Epoca Shoulder Arthroplasty System – Fracture. Hemi and total joint replacement for fractures. Surgical Technique This publication is not intended for distribution in the USA. Instruments and implants approved by the AO Foundation. Discontinued – December 2018 103408-181130
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Epoca Shoulder Arthroplasty System – Fracture. Hemi and total joint replacement for fractures.
Surgical Technique
This publication is not intended for distribution in the USA.
Instruments and implants approved by the AO Foundation.
WarningThis description alone does not provide sufficient background for direct use of DePuy Synthes products. Instruction by a surgeon experienced in handling these products is highly recommended.
Processing, Reprocessing, Care and MaintenanceFor general guidelines, function control and dismantling of multi-part instruments, as well as processing guidelines for implants, please contact your local sales representative or refer to:http://emea.depuysynthes.com/hcp/reprocessing-care-maintenanceFor general information about reprocessing, care and maintenance of Synthes reusable devices, instrument trays and cases, as well as processing of Synthes non-sterile implants, please consult the Important Information leaflet (SE_023827) or refer to: http://emea.depuysynthes.com/hcp/reprocessing-care-maintenance
Epoca Shoulder Arthroplasty System.Anatomic reconstruction of the proximal humerus.
The Epoca resurfacing head is intended for minimally invasive treatment of early stage arthritis or other arthropathies with cartilage damage. – Thin surface allows for minimum
bone removal – Anatomic reconstruction of
articulat ing surface – Stable and bone sparing crown
fixation – TiNb coated version for nickel
sensitive patients
Head
– Height proportional to radius – Anatomic design – Can be adjusted for medial
and posterior fit – TiNb coated version for nickel
sensitive patients
Stem
The Epoca Shoulder Arthroplasty sys-tem aims to restore glenohumeral kine-matics in fractures and degenerative cases. The Epoca implant facilitates anatomic reconstruction of the proxi-mal humerus. – Anatomic design mimics contour of
the medial calcar and medullary canal
– Non-protruding lateral design reduces risk of damage to the inser-tion facet of the supraspinatus tendon
– Medial and lateral holes in the stem allow for stable reattachment of the tuberosities
– Available in a variety of diameters and lengths, L and XL stems for revision
– Titanium for nickel sensitive patients
RH Resurfacing Head Stem for Fractures and Degenerative Conditions
The Epoca shoulder prosthesis is intended for use as a hemi- or total shoulder replacement – Ensures congruent glenohumeral
implant surfaces to achieve normal range of motion
– Reduced size and beveled rim for normal mobility and reduced risk of impingement
– Hybrid application with shell screws – Cementless application with metal-
back glenoid
The Epoca Reco glenoid reconstruction device is intended to reestablish a stable fulcrum in order to prevent antero superior subluxation of the humeral head.
Indications – Irreparable fractures of the proximal humerus – Posttraumatic conditions with advanced joint destruction – Failed previous osteosynthesis
A glenoid component may be indicated in cases of cartilage destruction or in case of an associated irreparable glenoid fracture where gleno-humeral stability is a concern. Contraindications – Infections, acute or chronic, local or systemic – Severe muscular, neurological or vascular deficiencies,
which compromise the affected extremity – Destruction of bone or poor bone quality, which may
affect stability of the implant – Any concomitant disease which may compromise the
function of the implant – Any other pathology which needs treatment priority
Conditions which can adversely affect joint replacement success – Severe osteoporosis – Severe deformities, congenital dislocation – Allergic reaction to any of the materials used – Local tumors of the bone – Systemic and metabolic disorders – History of infectious disease – History of falls – Drug or alcohol addiction and / or abuse – Obesity – High level of physical activity, involving shocks and
shaking in which the prosthesis is subject to pounding and / or excessive strains (e.g.: heavy physical labor, repetitive stress from sports, etc.)
Complete the preoperative radiographic assessment withstandard AP, lateral and axillary views. A CT scan is required when the axillary view is not optimal, i.e. when more infor-mation about the lesser tuberosity is required.
An AP view of the contralateral humerus is optional. It is helpful to estimate the size of the prosthetic head and stem.
Place the template on the AP view of the contralateral humerus to estimate the head and stem size. Then, draw the outer contour of the proximal humerus and the implant on transparent paper or on an electronic support using a com-puter assisted planning tool.
Flip the image horizontally and superimpose it on the patho-logical side. Determine the required corrections.
Preoperative planning for glenoid replacementGlenoid replacement may be indicated in cases of anterior fracture dislocations which are associated with significant glenoid fractures, such as Ideberg type II fractures. When planning a glenoid replacement procedure, axial CT scan views are recommended in order to assess the amount of glenoid damage and the correction needed.
Additionally, a CT-based three-dimensional reconstruction of the glenoid (with the removal of the humeral head from the 3-D model) could help estimate the shape and size of glenoid defects.
Standard deltopectoral approachStart the incision over the acromioclavicular joint and extend it 8 cm inferior over the anterior deltoid, lateral to the del-topectoral groove. Alternatively, follow Langer’s skin tension lines starting from the acromioclavicular joint.
Open the fascia over the deltopectoral groove and identify the cephalic vein. Retract the deltoid with the cephalic vein laterally, and the pectoralis major medially.
Incise the clavipectoral fascia.
Hemiarthroplasty for Fractures
2Expose fracture
Irrigate and remove the hematoma to expose the fracture. Check the vascularity of the humeral head and confirm that joint replacement is the optimal form of care.
Pass stay sutures through the infraspinatus tendon to aid manipulation of the greater tuberosity fragment.
Expose and transect the biceps tendon in its extraarticular path. Suture the biceps tendon to the pectoralis major fascia.
Locate the split in the supraspinatus tendon induced by the fracture. Enlarge the split in the supraspinatus tendon, as required, for access to the joint.
Retrieve the fractured humeral head and set it aside for later use. Examine the glenoid. Consider ORIF or glenoid replace-ment if there is a relevant fracture of the glenoid or glenoid rim.
Pass stay-sutures through the subscapularis, supraspinatus, and infraspinatus tendons.
Drill two holes in the greater tuberosity with a 2.0 mm drill bit. The two holes should be approximately aligned with the medial and lateral perforations of the prosthetic stem. Drill the holes close to the point of transition from tendon to bone.
Using the wire portion of the wire-cable, pass the 1.0 mm wire-cables through the drill holes. Alternatively, cerclage wires or high strength sutures can be used. Park the wire- cables posteriorly, so that they do not interfere with the remaining steps of the procedure.
Note: The wire portion of the wire-cable can be shortened to the desired length.
Expose the shaft by extending, adducting, and externally rotating the humerus.
Osteotomize any remaining metaphyseal extensions to better visualize the head. Compare the retrieved humeral head with the available trial heads. Choose the trial head that closely matches the retrieved head. Save the humeral head for later use as bone graft.
Note: If the AP and lateral radii differ, choose an intermedi-ate trial head size.
Hemiarthroplasty for Fractures
4Determine stem height
Instrument
03.401.083 Ruler, length 250 mm, Stainless Steel
Measure the medial metaphyseal extension on the retrieved head. This distance determines the precise height of the stem, i.e: how much the stem must protrude in respect to the medial fracture line. Note the height for later reference.
03.401.084 Curette, oval, with Toothing, length 300 mm
Probe and clean the medullary cavity with a sharp curette. Insert the size 6 rasp into the canal.
To check the rotational alignment, insert the 6.0 mm retro-torsion bar into the threaded hole of the rasp. Hold the gonio meter onto the lateral side of the retrotorsion bar. For the first rough adjustment, align the rasp to 25° retrotorsion with reference to the axis of the forearm. This measurement reflects the median retrotorsion value for a normal popula-tion.1
Hammer in the rasp until proper seating is obtained. If the rasp penetrates too deep into the medullary cavity, use the next larger rasp size until the correct prosthetic height is ob-tained. Should you have difficulties fully inserting the chosen rasp, remove additional bone along the medial endosteal region using a sharp curette. This will allow the rasp to seat and self-lock a few millimeters deeper.
The pronounced calcar design provides the rasp and the implants with self-centering, self-rotating and self-locking capabilities.
Confirm the retrotorsion by cross-checking against the bicipi-tal groove. The distance between the deepest point in thebicipital groove and the center line of the rasp should beapproximately 8 mm.2
Attach the inserter/extractor to the selected trial stem. Apply controlled light blows to the top of the inserter / extractor with the hammer. Hammer until the trial stem protrudes above the shaft, as determined in step 4.
To confirm the retrotorsion of the trial stem, insert the 3.0 mm retrotorsion bar into the hole of the trial stem.
E5115-4 / 2 Screwdriver Epoca, width across 2.0 mm, for Trial Implants
E5115-4 / 3 Screwdriver Epoca, width across 2.5 mm, for Trial Implants
E5117-20 Trial Eccenter Disc
Use a 2.0 mm hex screwdriver to back out the set screws from the trial head in order to allow for correct seating. Be careful not to back out the set screws too far, as they may fall out.
Mount the trial head on the trial eccenter disc. Align the ap-propriate marking on the trial head with the center line on the trial stem (‘L’ for left humerus, ‘R’ for right humerus).
Lock the trial head in position by tightening the anterior set screw. Verify that the offset is appropriate for the patient’s anatomy. The ideal position is reached when the head meets the medial calcar line with a continuous or unbroken line, i.e.: no overhang or medial step-off.
If the offset is not appropriate, adjust the anteroposterior position and / or the mediolateral offset. Loosen the trial eccenter disc with the 2.0 mm hex screwdriver. Use the 2.5 mm hex screwdriver to rotate the trial eccenter disc until the desired head position is achieved.
Note: Should the screw in the trial head be missing, a screw from another trial head may be used instead.
For further adjustment, loosen the anterior set screw on the trial head with the 2.0 mm hex screwdriver and manually rotate the trial head until the desired position is obtained. Lock the position by tightening the set screw.
Note: The 2.0 mm hex screwdriver is used for locking and unlocking the set screws, the 2.5 mm hex screwdriver is used only to rotate the eccenter disc.
E5115-4 / 2 Screwdriver Epoca, width across 2.0 mm, for Trial Implants
E5117-20 Trial Eccenter Disc
Once the offset position of the trial head is recorded, remove the trial head using the 2.0 mm hex screwdriver.
Record the offset position of the trial eccenter disc.
Note: Record the determined offset (number and letter) as these will be used to assemble the final implants.
Remove the trial eccenter disc using the 2.0 mm hex screw-driver. Mount the inserter / extractor onto the trial stem. Lightly tap against the inserter / extractor to back out the trial stem.
Note: To avoid possible damage to the thread, ensure that the inserter / extractor is fully threaded into the trial stem.
E5115-5 / 6– Holders for Press, sizes 6 to 14E5115-5 / 14
Choose the stem holder that corresponds to the size of the shaft. Hold the half of the stem holder with two pegs with the etched side facing up. Orient the distal end of the stem toward the operator and slide the stem over the pegs. Slide the other half of the stem holder over the pegs. This assembly allows the stem to be firmly held in the press.
Note: Ensure that the etched side of the stem holder is facing up. Improper assembly may cause jamming.
Position the eccenter on the stem. Align the letter recorded during trial implantation (step 9) with the center line of the stem. Place the assembly in the press and place the eccenter/ impactor over the eccenter. Make sure that the eccenter sits flush on the stem. Using the torque wrench, turn the handle of the press clockwise in a controlled, slow motion, until a click is heard, signifying the positive engagement of the ec-center and the stem.
Turn the torque wrench counterclockwise and remove the eccenter / impactor. Remove the stem-eccenter assembly from the press.
Notes: – Handle coated stems with care to avoid disrupting
the coating. – Ensure that the etched side is readable, to allow proper
Remove the implant from the press. Remove the stem holder and check for adequate seating of the head and the eccen-ter.
Note: No visible gap should be present between the base of the head and the humeral stem.
Place the head on the stem assembly. Align the recorded offset position with the lateral marking on the implant or the contact line between the two halves of the stem holder.
Place the head and the stem eccenter assembly in the press. Compress components by turning the torque wrench clock-wise until a click is heard.
Remove the implant from the press by turning the torque wrench counterclockwise. Remove the stem holder from the implant.
Choose the final implantation method according to the type of stem being used (cemented / uncemented).
Instruments
359.221 Combined Hammer
E5115-2 Goniometer
E5115-6 Retrotorsion Bar B 3.0 mm
E5115-7 Impactor
Mount the plastic liner onto the head impactor.
Remove any excess bone cement from the collar region before it sets to provide room for bone graft.
Fill the collar region with autogenous bone graft harvested from the retrieved head to improve healing between tuber-osities and shaft.
Note: Follow the manufacturer’s instructions for prepara-tion, injection and setting of the bone cement.
12aFinal implantation for cemented stems
Do a final irrigation of the medullary canal. Insert a cement restrictor to prevent excess cement from flowing into the distal humerus.
Place a vent tube in the medullary canal. Dry the cavity. In-ject cement into the canal. Remove the vent tube while the cement is being injected.
Ensure that the implant assembly is clean before inserting it. Check the final retrotorsion using the 3.0 mm retrotorsion bar.
Insert the implant, first manually, then using the head impac-tor until the predetermined anatomic prosthetic height is reached. The implant will be protruding as defined in steps 4 and 7 of this procedure.
12bFinal implantation for pressfit, cementless stems
Introduce the prosthesis into the medullary canal. To confirm proper placement and orientation of the implant, use the 3.0 mm retrotorsion bar and the goniometer to recheck the retrotorsion. Lightly tap on the head impactor with the hammer until the implant is fully seated.
The position must correspond to the predetermined ana-tomic prosthetic height. If the implant’s position is too high, more bone rasping along the medial cortex is required. If the implant finds its stable position in a location that is too dis-tal, use a shaft one size larger. Alternatively, the smaller shaft can be stabilized in the correct position using bone cement.
Note: The implant must protrude as defined in steps 4 and 7.
Fill the collar region with autogenous bone graft harvested from the retrieved head to improve healing between tuberosities and shaft.
With the humeral head still in the anteriorly dislocated posi-tion, pass the wire-cables that were initially placed in step 3 through the greater tuberosity / rotator cuff junction through the medial and lateral perforations of the stem.
Reduce the joint i.e. the prosthetic head to the glenoid and to the greater tuberosity. Pass the wire-cable through the lesser tuberosity.
Note: After passing the wire-cable through the tuberosities and stem, cut the wire portion of the wire-cable off at the 10 mm intermediate section only.
Reduce the lesser tuberosity to the prosthesis. Use sutures to readapt the split in the rotator cuff to obtain preliminary re-duction of the tuberosities. Avoid over-reduction of the greater tuberosity, especially in a distal direction. The most medial insertion line of the supraspinatus must be fl ush with the edge of the prosthetic head, not distal to it. Fill any void under the tuberosities with cancellous bone graft harvested from the retrieved head. Use absorbable sutures for prelimi-nary reduction and adaptation of the relevant fragments.
Embrace and compress the tuberosities to the rectangular cross section of the shaft to obtain rotational stability.
Pass the end of the distal cable through the crimp and repeat the step with the proximal cable.
Tension the cables manually but do not tighten them too much. Hold the distal cable and apply the wire tightener.
Open the cable tightening nut and pass the cable. Tighten the nut so that the cable is fi x. Before fully tightening, apply the crimping pliers over the crimp.
Note: Do not tighten the cable too much before applying the crimping pliers. Once the cable is fully tightened, apply-ing the crimping pliers will be diffi cult.
Fully tighten the cable with the wire tightener. Crimp the cable using the pliers.
Repeat this step for the proximal cable.
Note: To prevent deformation of the tuberosities, be sure to not over-tension the cables. When using embracing cables, additional devascularizing vertical sutures between shaft and tuberosities are not necessary. The use of embracing cables requires a tenotomy and tenodesis of the biceps tendon.
A glenoid component may be indicated in cases where there is associated cartilage damage to the glenoid or where there are irreparable glenoid fractures in which gleno-humeral stability is a concern.
Note: The size of the glenoid implant is determined by the size of the humeral head component.
Implantation of a Glenoid Component
1Approach and exposure
Adequate exposure of the glenoid is essential for implanta-tion. Exposure must permit the use of straight instruments such as reamers and drill bits. In fractures, exposure of the glenoid generally follows the space between the tubero-sities.
Introduce a tear-drop ring retractor (or another instrument such as a Fukuda Ring Retractor) to displace the greater tuberosity in a posterior and inferior direction.
Locate the true center of the glenoid, which is slightly infe-rior to the midpoint of Saller’s line (vertical line dividing the glenoid into anterior and posterior halves). This is the slip-page point of the humeral head during concentric motion.
03.401.085 Guide Extension Epoca, rigid, with Quick Coupling
E5211-4L Drill Guide, left
E5211-4R Drill Guide, right
03.401.128 Reamer Epoca B 28 mm, for Glenoid, with Quick Coupling
03.401.132 Reamer Epoca B 32 mm, for Glenoid, with Quick Coupling
The shape of the drill guide matches the shape of the gle-noid implant. Determine the desired anatomic position of the glenoid implant by placing the drill guide (left or right) on the glenoid. The central hole of the drill guide should cover the center point located in step 2. Hold the drill guide in the corrected position. Introduce the 2.5 mm Kirschner wire and re-check the positioning.
Assemble the smallest reamer (28 mm) onto the rigid guide extension.
Note: Ensure the reamer and the rigid guide extension are coaxially aligned during assembly. Check that the reamer is properly attached to the rigid guide extension.
Couple the assembly to power equipment. If there is suffi-cient exposure, place the reamer assembly over the Kirschner wire, position the reamer firmly against the glenoid, and ream.
If there is not enough exposure to be able to slide the reamer over the Kirschner wire, remove the Kirschner wire. Place the reamer assembly on the glenoid, then reintroduce the Kirschner wire through the assembly into the previously drilled central hole, and ream.
OptionalAlternatively, free-hand reaming is possible without the use of guide wires. The reamer produces a uniformly concave surface, which is independent of the size of the glenoid.
Ream clockwise at high speed with steady light pressure. Windows in the reamer allow for visualization of the glenoid and the extent of reaming. During the reaming process, cor-rect the retro- or anteversion while preserving as much dense subchondral bone as possible.
Warnings: – Too much axial pressure on the reamer while reaming
weak or osteopenic bone may lead to overreaming. – While retracting the reamer, ensure that it does not
detach from the rigid guide extension.
Notes: – The reamer B 28 mm can be used for glenoids for head
B 40/42, 44 and 46. For larger glenoid sizes (48 and big-ger) continue reaming with the reamer B 32 mm to gain superior and inferior extension of the prepared surface.
– The drop shape of the drop-shaped ring retractors (avail-able in the General Shoulder Instruments Set 01.401.039) facilitate glenoid reaming by creating sufficient and com-fortable working space for the reamer.
– To facilitate cleaning of the reamers, place them in water immediately following usage.
E5211-6K Drill Bit B 7.4 mm, length 150 mm, for Glenoid and Shell Screw
E5211-6L Drill Bit B 7.4 mm, length 200 mm, for Glenoid and Shell Screw
If the Kirschner wire has been removed, reinsert it. Reintro-duce the drill guide (left or right) over the Kirschner wire. Rotate the drill guide until anatomic alignment is obtained.
Note: Use the insertion point of the biceps tendon as a landmark to determine the alignment of the longitudinal axis of the glenoid. It is recommended to position the inferior hole slightly posterior and the superior hole slightly anterior to Saller’s Line. Bone stock is typically better in this location.
Using the shorter (150 mm) drill bit, drill the distal hole first. The depth of the drill hole depends on the planned implant type.
For cemented all-poly glenoid, drill to a depth of 19 mm.
4cPressfit metalback glenoid
For pressfit metalback glenoid, drill to a depth of 21 mm.
4bHybrid glenoid with shell screws
For shell screw 10 mm, drill to a depth of 21 mm.For shell screw 15 mm, drill to a depth of 26 mm.For shell screw 20 mm, drill to a depth of 31 mm.
The smallest (10 mm) shell screw is the standard implant. Longer versions are typically used when bone defects such as comminuted anterior glenoid rim fractures require bridging.
Remove the Jacobs chuck but leave the drill bit in situ to sta-bilize the drill guide while drilling the second hole. Prepare the proximal hole using the long drill bit (200 mm). Remove the drill bits, Kirschner wire and drill guide.
Use the trial glenoid holding forceps to insert the trial gle-noid. Check the fit of the trial implant and ensure that the rear surface of the trial fits firmly to the reamed surface of the glenoid. If not, additional reaming of the glenoid is re-quired. Alternatively, gaps may be filled with autogenous bone graft.
In case of a comminuted anterior glenoid rim fracture, the glenoid implant is stabilized by 15 or 20 mm shell screws while the fracture fragment can be reduced and fixed with a simple osteosuture.
Note: A simple suture loop to readapt the radial labral tear occurring at the 2 o’clock position is often sufficient.
F017-4.5 Screwdriver, hexagonal, width across 4.5 mm
F017-2.5 Screwdriver, hexagonal, width across 2.5 mm
E5211-10 Glenoid Impactor
E5221-1 Metalback Impactor
E5221-2 Drill Sleeve 2.5 (22)
E5221-3 Drill Bit B 2.5 mm
03.401.081 Tap for Epoca Shell Screws, length 200 mm
03.401.082 Insertion Guide for Epoca Shell Screws
03.019.005 Handle with Quick Coupling, length 150 mm
Ensure that the plastic impactor liner is mounted on the glenoid impactor.
Option A. Cemented all-poly glenoidClean and dry the drilled cavities. Consider using a suction device introduced through the base of the coracoid process to evacuate undesired fluids. Introduce a small amount of bone cement (methylmethacrylate) into the two drilled cavi-ties (0.15 ml in each cavity) using a 1 ml syringe.
Note: Avoid overflow of the cement onto the faceplate of the glenoid as this will lead to a thin and brittle cement layer. Consult the manufacturer’s instructions for proper bone cement usage.
Mount the glenoid implant on the special holding forceps and introduce the implant in the correct orientation (the nar-row part facing up). Introduce the glenoid implant and seat it into its final position with light hammer taps on the glenoid impactor.
Option B. Hybrid glenoid (with shell screws)Position the insertion guide for the shell screws over the guide wire.
Optional (in cases of dense or sclerotic bone)Align the insertion guide with the pre-drilled holes and man-ually tap using the tap for Epoca Shell Screws.
Note: The color coding on the tap corresponds to the shell screw lengths (10 mm = green, 15 mm = blue, 20 mm = yellow).
Insert the previously selected shell screws (see step 5) with the long, 4.5 mm, hexagonal screwdriver.
The shell screw should be slightly below the surface of the bone.
Note: The shell screws can be inserted with or without the use of the insertion guide for Epoca Shell Screws.
Place the glenoid implant in position using the glenoid hold-ing forceps. Set the glenoid implant into place using the hammer and glenoid impactor.
Introduce a small amount of bone cement (0.13 ml methyl-methacrylate) into each shell screw using a 1 ml syringe.
Note: Avoid overflow of the cement onto the faceplate of the glenoid, as this will lead to a thin and brittle cement layer. Consult the manufacturer’s instructions for bone cement usage.
Option C. Pressfit metalback glenoidPlace the metalback glenoid implant in position using the metalback impactor. Lightly tap the glenoid implant into place using the hammer and glenoid impactor.
Note: The metalback glenoid can be fixed with 3.5 mm cor-tex screws at the bottom of the pegs for additional stability.
OptionalAdditional screw fixation depends upon surgeons’ intraoper-ative judgment and preference. For this purpose, a special aiming drill guide is available. Introduce the cylindrical drill guide in the cylindrical metal-back peg and drill with a 2.5 mm drill bit. Measure the screw length and introduce a standard 3.5 mm cortical screw.
519.970 Oil Dispenser with Synthes Special Oil, 50 ml
Note: Synthes special oil is to be applied to the Epoca Press just prior to sterilization. To ensure proper performance, oil the following locations and repeat as necessary until a noticeable smooth actuation of the screw mechanism is achieved.
Failure to apply oil prior to use may cause undesired performance and lack of calibrated force upon the implant assembly.
Note: The autoclavable oil is purchased separately.
For best results turn the press with torque wrench clockwise and counterclockwise until smoother movement is noticed.
Care and Maintenance
03.401.128 Reamer Epoca B 28 mm, for Glenoid, with Quick Coupling
03.401.132 Reamer Epoca B 32 mm, for Glenoid, with Quick Coupling
Stanley Hoppenfeld and Piet deBoer, Surgical Exposures in Orthopaedics–The Anatomic Approach, Third Edition, 2003, pp. 2–8.
Hertel R, Knothe U, Ballmer FT. Geometry of the proximal humerus and implications for prosthetic design. J Shoulder Elbow Surg. 2002;11(4):331-8.
Hempfing A, Leunig M, Ballmer FT, Hertel R. Surgical land-marks to determine humeral head retrotorsion for hemi-arthroplasty in fractures. J Shoulder Elbow Surg. 2001;10(5):460-3.
Torque, Displacement and Image Artifacts according to ASTM F 2213-06, ASTM F 2052-06e1 and ASTM F2119-07Non-clinical testing of worst case scenario in a 3 T MRI system did not reveal any relevant torque or displacement of the construct for an experimentally measured local spatial gradient of the magnetic field of 3.69 T/m. The largest image artifact extended approximately 169 mm from the construct when scanned using the Gradient Echo (GE). Testing was conducted on a 3 T MRI system.
Radio-Frequency-(RF-)induced heating according to ASTM F2182-11aNon-clinical electromagnetic and thermal testing of worst case scenario lead to peak temperature rise of 9.5 °C with an average temperature rise of 6.6 °C (1.5 T) and a peak temperature rise of 5.9 °C (3 T) under MRI Conditions using RF Coils [whole body averaged specific absorption rate (SAR) of 2 W/kg for 6 minutes (1.5 T) and for 15 minutes (3 T)].
Precautions: The above mentioned test relies on non-clin-ical testing. The actual temperature rise in the patient will depend on a variety of factors beyond the SAR and time of RF application. Thus, it is recommended to pay particular attention to the following points: – It is recommended to thoroughly monitor patients under-
going MR scanning for perceived temperature and/or pain sensations.
– Patients with impaired thermo regulation or temperature sensation should be excluded from MR scanning proce-dures.
– Generally it is recommended to use a MR system with low field strength in the presence of conductive implants. The employed specific absorption rate (SAR) should be reduced as far as possible.
– Using the ventilation system may further contribute to reduce temperature increase in the body.