Tag Archives: wound

Reconstructing Limb Deformities using the VCAM™ External Fixator: A series of 3 cases

by Michael P. DellaCorte, DPM, FACFAS , Panagiotis Panagakos, DPM ,
Tarika Singh, DPM , Howard Goldsmith, DPM, AACFAS

The Foot and Ankle Online Journal 4 (1): 2

External fixation was used almost exclusively for fracture management. It is also used for arthrodesis, management of lower extremity deformities such as Charcot neuroarthropathy, limb lengthening, osteotomy stabilization, osteomyelitis, nonunion or pseudoarthrosis. It has proven extremely useful in the treatment of a number of conditions because it can provide distraction, compression, stabilization and neutralization as needed. Traditional external fixators involve driving pins through the tibia and fibula. The VCAM™ is a unique below the ankle external fixator. The VCAM™ can avoid possible disruptions and complications that are often seen with traditional Ilizarov fixators. The indications for the VCAM™ external fixator are identical to the Ilizarov fixators, such as off-loading, fracture reduction and reconstructive procedures. In our institution, we have used the VCAM™ device to off-load ulcerations and correct limb deformities. In the cases presented in this paper the VCAM™ was used to off-load wounds secondary to Charcot arthropathy and transmetatarsal amputations, as well as to gradually correct a rearfoot deformity such as seen in a Chopart’s amputation. The VCAM™ can be constructed into an Ilizarov type frame or a hybrid frame which can be used to achieve gradual triplanar correction. We have seen good results using the VCAM™ for wound care and limb deformities and recommend this approach when tibia and fibula intervention is not necessary.

Key words: Limb deformity, Charcot foot, ulceration, VCAM™, wound, external fixation.

Accepted: December, 2010
Published: January, 2011

ISSN 1941-6806
doi: 10.3827/faoj.2011.0401.0002

External fixators have proven very versatile in treatment as they can be used with open, closed or limited open surgical techniques. They provide access to the involved limb for wound healing and dressing changes and can be designed to correct complex deformities such as Charcot joint. They allow for gradual, precise correction over the postoperative course rather than a single intra-operative correction by osteotomy or fusion.

Ring fixators are typically used to treat complex Charcot neuroarthropathy. [1] External fixators provide multiplanar correction including angulation, translation, rotation, stabilization, compression, distraction and neutralization while allowing for surrounding soft tissue adaptation; this also helps to minimize wound complications and vascular compromise that may result from overcorrection in a single-stage procedure. [2,4,5,6] In general, external fixators can be used to correct coexisting deformities separately, successively or simultaneously. [3]

The VCAM™ fixator allows for adjustment and alteration as needed during the post-operative period. Full immediate weight bearing postoperatively is also possible with the external fixator. [2] This is extremely important in Charcot reconstruction with concomitant ulcerations that require offloading. Additionally, external fixation is the only treatment option for Charcot with associated osteomyelitis or in Eichenholtz stage I and II, where internal fixation is contraindicated. [4]

There are two main types of fixators. The monolateral fixator which consists of threaded half-pins attached to a bar which allows for axial compression or distraction. The other main type is the ring fixator which was made popular by G.A. Ilizarov. The ring fixators use trans-osseous wires and pins placed under tension for bone fixation; they are more versatile and complex than the monolateral fixators. The hybrid fixator is a combination of these two main types and may be more appropriate for certain indications. [2,3]

Lower limb deformities secondary to trauma, diabetes or any other pathological cause can be devastating to patients and frustrate foot and ankle surgeons treating them. Charcot arthropathy is one of the limb deformities discussed in this paper that can lead to ulceration. Treatment of Charcot foot may require internal as well as external fixation. Ilizarov type fixators have been used for surgical reconstruction of this deformity. Surgery is indicated for treatment of Charcot arthropathy if chronic or recurrent ulcers are associated with the deformity, if the deformity is unstable and if there is an acute fracture in a neuropathic patient with good circulation. [1,2]

There is limited mention in the literature of external fixation devices that do not extend proximal to the ankle. The purpose of this paper is to introduce the VCAM™ external fixator and present its various uses and construct designs.

The VCAM™ has been available for nearly a decade. In our opinion it is an underutilized external fixator because it has not been previously reported in the literature which has lead to an ignorance of the device in the orthopaedic community.

It has mainly been used in locations where ankle privileges are not available to podiatrists. The VCAM™ consists of a leg portion with a boot construct similar to a CAM walker with Velcro straps lined along the leg sleeve, plastic upright Velcro extensions attached to posts, various size threaded rods, half rings, foot plates and a rocker bottom with rubber treads with Velcro straps. We believe this unique external fixator has many advantages over traditional Ilizarov frames. It reduces the number of pins or wires placed across the tibia and fibula, therefore decreasing pin site infections, calf edema does not become an issue, fractures of the tibia and fibula when inserting, removing and/or tensioning the wires and decrease in thermal necrosis of neurovascular and muscular structures in the leg. The VCAM™ cannot be used for limb lengthening procedures, ankle fractures, pilon fractures, or any other surgical procedure involving the tibia or fibula


When all ancillary pedal procedures are complete and the half rings and wires have been applied to the operative site and tensioned, the VCAM™ leg sleeve is first applied over cast-padding. Next, the plastic extensions are attached by velcro and are secured. Then three or four hole posts are secured to the plastic extensions to which various sized rods are attached spanning from the leg down to the foot. These rods are connected to the foot plate and half rings with the use of posts, if needed. Note that the foot plates and half rings are secured in place with nuts and bolts to the smooth olive transfixation wires during the surgical reconstruction. Lastly, the rubber rockerbottom foot attachment allows protection and partial weight bearing. Constructs are designed based on the pedal pathology present.

Once there is clinical and radiographic evidence of consolidation at the fusion site, or there is clinical correction of a specific limb deformity the external fixator may be removed. The frame is often removed after 8 to 12 weeks and the patient is fitted for a Charcot Restraint Orthotic Walker (CROW) and remains in this device for 6 months.

Thereafter, patients are fitted for ankle foot orthoses (AFO) and custom extra depth shoes with appropriate fillers if necessary.

Case Report 1

This diabetic male patient presented to the Emergency Department with an infected 2nd toe leading eventually to a proximal Chopart’s Amputation. The patient had multiple debridements and fasciotomies of the leg over a 6 month period. He developed a lateral ankle ulcer and an adducto-varus foot type as a result of muscle imbalances. (Figs. 1A and 1B)

Figure 1A and 1B Case 1: Lateral aspect of the lower extremity with adducto-varus deformity and ulceration over the fibular malleolus before VCAM™ application. (A)  A superior view of the lower extremity with adducto-varus deformity. (B)

He had the VCAM™ external fixator applied to offload the ulcer and to gradually correct the adducto-varus deformity. The pins were placed distally through the amputation site to create a more stable frame. He had an adjunctive Achilles tenotomy. Weekly adjustments consisted of tightening the lateral aspect of the frame and loosening the medial components to bring the foot perpendicular to the leg. (Figs. 2A, 2B and 2C) After six weeks of weekly adjustments clinical correction of the deformity was achieved and the lateral ulcer healed. The VCAM™ was then removed. (Figs. 3A and 3B) He was then placed in a CROW Walker to weight bear.

Figure 2A, 2B and 2C Case 1:  Day of VCAM™ application. (A)  1 week after the VCAM™ application with the first adjustment after VCAM™ application. (B)  4 weeks after VCAM™ application with the fourth adjustment. (C)

Figure 3A and 3B Case 1:  6 weeks after VCAM™ application and there is clinical correction of deformity.  The VCAM™ was then removed. (A) The lateral view shows clinical correction of deformity and healed ulceration. (B)

Even though the VCAM™ is primarily a below ankle frame it can be designed to imitate a Taylor Spatial™ external fixator, as it was for this case. A half ring was able to be applied above the ankle without any pins inserted into the leg and six struts were fashioned to help achieve gradual triplanar correction of the lower extremity deformity.

Case Report 2

A 60 year-old male with history of Diabetes Mellitus with peripheral neuropathy and ESRD, presented to wound care center with a chief complaint of chronic non-healing plantar ulcers of six months duration. The patient had a previous left foot trans-metatarsal amputation (TMA) with an ulcer on the distal plantar lateral aspect of the TMA site and a plantar heel ulcer. Local wound care with weekly debridements failed to heal the ulcers. The plantar heel ulcer measured 5cm x 6cm and probed to bone.

It was then decided to proceed with surgical debridement of the ulcer and VCAM™ application. On March 3rd, 2008 a percutaneous tendo-Achilles lengthening (TAL) and tenotomy of the anterior tibial tendon were performed to relieve forefoot pressure on the distal plantar lateral TMA site ulcer. The Versajet Hydrosurgery System™ (Smith & Nephew) was used to debride the plantar ulcers of all necrotic tissue and then application of Apligraf® (Organogenesis) skin substitute was applied to the heel ulcer. At this point, a VCAM™ external fixator was applied to offload the plantar ulcerations and help maintain angular correction after TAL and anterior tibialis tenotomy. The pins for the frame were thrown distally through the TMA site exiting posterior to the heel to help create a more stable construct. The VCAM™ in this case is a standard Ilizarov type frame and was primarily used to offload the ulcers. (Fig. 4A and 4B) The ulcers were progressing well and had decreased in size significantly until the patient tripped and fell while ambulating which ultimately led to several pin tract infections. (Figs. 5A and 5B) The causative organism of the pin site infections was MRSA. The patient was started on Zyvox® (Pfizer) and the VCAM™ fixator was removed on April 17, 2008.

Figure 4A and 4B Case 2:  Clinical appearance the day of VCAM™ application. (A) The lateral view 1 week after VCAM™ application. (B)

Figure 5A and 5B Case 2:  2weeks after VCAM™ application showing ulcer healing with associated pin tract infections. (A)  4 weeks after VCAM™ application with progressive closure of the ulcers.

The distal plantar ulcer healed before the fixator was removed and all wounds healed with continued off-loading after removal. Pin site infections are the most common complication with external fixators. In this case, patient selection was appropriate. He could ambulate without any significant issues prior to VCAM™ application that would deter a foot and ankle surgeon from applying an external fixator. In our opinion the result of the patient falling was accidental.

Case Report 3

A 51 year-old diabetic female with history of Hypertension, Hypercholesterolemia, Charcot Neuroarthropathy and a non-healing Wagner Grade 3 ulcer measuring 2.4 cm x 2.5 cm x 2.4 cm present for more than 1 year duration, was seen in the Wound Care Center. (Figs. 6A and 6B) Radiographs revealed a Charcot foot deformity with dislocation at the LisFranc and Chopart joints. (Figs. 7A and 7B) After 17 hyperbaric oxygen treatments helped to resolve cyanosis of the digits, it was decided that surgical intervention would be necessary to realign the midfoot and to offload the ulcer.

Figure 6A and 6B Case 3:  The Initial clinical appearance; plantar view of the foot. (A)  The Initial clinical appearance demonstrating the depth of the ulcer. (B)

Figure 7A and 7B Case 3:  The initial radiographic lateral view. (A) The initial radiographic dorsoplantar view. (B)

The patient had a wound debridement, left talar osteotomy, percutaneous Tendo-Achilles lengthening and VCAM™ application. This frame was constructed to offload the ulcer and to compress and realign the midfoot to the hindfoot. One half ring was placed on the dorsal aspect of the foot and another half ring placed posterior to the heel to aid with compression. Realignment of the dislocated joints is evident on the immediate post operative radiographs. The frame was adjusted on a weekly basis. The VCAM™ was successful in producing a more plantigrade foot and offloading the ulcer long enough for it to decrease greatly in size. The frame was removed after 8 weeks and the patient was subsequently put into an ankle foot orthosis. Conservative wound care continued for approximately 2 months until the ulcer healed successfully. (Figs. 8A, 8B and 8C)

Figure 8A, 8B and 8C Case 3: Day of VCAM™ application. (A)  The foot is placed in a more plantarflexory position to promote ulcer closure. (B)  The immediate post-op lateral radiograph. (C)


External fixators are now almost exclusively used for arthrodesis, management of lower extremity deformities such as Charcot neuroarthropathy, limb lengthening, osteotomy stabilization, osteomyelitis, nonunion or pseudoarthrosis. [1,2] In wound and ulcer management it provides offloading and potentiates healing. It has proven extremely useful in treatment of these conditions because it can provide distraction, compression, stabilization and neutralization as needed. [2]

There is limited mention in the literature of external fixation devices that do not extend proximal to the ankle. Herbst uses two types of external fixation devices for the treatment of Charcot Arthropathy. One is a foot frame and the other a tibiocalcaneal frame. He uses the foot frame for the correction of midfoot deformity. The main characteristics are a hindfoot ring and a forefoot ring in the coronal plane. The two rings have a spanning device between them to provide compression across the midfoot. [7] Malizos, et al., described an Ilizarov below the ankle circular frame to treat displaced calcaneal fractures. There are 2 rings both confined to the foot.

The proximal ring serves a stable ground through the talus and midfoot bones and supports the distal ring. The 2 rings are distracted to withstand the deforming forces of the Achilles tendon, the plantar musculature, aponeurosis and peroneal retinaculum. Ligamentotaxis can be used for reduction of fragments. Reduction of the shape and height of the calcaneus is easy with the use of gradual distraction. They concluded that rings attached to the distal tibia are not necessary.

Possible complications associated with the external fixator include: uncontrollable edema with drainage exiting at the pin tract sites, pin tract infections, pin loosening, pin irritation, pin/wire breakage, thermal necrosis, non-union, delayed union, malunion, osteomyelitis, joint contractures/subluxation, wound dehiscence, compartment syndrome, reflex sympathetic dystrophy and fracture after frame removal. [2] Many of these complications can be avoided with post-operative compliance and follow-up care. Edema can be alleviated by elevation and partial weight-bearing immediately post-op. Another potential complication is severe pain and damage due to pins or wires compromising muscles, tendons or neurovascular structures.

This complication is decreased with the use of the VCAM™, as no pins are passed through the leg. Major complications such as infection and wire breakage alter the postoperative course and often require removal of the external fixator. [9]

In the cases presented it is evident that the VCAM™ can be constructed in many configurations and therefore be used to treat a variety of lower limb deformities that could lead to ulcerations. In the first case the VCAMTM was applied to achieve gradual correction of a triplanar deformity. It was successful in doing so without the use of leg pins or wires. In the second case it was used a traditional Ilizarov frame to simply offload the extremity to assist in healing two plantar ulcers. In the third case it was again constructed as an Ilizarov type frame to offload a plantar ulcer and to provide compression of the midfoot to the hindfoot. In all three of these cases the VCAM™ was successful and proved to be a useful device to heal ulcerations and correct deformities without the use of leg pins or wires. One of the disadvantages of the VCAM™ as seen in the second case was the development of pin tract infections. This is the most common disadvantage with any external fixator, but the absence of leg pins in our opinion decreases the chance of pin tract infections with the VCAM™. More case studies and research should be explored with the VCAM™ in the areas of trauma especially Lisfranc fractures since it is a midfoot deformity and other lower limb deformities.

In conclusion we feel that the VCAM™ is an excellent modality when managing limb deformities that have lead to the development of ulcerations. It provides a means of realigning the foot in all necessary planes while simultaneously offloading ulcerations. The benefits greatly outweigh the risks associated with use of this device. We have seen good results using this device and recommend it for offloading ulcerations secondary to limb deformities. More case studies and research should be explored with the VCAM™ in the areas of trauma especially Lisfranc fractures since it is a midfoot deformity and other lower limb deformities.


1. Hamilton GA, Ford FA. External fixation of the foot and ankle Elective indications and techniques for external fixation in the midfoot. Clin Podiatr Med Surg 2003 20:45-63.
2. Baker MJ, Offutt SM. External fixation Indications and patient selection. Clin Podiatr Med Surg 2003;20:9-26.
3. Vito GR, Talarico LM, Kanuck DM. Use of external fixation to correct deformities of the lower leg. Clin Podiatr Med Surg 2003 20:119-157.
4. Cooper PS. Application of external fixators for management of Charcot deformities of the foot and ankle. Foot Ankle Clin N Am 2002 7:207-254.
5. Cooper PS. Application of external fixators for management of Charcot deformities of the foot and ankle. Semin Vasc Surg 2003 16: 67-78.
6. Jolly GP, Zgonis T, Polyzois V. External fixation in the Management of Charcot Neuroarthropathy. Clin Podiatr Med Surg 2003 20:741-756.
7. Herbst, S. External fixation of Charcot Arthropathy. Foot Ankle Clin N Am 2004 9:595-609.
8. Malizos KN, Bargiotas K, Papatheodorou L, Dimitroulias A, Karachalios T. The below-the-ankle circular frame: A new technique for the treatment of displaced calcaneal fractures. J Foot and Ankle Surg 2005 45(5):295-299.
9. Bevilacqua NJ, Rogers LC. Surgical management of Charcot midfoot deformities. Clin Podiatr Med Surg 200825:81-94.

Send correspondence to: Michael P. DellaCorte, DPM, FACFAS, Director of Podiatric Medical and Surgery Program at NorthShore Forest Hills LIJ; 5901 69th street, Maspeth, NY 11378. (718) 639-3338

1 Director of Podiatric Medical and Surgery Program at NorthShore Forest Hills LIJ; 5901 69th street, Maspeth, NY 11378.
2 PM&S 36 Resident; Hahnemann University Hospital.
3 PM&S 36 Resident; Hahnemann University Hospital.
4 Private Practice New York, NY.

© The Foot and Ankle Online Journal, 2011

Collagen in Wound Healing: Are We Onto Something New or Just Repeating the Past?

by Ryan H. Fitzgerald, DPM1 , John S. Steinberg, DPM2

The Foot and Ankle Online Journal 2 (9): 3

Lower extremity amputations in patients living with diabetes have significant morbidity and mortality. Given the obvious link between lower extremity amputations and the ulcerations that precede them, it is incumbent upon the wound care provider to become familiar with advanced wound care products. The importance of re-establishing a functional extracellular matrix (ECM) in chronic wounds has led to a renewed interest in collagen-based wound healing products. These products can be applied either in the surgical or clinical setting. An intact functional ECM will seek to promote normal progression through the stages of wound healing. This article presents several representative collagen-based advanced wound care products utilized in wound healing, discusses their mechanism of action, and the appropriate indication for each product’s usage.

Key Words: Collagen, wound, diabetes, matrix metalloproteases, bioengineering, alternative tissue.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.  It permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©The Foot and Ankle Online Journal (www.faoj.org)

Accepted: July, 2009
Published: September, 2009

ISSN 1941-6806
doi: 10.3827/faoj.2009.0209.0003

Chronic lower extremity wounds demonstrate a considerable health care dilemma and substantial health care cost in the United States. [1,2] Chronic wounds and diabetic ulcerations represent a large component of this cost, with nearly one million new lesions diagnosed each year. [3,4,5] Furthermore, greater than 60% of non-traumatic amputations in the western world are performed on persons with diabetes [6] and the majority of these amputations are preceded by some form of infected ulceration. Therefore we can surmise that aggressive efforts at ulcer healing will have a direct influence on amputation rates. The risk is obvious; the relationship between diabetic foot ulcerations and subsequent amputation has been well documented and is well understood. [7]

There is significant morbidity and mortality at five years following amputation in this patient population. [8] This staggering data has prompted further research into the science of wound healing in an attempt to reduce diabetic foot ulcerations and their life changing sequelae.

Many of today’s wound care concepts have developed from research associated with burn therapies. [9] More recent research has focused on the wound environment, and on both the cellular and extracellular components necessary to promote wound healing. A better understanding of vasculopathy, infection, and poor nutritional status have enabled industry to target the failing biology of wounds with new products including many new collagen derivatives.

The Science

Throughout the four phases of wound healing, the extracellular matrix (ECM) provides a significant role in regulating and providing a framework for the many processes of healing. The ECM is the largest component of the dermal skin layer and is composed of a variety of polysaccharides, water and collagen proteins. [10] Collagens make up the largest fibrous components of the ECM; in the dermal matrix, the majority of collagen is type I and type III. These collagens demonstrate a fibrillar or rod shape and are composed of three triple-helix protein chains arranged in a linear fashion. This linear orientation provides much of the tensile strength of skin. In addition to longitudinal strength, bundles of collagen molecules in the ECM cross link with adjacent collagen molecules to provide additional strength and stability against shearing forces. [11]

Acute wounds create a provisional wound matrix which contains fibrin and fibronectin, which act as chemical mediators to direct cells to the site of injury and to motivate cells to proliferate and to differentiate into new, provisional matrix structures. [4,6] However, in chronic wounds, increased levels of inflammatory cells and proteases degrade the ECM components which are essential for healing. [8,12] Among these proteases, matrix metalloproteases (MMPs) play an important role in damaging the ECM and the extracellular growth factors present in a chronic wound. These MMPs are synthesized by multiple cell types, including neutrophils, fibroblasts and macrophages at the direction of chemical mediators such as inflammatory cytokines. [6] In normal healing, the MMPs function to debride away denatured elements of the ECM, thus exposing areas of intact functional matrix that are needed for wound healing. This process is highly regulated and controlled via tissue inhibitors of metalloproteases (TIMPs). [12] In chronic wounds, however, in addition to an excess number of MMPs, there is a failure in the regulation of protease activity between the MMPs and TIMPs which can result in further degradation of the ECM. This is followed by the destruction of growth factors, inhibition of angiogenesis, and breakdown of granulation tissue. [13]

For wound healing to occur, a balance is needed between the protein degrading activities of MMPs and other cellular activity that synthesizes and deposits protein components of granulation tissue. Many new collagen based wound care products aim to reduce excessive protease levels and reestablish balance in the wound environment. In addition, these products serve to contribute functional ECM proteins to stimulate the healing process. [1] Research has demonstrated that topically placed collagen can initiate wound healing by activating inflammatory cells and promoting increased vascularization of the healing tissue. [14] Other research has demonstrated that the physical three-dimensional structure of collagen has the ability to induce fibroblastic growth, which is essential in the formation of granulation tissue. [1]

The Products

There are an abundance of collagen-based products on the market today. These products can be loosely divided into groups based upon the setting in which they are applied (either in the clinic setting or in the operating room). In addition to differences in the application process, these collagen-based products can be combined with other treatment modalities, such as the addition of an alginate to manage exudate or the addition of silver to provide antimicrobial effects (See attached table).

Attached Table:  Collagen based products and their properties.

Below is a detailed discussion of several representative topical collagen products that are intended for use in the outpatient dressing setting:

FIBRACOL PLUS® (Systagenix Wound Management) combines the structural support of collagen with the exudate management of an alginate. In this way, the alginate component maintains a moist wound environment while the collagen component allows for cellular and vascular in-growth, which promotes formation of granulation tissue and neo-epithelialization at the wound site.

Promogran® (Systagenix Wound Management) combines oxidized regenerated cellulose (ORC) and collagen. This bioactive collagen product binds to and neutralizes destructive proteases in chronic wound fluid. [14]

Once bound, MMPs are rendered inactive due to alteration of their protein structure. Reduction of MMP burden in the chronic wound allows endogenous ECM protein cells to proceed to the formation of granulation tissue and normal wound healing.

PRISMA® (Systagenix Wound Management) is the next generation in the Promogran® line. This product provides the MMP binding function of Promogran® in the form of ORC and collagen with the addition of silver to provide antibiosis, thus lowering the bioburden in chronically colonized wounds. [14] PRISMA® provides a biodegradable cellular matrix that promotes cellular migration and neo-vascularization while helping to maintain bacterial balance at the wound site and to create an optimal wound healing environment.

PURACOL PLUS® (Medline Industries, Inc) is a bovine derived collagen matrix, which utilizes a native, triple-helical structure to stimulates fibroblastic activity in the wound bed to promote ECM formation and thus stimulate local wound healing. Additionally, this product controls moisture in the wound environment by converting to soft, gel-like sheet that maintains intimate contact with wound bed as it absorbs exudate. PURACOL PLUS® is most commonly utilized in chronic, partial thickness wounds which demonstrate light to heavy exudate and are non-infected and non-ischemic.

Biostep® and Biostep Ag® (Smith & Nephew) are two new collagen products which are demonstrating a great deal of success in the treatment of chronic wounds. The semi-denatured porcine collagen in Biostep® attracts and bind excess MMPs present in the chronic wound environment, and the EDTA component in the product irreversibly deactivates MMPs by binding to their zinc ions. In this way the collagen in Biostep®, coupled with EDTA, functions as a competitive substrate for the MMPs and thus allows endogenous collagen matrix formation to progress undeterred as granulation tissue forms. In addition, the product contains carboxy methyl cellulose and alginate which helps to provide moisture management in an actively draining wound environment.

Biostep Ag® provides similar anti-MMP activity, while the addition of silver ions helps to maintain bacterial balance in the wound site.

OASIS® Wound Matrix (HealthPoint) is a biologically derived extracellular matrix-based wound product which is derived from porcine small intestine submucosa. Indicated in the management of partial and full thickness wounds, this product provides intact acellular collagen scaffold that allows promotes a favorable host tissue response and stimulates cellular migration, leading to restoration of tissue structure and promotion of wound healing.

Integra® Matrix (Integra Life Sciences) consists of a cross-linked bovine tendon collagen and glycosaminoglycan matrix which is available with and without a semi-permeable polysiloxane layer. [2] Glycosaminoglycans are large saccharide polymers that are important elements of the ECM; these proteins aid in cellular adhesion to the matrix, as well as playing a role in cell and tissue differentiation necessary for wound healing. [9] The semi-permeable polysiloxane membrane of the bilayer matrix functions as a temporary epidermis by protecting the deeper collagen graft tissue and wound while also controlling water vapor loss. Below the silicone layer, the collagen-glycosaminoglycan biodegradable matrix provides a scaffold for cellular invasion and capillary growth. As the graft is incorporated, the silicone layer peels away to expose new granulation tissue formation and neo-epithelialization. Additionally, this product is available in a “flowable” or injectable form that can be utilized to provide collagen and glycosaminoglycan matrix to difficult to manage wounds with tunneling or tracking components. Often this modality can be used in conjunction with the conventional graft to provide three dimensional reconstruction at complex wound sites.

GraftJacket® Regenerative Tissue Matrix (Wright Medical), which is a collagen based graft processed from donated cadaveric skin. As an allograft, this product contains components of normal skin including collagen, elastin, hyaluronan, fibronectin, and blood vessel channels. [8]

In this way, GRAFTJACKET® provides soft tissue coverage over deep structures, functions as a scaffold for new cellular in-growth. It preserves the vascular channels in the donor graft and allows for rapid revascularization necessary for wound healing.

In the operating room setting, collagen-containing products are often applied to provide coverage over a soft tissue deficit following surgical debridement or serve as a scaffold initiate the filling of a void. As with the clinically applied products described above, these collagen grafts were originally designed to be used in the treatment of partial and full thickness burns. These surgically applied collagen products, such as Integra® Matrix and GraftJacket® Regenerative Tissue Matrix, are not specifically designed to neutralize proteases as several of the previously described products. Instead, they provide a functional cellular scaffold that promotes cellular in-growth and formation of granular tissue while also providing soft tissue coverage over bone, tendons, and other deep structures. As a result, it reduces the risk of contamination and subsequent infection.

To reduce MMP burden in a wound site prior to application of these surgically applied collagen grafts, it is recommended that the wounds be debrided sharply to promote local bleeding and to remove any nonviable and necrotic soft tissue and bone that will further stagnate a wound site. Localized bleeding following debridement stimulates influx of alpha-2-macroglobin (A2M), which is a chemical agent that acts as a protease inhibitor, thus reducing proteolytic destruction of the graft. [1,11]


In discussion of collagen products in wound healing, it is important to understand the underlying etiologies of wound chronicity. Vascular and nutritional status, the presence of an infection or colonization, and the microenvironment present in the wound bed all combine to affect healing. Each barrier must be addressed to ensure that the wound progresses through the normal stages of healing. [1]

Research has demonstrated the importance of re-establishing a functional ECM in chronic wounds and this has led to a renewed interest in collagen based wound healing products. [8] These products seek to provide a functional ECM as well as to reduce MMP levels present in the wound bed and seek to promote normal progression through the stages of wound healing. In addition, these products can be combined with other modalities, such as alginates or heavy metals to provide additional effects to the wound environment such as management of exudate or bacterial load.

The collagen-based surgical grafting materials, such as Integra Matrix® and GraftJacket® have filled a niche that have allowed for significant increases in salvage options due to the ability to provide collagen ECM to the wound site, following sharp debridement. These surgically applied collagen wound fillers can provide soft tissue coverage over deeper structures to reduce the risk of infection. Pioneered in the burn community, much of these techniques are now being utilized to preserve limb length in partial foot amputations, which is important as the costs of health care spiral and the annual incidence of foot ulcerations continue to climb. [2]

Considering the significant morbidity and mortality associated with lower extremity amputations, and the obvious link between lower extremity amputations and the ulcerations that precede them, it is incumbent upon the clinician involved in wound care to become familiar with these advanced wound care products in order to provide patients with the greatest possibility for successful outcomes in the treatment of chronic wounds.


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Address correspondence to: Ryan H. Fitzgerald, DPM, AACFAS. Hess Orthopaedics & Sports Medicine, PLC
4165 Quarles Court, Harrisonburg, Virginia 22801.

Attending physician, Hess Orthopaedics & Sports Medicine, Harrisonburg Virginia.
Assistant Professor, Department of Plastic Surgery, Georgetown University School of Medicine.

© The Foot and Ankle Online Journal, 2009