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of implants. The amount of metal compounds released
into the body system will also increase. Internal fixation
devices, such as rods, hooks, wires, etc., that come into
contact with other metal objects, must be made from like
or compatible materials.
4.
PATIENT SELECTION. In selecting patients for internal
fixation devices, the following factors can be extremely
important to the eventual success of the procedure:
A.
The patient’s occupation or activity. If the patient is
involved in an occupation or activity that includes heavy
lifting, muscle strain, twisting, repetitive bending, stoop-
ing, running, substantial walking, or manual labor, he/
she should not return to these activities until the bone
is fully healed. Even with full healing, the patient may
not be able to return to these activities successfully.
B.
A condition of senility, mental illness, alcoholism,
or drug abuse. These conditions, among others, may
cause the patient to ignore certain necessary limitations
and precautions in the use of the appliance, leading to
implant failure or other complications.
C.
Certain degenerative diseases. In some cases, the pro-
gression of degenerative disease may be so advanced
at the time of implantation that it may substantially
decrease the expected useful life of the appliance. For
such cases, orthopedic devices can only be considered
a delaying technique or temporary remedy.
D.
Foreign body sensitivity. The surgeon is advised that
no pre-operative test can completely exclude the pos-
sibility of sensitivity or allergic reaction. Patients can
develop sensitivity or allergy after implants have been
in the body for a period of time.
E.
Smoking. Patients who smoke have been observed
to experience higher rates of pseudarthrosis follow-
ing surgical procedures where bone graft is used.
Additionally, smoking has been shown to cause diffuse
degeneration of intervertebral discs. Progressive
degeneration of adjacent segments caused by smoking
can lead to late clinical failure (recurring pain) even
after successful fusion and initial clinical improvement.
PRECAUTIONS
1.
SURGICAL IMPLANTS MUST NEVER BE REUSED. An
explanted implant should never be reimplanted. Even
though a device appears undamaged, it may have small
defects and internal stress patterns that may lead to early
breakage. Reuse can compromise device performance
and patient safety. Reuse of single use devices can also
cause cross-contamination leading to patient infection.
2.
CORRECT HANDLING OF THE IMPLANT IS
EXTREMELY IMPORTANT. Contouring of metal implants
should be done only with proper equipment. The operat-
ing surgeon should avoid any notching, scratching or
reverse bending of the devices when contouring. Altera-
tions will produce defects in surface finish and internal
stresses that may become the focal point for eventual
breakage of the implant.
3.
BENDING THE CONSTRUCT. Titanium alloy components
should never be bent sharply or reverse bent. If a
construct is over-contoured it is recommended that a new
construct is contoured correctly rather than reverse bend-
ing the over-contoured construct.
4.
REMOVAL OF THE IMPLANT AFTER HEALING. If
the device is not removed after the completion of its
intended use, any of the following complications may
occur: (1) Corrosion, with localized tissue reaction
or pain; (2) Migration of implant position resulting in
injury; (3) Risk of additional injury from post-operative
trauma; (4) Bending, loosening, and/or breakage, which
could make removal impractical or difficult; (5) Pain,
discomfort, or abnormal sensations due to the presence
of the device; (6) Possible increased risk of infection;
and (7) Bone loss due to stress shielding. The surgeon
should carefully weigh the risks versus benefits when
deciding whether to remove the implant. Implant removal
should be followed by adequate postoperative manage-
ment to avoid refracture or deformity. If the patient is
older and has a low activity level, the surgeon may
choose not to remove the implant thus eliminating the
risks involved in a second surgery.
5.
ADEQUATELY INSTRUCT THE PATIENT. Postoperative
care and the patient’s ability and willingness to follow
instructions are among the most important aspects of
successful bone healing. The patient must be made aware
of the limitations of the implant, and instructed to limit and
restrict physical activities, especially lifting and twisting
motions and participating in any type of sports. The patient
should understand that a metallic implant is not as strong
as normal healthy bone and could loosen, bend and/or
break if excessive demands are placed on it, especially
in the absence of complete bone healing. Implants
displaced or damaged by improper activities may migrate
and damage the nerves or blood vessels. An active,
debilitated, or demented patient who cannot properly
use weight supporting devices may be particularly at risk
during postoperative rehabilitation.
POSSIBLE ADVERSE EFFECTS
1. Nonunion, delayed union.
2. Bending or fracture of implant. Loosening of the implant.
3. Metal sensitivity, or allergic reaction to a foreign body.
4. Infection, early or late.
5. Decrease in bone density due to stress shielding.
6. Pain, discomfort, or abnormal sensations due to the
presence of the device.
