Charcot Arthropathy: When Mechanical Treatment Can Help
Charcot arthropathy is an extremely challenging disease process to treat for many reasons, according to David Levine, DPM, CPed. He says one of the big problems is not being able to rely upon the patient for feedback. Given the profound peripheral sensory neuropathy present in these patients, Dr. Levine says vigilant monitoring of any changes in the foot is essential for preventing further complications. With this in mind, our expert panelists take a closer look at mechanical management of Charcot arthropathy and when it can help facilitate successful treatment outcomes. Q: In your opinion, what are the most important biomechanical considerations in managing Charcot arthropathy? A: Daryl Phillips, DPM, says the three major goals in treating this condition are: 1) immobilizing the Charcot joint; 2) equalizing pressure across the entire plantar foot surface; and 3) equalizing inversion and eversion moments around the ankle and subtalar joints. Bret Ribotsky, DPM and Dr. Levine agree that you should first determine the stage of Charcot arthropathy before weighing the appropriate treatment course, biomechanical or otherwise. In the acute stage, Dr. Levine says you should emphasize nonweightbearing and immobilization. However, he points out that crutch walking may be impractical and you may have to employ another method to reduce weightbearing forces on the affected foot. Dr. Levine says biomechanical considerations play a larger role when your patient has chronic Charcot arthropathy. Reducing pressure areas and improving propulsion are two key goals, according to Dr. Levine. He also emphasizes assessing the stability of the deformity. Determining the region of the foot that is involved will help you determine the stability. Dr. Levine says treating unstable feet biomechanically can be challenging as they are susceptible to changes. However, he explains that if your patient has stable feet, you can provide biomechanical treatment in order to help him or her offload specific areas and improve propulsion. It’s also important to address any equinus deformity, according to Drs. Levine and Ribotsky. As the bones and joints change positions, Dr. Levine says the muscles and tendons fight over the balance of power. “Often times, the tendoachillis will win out, producing primarily a sagittal deformity that may be difficult to control conservatively,” warns Dr. Levine. Q: Assuming that neither patient is currently ulcerated, how does your strategy differ between patients with and those without a history of ulceration? A: Nicholas Sol, DPM, CPed and Dr. Ribotsky note that patients who have had previous ulcers are obviously prone to reulceration, so offloading pressure from the particular area is essential. For these patients, Dr. Phillips says it is equally important to equalize pressure across the plantar foot surface and immobilize the affected joint. Dr. Ribotsky concurs and also cautions DPMs to avoid transferring the weight to an area that overloads another portion of the foot. Unless there is less soft tissue under the previously ulcerated area than under the surrounding area, Dr. Phillips tries to avoid decreasing the pressure in the previously ulcerated area to an amount less than the surrounding area. In order to meet these goals, Dr. Phillips emphasizes doing an in-shoe dynamic pedobarograph study. In his quest to reduce or eliminate as much direct pressure and shear forces over previously ulcerated areas as possible, Dr. Sol relies on in-shoe pressure analysis. He says it’s his primary tool for fabrication, adjustment and monitoring efficacy. Dr. Levine employs a simple ink mat impression test, whether the patient has had previous ulceration or not. He says this “fast and easy” helps assess regions of increased weighbearing pressures. His goal is to reduce pressures where there is too much and help facilitate a more propulsive gait. Q: What specific clinical criteria do you use to decide between using a custom foot orthosis, custom shoes, an AFO device or a CROW walker? A: Drs. Ribotsky and Sol say it’s important to assess the level of deformity as well as the level of impairment. For example, if you’re treating a patient who has developed a significant Charcot arthropathy with a contracted Achilles tendon and a dysfunctional posterior tibial tendon, Dr. Ribotsky says it’s essential to ensure control above the ankle joint.