Plantar space abscesses in the diabetic foot: diagnosis and treatment

Plantar space abscesses in the diabetic foot are relatively uncommon. These abscesses are an anatomic type of foot infection. Three plantar spaces have been identified: the medial, central, and lateral. The central plantar space is by far the most important. Within the central plantar space are tendons of the flexor digitorum longus, flexor digitorum brevis, quadratus plantae, lumbricales pedes, the medial and lateral plantar nerves, and the plantar arterial arch. Located within the lateral and medial spaces are the short flexor and abductor muscles to the first and fifth rays. Plantar space infections may arise from a variety of causes. Infections of the fibrofatty tissue of the toe pad or the long flexor tendon sheaths and lumbrical tendons secondary to web space infections, poor nail care, trauma, and mal perforans ulcers have been implicated. A medial incision is recommended for drainage of both the medial and central plantar spaces. This avoids a painful plantar scar and allows for extensive incision and drainage of these abscesses. The lateral plantar space is best drained by a lateral incision. Both incisions heal without a sensitive scar. Control of sepsis is of primary importance. If left uncontrolled, obliteration of the plantar arterial arch occurs. Necrosis of the distal foot and central three toes results, thereby preventing any effort to save the diabetic foot.