May 2013

How Effective Is HBOT For Diabetic Foot Ulcers?

By Brian McCurdy, Senior Editor

Although a recent study concludes that hyperbaric oxygen therapy (HBOT) is not effective for healing diabetic wounds, several physicians note that HBOT does have a benefit as an adjunctive treatment for non-healing diabetic foot ulcers.

   The longitudinal observational cohort study, published in Diabetes Care, focused on 6,259 patients with diabetes, adequate lower limb arterial perfusion and foot ulcers extending through the dermis. In their propensity score–adjusted models, researchers note that those receiving HBOT were less likely to heal their foot ulcer and more likely to have an amputation than those using conventional therapies. The study authors concluded that HBOT would not improve the likelihood that a wound might heal or decrease the likelihood of amputation. They add that the “usefulness of HBO in the treatment of diabetic foot ulcers needs to be reevaluated.”

   Phi-Nga Jeannie Le, MD, notes that the Diabetes Care study only “appears to contradict” previous studies that established the efficacy of HBOT for healing diabetic foot ulcers. Dr. Le notes the study is an effectiveness study rather than an efficacy study.

   “The two are not equatable,” says Dr. Le, who is affiliated with the Undersea and Hyperbaric Medical Society. “They signify two different objectives. One tries to determine if something actually works (efficacy) and the other tries to discern if that something has been beneficially employed (effectiveness).”

   As Dr. Le says, this study does not deny that HBOT is efficacious as adjunctive treatment for healing diabetic wounds and preventing major amputation, but it does conclude that HBOT has not displayed the same beneficial outcomes in an existing clinical practice as it has in several clinical trials. For situations when amputation is necessary, she says HBOT can obviate a major amputation by exchanging it for a minor amputation, an exchange generally agreed to increase quality of life. Dr. Le adds that the Diabetes Care study classifies any amputation as a negative outcome so one could not identify the beneficial effects of minor amputations in the study.

   Lee Brill, DPM, CWS, the President of the BrillStone Corporation in Dallas, says his center has had good results with HBOT. However, he notes that HBOT does not replace good wound care and debridement as well as establishing adequate perfusion and control of infection before and during HBOT.

   “Rather than showing the lack of effectiveness of HBOT,” the study raises questions for Dr. Brill. Among those questions, he asks how many patients in the study had subsequent osteomyelitis after a series of HBOT treatments due to inadequate workup prior to treatment? Dr. Brill also questions how many patients had inadequate debridement during HBOT treatment and whether offloading was standard throughout the patient population.

   “I agree that a great deal more research needs to be done and the variables need to be narrowed to be accurate,” asserts Dr. Brill.

   Dr. Le notes that she and the Undersea and Hyperbaric Medical Society agree with the study authors that physicians should use HBOT as a part of the overall strategy in healing recalcitrant diabetic foot ulcers rather than as a single agent to completely heal those wounds. She cites AHA Level 1A evidence that hyperbaric oxygen is efficacious as adjunctive therapy for the healing of diabetic foot ulcers. Dr. Le cautions that due to variability in practitioner utilization of HBOT, the results of this study cannot be generalized to wound care or hyperbaric medicine practices nationally.

Study Looks At Effect Of Neuropathic Midfoot Deformity On Ankle Joint Motion

By Danielle Chicano, Editorial Associate

A recent study in The Journal of Foot and Ankle Research asserts that an increasing talar declination angle and decreasing calcaneal inclination angle are associated with decreases in ankle joint mobility in individuals with neuropathic midfoot deformity.

   The study notes that researchers used goniometry and lateral view radiography to assess ankle joint mobility in three groups of patients: 20 patients with diabetic peripheral neuropathy and midfoot deformity due to Charcot neuroarthropathy, 20 patients with diabetic peripheral neuropathy with no deformity and 20 patients without diabetes, neuropathy or deformity.

   According to the study, the association between talar declination and calcaneal inclination angles with ankle plantarflexion range of motion was strongest in participants with neuropathic midfoot deformity due to Charcot neuropathy. In addition, researchers note that Charcot neuropathy may contribute to excessive stresses and ultimately plantar ulceration of the midfoot.

   Andrew Rice, DPM, FACFAS, notes these findings are consistent with the majority of his patients with neuropathic midfoot deformity. The first step in assessing such patients is to conclude that your findings are not due to acute neurotrophic changes, such as Charcot osteoarthropathy, notes Dr. Rice, an Assistant Clinical Professor in the Department of Orthopaedics and Rehabilitation at the Yale University School of Medicine.

   “I will initially manage patients (with neuropathic midfoot deformity) with a deep seated orthosis with a high medial and lateral flange shoe with stability,” explains Dr. Rice. “Secondly, I will utilize an AFO or Richie Brace with soft cover for protection. Thirdly, if the ankle is very unstable, I will use a CROW walker, FROG walker or Freedom Brace (FWD Mobility).”

   Regarding measures to prevent abnormal stresses in patients with neuropathic deformities, Dr. Rice recommends a variety of orthotics and walkers. In cases of acute neurotrophic changes, he recommends complete offloading.

   According to Dr. Rice, podiatrists might benefit from a three-phase bone scan to help differentiate between acute changes versus chronic, slowly progressive deformities. Practitioners might also want to assess the presence of associated bony deformation, which would increase the incidence of ulceration and require surgical resection, adds Dr. Rice.

Is Arthroscopic Debridement Effective Long-Term For Osteochondral Defects?

By Brian McCurdy, Senior Editor

A recent study in the Journal of Bone and Joint Surgery gives high marks to the long-term efficacy of arthroscopic debridement and bone marrow stimulation for talar osteochondral defects.

   The study involved 50 patients with primary osteochondral defects who received arthroscopic debridement and bone marrow stimulation. Evaluating these patients after a mean follow-up of 12 years, researchers noted that 94 percent of patients had resumed work and 88 percent had resumed sports.

   Radiographs indicated an osteoarthritis grade of 0 in 33 percent of the patients, I in 63 percent, II in 4 percent, and III in 0 percent, according to the study. The authors added that in comparison with the preoperative osteoarthritis classification, 67 percent of radiographs showed no progression and 33 percent showed progression by one grade.

   Jeffrey Bowman, DPM, MS, cites several advantages to arthroscopic procedures. He notes that since the incisions are small, there is less chance of infection and in some cases, patients can walk the day of surgery or the next day. Minimal dissection also means less pain and swelling, according to Dr. Bowman, a Past President of the Texas Podiatric Medical Association.

   How patients fare in the long term following arthroscopy for talar defects depends on what age patients undergo the procedure as well as their weight and overall health, notes Dr. Bowman. If patients have the procedure at an early age, he has found it is more likely they may need an additional procedure if they are active. Patients who have arthroscopic procedures for talar defects in their 50s or 60s tend to have more lasting results, which he most likely attributes to less activity in their lifestyle.

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