY OF THE SPINE on this website.
In our practice, the majority of Cervical Spine surgery is carried out on
a "Day Surgery" / "Out-patient" basis. All of the operations are conducted
Microneurosurgical Techniques, some incorporating Minimally Invasive
The indications for surgical intervention in the Cervical Region are
quite specific. They are:
High grade Spinal Stenosis (narrowing)
resulting in significant Spinal Cord compression with or without
neurological deficit. Generally, Spinal Canal diameters
of 9 millimeters or less are regarded as "significant
stenosis" warranting surgical consideration.
Foraminal Stenosis resulting in Nerve Root injury and
Neurological Deficit resulting from an
Intraspinal "mass". This can be an Extruded Disc,
Calcified Posterior Longitudinal Ligament, Large Bone Spur (or any
combination of these) as well as Spinal Cord or Vertebral Tumors.
Spinal Instability with resulting risk to
Spinal Cord injury.
For those patients with conditions that are amenable to a Minimally
Invasive approach (such as has been described in:
What is Minimally Invasive and Endoscopic Neurosurgery?)
we are pleased to offer this alternative. The conditions that do lend
themselves to this technique include Far Lateral Extruded Cervical
Intervertebral Discs, Foramenal Stenosis secondary to Cervical Facet
Hypertrophy, Spinal Stenosis secondary to Hypertrophic Ligamentum Flavum as
well as some Spinal Cord Tumors.
B. Microsurgical Treatment of Herniated Cervical Disc and Bone
The majority of Herniated (extruded) Cervical Discs are
operated upon using an Anterior (front) Approach since the "herniations"
(and Bone Spurs) compress the Spinal Cord and/or Nerve
Root in the front of the Spinal Cord. We frequently find, at
surgery, that the Herniated Disc has torn a hole in the Posterior
Longitudinal Ligament at or near the center of the Spinal Canal.
As part of the operation, we also routinely remove the
Bone Spurs along with the Herniated Disc. The Neural Foramena,
through which the Spinal Nerve Roots leave the Spinal Canal,
are also opened in order to relieve any pressure on these exiting
Nerve Roots. This often includes an aggressive removal of HYPERTROPHIC
UNCOVERTEBRAL JOINTS (Please see
Figure 5B in Cervical Spine
Anatomical Location of the "UNCOVERTEBRAL JOINTS".) These procedures
(Figures 4A & 4B) are conducted using a sophisticated Operating Microscope
and a Microneurosurgical Drill in conjunction with specially designed
Microneurosurgical instruments. (See Figures 7 - 11 Below for Examples
of this type of surgery)
We specialize in the reconstruction of the Cervical Spine
for complex and extensive problems such as High-Grade Spinal Stenosis
(resulting from Calcified Posterior Longitudinal Ligament, large Bone
Spurs and/or Migrated Extruded Disc), Bone Tumors and Instability. For
those patients with conditions that warrant this type of procedure, we can
routinely remove and replace entire Vertebral Bodies with highly
advanced and engineered materials such as with
Medtronic's Titanium "Pyramesh" Cage System.
The Cage is interposed between the remaining "normal" Vertebral Bodies
after the "targeted" Vertebral Bodies have been removed (Figure 5A). Once
the Cage is in place, a rigid Anterior Internal Fixation Plate is attached
to the FRONT of THE VERTEBRAL BODIES (Figure 5B) as part of the
"Reconstruction" procedure. This is usually sufficient to support the patient
which avoids the requirement for an additional operation for a "Posterior
Screw & Rod Fixation System".
We use the patient's own Vertebral Body Bone, that we remove
during the operation (as part of the procedure to alleviate the pressure on
the Spinal Cord and Nerve Roots), to fill the Cage. This usually
obviates any requirement to obtain bone from any other area of the patient
nor do we generally need cadaver bone. THE TITANIUM "PYRAMESH CAGE" REMAINS
PERMANENTLY IN PLACE. ULTIMATELY THE "NORMAL" VERTEBRAL BODY BONE at BOTH
ENDS OF THE CAGE WILL "FUSE" WITH THE BONE THAT WAS USED TO FILL THE CAGE
(see Figures 6A&B and 14A-C for additional examples.) It has been our
practice to incorporate "Bone Morphogenic Protein" (BMP) within the
implanted Cage which is mixed with the "harvested" Vertebral
Bone that is filling the Cage. In our experience the
availability of Bone Morphogenic Protein (please see the explanation
in the next paragraph) has resulted in earlier, more extensive and
stronger bone growth through the Cage.
One of the important long-term goals of the Anterior Cervical "Fusion"
and "Cervical Spine Reconstruction" operations is early and strong bone
union (fusion.) BMP is a "medication" (incorporated in the "reconstruction"
process) that acts as a "bone growth accelerant" and offers
considerable advantage in assisting the patient to grow bone and meet
these long-term goals for Spine Stability.
Bone Morphogenic Protein 2 (which is symbolized as BMP2)
belongs to a super-family called "transforming growth factor beta"
(TGF-beta) and is a protein that induces the formation of bone and
cartilage. "RhBMP-2" is the symbol for "recombinant human bone
morphogenetic protein". RhBMP-2 has long been recognized
for its remarkable potential as a bone graft substitute. In fact,
BMPs are the only known proteins capable of inducing new bone
formation. The first commercially available BMP ever to
exhibit clinically proven osteoinductivity is the INFUSE®
Bone Graft (distributed by Medtronic Sofamor-Danek Memphis, Tennessee.)
WE USE (SEE *DISCLAIMER BELOW) "rhBMP-2" IN THE "RECONSTRUCTION"
PORTION OF AN "ANTERIOR CERVICAL FUSION", AS WELL AS THE MORE
EXTENSIVE "ANTERIOR CORPECTOMY" (See Figures 5 & 6), OPERATIONS.
WE MIX THE BMP WITH THE PATIENT’S OWN BONE (that is saved when we remove
the patient's Bone Spurs at the time of operation) TO FILL THE HOLLOW
CENTER OF THE INTERVERTEBRAL "SPACER" (or the reconstruction Titanium Cage)
THAT IS USED TO MAINTAIN THE CRITICAL DISTANCE BETWEEN THE VERTEBRAL BODIES
("intervertebral distance") AFTER THE DISC HAS BEEN REMOVED.
(Please see Section 2 A and Figures 7, 8A-E, 9A, 9E & 10 for information
on Advanced Materials used for the "spacers".)
The PRIMARY GOALS of most Anterior Cervical operations
ANY "ANTERIOR CERVICAL FUSION" OPERATION REQUIRES THE REMOVAL OF THE
CERVICAL DISC AT THE PATHOLOGICAL INTERVERTEBRAL DISC SPACE LEVEL(S). ONCE
THE SPINAL CORD AND NERVE ROOTS HAVE BEEN SUCCESSFULLY "DECOMPRESSED", THE
INTEGRITY OF THE SPINAL COLUMN MUST BE RESTORED. There are TWO (2) STEPS
INVOLVED IN THIS "RESTORATION" PROCESS. (The FIRST STEP, involving the
insertion of "Spacers" is reviewed in the next few paragraphs while the
SECOND STEP, which involves the installation of an "Anterior Internal
Fixation System", is discussed in Sections 3 & 4 Below.)
- REMOVE THE PATHOLOGICAL CONDITION(S) (Herniated Disc and/or
Bone Spurs/Calcified Posterior Longitudinal Ligament and
Hypertrophic Uncovertebral Joint) responsible for the Spinal
Cord and/or Nerve Root compression
- RESTORE NEUROLOGICAL FUNCTION & MAINTAIN STRUCTURAL STABILITY
- RELIEVE PAIN.
The FIRST STEP is to RECONSTITUTE THE STRUCTURAL INTEGRITY OF THE SPINE
AND THE CRITICAL DISTANCE BETWEEN EACH VERTEBRA IN ORDER TO MAINTAIN THE
"WINDOW" (FORAMEN) THROUGH WHICH EACH NERVE ROOT EXITS THE SPINAL CANAL.
IN PATIENTS WHO UNDERGO AN "ANTERIOR CERVICAL FUSION", THIS IS ACCOMPLISHED
BY INSERTING A "SPACER" TO REPLACE THE DAMAGED DISC THAT HAS BEEN REMOVED
AND TO MAINTAIN THE CRITICAL INTERVERTEBRAL DISTANCE.
THE "SPACER" ALSO FACILITATES THE GROWTH OF BONE FROM ONE VERTEBRA TO THE
NEXT (AT THE OPERATIVE LEVELS) AS PART OF THE ULTIMATE OPERATIVE DESIGN,
WHICH IS TO "FUSE" THE VERTEBRAE TOGETHER (meaning that the adjacent Vertebrae
will become a single solid unit once the bone has grown through the
THERE ARE SEVERAL RELIABLE DEVICES CURRENTLY AVAILABLE THAT ARE DESIGNED
TO PERFORM THIS FUNCTION. WE CURRENTLY OFFER THE LATEST IN HIGHLY RELIABLE
"IMPLANTS" USED TO RESTORE THE INTERVERTEBRAL BODY "SPACING". (Older
techniques used a wedge of the patient's own bone (usually a piece taken
from the pelvis which was a rather painful experience) as the "spacer".
Cadaver bone grafts are also available for this function.)
ONE OF THE LATEST MATERIALS USED AS A "SPACER" IS A "BIOABSORBABLE"
"co-polymer" compound called HYDROSORB® which is a PLDLA co-polymer consisting
of 70 percent Poly (L-lactide) and 30 percent Poly (D,L-lactide). THESE
"SPACERS" WILL BE REPLACED BY THE PATIENT'S OWN BONE WITHIN 18 MONTHS AS IT
SPONTANEOUSLY TURNS INTO WATER (H2O)AND CARBON DIOXIDE (CO2) AND DISAPPEARS.
(See Figures 7, 9-13)
This "SPACER" has a HOLLOW CENTER WHICH IS FILLED WITH THE PATIENT'S
OWN BONE THAT IS SAVED WHEN WE REMOVE THE PATIENT’S BONE SPURS AT THE TIME OF
OPERATION AND MIXED WITH THE "BONE GROWTH ACCELERANT" (BMP) IN ORDER TO
FACILITATE A MORE COMPLETE AND RAPID BONE GROWTH.
PEEK is an inert, long-lasting "plastic" substance
that has been used in all manner of implants including for cardiac surgical
devices. One of the "revolutionary" designs made from PEEK incorporates
an intervertebral "Spacer" that is integrated with an Anterior Internal
Fixation System (See Figures 8A - 8E.)
Among the latest advances in Cervical Spine surgery is the adaptation
of the bioreabsorbable materials for the Anterior Internal Fixation devices.
These plates and screws are only available one or two-level operations
since their strength is insufficient for multilevel procedures.
Nevertheless, they do offer the advantage (for the appropriate patient)
for the plate and screws to "disappear" in 18 months without having a
permanent implant. These devices are now available from several
different surgical equipment manufacturers including Inion
The Medtronic Sofamor-Danek (Memphis, Tennessee) device is
called the "MYSTIQUE Resorbable Graft Containment Plating System".
It uses the same high-tech biologic co-polymer material
described in previous paragraphs) that is absorbed by the body over
time, a feature not found in traditional metal implants. The MYSTIQUE
Plate helps to stabilize the "fusion", prevent "spacer" dislodgement and
facilitate healing. (See Figure 9B)
The PLATE IS SOMEWHAT FLEXIBLE and CAN BE CONTOURED TO
BETTER MATCH THE PATIENT'S UNIQUE ANATOMY BEFORE INSERTION.
This "HYDOSORB®" material dissolves in the body within 18 to 36
months after implantation. As the plate dissolves,
its by-products, Carbon Dioxide and Water, are released through the lungs.
More than 10 years of clinical experience and research have shown that
implants manufactured from this co-polymer material offer a high level of
2-level Bioabsorbable Anterior Plate and Screw System (Figures 9 E & F)
is a major new advance in our therapeutic armamentarium. This is, of
necessity, more robust than the "Mystique" variety (which is restricted
to a single level.) The Inion system can be used instead of a Titanium
Plate and Screw system where "strength" is not a major issue such as
would be required for a) short, heavy-set necks; b) patients with
significant osteopenia or osteoporosis; c) patients who smoke; d) patients
in whom extensive resection of one or more vertebrae is required.
An excellent example is demonstrated in Figure 9C. This 44 year old
female had Left C6 and C7 nerve root deficits with spinal cord compression
consequent to bone spurs, calcified Posterior Longitudinal Ligament and
Bilateral Uncovertebral Joint Hypertrophy. An Anterior Cervical approach
allowed for the resection of the spurs, calcified ligament and bilateral
uncovertebral joints at both the C5,6 & C6,7 levels. The cervical spine
required "re-contouring" (Figure 9C) in order to accommodate her
reconstruction which was accomplished using 2 "Hydrosorb" bioabsorbable
"spacers" (Figure 9E) augmented by an Inion 2-level anterior plate and
6 Inion bioabsorbable screws (2 in each of the C5, C6 and C7 vertebral
bodies. See Figure 9F)
WHERE THE BIOABSORBABLE ANTERIOR PLATE WOULD NOT BE SUFFICIENTLY ROBUST,
(such as where MORE THAN ONE INTERSPACE UNDERGOES OPERATION or in most men and
"larger" patients as well as in patients REQUIRING MORE COMPLEX AND EXTENSIVE
"FUSION" and "RECONSTRUCTION" OPERATIONS) it is important to STABILIZE THE
SPINE with a STRONGER "ANTERIOR (FRONT) INTERNAL FIXATION" DEVICE.
This is a "permanent" Titanium Plate placed on the front (Anterior)
aspect of the Cervical Spine and held in position with special fixation
screws placed into the Cervical Vertebrae (SEE FIGURES 11, 12 & 13
BELOW). There are several reliable "plating systems"
available. We currently use the latest in
Aesculap USA, Inc.
technology in the form of their Titanium ABC Plate and Screw
System. and the "Atlantis Translational Plate"
(Please see Figures 11D and 11E below.) from
Both of these "plates" are "load sharing" meaning that they assist in
stabilizing the segments of the spine operated upon but the spine itself
is the primary weight bearing and stabilizing entity which is the greatest
stimulus to bone formation. A major goal of these operations is the
permanent "fusion" meaning that the cervical spine segments operated
upon have been permanently united by this bone growth.
There are conditions that require the removal of entire Vertebral
Bodies (an operation called "ANTERIOR CORPECTOMY") such as:
WHEN AN ENTIRE VERTEBRAL BODY HAS BEEN REMOVED, IT THEN BECOMES
IMPERATIVE TO "RECONSTRUCT" THE SPINAL COLUMN AND RESTORE ITS STRUCTURAL
- SPINAL CORD COMPRESSION from Extruded Discs that
have migrated a considerable distance from the intervertebral
- CALCIFIED POSTERIOR LONGITUDINAL LIGAMENT that extends
behind the Vertebral Body at a considerable distance for the
intervertebral space and is inaccessible through the limited
approach offered by an Anterior Discectomy operation.
- DISEASES THAT AFFECT AND/OR DESTROY THE VERTEBRAL BODY
(tumors; infection; trauma) may also require the removal of the
entire Vertebral Body.
In past years, the reconstruction portion of the operation required
the use of a long bone "strut" harvested from the patient's leg (a
piece of Fibula), from the Pelvis (Iliac Crest bone) or from a Rib.
Cadaver bone also became available.
The availability of Titanium Cages that can be used to replace
entire Vertebral Bodies has made this type of surgery faster, safer,
more reliable and less painful than in the past. These "Cages" are
permanent implants and can be used for single or multi-level
reconstructions (See Figures 5, 6 & 14).
For many years, and even at the present time for most patients, the
"best" form of surgical therapy for Herniated Disc and/or Degenerative
Cervical Osteoarthritis (Spurs/Calcified Posterior Longitudinal Ligament
and Hypertrophic Uncovertebral Joints) that result (either alone or in
combination) in significant Spinal Cord or Nerve Root compression,
comprises some form of Anterior Cervical Spine operation for removal
of the offending pathology followed by an immobilization (fusion) of
the diseased joint(s).
One of the THEORETICAL DISADVANTAGES of this "fusion" is the
transference of “motion” and the forces of that motion to the
immediately adjacent joints which may result in an acceleration of
progressive degenerative changes (bone spurs) at those adjacent Disc
Space levels. Recent Neurosurgical and Orthopedic professional
publications have paid considerable attention to this issue (under
the newly minted term, "Adjacent Level Disease"). While the
actual risk, in our considerable experience, is exceptionally
low, there is some truth to the concept.
Cervical Spine "motion preservation" is the theoretical
concept underlying the development of "Cervical Spine Replacement
Discs". The "artificial discs" have been designed to hopefully, reduce
the risk for the progression of Spondylosis at the adjacent levels by
preserving Cervical Spine motion. These devices are, in fact,
definitely not "disc" material, but rather are
surgical implants made of one or several durable materials such
as advanced polymers and/or metallurgical materials. The first of these
new devices became available in mid-July 2007. Currently there are
other similar technologies (Figure 18), created by several different
commercial enterprises, in various "clinical trial" phases or awaiting
FDA approval. THESE OTHER DEVICES ARE AVAILABLE ONLY ON AN EXPERIMENTAL
BASIS. This includes the "Bryan" Disc (Figures 15 & 16) and
"PRODISC-C®" (manufactured by SYNTHES, Inc. - Figure 17) among
Several scientific reports regarding "Artificial Cervical Joint
Devices" have become available. One such initial "long term
follow-up" for "Artificial Disc Implantation" was reported
at the American Association of Neurological Surgeons Annual Meeting
held in San Francisco on 26 April 2006. The report was based
upon a European Multi-center Study that was tabulated in Leuven,
Belgium and consisted of 67 patients, some of whom have been
monitored for up to 9 years. The authors identified several
unanticipated consequences of the "artificial disc" that was used
in this study (the "Bryan"-type device shown in Figures 15 & 16
above.) Whereas it was hoped that progression of
Spondylosis (Bone Spur formation) at the adjacent Cervical Levels would
be markedly reduced, if not aborted entirely, in actual fact there
was progression of the Spondylosis at the adjacent level(s) in 20 of 38
It appears that the device designers and manufacturers, have
underestimated the likelihood of significant PROGRESSION of
DEGENERATIVE SPONDYLOSIS (BONE Spurs) AT THE OPERATED LEVEL(S)
as well as impressive progression of paravertebral calcification
(calcification in the "Lateral Longitudinal Ligaments" and the
"Uncovertebral Joints" that are positioned on either side of each
Vertebra) in 22.4% of these patients. (For information on
"Uncovertebral Joints" see Figure 5B of the previous Section)
In fact, once one understands the underlying pathological anatomy
and the progressive nature of the Degenerative process, it becomes
clear that MOTION IS, IN PART, THE SOURCE OF THE DEGENERATIVE ARTHRITIC
CHANGES. Therefore IF A PATIENT ALREADY HAS DEGENERATIVE ARTHRITIS AT
THE "ADJACENT LEVEL(S)", ONE WOULD EXPECT THE NATURAL PROGRESSION OF
THAT DISEASE PROCESS (at the "adjacent levels") WHETHER OR NOT MOTION
IS "PRESERVED" AT THE OPERATED LEVEL.
IN A SIMILAR WAY, IF THERE IS ANY "ARTHRITIS" REMAINING AT THE
OPERATED LEVEL (SUCH AS POSTERIOR SPURS AND/OR HYPERTROPHIC
UNCOVERTEBRAL JOINTS), THEN THE "PRESERVATION OF MOTION" WILL
UNDOUBTEDLY RESULT IN PROGRESSION OF BONE SPUR GROWTH AT THE OPERATIVE
LEVEL. IT IS, THEREFORE, HIGHLY LIKELY IN OPERATIVE CASES WHERE THERE
IS "PRESERVATION OF MOTION", THAT THERE WILL BE PROGRESSSION OF THE
UNRELIEVED SPINAL AND/OR FORAMENAL STENOSIS IF THE SURGEON FAILS TO
REMOVE THE SOURCE(S) OF THIS NARROWING.
IN OTHER WORDS, IT IS IMPERATIVE FOR THE SURGEON TO RECOGNIZE THAT
ANY PRE-EXISITING DEGENERATIVE (HYPERTROPHIC) UNCOVERTEBRAL JOINT
ARTHRITIS MUST BE REMOVED AT THE TIME OF "CERVICAL ARTHROPLASTY".
Pre-existing Hypertrophic Cervical FACET JOINT Arthritis would be
expected to progress and worsen at any level where motion is
The Medtronic Sofamor Danek Company
received FDA approval for implantation of the "PRESTIGE®" Cervical
Joint Device in mid-July 2007. This Stainless Steel device has gone
through multiple developmental stages since 1991. THE CURRENT MODEL
MOST CLOSELY REPRODUCES THE NORMAL MOTION AT THE DISC SPACE LEVEL
INCLUDING THE "SLIDING" MOTION ASSOCIATED WITH THE FACET JOINTS AT THAT
THE OPERATION TO IMPLANT THIS DEVICE is called "CERVICAL DISC
ARTHROPLASTY". An important scientific clinical study was recently
reported concerning the results in 276 patients undergoing Cervical
Arthroplasty using the "PRESTIGE®" "ARTIFICIAL CERVICAL JOINT" followed
for up to 2 years (October 2002-August 2004) and COMPARED TO "MATCHED
PATIENTS" UNDERGOING SINGLE LEVEL ANTERIOR CERVICAL FUSION. For those
patients in whom this
"PRESTIGE®" Cervical Joint Device
was implanted, the study suggested a favorable clinical outcome compared
to a similar number of patients who underwent a more standard "Anterior
Cervical Fusion". Although this comprises a relatively small group of
patients followed for a short time, the results are significant.
A video relating to this device is available online.
THIS DEVICE CANNOT BE USED IN PATIENTS WHERE THERE IS:
For additional information and/or to determine who qualifies for
any of these procedures, please
CONTACT OUR OFFICE.
This website also offers
Cervical Spine Disease monographs
which you may download at your convenience.
- LOCAL INFLAMMATION
- SEGMENTAL INSTABILITY (ABNORMAL MOTION AT THE CERVICAL LEVEL BEING CONSIDERED FOR "ARTHROPLASTY")
- MORBID OBESITY
- MENTAL ILLNESS OF INCOMPETENCY
- DOCUMENTED (OR SUSPECTED) METAL ALLERGY OR INTOLERANCE
- RAPIDLY ADVANCING BONE DISEASE, BONE ABSORPTION, OSTEOPENIA OR OSTEOPOROSIS
- KNOWN HEREDITARY OR ACQUIRED BONE FRIABILITY OR CALCIFICATION PROBLEMS
- IMMATURE GENERAL SKELETAL GROWTH (PEDIATRIC-TYPE)
- METABOLIC BONE DISEASE OR SEVERE OSTEOMALACIA
- CERVICAL SPINE TUMOR,
CERVICAL SPINE INFECTION,
CERVICAL SPINE CONGENITAL ANOMALIES,
LOCAL OPERATING SITE FRACTURE, ELEVATED SEDIMENTATION RATE OR MARKED
"LEFT SHIFT" IN THE WBC (WHITE BLOOD CELL) "DIFFERENTIAL COUNT"
(This latter finding would indicate an "inflammatory" condition or
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This page last edited on 2/19