Crushed vs Diced Cartilage: Similarities and Differences

Looking at some forums I noticed some people are using the words crushed and diced cartilage interchangeably as if they are same thing. Another important  issue i would like to address here is correlation between  the degree of crushed cartilage and how it effects the long term outcome (re absorption rate) of the surgery.

Crushing cartilage is procedure that takes pieces of cartilage and crushes it in a device called Cottle cartilage crusher and/or using a mallet. They can be crushed to varying degree's from slightly crushed to severely crushed. They are then inserted in the desired area of the nose using a medical tweezer.

Dicing cartilage is procedure where the cartilage is sliced using a straight edge razor blade into small fine pieces.  The cartilage is normally diced into <0.5mm squares, using two #11 blades avoiding, not being morselized or crushed. . Then it is placed in a syringe to be later injected in the desired area and molded/shaped accordingly. Usually diced cartilage  is wrapped in soft material preferably deep temporal fascia.

Both crushed and diced cartilage is used to smoothen out or camouflage nasal surface area's where cartilage is placed in the nose , like the dorsum, to conceal any irregularities. Both can be wrapped or combined with different material as well.

Crushed cartilage grafts can be used for the following purposes: (1) to cover the sharp edges of an irregular nasal framework after hump resection    (2) to serve as an underlying padding material to prevent skin adhesion   (3) to fill pit holes and, thus, mask irregularities   (4) as a filler to mask asymmetries and depressions on the side walls  (5) for tip grafting   (6) to camouflage the edges of solid onlay grafts  , (7) to supply minor dorsal augmentation for the correction of an overresected dorsum, and (8) to increase the thickness and natural color of the overlying skin where skin atrophy had occurred. I believe diced cartilage can be used in most of the above situations as well.

Crushed Cartilage Grafts for Concealing Irregularities in Rhinoplasty

1. Ozcan Cakmak, MD;
2. Fuat Buyuklu, MD

Our current clinical series confirmed our previous animal⁹ and human cell culture¹³ studies that the degree of crushing applied is important to the long-term clinical outcome of crushed cartilage grafts used in rhinoplasty.

The results showed a correlation between the degree of crushing applied and the resorption rate of the crushed graft, especially in grafts applied at the dorsum. The resorption rate was zero in slightly crushed grafts, 2.1% in moderately crushed grafts, and 13.1% in significantly crushed grafts. Our results show that slight or moderate crushing of the autogenous cartilage produces an outstanding graft material that is effective in concealing irregularities, filling defects, and creating a smoother surface, with excellent long-term clinical outcome and predictable esthetic result. We suggest that intact cartilage should be used to correct major deformities and that moderately crushed grafts should be used for smaller depressions to minimize resorption. The severely crushed form of cartilage should not be used as filler except to correct negligible depressions in atrophic skin.

The edges of solid onlay grafts might be softened by placing small pieces of moderately crushed grafts on or around the solid graft. The tiny pieces of moderately or significantly crushed grafts might be successfully used in final contouring at the conclusion of surgery. In patients with thin skin or in whom revision is required, a thin layer of moderately or significantly crushed cartilage would be the proper option as a padding material to prevent the adhesion of skin and to camouflage the sharp edges of the nasal skeleton that might be visible after edema has subsided.

From the above study,  one would presume that  thinner and smaller diced cartilage would also have higher resorption rates then thicker larger pieces, but I haven't seen any clinical studies to support or contradict that conclusion. 

http://archfaci.ama-assn.org/content/9/5/352.full

The Role of Diced Cartilage Grafts in Rhinoplasty

The fundamental technique for the use of diced cartilage in rhinoplasty has been known for over 50 years. One of the most impressive uses of diced cartilage is in cranioplasty, which demonstrates that the individual pieces coalesce into a semirigid graft over time. The term diced cartilage graft may refer to several different types of cartilage, methods of preparation, and methods of containment. In the present report, only autogenous cartilage derived from excised material, septum, or distant grafts is used. Containment refers to placement of the diced cartilage directly into a tight pocket for contour, layering of the cartilage on either side of rigid dorsal graft for blending, or placement of the cartilage in peripyriform pockets to advance the midface. The technique and benefits of diced cartilage grafts in rhinoplasty were reviewed.

A prospective study of more than 150 patients in 3 years found no evidence of absorption and no warping. Any problems thus far with the diced cartilage graft have been technical problems rather than problems with the graft material itself. One problem has been the visibility of radix grafts, particularly in patients with very active eyebrows. This problem is easily corrected by reduction with a pituitary rongeur or replacement with fascia alone. Dorsal grafts may have “edge show” cephalically, and caudally there may be inadequate grafting of the supratip region. This problem is easily corrected with the patient under local anesthesia by use of a pituitary rongeur. A minor depression may develop in the supratip area because the surgeon has initially undercorrected in pursuit of an immediate supratip break. This problem is corrected by keeping the graft truly full length rather than shortening it to get tip set off.

Conclusions: 

In using diced cartilage grafts in rhinoplasty, diced cartilage wrapped in fascia is simpler to use, quicker, and aesthetically superior to solid cartilage grafts, without risks of warping, malalignment, and K-wire extrusion.

 http://www.eclips.consult.com/eclips/article/Plastic-and-Aesthetic-Surgery/S1535-1513%2808%2970596-4

For the author,Rollin K. Daniel, MD; diced cartilage grafts have revolutionized dorsal grafts in rhinoplasty, replacing layered septal grafts, stacked conchal grafts, and carved costal cartilage grafts. He asserts that diced cartilage wrapped in fascia is simpler to use, quicker, and aesthetically superior to solid cartilage grafts, without risks of warping, malalignment and K-wire extrusion.

Diced cartilage grafts in rhinoplasty surgery: current techniques and applications. 

Dr.Rollin K. Daniel has used diced cartilage grafts in nasal surgery for more than 30 years. However, the number of cases and the variety of techniques have increased dramatically over the past 6 years.  

http://www.ncbi.nlm.nih.gov/pubmed/19050542

Autogenous Dorsal Reconstruction: Maximizing the Utility of Diced Cartilage and Fascia

Jay Calvert, M.D., F.A.C.S.^1,2 and Kevin Brenner, M.D.²

 The problem of reconstructing the dorsum of the nose is complex and a source of frustration for both patients and surgeons. Dorsal deficiencies due to various etiologies and the need for dorsal contouring cause the plastic surgeon to look to time-honored techniques such as osseocartilaginous rib grafts while also searching for other options that may be less technically challenging and have the benefit of temporal success. Diced cartilage wrapped with deep temporal fascia is just such a method to achieve reliable dorsal reconstructions. The various ways to use diced cartilage and deep temporal fascia are discussed

The complications of using this technique are predictable and correctable. Because the cartilage is mobile for 10 to 14 days after placement, there can be defects that arise from poor management of the graft postoperatively. Edges are usually not visible, but they can be in a particularly thin-skinned patient. Overcorrection and undercorrection are probably the most common complications seen with this technique and must be managed accordingly. Malposition of the graft and mobility of the graft may also be seen in a rare number of cases. Absorption of the graft has not been seen in the longest of follow-ups (6 years).

In conclusion, the technique of diced cartilage with fascia (DC-F ) has been a useful method of dorsal reconstruction as a stand alone technique and in concert with other methods of building the dorsum. There are many permutations and surgical variations of the technique. The authors believe that proper preoperative analysis will help the surgeon to derive clear indications so that the correct graft variation is used with a clear purpose. There is no substitute for preoperative diagnosis and planning when using the DC-F graft. The technique is safe, easy to perform, has minimal morbidity, and is our favored method for addressing difficult problems in dorsal reconstruction.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884865/

Perichondrium vs Deep Temporal Fascia

When performing Augmentation or Revision nose surgery, soft tissue is needed. For instance it is used to cover cartilage used to build up area along the dorsum or tip or simply for augmenting an area, say's Dr. Paul Nassif. If doing Rib Harvesting, you can then use the Perichondrium which is soft tissue that lays on top of the rib instead of using temporal fascia. According to Dr. Nassif, it's a little more thicker, heavier, and firmer then Temporal fascia. He feels it's an excellent source of soft tissue. He also has a you tube video on how deep temporal fascia is harvested, but warning it is not for weak at heart. I assume he use's deep temporal fascia as a choice when not performing rib cartilage graft, to build up the radix or dorsum area's. This video  on harvesting Perichondrium.is less graphic, but still takes place in Operating Room.

Nomenclature of nose: This could be especially helpful to prospective patients who want to be more specific in communicating to their surgeon what they would like modified on their nose, for those concerned about their cosmetic outlook. You may want to make sure the pre-op report mentions the specific area of concern you addressed in your consult .

Key surface landmarks are shown from the frontal and profile perspective. Most are soft tissue landmarks critical to nasal analysis and surgical modification.

Allografts and the risks of infection and disease transmission

Here is some valuable information on the risks associated with implantation of allografts [i.e. cadaver grafts in nose surgery]

 AAOS 2004: All About Allografts -- Select Highlights of the 71st Annual Meeting of the American Academy of Orthopaedic Surgeons

 Controlling Infection is Crucial

In limiting infection during allograft procedures, it is important to determine whether the tissue bank that you or your hospital is using is a member of the American Association of Tissue Banks (AATB). This organization requires that its members perform full screening that meets US Food and Drug Administration requirements; however, secondary sterilization of the grafts is still optional. Not all tissue banks are members of AATB, and not all tissue banks are inspected. The review by Vangsness and colleagues^[2] describes the process of procurement, processing, and storage, and should be required reading for anyone who is using allograft tissue. Be sure that you know your tissue bank and its procedures.
Infection of tissue can be controlled by screening the tissue donor and through secondary sterilization of the tissue. At this time, we can screen for both hepatitis B and C, which should prevent infection by these entities. There have only been 2 cases of HIV infection through allograft tissue, and both of these incidents occurred in the 1980s. These reported infections occurred with frozen bone as the vector, but none of the freeze dried grafts from the same donor transmitted the disease. The AATB has formulated guidelines for their members; these guidelines recommend donor screening.

There are a number of methods and federal guidelines for storing tissue after procurement. The methods of storing the tissue are: fresh frozen, deep frozen, freeze dried, demineralized, and proprietary treatments, such as CryoLife (CryoLife Inc., Kennesaw, Georgia

Factoring Relative Risk
The risk of hepatitis B after blood transfusion is 1/63,000. The risk of hepatitis C is 1/100,000, and the risk of HIV is 1/1,000,000. The risk of HIV after bone transplantation is 1/1,500,000. The risk of HIV after soft tissue transplantation is 1/1,600,000 with secondary sterilization.
To put this in the proper perspective, one should remember that the risk of death due to pregnancy is 1/10,000, the risk of death from administration of penicillin is 1/30,000, and the risk of death with oral contraceptives is 1/50,000. In fact, it may be more dangerous driving to the hospital than receiving a bone graft at the hospital.
In summary, allografts are a valuable treatment option for today's orthopaedic practice. The academy believes allografts to be safe if used within the guidelines, when they are supplied by an accredited tissue bank, and if the appropriate surgical techniques are employed.

How safe are soft-tissue allografts?

By C. Thomas Vangsness Jr., MD

 Although several cases of viral infection—specifically human immunodeficiency virus (HIV), viral hepatitis, and human T-lymphotropic virus (HTLV)—have been reported, these transmissions occurred before the guidelines for donor screening for viruses and bacteria were implemented and before the availability of currently validated serologic tests.

Sterility is expressed as a mathematic probability of relative risk. According to the FDA, a sterility assurance level (SAL) of 10-3 means there is a 1 in 1,000 chance that a nonviral viable microbe exists in or on the implanted material. The Association for the Advancement of Medical Instrumentation (AAMI) states that an SAL of 10-6 (one in a million chance) in organisms is more desirable. The American Association of Tissue Banks (AATB) requires an SAL of 10-6 for tissue bank allografts.

Contamination of the graft can also occur during the final handling and packaging of tissue. Gamma irradiation is commonly used to terminally sterilize allograft tissue with lower doses of radiation.

Freeze drying (lyophilization) is a preservation process that allows tissues to be stored at room temperature. Lyophilization freezes the tissue and reduces the water content to less than 6 percent of initial weight through a primary drying process (sublimation) and a secondary drying process (desorption). Although freeze-dried allografts (lyophilized grafts) are not commonly used for sports medicine applications in the United States, this process is commonly used with soft-tissue patches.

With improved donor screening techniques, such as nucleic acid testing (NAT), the current risk of transplanting tissue from an HIV-infected donor is reported to be between 1 in 1 million and 4 in 1 million.

According to a recent AATB survey covering data from 2003 to 2004, the current risk of an allograft infection to the average patient appears to be much less than the risk of infections surrounding the surgery itself. According to the report, there were 192 reports of suspected allograft-related infections in 2003-2004; 42 percent involved soft-tissue grafts and 37 percent involved bone grafts, with an overall incidence of 0.014 percent. Currently, better reporting of infections is actively under investigation to improve the accuracy of these numbers.

Do not do routine culturing of allograft tissue in the operating room immediately prior to implantation. These cultures are documented to be inaccurate and may reflect the native airborne or backtable contamination.

Musculoskeletal tissue regeneration: biological materials and methods  By William S. Pietrzak, Charles A. Vacanti

Although the risk is low, bacteria, hepatitis, HIV, and syphilis can be transmitted from donor to recipient. There is also the theoretical possibility of transmitting slow viruses (prions) with allograft use.
Irradiation of the soft tissue allografts with high dose (>3Mrad) radiation can sterilize allograft tissue, destroying bacteria and viruses including HIV and hepatitis. Bone plug allografts may still be capable of transmitting hepatitis despite treatment with 3 Mrad irradiation. Although, allograft irradiation will reduce the risk of disease transmission, it does so at the expense of diminishing the biomechanical properties of the tissue. Newer screening tests such as polymerase chain reaction (PCR) and nucleic acid testing (NAT) improve the detection of viral and bacterial DNA and RNA, and many increase the accuracy of identifying infected donor tissue and minimizing false-negatives. By improving the sensitivity and specificity of infected donor  tissue identification, the risk of bacterial and viral disease transmission should be less, thereby increasing the safety of allograft use. These newer techniques could potentially decrease the need for graft irradiation and other sterilization techniques that many affect allograft properties.

Surgeons can minimize complications associated with infected allograft tissue by only using tissue processed from a tissue bank accredited by the American Association of Tissue Banks (AATB). It is imperative that surgeons know the source of their allograft tissue, particularly if they rely on the hospital or a surgery center to obtain the allograft tissue for their patients.

http://www.aaos.org/news/bulletin/aug07/clinical1.asp

http://www.medscape.com/viewarticle/491618

http://books.google.ca/books?id=2qq56LYomagC&pg=PA397&lpg=PA397&dq=RISK+OF+TRANSMITTED+DISEASE+WITH+ALLOGRAFTS&source=bl&ots=cU9MnbRoBB&sig=KSY91n5fKiD2lVksKSU6A8vG204&hl=en&ei=iqHuTMmwAcnFnAf0u5jwCg&sa=X&oi=book_result&ct=result&resnum=10&ved=0CFIQ6AEwCTge#v=onepage&q=RISK%20OF%20TRANSMITTED%20DISEASE%20WITH%20ALLOGRAFTS&f=false

Using freeze dried bone grafts for Nasal Dorsal Augmentation

Recently in a PRSjournal a study was conducted and reported by Dr.Richard Clark called Nasal Dorsal Augmentation with Freeze dried allograft bone. Non irradiated freeze dried bone typically comes from tibia and femur shafts (more specifically cortical shafts).

Here's some general background information on bone grafts.

Type of Grafts:

Per definition there are four types of grafts, i.e. autografts, allografts, alloplasts and xenografts:

Autografts refers to tissue transplanted from one site to another
within the same individual.
Allografts are obtained from cadavers or living individuals from the same species. In human medicine they can be obtained from tissue banks (KÜBLER 1997).
Alloplasts are synthetic materials consisting of biological inert substances.
Xenografts are composed of tissue taken from another species (i.e. from an animal source, usually bovine). In case the organic material is removed from xenogenic bone, it may be considered as an alloplast (GARG 1999).
The term 'composite grafts' refers to grafts that are composed of materials from different origins, usually autogenous bone mixed with other materials (HABAL1991).

Depending on where the bone graft is needed, a different doctor may be requested to do the surgery. Doctors that do bone graft procedures are commonly orthopedic surgeons, otolaryngology head and neck surgeons, neurosurgeons, craniofacial surgeons, oral and maxillofacial surgeons, and periodontists.^[9]
There are three types of bone allograft available:

1. Fresh or fresh-frozen bone
2. Freeze-dried bone allograft (FDBA)
3. Demineralized freeze-dried bone allograft (DFDBA)

Freeze dried bone describes the method used to process the bone, not the source, and there is freeze dried bone available that comes from cadavers.

The most commonly used allograft is demineralized and freeze-dried bone.
The latter is used for minimising the antigenicity (BLOCK and POSER 1995), resulting in a demineralized bone matrix (DFDBA).

Freeze-drying and gamma irradiation are the techniques widely use in tissue banking for preservation and sterilization of tissue grafts respectively.
Frozen allografts are stored at temperatures below −60°C,
which decreases enzyme degradation and host immune response.
Freeze-drying involves removal of water from the tissue
with subsequent vacuum packing and storage at room temperature.

Some medical terminology:
➤Osteoinduction is a process that supports the mitogenesis of undifferentiated mesenchymal cells, leading to the formation of osteoprogenitor cells that form new bone.
➤ The human skeleton has the ability to regenerate itself as part of the repair process.
➤ Recombinant bone morphogenetic protein has osteoinductive properties, the effectiveness of which is supported by Level-I evidence from current literature sources.
➤ Osteoconduction is a property of a matrix that supports the attachment of bone-forming cells for subsequent bone formation.
➤ Osteogenic property is a relatively new term that can be defined as the generation of bone from boneforming cells.

For more info on bone grafts:
http://www.master-biomed.ethz.ch/education/bio_courses/Mechanobiology/DeLong_et_al_2007.pdf

http://dare.ubn.kun.nl/bitstream/2066/18869/1/18869_autoboanb.pdf

Related articles: 

Does Type of Bone Graft Used in Spinal Fusion Increase Risk of Infection?
http://activemotionphysio.ca/Injuries-Conditions/Lower-Back/Research-Articles/Does-Type-of-Bone-Graft-Used-in-Spinal-Fusion-Increase-Risk-of-Infection/a~2442/article.html 

Effect of freeze-drying and gamma irradiation on the mechanical properties of human cancellous bone 
http://www.ncbi.nlm.nih.gov/pubmed/10937629 

Bone graft substitutes
http://books.google.ca/books?id=QnCbGDbl-UwC&pg=PA46&lpg=PA46&dq=freeze+dried+bone+non+irradiated&source=bl&ots=nwVtoPS1vS&sig=DyEXoQ0s_QHAzC042e3ltfQMdyo&hl=en&ei=R6TtTLa3MIvDnAeAoZyRAg&sa=X&oi=book_result&ct=result&resnum=8&ved=0CFYQ6AEwBw#v=onepage&q=freeze%20dried%20bone%20non%20irradiated&f=false

According to Dr.Clarks site; 

Dr. Clark has currently published pilot study using freeze dried and frozen bone to augment and straighten the nasal dorsum (bridge). Dr. Clark uses American Bone Bank approved treated bone which has an excellent history of use in orthopedic surgery for over 10 years without transmission of any disease or rejection of implants. (For details of the extensive evaluation of bone donors and cleansing of the bone, please contact Dr. Clark.) The first patient receiving a dorsal implant with a frozen bone was in June, 2004. That patient's bone graft remains in perfect position and has maintained it's size and remains thus far to be a success. This bone graft has revascularized and become live healthy bone. We are following over 10 patients with excellent results, and time will tell as to whether this will be an answer to the quandary of dorsal augmentation, and we remain very hopeful.

 http://www.ncbi.nlm.nih.gov/pubmed/19935318

Techniques used to lessen the degree of rib (costal) graft warping in nose surgery

Rib carving is a tedious procedure, says Dr. Paul Nassif in this video. He soaks the rib graft in normal saline solution to soften it up and gives you the curve of where the cartilage is going to go.  The inner cortex of rib has less chance of warping, so its left intact. For rim grafts you need to carve the cartilage which is very delicate process, since you have to make sure the graft doesn't end up splintering.


Symmetric carving of the costal cartilage graft will minimize the chance of the graft warping over time.

Here's an interesting study on comparison of  warping after using different techniques of carving.  Concentric grafts warped less than Eccentric grafts.

David W. Kim, MD; Anil R. Shah, MD; Dean M. Toriumi, MD

  http://www.shahfacialplastics.com/carvedcostal.html

Dr.Jack Gunter, has devised a technique in which the larger grafts, the dorsal onlay graft and the columellar strut, are reinforced with a centrally placed Kirschner (K)- wire to decrease warping and provide a more stable and predictable result.
"Graft warping can occur in autogenous rib cartilage and lead to long-term postoperative distortions of nasal shape. The use of stabilizing K-wires placed through the center of these grafts has been a successful technique to counterbalance the tendency of the grafts to warp. To avoid warping of smaller grafts, we follow the principle of carving balanced cross-sections originally described by Gibson and later substantiated by Kim et al"
 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884866/

 http://journals.lww.com/plasreconsurg/Abstract/1997/07000/Internal_Stabilization_of_Autogenous_Rib_Cartilage.26.aspx

Control of grafted rib cartilage warping using K wire by Dr. A. Nakamura
http://www.springerlink.com/content/t33w777gk6668438/

More info regarding techniques to avoid warping of costal grafts:

Controversies in Otolaryngology: By Myles L Pensak
http://books.google.ca/books?id=xJNDV-KxYjcC&pg=PA176&lpg=PA176&dq=how+to+avoid+rib+warping+k+wire&source=bl&ots=yqnbTNt4GH&sig=M50C2vLAynJ_zlsAvkUBkhIlY90&hl=en&ei=_Z_TTLW5KIzCnAfTwLyOBg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCIQ6AEwAg#v=onepage&q=how%20to%20avoid%20rib%20warping%20k%20wire&f=false

Revision Rhinoplasty: By Daniel G. Becker, Stephen S. Park
http://books.google.ca/books?id=vwHmwB8qSeAC&pg=PA112&lpg=PA112&dq=how+to+avoid+rib+warping+k+wire&source=bl&ots=wJ4csX9UTT&sig=AY6roDDVffKe5bniZhAz3neSmAM&hl=en&ei=_Z_TTLW5KIzCnAfTwLyOBg&sa=X&oi=book_result&ct=result&resnum=6&ved=0CC4Q6AEwBQ#v=onepage&q=how%20to%20avoid%20rib%20warping%20k%20wire&f=false