Lower Extremity Ulcer Management: Practical Concepts

  Lower extremity ulcerations are an ever-increasing problem in this country, particularly among those patients living with diabetes. Due to the continued surge in the disease’s presence throughout the general population (along with comorbidities of hypertension and obesity), the incidence of these ulcerations and secondary complications continues to grow over time. Despite advances in wound care, these ulcers remain very challenging to manage. Offloading, a removal of pressure from the site, is commonly needed on lower extremity ulcerations, as many of these ulcers occur on the bottom (plantar) aspect of the foot. This pressure cannot be removed per se, but rather be redistributed to help promote wound healing.   This article seeks to discuss preliminary evaluation of a lower extremity ulcer, offloading, and surgical considerations.

Assessment & Examination

  As with any wound that presents to the clinician, a thorough patient history and physical are needed to assess a lower extremity ulceration. By obtaining an accurate history, the clinician should be able to determine if the ulcer is acute, chronic, recurrent, or acute and likely to become chronic. A detailed history should contain all previous treatment modalities that may have helped or failed, provided the patient has a documented history of past wounds. A comprehensive history should also include any prescribed antibiotics (ie, oral, IV, topical, antibiotic bead placement). Consideration should also be made if the patient has experienced MRSA or if the patient has had any joint replacement or implant. Social history remains very important in developing a treatment protocol for a lower extremity ulceration. For example, one’s vocation or profession could limit ability to maintain offloading compliance. A thorough discussion between the healthcare provider and the patient is required to best decide upon a method of offloading that will provide the best opportunity for favorable outcomes to promote healing. Decisions also have to be made regarding how often dressings need to be changed with consideration to the wound and the overall activity level of the patient. As patients’ demands and limitations vary greatly, this remains a very challenging aspect of the treatment protocol.   A thorough exam should include vascular, neurologic, orthopedic, and dermatologic evaluation. Complete blood count, metabolic panel, hemoglobin A1c, albumin, sedimentation rate, and wound culture comprise comprehensive lab work. Bone biopsy may also need to be performed. Imaging should include radiographs, bone scan, and possibly MRI. When a patient presents to clinic, over-the-counter devices are often employed to help offload the foot. These devices offer the ability to be readily available in the clinic to immediately begin to offload an area of pressure, proving effective for acute ulcerations; however, if the ulcer is chronic or is due to significant deformity, custom types of offloading will likely be required in the long term.

Opportunites & Obstacles

  A number of different options exist to perform offloading. These include:   1) Shoes and boots. One of the most common means of offloading foot ulcers remains the postoperative (surgical) shoe, which consists of a rigid wood bottom and Velcro straps to allow closure of the shoe. Beneficial in accommodating bandages from dorsal wounds, these shoes also help protect any compression bandage or hose that may also be worn on the lower extremity. The surgical shoe also helps remove pressure on the plantar aspect of the foot; however, other devices should be considered when plantar pressure needs to be limited due to an existing ulceration.   The OrthoWedgeTM “healing shoe” is similar to the postop shoe, except for a wedge that’s placed either at the front of the foot (to offload the hindfoot) or vice versa. These shoes are superior in offloading for plantar ulcerations relative to surgical shoes, although, due to the wedge, patients may need to have a lift added to the unaffected foot to accommodate for relative limb length discrepancy that will now exist. Careful consideration needs to be given to the patient’s stability, and adjunct devices such as walkers may need to be used to prevent fall risk.   Cam Walker® and diabetic fracture walking boots are other viable options. Intended to fix the ankle relative to the leg, these devices help offload plantar ulcerations by removing propulsion from the gait cycle and are superior in relieving pressure on plantar ulcerations. Walking boots have an added honeycomb inset under the foot that’s secured with Velcro and can be easily removed to customize the bottom of the boot to relieve pressure directly under any existing ulcer. These boots are generally well tolerated by the patient, as they can be removed easily to allow bathing and necessary bandage changes.   CROWs (Charcot Restraint Orthotic Walkers) are custom-molded, bivalved boots used to control patients with Charcot foot deformities. These boots can be removed for sleeping and bathing, and are generally well tolerated. They often feature a molded insert at the plantar foot that can be accommodated to the patient to maximize pressure relief on the bottom of the foot. These boots are best used for long-term control once an ulcer has healed or can be used if a small ulcer is present, as they will often fit a small bandage.   2) Shoe inserts. Extra-depth diabetic shoes provide a multidensity insert that helps offload the foot. These inserts can be customized to accommodate partial amputation and are commonly fitted with “fillers” that help reduce the space within the shoe from an amputated site.   Shoe modifications may also be needed to further offload the plantar aspect of the foot. Steel bars may be added along the length of the sole of the shoe to prevent pressure on the forefoot from the rearfoot. Rocker bottoms are often added with a steel bar to help promote propulsion in a shoe by allowing the shoe to rock forward as opposed to having the flexibility in the shoe to allow propulsion but still limit plantar pressures. Ankle Foot Orthoses are L-shaped devices that incorporate control at the level of the ankle joint and are helpful in limiting plantar pressures. A drop foot brace, commonly used among stroke patients, is an example. This device fits in a shoe and helps control plantarflexion of the foot at the ankle, thus limiting pressure, helping ulcers resolve or preventing them from recurring. These orthoses can be fixed, removing all motion across the ankle, or hinged (with or without a spring) to allow motion at the ankle to maintain greater level of function.   3) Total contact casting. These casts may be left in place for weeks at a time and allow “windows” to be created to provide access to a wound for bandage changes and treatments. Casting is often found to be cumbersome among patients, as bathing is rather difficult and access to the casted limb is prevented.   4) Weight-Bearing devices. Due to the nature of deformity and ulcer, complete offloading may be desired. The patient’s physical abilities and needs of daily living may limit the ability to perform this successfully. Commonly used in limiting weight-bearing of the lower extremity, crutches can present challenges. Many chronic wound patients live with multiple comorbidities and may lack the strength and conditioning needed to ambulate safely with crutches. Walkers also present a similar challenge in that they require a patient who is to be completely non-weight-bearing on a lower extremity to support body weight with only upper-body strength. Roll-A-Bout devices may be more secure for low-strength patients, but they still require enough strength in the contralateral extremity to ambulate safely. While wheelchairs allow patients to relieve pressure, they often present significant challenges among those who continue to work and/or lead more active lifestyles.

Determining Surgery

  Clinicians must balance wishes, needs, comfort level and best chance of a patient’s healing success when choosing a method of offloading. At some point, despite all attempts, an ulcer may fail to heal.   The extent of the underlying deformity may be so severe that surgical correction is needed, and many types of corrective procedures exist to relieve pressure and prevent amputation.   Distal tip (toe) ulcerations can often be relieved by an arthroplasty at the proximal or distal inter-phalangeal joint, relieving pressure on the tip and preserving the toe. Lesser metatarsal ulcerations may be caused by retrograde pressure from an associated hammertoe deformity or by a deformity relating to the length or plantarflexion of the metatarsal. Bony prominences can often be relieved by a simple exostectomy. Tendon-balancing procedures may be needed in correcting a flexible deformity. These are only a few examples of the procedures available to the foot and ankle surgeon in correcting and underlying ulceration. In attempting to offload the foot and promote wound healing, the clinician should keep all options available. Offloading can be an art as much as a science. Modifications of the devices presented permit customizing that is only limited by the ideas of the clinician. Working closely with an orthotist will also be valuable when needing to modify a device. Referral to a foot-and-ankle surgeon should be conducted if attempts at offloading and proper wound care fail to provide adequate improvement.   One other important thing to always consider: Offloading devices that can be easily removed and promote higher levels of comfort may also lead to noncompliance. Clinicians should inspect the condition of a patient’s offloading device during each visit to assess wear, or lack thereof. Oftentimes, if compliance is an issue, placing the patient in something more restrictive could actually be more productive.   Additionally, remember that offloading often needs to be continued even after a wound has healed. Custom devices, which offer advanced comfort and limit risk of reoccurrence, are often employed at this time. Steven J. Lieberson is in private practice in Houston and Sugar Land, TX. He is board certified by the American Board of Podiatric Surgery; is an attending clinician at the Advanced Wound Care Center, Houston; and serves as the academic chief and director of the podiatric medicine and surgical residency program at St. Joseph Medical Center in Houston.