The Too Few Toes principle: A formula for limb-sparing low-level amputation planning

Both single and multiple toe amputations biomechanically alter foot function to varying degrees. In patients with diabetic neuropathy, these changes often lead to increases in deformity, plantar pressure and risk for ulceration, infection and reamputation. While a philosophy that strives to maximize limb length and function by performing the fewest and most distal amputations possible is likely a good one, we believe that a basic "formula" might help serve as a guide for surgeons to balance limb function with tissue preservation. Digital amputations that exceed a "hallux plus one lesser toe" or "lesser toe plus two" digital/ray amputations in our experience often surpass a threshold of mechanical function. For any clinical scenario in which amputation would extend beyond this threshold, a transmetatarsal amputation (TMA) or pan metatarsal head resection (PMHR) should strongly be considered to avoid costly foot complications and the need for excessive revisional surgery. Such an approach still maintains an underlying philosophy of functional limb preservation. We are unaware of any other attempt to standardize the advancement of surgical intervention from multiple toe resections to a full metatarsal level or higher resection. Therefore, we present this simple formula for surgical planning in the hopes of providing the most durable and efficient care of the high-risk diabetic foot when multiple toe amputations are needed.