Anatomical and histologicalstudy of the tendo achilles

Tendo Achilles is the common tendon of soleus and gastrocnemius muscles. Achilles tendon disorders and abnormalities are commonly seen by sports medicine physicians. Posterior heel pain is multifactorial and may be due to changes of the tendo Achilles near its insertion. Moreover, anatomic and operative textbooks did not clearly describe the Achilles tendon attachment to the calcaneus. Was to study the length, width and mode of insertion of the tendo Achilles and its relation to the sural nerve. The study was carried out on 25 dissected lower limbs of adult human cadavers. Three tendons were prepared for histological study under light microscope. The study revealed that in 72% of cases, the tendon was inserted into the back of calcaneus with a crescentic opposing surface to the calcaneus, in 12% of cases, there was an extension of the tendon to the plantar aponeurosis but in 8% of cases, the insertion continued to the plantar aponeurosis giving origin to the abductor hallucis muscle. The remaining 8% of cases showed a prolongation of tendo Achilles joining another prolongation from the plantar aponeurosis extending to the tuberosity of navicular bone. In all cases, there was an intervening bursa between the tendon and the back of calcaneus. The mean length of the tendon from the musculo-tendinous junction of gastrocnemius and soleus muscles till the calcaneus was 22.18 +/- 3.12 cm and 7.62 +/- 1.71 cm respectively. The mean width of the tendon was 6.62 +/- 0.52 cm at its junction with the gastrocnemius, 2.88 +/- 0.32 cm at its junction with the soleus and 2.55 +/- 0.34 cm at its attachment to the calcaneus. The sural nerve was found 1.48 +/- 0.41 cm on the lateral aspect of tendo Achilles at its insertion. The histological study of the tendon revealed that it was formed of parallel collagen fibers with a fibrocartilage at the insertion site. The insertional region of the tendon is said to have stress concentration. Hence, the presence of fibrocartilages for protection of the tendon. Extensions of the insertion of the tendo Achilles has a role in the biomechanics and movements of the ankle and subtalar joints. The relation of the sural nerve to tendo Achilles should be concerned when suturing a ruptured tendon or any surgical interference

Ultrastructural changes of the epineurial and endoneurial fibroblasts in diabetic rats

Peripheral neuropathy can be produced by several diseases, the most common of which is diabetes mellitus. Diabetic neuropathy is a degenerative complication of diabetes mellitus. It is a disease reversible with treatment and is characterized by attacks of degeneration of the peripheral nerves alternating with nerve regeneration but its mechanisms remain poorly understood. A variety of mechanisms have been implicated in the pathogenesis and progression of peripheral diabetic neuropathy. The epineurium and the endoneurium of the peripheral nerves contain fibroblasts which form the collagen fibrils. It was recorded that theses fibroblasts showed several structural and morphological changes in different types of nerve injuries and peripheral neuropathy. Was to study the ultrastructural changes in the epineurial and endoneurial fibroblasts in diabetic neuropathy. Twelve albino rats with streptozotocin-induced diabetes and six control rats were used. The sciatic nerves were processed and examined using transmission electron microscope. The epineurial fibroblasts were increased in number and possessed cytoplasmic processes which were in direct contact with each other and with the epineurial mast cells stimulating these cells to release their granules with increased epineurial vascular permeability and macrophage infiltration with the release of cytokines that participate at nerve damage and others that promote nerve regeneration. The epineurial fibroblasts showed interruptions of their membranes indicating the sites of exocytosis of the newly formed collagen fibrils into the epineurium. The endoneurial fibroblasts showed branching cytoplasmic processes which may be used in the phagocytosis of the degenerated myelin in the diabetic nerves and also to separate the newly formed nerve fibers from the endoneurial edema. These fibroblasts also released ciliary neurotropic factor that improves nerve conduction and regeneration. They also showed cytoplasmic vacuoles of different sizes or shapes. Some of these vacuoles contained electron lucent substances suggested to be nerve growth factors to promote regeneration while others contained electron dense membrane suggested to be degenerated myelin. The endoneurial fibroblasts formed several parallel layers in the subperineurial space to separate the nerve fibers from the endoneurial edema. The increase in the epineurial and endoneurial fibroblasts in the diabetic nerves could be beneficial in nerve fibers regeneration