Point-Counterpoint: Is An Initial TMA Better Than A Partial Ray Amputation in Patients With Diabetic Neuropathy?
Surveying the research and drawing on her own experience, this author says partial ray amputations in this population can lead to complications and further amputation whereas initial TMA procedures can facilitate a durable and functional residual limb.
By Valerie L. Schade, DPM, AACFAS
The primary goal of any limb salvage procedure is to maintain a stable, plantigrade foot that a custom orthotic and extra-depth or custom shoe gear can easily protect. This primary goal serves a secondary outcome of minimizing the potential for future ulceration, infection and amputation.
In the past, the focus has been on saving as much of the foot as possible, taking only the minimum necessary for resolution of the current presentation. This can often lead to one of the most dreaded labels of podiatric surgeons as “whittlers” of the foot. In this era of evidence-based medicine, the reality is that these minimalist efforts often result in a deformed and non-functional foot doomed for repeat incidences of ulceration, infection and amputation.
What The Emerging Research Reveals
Borkosky and Roukis conducted a systematic review of patients with diabetes mellitus and peripheral sensory neuropathy who underwent partial first ray amputation defined as permanent removal of any portion of the osseous structures distal to the medial cuneiform.1 The review excluded patients with critical limb ischemia. A total of five studies (21 percent) met the inclusion criteria. The weighted mean age of the 435 included patients was 59 years. The weighted mean follow-up was 26 months. Results of the systematic review found that one in every five patients required more proximal amputation with the final level being an additional digit (37 percent), transmetatarsal amputation (TMA) (37 percent), below-knee amputation (BKA) (29 percent) and LisFranc amputation (1 percent).
The authors determined that a partial first ray amputation in patients with diabetes and peripheral sensory neuropathy and without vascular compromise may not result in a durable, functional foot.1 They postulated that a well-balanced TMA may be a more predictable level of amputation in regard to durability and longevity.
Taking this data, Borksoky and Roukis performed a retrospective review using the same inclusion and exclusion criteria as described above for analysis of their own facility’s results over an 11-year period.2 A total of 59 patients who had a partial first ray amputation met the inclusion criteria. The mean age was 67 years. The mean follow-up time was 34 months. A total of 69 percent of these patients developed a new ulceration at a mean of 11 months from the index procedure. The mortality rate was 48 percent with death occurring at a mean of 35 months from the index procedure. In addition, 36 percent of patients required an average of two ancillary procedures such as flexor tenotomies and an average of 27 clinical visits from index procedure to the time of definitive treatment defined as complete healing of the index wound or time to reamputation. Ninety-two percent of patients required prolonged postoperative antibiotic therapy with a mean of two different antibiotics prescribed.
Combining their own facility’s data with that from their previously performed systematic review, the authors felt that a partial first ray amputation at any level is neither reliable nor durable.2 The question of whether these patients would be better served by the predictability, durability and longevity of a well-balanced transmetatarsal amputation still existed.