Diabetic patients are prone to foot infections and ulceration due to factors like neuropathy, arteriopathy and increased susceptibility to infection. 18,19 Infection may involve the soft tissues as cellulitis, osteomyelitis or septic arthritis (Figure 9). Most of the foot infections result from contiguous spread from an ulcer or skin defect. 18–20 Ulcers are most commonly located in the forefoot, around the ﬁrst andﬁfth metatarsal heads and the distal phalanx of the great toe and occur in the region of the heel. 18 They are uncommon in the midfoot. These areas also correspond to the most common sites of soft-tissue infection and osteomyelitis. 18
Historically, thromboplastin was a lab reagent, usually derived from placental sources, used to assay prothrombin times (PT time). Thromboplastin, by itself, could activate the extrinsic coagulation pathway. When manipulated in the laboratory, a derivative could be created called partial thromboplastin. Partial thromboplastin was used to measure the intrinsic pathway. This test is called the aPTT , or activated partial thromboplastin time. It was not until much later that the subcomponents of thromboplastin and partial thromboplastin were identified. Thromboplastin is the combination of both phospholipids and tissue factor, both needed in the activation of the extrinsic pathway, and partial thromboplastin is just phospholipids without tissue factor. Tissue factor is not needed to activate the intrinsic pathway.