Offloading — The Total Picture

  To paraphrase an adage, “it is not only what you put on a wound that is important, but what you take off the wound as well.” While dressing selection is important to a degree, offloading plays a critical role in wound healing, especially in diabetic, neuropathic and pressure ulcers of the foot. Conceptually, it is increased pressure over an underlying boney prominence that is often responsible for ulcer formation and non-healing. Prolonged or repetitive pressure over a boney prominence reduces perfusion to tissue, and the resulting lack of oxygen to the tissue results in ulcer formation.

Goals

  Goals of offloading are redistribution of focal pressure from one specific area to a broad area of dispersed force. This allows for the phases of wound healing proceeding without disruption from ground reactive force or other external source of pressure. Offloading should move a wound towards healing in as efficient manner as possible. When considering methods of offloading, several considerations should be addressed, including the ambulatory status of the patient, their quality of gait, and willingness of the patient to comply with the proposed methods. The practitioner must consider their lifestyle, activity level, and address the hidden concerns, such as bathing and mobility.

  The area at the periphery of an ulcer with hyperkeratotic rim represents the area of highest pressure, as well as the area of decreased metabolic activity, and senescent, phenotypically altered cells.¹ In a plantar foot ulcer, it is common to see an area of macerated tissue (a white ring surrounding the periphery of the ulcer). This area of increased pressure has been described as the “edge effect.”²

  The first step in offloading, especially in plantar foot ulcers, is a thorough debridement of the macerated tissue surrounding the ulcer.

Ensuring Offloading Is Effective

  For offloading to be truly effective, it must be consistent and continuous, therefore, “24 hours, 7 days a week” is ideal. Patients cannot be relied upon to use offloading devices consistently. Surgeons do not send patients home with scalpel blades and instructions on how to perform self-debridement, so why would a provider entrust patients to perform their own offloading? Ulcers are not the only things that require protection and monitoring; patients must also be protected from themselves.

Techniques Vary

  Offloading techniques vary and as previously stated, a variety of factors must be considered when choosing they type of offloading to employ, especially in an ambulatory patient.

The Gold Standard

  When offloading plantar foot ulcers, the gold standard still remains the total contact cast (TCC). Numerous articles have been written to date on the subject of the TCC. Dr. Paul Brand first used the TCC in the United States during 1965 at the National Hansen’s Disease Center in Carville, Louisiana and there is a long list of studies documenting the utility and success of the TCC.^3,4 TCC has been shown to be safe and effective for complicated ulcers, and when compared with half-shoes and removable cast walkers, TCC achieved faster healing rates than either of the two other treatment options.^4-6 It also provides constant protection as it is not removable by the patient, and its weight tends to decrease activity levels, thereby reducing additional trauma to the ulcer. Perceived drawbacks of its use are the time needed to remove and re-apply, and the technical knowledge required to apply. Infection and ischemia would be two contraindications for TCC application. Another contraindication would be patients with unsteady gaits or who have no form of transportation other than driving their own car.

  The TCC would not be suitable for these candidates.

“Instant” Total Contact Cast

  Armstrong, et al in an attempt to address the time and technical knowledge required in Total Contact Cast application, suggested the use of the “Instant” Total Contact Cast, which involves the application of a fiberglass, plaster or cohesive bandage roll over a CAM walker. This method also reduces the likelihood of a patient removing the cast.⁷

Other Methods

  Other methods for offloading include the CROW (Charcot Resistant Orthotic Walker), Ankle Foot Orthoses, CAM Walkers, Bledsoe Boot and the Active Offloading Walker. These are removable devices, worn by patients, that allow for daily dressing changes, if needed, and/or for maintenance of a healed ulcer.

Bring in the Experts

  Utilizing the services of a Certified Pedorthist is recommended where possible. Casting for custom shoes, AFO’s or CROW walkers can be time intensive and the expertise of a CPed makes them valuable additions to the limb preservation team.

  A method developed by this author to address offloading, a gait instability and compliance issue has been described as the “soft” total contact cast.

“Soft” Total Contact Cast

  The “soft” total contact cast has been described as a hybrid method devised to ensure offloading occurs in patients who may not be candidates for TCC or where a non-removable device is preferred to ensure greater compliance.⁴ It is comprised of soft materials, including cast padding, a paste bandage and elastic self-adherent bandage wrap. This method has not only proven effective over years of clinical application, but has been found to be well tolerated, easy and inexpensive to apply.

Shoes

  Among the least effective methods of offloading are surgical shoes and “half” shoes. These do provide a degree of offloading, but the potential for lack of patient compliance make these the last methods that should be considered. Fleschli, et al found the half-shoe to be the least effective method in an offloading comparison study while Needleman found the device to be useful, but also reported a 30% complication rate, including balance problems, falls and joint pain.^6,7

Bedbound or immobile Patients

  Offloading is not limited to our ambulatory patients and creativity must often be employed where bedbound or immobile patients are being managed. When patients are bedbound or immobilized, they are at significant risk to develop pressure ulcers, especially at the heel or other areas of underlying boney prominence. Intervention must occur to prevent skin breakdown. Support surfaces, including air loss mattresses, should be ordered. Additionally, care must be taken to “float” heels to prevent contact with the bed, ground or wheelchair foot pedals.

Devices

  Pillows positioned behind the legs are helpful, especially when the patient does not tolerate offloading devices. Devices such as multi-podus boots or Linard splints are proven to offload heels and feet. However, when using such devices, legs and feet must be inspected at least twice a day for signs of additional skin breakdown. Rigid plastic frames of each may potentially create new pressure areas for frail skin to rest against.

  Heelift® (DM Systems, Evanston, Illinois) or heel guards are foam devices that protect feet and heels and allow for floating of heels, conceptually similarly as with multi-podus splints. The Heelift style products are entirely made from foam so there are no rigid components that may cause areas of focal pressure. These type devices should also be removed at least twice daily for skin inspection.

The Challenges

  Offloading presents multiple challenges. Regular re-assessment of efficacy of employed methods is essential. Finding the right method patient requires insight by the Provider regarding the lifestyle, gait, compliance and comprehension of the patient. Offloading typically requires customization. One size does not fit all and random dispensing of certain products can do a great disservice to both patient and provider alike.

  Dr. Desmond Bell is a Board Certified Wound Specialist (CWS)-(American Academy of Wound Management), and a Fellow of the American College of Certified Wound Specialists. He presently serves on the Board of Directors of the American Academy of Wound Management. Dr. Bell is the founder of the “Save A Leg, Save A Life” Foundation, a multi-disciplinary non-profit organization dedicated to the reduction in lower extremity amputations and improving wound healing outcomes through evidence based methodology and community outreach. www.savealegsavealife.com. Dr. Bell is the founder of the Limb Salvage Institute and Wound Care on Wheels, LLC a service providing wound care to patients in the hospital, home or long term care settings. Wound Care on Wheels evolved from his previous practice model, the First Coast Diabetic Foot & Wound Management Center, a freestanding outpatient wound management center. He also previously served as the assistant Medical Director of the Wound Management Center of Jacksonville, FL.

  Dr. Bell is a graduate of Tulane University and the Temple University School of Podiatric Medicine. He served his residency training programs at the Department of Veterans Affairs Medical Center in Philadelphia and Delaware Valley Medical Center in Langhorne, Pennsylvania. While at the VA, Dr. Bell received a commendation in part for his role in wound care. He served as Chief Podiatric Surgical resident and was actively involved in the Wound Care Center at Delaware Valley.

  He is a frequent lecturer and author on the subject of wound care, peripheral arterial disease, and diabetes. Dr. Bell was awarded the First Humanitarian Award by Specialty Hospital for 2009. He is a member of the Speaker's Bureau of Organogenesis and serves as a consultant with Biolife, LLC, Sanofi-Aventis, Libertas Health Company, LLC and LifeCell. He has been in private practice in Jacksonville, Florida since 1997 and is on staff at Memorial Hospital of Jacksonville, St. Luke’s Hospital, St. Vincent’s Medical Center and Specialty Hospital of Jacksonville. Dr. Bell served on the Medical Executive Committee at Specialty Hospital and is active in the Wound Management program there.

  For more information visit www.savealegsavealife.com; www.wounddr.com.

References

1. Falanga V. Wound bed preparation and the role of enzymes: a case for multiple actions of therapeutic agents. Wounds. 2002; 14 (2): 47-57.

2. Armstrong DG, Athanasiou KA. The edge effect: how and why wounds grow in size and depth”. Clin Pod Med Surg. 1998; 15 (1): 105-8.

3. Birke JA. The contact cast: an updated case study report. Wounds. 2000; 12 (2):26-31.

4. Bell D. Evidence –based rationale for offloading treatment modalities. Surgical Technology International XVII. May 2008; 113-7.

5. Nabuurs-Franssen MH, Sleegers R, Huijberts MS, et al. Total contact casting of the diabetic foot in daily practice: a prospective follow-up study. Diabetes Care. 2005; 28 (2): 243-7.

6. Armstrong DG, Nguyen HC, Lavery LA, et al. Off-loading the diabetic foot wound: a randomized clinical trial. Diabetes Care. 2001; 24 (6): 1019-22.

7. Armstrong DG, Short B, Espensen EH, et al. Technique for fabrication of an “instant total contact cast” for treatment of neuropathic diabetic foot ulcers. J Am Pod Med Assoc. 2002; 92 (7): 405-8.

8. Fleischli JG, Lavery LA, Vela SA, et al. Comparison of strategies for reducing pressure at the site of neuropathic ulcers. JAPMA. 87 (10): 466-72, 1997.

9. Needleman RL. Successes and pitfalls in the healing of neuropathic forefoot ulcerations with IPOS postoperative shoe. Foot Ankle Int. 1997;18(7): 412-7.