Product Description
The Zyston Straight Spacer System was designed to restore
height and lordotic angle in the spine. The Zyston Straight Spacer
System is available in two styles (lordotic and convex), in a variety
of lengths, widths and heights to optimize fit. The convex style is
elliptical in shape to match the natural contours of the endplates
with an endplate sparing design to resist subsidence. The lordotic
style is tapered to aid in the restoration of lordosis in the
anterior-posterior plane with an endplate sparing design to resist
subsidence. The top and bottom walls of the implant body have serrated
teeth to provide stability by engaging the endplates to help resist
shear and rotational forces. Curved superior and inferior surfaces
provide structural integrity. The central area allows for placement of
autograft material allowing for subsequent bone growth through the
interior of the device. When used for vertebral body replacement, bone
graft material may be used. The PEEK-OPTIMA™ LT1 material (PEEK-OPTIMA
is a trademark of Invibio Limited) is radiolucent and permits
unobstructed radiographic assessment of the fusion mass. However, due
to its radiolucency, the Zyston Straight device has tantalum markers
within the body of the spacer to help visualize implant orientation
within the spine during surgery and post-operatively. A threaded
insertion feature is machined into the PEEK body to allow use of an inserter.
The Zyston Curve Interbody Spacer System is intended to be
inserted into the intervertebral disc space for intervertebral body
fusion. The Zyston Curve Interbody Spacer is designed to restore
height and lordotic angle in the spine. The Zyston Curve
Interbody Spacer is available in two lengths (27mm and 32mm), two
lordotic angles (0 and 6 degrees) and in heights from 7mm to 18mm in
one millimeter increments. The device is curved (kidney shaped) to
match the anatomical shape of the anterior spine with an endplate
sparing design to resist subsidence. The spacer has a tapered leading
edge to aid in insertion of the implant, and allows the implant to be
self-distracting. The spacer has teeth on the endplate-engaging
surfaces to provide stability, resist shear and rotational forces, and
to help prevent migration of the spacer within the disc space. The
open central cavity allows for placement of autograft material
allowing for subsequent bone growth through the interior of the
device. The Zyston Curve Spacer is a lumbar spacer with an internal
articulating feature to facilitate implant placement. The design
incorporates a threaded titanium insert which has the potential to
pivot within the body of the spacer. When connected to the inserter,
the insert allows the implant to pivot relative to the shaft, enabling
the user to guide the implant into the desired position within the
intervertebral space. The PEEK -OPTIMA™(a trademark of Invibio
Limited) material is radiolucent and permits unobstructed radiographic
assessment of the fusion mass. However, due to its radiolucency, the
Zyston Curve device has tantalum markers within the body of the spacer
to help visualize implant orientation within the spine during surgery
and post-operatively.
Indications
The Zyston Straight Spacer System is indicated for vertebral
body replacement and intervertebral body fusion. When used for
vertebral body replacement, the Zyston Straight Spacer System is
indicated for use in the thoracolumbar spine (i.e., T1- L5) for
partial replacement of a diseased vertebral body resected or excised
for the treatment of tumors in order to achieve anterior decompression
of the spinal cord and neural tissues, and to restore the height of a
collapsed vertebral body. The Zyston Straight Spacer System is also
indicated for treating fractures of the thoracic and lumbar spine.
The Zyston Straight Spacer System is designed to restore the
biomechanical integrity of the anterior, middle, and posterior spinal
column even in the absence of fusion for a prolonged period of time.
When used for vertebral body replacement, the Zyston Straight Spacer
System is designed for use with bone graft and is intended for use
with supplemental fixation systems cleared for use in the
thoracolumbar spine. As an intervertebral body fusion device, the
Zyston Straight Spacer System is indicated for intervertebral body
fusion at one level or two contiguous levels in the lumbar spine from
L2 to S1 in patients with degenerative disc disease (DDD) with up to
Grade 1 spondylolisthesis at the involved level(s). DDD is defined as
back pain of discogenic origin with degeneration of the disc confirmed
by patient history and radiographic studies. These patients should be
skeletally mature and have had six months of non-operative treatment.
When used as an intervertebral body fusion device, the Zyston Straight
Spacer System is designed for use with autograft to facilitate fusion
and is intended for use with supplemental fixation systems cleared for
use in the lumbar spine. The Zyston Straight Spacer System may also be
implanted using the AccuVision System to provide the surgeon with a
minimally invasive approach for posterior or posterolateral spinal surgery.
The Zyston Curve Interbody Spacer System is indicated for
intervertebral body fusion at one level or two contiguous levels in
the lumbar spine from L2 to S1 in patients with degenerative disc
disease (DDD) with up to Grade 1 spondylolisthesis at the involved
level(s). DDD is defined as back pain of discogenic origin with
degeneration of the disc confirmed by patient history and radiographic
studies. These patients should be skeletally mature and have had six
months of non-operative treatment. The Zyston Curve Interbody Spacer
System is designed for use with autograft to facilitate fusion and is
intended for use with supplemental fixation systems cleared for use in
the lumbar spine. The Zyston Curve Interbody Spacer System may also be
implanted using the Accuvision System to provide the surgeon with a
minimally invasive approach for posterior or posterolateral spinal surgery.
Contraindications
Contraindications include, but are not limited to:
- Infection, systemic, spinal or localized
- Morbid
obesity
- Signs of local inflammation
- Fever or
leukocytosis
- Metal sensitivity/allergies to the implant
materials
- Any medical or surgical condition which would
preclude the potential benefit of spinal implant surgery, such as
the elevation of sedimentation rate unexplained by other diseases,
elevation of white blood count (WBC), or a marked left shift in the
WBC differential count
- Grossly distorted anatomy due to
congenital abnormalities
- Rapid joint disease, bone
absorption, osteopenia, and/or osteoporosis (osteoporosis is a
relative contraindication since this condition may limit the degree
of obtainable correction, the amount of mechanical fixation, and/or
the quality of the bone graft)
- Any case not needing a bone
graft and fusion or where fracture healing is not required
- Any case requiring the mixing of metals from different
components
- Any patient having inadequate tissue coverage over
the operative site or where there is inadequate bone stock, bone
quality, or anatomical definition
- Any case not described in
the indications
- Any patient unwilling to cooperate with the
postoperative instructions
- Any time implant utilization
would interfere with anatomical structures or expected physiological
performance.
- Prior fusion at the level(s) to be treated.
Warnings
The surgeon should be aware of the following:
- The correct selection of the implant is extremely important.
The potential for success is increased by the selection of the
proper size, shape and design of the implant. The size and shape of
the human spine presents limiting restrictions of the size and
strength of implants. No implant can be expected to withstand the
unsupported stresses of full weight bearing.
- The surgeon
must ensure that all necessary implants and instruments are on hand
prior to surgery. The device must be handled and stored carefully,
protected from damage, including from corrosive environments. They
should be carefully unpacked and inspected for damage prior to
use.
- All instruments must be cleaned and sterilized prior to
surgery.
- As with all orthopaedic implants, the Zyston
Straight Spacer System and the Zyston Curve Interbody
Spacer System should never be reused under any
circumstances.
- Proper implant selection and patient
compliance to postoperative precautions will greatly affect surgical
outcomes. Patients who smoke have been shown to have an increased
incidence of nonunion. Therefore, these patients should be advised
of this fact and warned of the potential consequences.
- Postoperative care is important. The patient should be
instructed in the limitations of his/her implant and should be
cautioned regarding weight bearing and body stress on the appliance
prior to secure bone healing.
- The Zyston Straight Spacer
System and Zyston Curve Interbody Spacer System have not
been evaluated for safety and compatibility in the MR environment.
The Zyston Straight Spacer System and Zyston Curve
Interbody System have not been tested for heating or migration
in the MR environment.
- Patients with previous spinal
surgery at the level(s) to be treated may have different clinical
outcomes compared to those without a previous surgery.
- Biomet Spine implants should not be used with implants or
instruments from another manufacturer for reasons of metallurgy,
mechanics and design.
- Based upon dynamic testing results,
the physician should consider the levels of implantation, patient
weight, patient activity level, other patient conditions, and any
other factor which may impact on the performance of the device.
Precautions
Preoperative:
- Only patients that meet the criteria described in the
indications should be selected.
- Patient conditions and/or
pre-dispositions such as those addressed in the Contraindications
Section should be avoided.
- Care should be used in the
handling and storage of the implant components. The implants should
not be scratched or otherwise damaged. Implants and instruments
should be protected during storage especially from corrosive
environments.
- All instruments should be cleaned and
sterilized before use.
Intraoperative:
- Any instruction manuals should be carefully followed.
- At all times, extreme caution should be used around the spinal
cord and nerve roots. Damage to nerves may occur resulting in a loss
of neurological functions.
Postoperative:
- The physician’s postoperative directions and warnings to the
patient and the corresponding patient compliance are extremely
important.
- Detailed instructions on the use and limitations
of the device should be given to the patient. If partial
weight-bearing is recommended or required prior to firm bony union,
the patient must be warned that bending, loosening or breakage of
the components are complications which can occur as a result of
excessive or early weight-bearing or excessive muscular activity.
The risk of bending, loosening, or breakage of an internal fixation
device during postoperative rehabilitation may be increased if the
patient is active, or if the patient is debilitated, demented, or
otherwise unable to use crutches or other such weight supporting
devices. The patient should be warned to avoid falls or sudden jolts
in spinal position.
- To allow maximum chances for a
successful surgical result, the patient or device should not be
exposed to mechanical vibrations that may loosen the device
construct. The patient should be warned of this possibility and
instructed to limit and restrict physical activities, especially
lifting, twisting motions and any type of sport participation. The
patient should be advised not to smoke or consume alcohol during the
bone graft healing process.
- If a nonunion develops or if
the components loosen, bend, and/or break, the device(s) should be
revised and/or removed immediately before serious injury occurs.
Failure to immobilize a delayed or nonunion of bone will result in
excessive and repeated stresses on the implant. By the mechanism of
fatigue these stresses can cause eventual bending, loosening, or
breakage of the device(s). It is important that immobilization of
the spinal surgical site be maintained until firm bony union is
established and confirmed by radiographic examination. The patient
must be adequately warned of these hazards and closely supervised to
ensure cooperation until bony union is confirmed.
- Do not
reuse implants. While an implant may appear undamaged, previous
stress may have created imperfections that would reduce the service
life of the implant. Do not treat patients with implants / devices
that have been even momentarily placed in or used on a different
patient.
Adverse Effects and Complications
Possible adverse effects include, but are not limited to:
- Bending, loosening or fracture of the implants or
instruments
- Loss of fixation
- Sensitivity to a
metallic foreign body, including possible tumor formation
- Skin or muscle sensitivity in patients with inadequate tissue
coverage over the operative site, which may result in skin breakdown
and/or wound complications
- Nonunion or delayed union
- Infection
- Nerve or vascular damage due to surgical
trauma, including loss of neurological function, dural tears,
radiculopathy, paralysis and cerebral spinal fluid leakage
- Gastrointestinal, urological and/or reproductive system
compromise, including sterility, impotency and/or loss of
consortium
- Pain or discomfort
- Bone loss due to
resorption or stress shielding, or bone fracture at, above or below
the level or surgery (fracture of the vertebra)
- Hemorrhage
of blood vessels and/or hematomas
- Misalignment of
anatomical structures, including loss of proper spinal curvature,
correction, reduction and/or height
- Bursitis
- Bone
graft donor site pain
- Inability to resume activities of
normal daily living
- Reoperation
- Death
