Braun Aesculap Orthopaedics Metha Mode D'emploi page 2

Metha® short-stem prosthesis
Intended use
The implant is used:
• as a component of a human hip endoprosthesis: Hip endoprosthesis stem
• to combine with Aesculap hip endoprosthesis components
• for implantation without bone cement
The short stem is available as either modular or non-modular implant.
The modular short stem consists of:
• Prosthesis stem
• Modular cone adapter
Materials
The materials used in the implant are listed on the package.
• ISOTAN®F titanium forged alloy Ti6Al4V acc. to ISO 5832-3
• PLASMAPORE®µ-CaP surface coating made of pure titanium acc. to
ISO 5832-2 with additional calcium phosphate layer
• ISODUR® cobalt chrome alloy CoCr29Mo acc. to ISO 5832-12
ISOTAN®, ISODUR® and PLASMAPORE® are registered trademarks of
Aesculap AG, 78532 Tuttlingen / Germany.
Indications
Use for acute disorders of the hip that cannot be treated by other therapies:
• Degenerative osteoarthritis
• Rheumatic arthritis
• Femoral head necrosis
Contraindications
Do not use in the presence of:
• Joint diseases that can be treated by reconstructive surgery (e.g.
displacement osteotomy)
• Acute or chronic periarticular or systemic infections
• Secondary diseases that could influence joint implant functionality
• Systemic conditions and metabolic disorders influencing the functioning
of the joint implant
• Acute osteoporosis or osteomalacia
• Severely damaged bone structures that could prevent stable implantation
of implant components
• Bone tumors in the region of implant fixation
• Bone deformities, axis misalignments, or other bone conditions that rule
out the implantation of a hip joint prosthesis preserving the collum
femoris
• Expected overload on the joint implant, especially due to high patient
weight or major physical strains and activities
• Medicinal or other drug abuse or alcohol addiction affecting the
functionality of the joint implant, especially through temporary loss of
control or impairment of the implant integration in the bone
• Expected lack of patient cooperation in dealing with the joint implant,
especially during rehabilitation, and non-compliance with doctors'
recommendations
• Foreign body sensitivity to the implant materials
• Skeletal immaturity
• Neuromuscular diseases impairing the affected extremity
• Cups whose implantation, in analogy to ISO 21535:2002, result in a
limited range of movement (less than 80° in flexion/extension or less than
60° in abduction/adduction), e.g. Bipolar cup.
• Prosthesis heads with neck length XL in combination with short-stem
prosthesis sizes 0 and 1.
• Prosthesis heads with neck length XXL
Side-effects and adverse interactions
• Dislocation, loosening, wear, corrosion and fracture of implant
components
• Joint dislocation and postoperative changes in leg length
• Primary and secondary infections
• Venous thrombosis, lung embolism, and cardiac arrest
• Tissue reaction to implant materials
• Injury to blood vessels and nerves
• Hematomas and wound healing disorders
• Periarticular calcification
• Reduced joint mobility and flexibility
• Arthralgia and reduced tolerance for exercise
Safety notes
• It is the operating surgeon's responsibility to ensure that the surgical
procedure is performed properly.
• General risk factors associated with surgical procedures are not described
in the present documentation.
• The operating surgeon must have a thorough command of both the
hands-on and conceptual aspects of the established operating
techniques.
• The operating surgeon must be thoroughly familiar with bone anatomy,
including the pathways of nerves, blood vessels, muscles and tendons.
• It is the operating surgeon's responsibility to ensure the correct
combination of implant components and their implantation.
• Aesculap is not responsible for any complications arising from incorrect
establishment of indication, incorrect choice of implant, incorrectly
combined implant components and/or operating techniques, the
limitations of treatment methods, or lack of asepsis.
• The instructions for use of the individual Aesculap implant components
must be observed.
• Do not use damaged or surgically excised components under any
circumstances.
• Implants that have been used once may not be reused.
• The implant components applied, along with their article numbers, the
name of the implant, as well as the batch number and serial number (if
available) must be documented in all patient records.
• During the postoperative phase, in addition to mobility and muscle
training, it is of particular importance that the physician keeps the
patient well informed.
• Damage to load-bearing bone structures can result in loosening of the
components, bone or implant fractures or other acute complications.
• To ensure the earliest possible detection of such catalysts of implant
dysfunction, the prosthetic joint must be checked periodically, using
appropriate techniques.
• Combine modular implant components only with suitable Aesculap hip
endoprostheses.
• Observe material, friction coupling diameter and cone specifications.
• Observe further restrictions for combined implants.
• Avoid damaging the implant, especially in the neck or cone region, by
applying instruments (e.g. HF surgical devices) close to the implant.
Risk of implant component breakage due to
combination with implant components from other
manufacturers!
Use Aesculap implant components only.
CAUTION
Sterility
• The implant components come individually packed in protective
packaging that is labeled according to its contents.
• The implant components have been sterilized by irradiation (min. dose
25 kGy).
Store implant components in their original packaging. Remove them
from their original protective packaging only just prior to application.
Prior to use, check the product expiry date and verify the integrity of the
sterile packaging. Do not use implant components that are past their
expiry date or whose packaging is damaged.
Do not resterilize the prosthesis stem.
Implants made of non-coated metal may be individually resterilized in steam
following appropriate preliminary cleaning and disinfecting.
Make certain that such implants are not damaged during cleaning and
sterilization.
The protective prosthesis cone caps (labeled accordingly) can be
resterilized with steam.
The responsibility for resterilization of implant
components lies with
resterilization is expressly prohibited by law in
certain countries (e.g. France).
Never resterilize and reuse surface-coated
WARNING
implants (PLASMAPORE®µ-CaP).
Sterilization method and parameters
Sterilize with steam according to the following rules:
Sterilization must be carried out through a validated steam sterilization
process (e.g. in a sterilizer according to EN 285/ANSI/AAMI/ISO 11134-
1993, ANSI/AAMI ST46-1993 and validated according to EN 554/
ISO 13683). For the fractionated vacuum process, sterilization must be
carried out using the 134 °C/2 bar program with a minimum holding
time of 5 minutes.
Application
The operating surgeon shall devise an operation plan that specifies and
accurately documents the following:
• Selection of the implant components and their dimensions
• Positioning of the implant components in the bone
• Location of intraoperative landmarks
The following conditions must be fulfilled prior to application:
• All requisite implant components are ready to hand
• Operating conditions are highly aseptic
• Implantation instruments, including the special Aesculap implant system
instruments, are complete and functional.
• The operating surgeon and operating room team are thoroughly
conversant with the operating technique and with the available range of
implants and instruments; information materials on these subjects must
be complete and ready to hand.
• The operating surgeon is familiar with the rules governing medical
practice, the current state of scientific knowledge, and the contents of
relevant scientific articles by medical authors.
• The manufacturer has been consulted if the preoperative situation was
unclear and if implants were found in the area operated on.
The surgical intervention has been explained to the patient and their
agreement concerning the following information has been recorded:
• The functionality of the prosthetic joint is essentially inferior to that of
the natural one.
• The prosthetic joint can bring about only limited improvement in the
patient's condition vis-à-vis their condition prior to the operation.
• The prosthetic joint insert can come loose due to excessive load, wear and
tear, or infection.
• The lifespan of the prosthetic joint depends on the body weight and the
load put on the joint.
• The prosthetic joint insert must not be subjected to overload through
extreme strain, or through work-related or athletic activities.
• Corrective surgery may become necessary if the implant loosens.
• In the event that corrective surgery is performed, it may not be possible
under certain circumstances to restore joint mobility and flexibility.
• The patient must undergo medical follow-up examinations of the
prosthetic joint at regular intervals.
The implantation site is prepared in the following way:
Following a high femoral neck osteotomy, open the femur with the
implant-specific awl.
Introduce the awl until it reaches the lateral corticalis.
Bone fractures/perforations in the implant bed will
adversely affect the implant fixation!
Avoid bone fractures by applying careful
operative techniques.
Treat bone fractures with appropriate intra-
WARNING
and postoperative therapies.
Handle the implant components properly.
Gradually prepare the implant bed with the implant-specific form rasps
(starting with the smallest size).
Check and, if necessary, correct the implant position, depth and
antetorsion.
Check the stem size against the form rasp that was introduced last in
the correct position.
Attach the rasp trail adapter and perform trial reposition with the
appropriate trial heads; change rasp trial adapter or trial heads as
appropriate.
Check the mobility/range of movement and stability of the joint and the
length of the leg.
Remove the trial implants and the rasp.
When using the modular short stem, couple the prosthesis shaft and the
modular cone adapter prior to insertion.
WARNING
Insert the short shaft (modular/non-modular) with specific insertion
instruments.
WARNING
Optional procedure
Trial reposition with inserted modular short stem
Remove the trial cone adapter only after the stem component has been
impelled.
Insert the stem component and punch it into the implant bed with well-
dosed blows.
If necessary, change the trial cone adapter, making certain that the
arrow points to "MEDIAL".
Carry out a trial reposition.
Check the mobility/range of movement and stability of the joint and the
length of the leg.
the end-user. Such Remove the trial implants.
WARNING
Select the implant cone adapter according to the fitting trial cone
adapter.
Carefully insert the implant cone adapter in the short stem already
implanted, making certain that the arrow points to "MEDIAL".
Fixate the implant cone adapter with hammer taps on the appropriate
insertion instrument.
Concluding steps for applying (modular/non-modular) short stems
Select a prosthesis ball according to the trial heads.
Verify that the cone size of the prosthesis stems are the same as the
cone size of the prosthesis heads (see cone size on the implant
packaging, e.g. 12/14).
Rinse, clean and dry the outside cone of the stem and, if necessary, the
inside cone of the prosthesis heads prior to setting the prosthesis head
in place.
Do not remove the protective cap until immediately before positioning
the prosthesis head.
Attach the prosthesis ball and prosthesis cone to each other at room
temperature only. If necessary, allow the implant to cool down to room
temperature.
Put the prosthesis ball in its position.
In order to forestall abnormal wear and tear on the prosthesis: Remove
all obvious bone cement residues and bone chips before closing the
wound.
Further information on B. Braun/Aesculap implant systems can be obtained
from B. Braun/Aesculap or the relevant B. Braun/Aesculap agency.
TA-Nr.: 012200
Implant malfunction due to insufficiently fixated
cone adapter!
Fixate the modular cone adapter in the short
stem by applying a hammer blow and using
instrument ND401R.
Securely fixate the modular cone adapter in
the short stem.
Loosening of the cone adapter during insertion
caused by impacting on the Metha stem!
Carry out the insertion procedure by impact-
ing on the cone adapter with the protective
cone cape in place.
Fracture and increased wear of the modular
implant components, or loosening of the implant
connection due to soiled or damaged joining
surfaces!
Carefully rinse the inside cone of the stem
and the joining surfaces of the cone adapter;
clean with cleaning swabs (ND619 or ND622)
and dry.
Check the joining surfaces for any damage.
Do not join modular implant components
more than once.
Always rinse, clean and dry the cone prior to
joining.
06/08 Änd.-Nr.: 32006