PyroCarbon CMC Implants

nugrip cmc implant
PyroCarbon
CMC Implants
PyrospherE
saddle cmc
PyroDisk

Raw Graphite
Material
Radiolucent
Carbon Coating
FIGURE 1. Manufacturing Process
CVD Reaction
Chamber
Precision
Machining
Surface
Polishing
Radiopaque
Graphite Substrate
Substrate
Coating
Finished
Implant
FIGURE 2. Elastic modulus of metal and ceramic are
much greater than that of bone or PyroCarbon.
PyroCarbon Material
PyroCarbon is a specific form of carbon that has been tailored for durability and compatibility. PyroCarbon has portions
of 2-D and 3-D crystalline structures, resulting in excellent strength and wear properties between those of graphite
and diamond. PyroCarbon should not be confused with carbon fibers, which are minute particles used to strengthen
other materials. Manufacturing a PyroCarbon implant begins with a precision-machined graphite substrate that
contains 1 atomic percent tungsten to make the core visible on X-ray. Using patented steady-state process controls,
a thick layer of radiolucent On-X ® pure carbon is deposited onto the graphite core, maximizing strength and
durability. FIGURE 1.
The elastic modulus of PyroCarbon is very similar to cortical bone resulting in biomechanical compatibility with bone.
Unlike surgical grade metals, PyroCarbon transfers load from implant to bone more effectively, thus reducing stress
shielding and potential bone resorption. 1 FIGURE 2.
PyroCarbon exhibits exceptional wear performance against bone compared to ceramic and metals. After cyclical testing
to 5,000,000 cycles, PyroCarbon demonstrated minimal wear into cortical bone. It was not possible to test the other
materials past 375,000 cycles with Cobalt Chrome, 50,000 cycles with Titanium and 25,000 cycles with Zirconia
because the bone specimens had worn away. 2 FIGURE 3.
Cortical Bone 23
PyroCarbon
29.4
Titanium
105
Zirconia
210
CoCr Alloy
230
FIGURE 3. Cyclic Wear Test Against Bone
FIGURE 4. Photomicrograph shows
appositional bone growth on material.
FIGURE 5. Left – PyroCarbon after 18 months; shows healthy cartilage and surrounding tissue.
Right – metal alloy after 18 months; shows damaged cartilage and tissue.
Wear Penetration Rate into Bone
(nanometer/cycle)
0
10
20
30
40
5,000,000
cycles
0.2
375,000
cycles
4.3
50,000
cycles
30.4
25,000
cycles
34.7
PyroCarbon CoCr Titanium Zirconia
Fixation
Pyrocarbon has a micro-porous structure that enhances bone fixation without the need for cement. This unique
fixation is achieved initially through a press fit design using precise instrumentation. Long term fixation is achieved
via appositional bone growth as bone remodels up to the biologically active surface of PyroCarbon. 3 FIGURE 4.
Cartilage Friendly
A study of cartilage wear in 45 canine acetabula was performed using both PyroCarbon and metal alloy hip prostheses.
PyroCarbon showed remarkably less wear damage to cartilage. After 18 months, cartilage articulating with PyroCarbon
exhibited a 92% survivorship probability compared to 20% survivorship with metal alloys. 4 FIGURE 5.

Ascension PyroCarbon CMC implants are designed for
high demand patients undergoing joint replacement who:
• Have healthy, strong bones
• Show no signs of joint infection
• Have muscles and tendons which are repairable
Ascension CMC Implants
• Do not have other devices that block implant insertion
or normal motion
• Do not have concerns with cuts healing or other skin
problems
• Do not have numbness or tingling in hands or fingers
The NuGrip CMC Implant is our most recent thumb arthroplasty design, bringing together viewpoints and years of expertise
from surgeons around the world. We continue to market multiple CMC options, and our challenge is explaining for whom
each implant should be used. Each design allows minimal bone resection and requires no use of cement – providing an open
pathway for revision. All Ascension PyroCarbon CMC implants require healthy and stable soft tissues for sucessful outcomes.
Stemmed Designs
CMC Saddle: STAGES 1 OR 2
Use of this implant requires the full shape of the trapezium to be intact. Minimal lateral erosion of
the trapezium is integral to the functionality of this implant, allowing a secure fit and permitting the
head of the implant to articulate on the trapezium without potentially dislocating radially. No bone
removal on the trapezium is required when using the CMC Saddle. The anatomical stem provides a
press fit within the metacarpal for additional stability.
Stages of Arthritis
Based on radiological features, clinical stages of arthritis
were first described by Eaton and Littler, and further defined
in an article by Dr. Sam Anand of the Horton NHS Treatment
Centre and Horton Hospital. These images and descriptions
help identify the proper implant for patient indication.
NUGRIP CMC: STAGES 2 OR 3
The NuGrip CMC Implant is a redesigned version of the original PyroHemiSphere, which is still
available. New design features include a neck collar and an anatomical stem specifically designed for
the 1st metacarpal to allow press fit and additional stability. The creation of a cup in the trapezium
holds the spherical head in place. This head provides generous range of motion and additional height
– minimizing bone-on-bone impingement.
Interpositional Designs
PYROSPHERE: STAGES 2 OR 3
This device may be used when there is evidence of joint space narrowing and/or sclerosis in the
trapeziometacarpal joint. Shallow cups are made in the metacarpal and trapezium using soft tissues
to stabilize and hold the implant in place. This spherical, interpositional spacer design provides height
to the joint space minimizing potential for impingement and restoring natural range of motion.
PYRODISK: STAGES 2 OR 3 (not available for distribution in the U.S.)
The PyroDisk is a biarticular disk design which incorporates the patient’s own anatomy to restore joint
space and minimize pain. It re-establishes proper alignment of the thumb using the patient’s tendon
for stabilization and preserves trapezial bone stock – only requiring minimal bone resection on the
trapezium and metacarpal – thereby limiting the risk of thumb shortening and weakness.
Stage 1: Synovitis as
evidenced by increased
joint space in X-ray
Stage 3: Sclerosis in the
trapeziometacarpal joint
Stage 2: Joint space
narrowing
Stage 4: Pan trapezial osteoarthritis
as evidenced by radiological
changes in the scapho-trapezialtrapezoidal
(STT) joint.

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Join the thousands of satisfied patients who have
returned to normal and productive lives after
joint replacement surgery using Ascension Orthopedic’s
cutting edge PyroCarbon joint implants.
Ask your doctor today how small joint implants
from Ascension Orthopedics can help you.
Ascension thumb implant options:
8700 Cameron Road
Austin, Texas 78754 USA
877-370-5001 (toll-free in U.S.)
512-836-5001
Visit our website at
www.ascensionortho.com/patient
for more information on
PyroCarbon joint replacements.
©2010
MK-03-407-001
with PyroCarbon implants
Dedicated to transforming
your surgical experience.
This brochure summarizes post-operative
guidelines for Ascension Orthopedics CMC
Arthroplasty. For more information, contact
customer service at 512-836-5001, or in
the U.S., 1-877-370-5001 (toll-free).
EPL
First Dorsal
interosseous
muscle
APL
Extensor
retinaculum
Flexor
retinaculum
Hamate
EPB
Proximal Phalanx
Extensor
digitorum tendons
Lumbricals
Abductor digiti
minimi
Flexion
Extension
Distal Phalanx
Metacarpal bones
Flexor digitorum
profundus
Proximal Phalanges
Middle Phalanges
Extensor
carpi ulnaris
Distal Phalanges
Extensor
digiti minimi
Ulna
Extensor digitorum
&
Extensor indicus
Radius
Extensor
retinaculum
Extensor
pollicis longus
Extensor carpi
radialis brevis
Extensor carpi
radialis longus
Extensor
pollicis brevis
Abductor
pollicis longus
SURGEON AUTHOR: Lorenzo Pacelli, MD, Scripps Clinic Torrey Pines, La Jolla, CA
R
R
R
Since this NuGrip case, an enhancement
to the implant design allows for preservation
of approximately two-thirds of the trapezium
during implantation. The new design is
R
now available worldwide.
443-CC01
Patient History
70-year-old female barber complained of severe pain in the right, non-dominant thumb with limited
mobility. There was no inciting event. She rates her pain at 6/10. The pain is aggravated by moderate
activities such as carrying a shopping bag, and she has severe difficulty, or no ability, with many activities
such as playing the piano and using a knife to cut food. Over the course of 24 months, she has failed
to improve despite the treatment of rest and medication. The severe pain and limited range of motion
have left her unable to continue working and performing normal activities. The patient wishes for
definitive treatment to lessen the pain and return to more normal function. Patient had previously
been treated with a NuGrip implant on left CMC for osteoarthritis.
Preoperative Assessment / ROM
A physical exam revealed primary diagnosis of osteoarthritis at the base of the thumb. Limited range
of motion noted. Right grip strength averaged at 23 with a lateral pinch of 9. DASH score rated at
52.275. Right opposition measured -1.5 cm to SF DPC. She has no motor or sensory deficits, and
reflexes are normal.
Selected Treatment
This patient is an excellent candidate for CMC Arthroplasty. Standard arthroplasty with ceramic
implants shows subsidence of the implants into the metacarpal and trapezium bone. Alternately,
synthetic spacers have been shown to loosen, causing infection and inflammatory response, with even
lower success rates. The Ascension NuGrip CMC Implant made of PyroCarbon was chosen as
the alternative treatment device. The device is a single component which minimizes bone resections
and preserves the trapezium. The stem is anatomically designed to press fit within the intramedullary
canal without the use of cement. This specifically-designed stem enhances stability and minimizes the
possibility of movement or toggling of the stem within the canal.
Outcome
Arthroplasty was performed using a dorsal approach on the right CMC joint. The articular surface of
the metacarpal is excised; the intramedullary canal is prepared with broaches. The canal is prepared
to accept the largest implant that will fit in the metacarpal easily. A centralized cup was made in
the trapezium with a full rim of cortical bone around the cup to properly to seat the head of the
implant allowing full range of motion while limiting the opportunity for subluxation. Interoperative
complications included removal of a bone cyst. Additional bone graft was used to ensure a snug fit
within the intramedullary canal. Patient tolerated the procedure without complications.
3 Months Postoperative
The patient reported improvement in pain intensity 4/10 (compared to 6/10 preoperative). Right
grip strength averaged at 20 with a lateral pinch of 8. DASH score rated at 47.725. Right opposition
measured -2.5cm to SF DPC.
6 Months Postoperative
Patient maintained improvement in pain intensity 4/10. Right grip strength increased with an average
of 20 and maintained a lateral pinch of 8. DASH score rated at 45.25. Normal household activities are
able to be performed with only moderate pain.
9 Months Postoperative
The patient showed continued improvement in pain intensity and denies any significant complaints
while showing excellent range of motion. X-rays reveal adequate longitudinal alignment of both
implants in bilateral thumbs. Right grip strength decreased slightly with an average of 18 while
maintaining a lateral pinch of 8. DASH score rated at 22.725. Normal household activities were
reportedly performed with little or no pain including using a knife to cut food and piano playing.
For More Information
P yro Carbon I m p l a n t s
Durability + Biocompatibility
PyroCarbon Implants Booklet
The Hand & Wrist
Dorsal View
Volar View
PIP
Cross Section of Wrist
Ascension NuGrip CMC Implant
surgical
technique
Transforming Extremities
CLINICAL CASE
Treatment of Osteoarthritis at the Base of the Thumb
with PyroCarbon NuGrip CMC Hemiarthroplasty
Additional upper extremity solutions:
First Choice ®
DRUJ System
PyroCarbon
Lunate
Hold on to
life’s simple
pleasures!
Thumb joint replacement
Patient
Brochure
c m c
Post-Operative
therapy
guidelines
post-operative therapy guidelines Ascension Orthopedics CMC Arthroplasty
Therapy
Protocol
Finger Movement
Skeletal View
PIP
MCP
MCP
First Choice ®
www.ascensionortho.com
Hand & Wrist Wall Poster
Surgical Techniques
Surgical Videos
Case Reports
Ascension ®
PyroCarbon
& Silicone
MCP Joints
Ascension ®
PyroCarbon
& Silicone
PIP Joints
1. Cook SD, Klawitter JJ, Weinstein AM, “The influence of implant elastic modulus on the stress distribution around LTI carbon and aluminum oxide dental implants,” J Biomed Mater Res 1981;15:879-887.
2. Strzepa P, Klawitter JJ, “Ascension PyroCarbon Hemisphere Wear Testing Against Bone,” Poster No. 0897, 51st Annual Meeting of the Orthopedic Research Society.
3. Cook SD, Beckenbaugh RD, Weinstein AM, Klawitter JJ, “Pyrolite Carbon Implants in the Metacarpophalangeal Joint of Baboons,” Orthopedics, 1983; Vol. 6/No. 8: 952-961.
4. Cook SD, Thomas KA, Kester MA, “Wear Characteristics of the Canine Acetabulum Against Different Femoral Prostheses,” JBJS, 1989; 71-B(2): 189-197.
Ascension Orthopedics, Inc.
8700 Cameron Road
Austin, Texas 78754
512.836.5001 PH
877.370.5001 TF
512.836.6933 FX
customerservice@ascensionortho.com
www.ascensionortho.com
Caution: U.S. federal law restricts these devices
to sale by or on the order of a physician.
MK-03-407-002 rev A
©2011
For more about Ascension CMC implants,
visit www.ascensionortho.com/thumb