Chronic Achilles Tendinopathy



Chronic Achilles Tendinopathy

Introduction

Achilles Tendinopathy is a widely spread condition of the musculoskeletal system with a relatively high morbidity rate in both the common population, as well as athletes. From the many proposed theories about the cause of Achilles tendinopathy, the most common and widely accepted theory states it to be a degenerative tendinopathy, which put the blame on relative overuse of the tendon during weight bearing activities. This particularly occurs in cases of chronic Achilles tendinopathy. In the early stages, the condition is known as tendinosis as no degenerative changes have taken place, the symptoms are less severe, and most often the condition is reversible. However, in chronic cases, the management of the condition becomes difficult. In this case, the causative factors should be specifically addressed in order to reduce the symptoms and minimize the risk of recurrence. This requires a sound knowledge of the anatomy and pathophysiology for accurate assessment of the musculoskeletal region impacting the load of Achilles tendon. As with all tendinopathy, the basic principle in the treatment involves exercise rehabilitation. Achilles tendinopathy is a difficult condition to treat due to critical points of management that requires specific, careful management as well as patience to achieve an optimal outcome (Paoloni, 2012).

Discussion

Anatomy of the Achilles Tendon

The Achilles tendon is known to be the strongest tendon in the body, named after a Greek God. It functions to join the muscles of the calf to the heel bone. The gastrocnemius muscles, present at the back of the leg merges with the Soleus muscle in two different ways, to form the Achilles tendon. Type 1 is much more commonly found than type 2. In this type, the two aponeuroses join about 12cm proximal to their insertion at calcaneus. On the other hand, in type 2 the aponeuroses get inserted directly in the aponeuroses of Soleus. Furthermore, the upper part of the Achilles tendon is somewhat rounded, whereas it is comparatively flatter at the distal 4cm. The fibers of the tendon are spiral 90°, which increases the elongation during locomotion and assists in releasing the energy which is stored within (Anatomy and Pathology of the Achilles Tendon, n.d.).

The Achilles tendon has a thin gliding membrane of loose connective tissue surrounding it, called paratenon, instead of a synovial sheath. Proximally, paratenon blends with the deep fascia of the leg, enclosing the gastrocnemius and Soleus muscles, and distally blends with the periosteum of the calcaneus. Blood vessels, supplying the tendon, run through the paratenon. The Doppler flowmetry shows a considerable low blood flow near its point of insertion at the calcaneus. Otherwise, it is evenly distributed in the rest of the tendon. Blood flow also varies with age, its use, and the presence of Achilles tendinopathy (Anatomy and Pathology of the Achilles Tendon, n.d.).

Histology of Normal Achilles Tendon

Up to 95% of the cellular component, that makes up the tendon comprises of tenocytes along with tenoblasts. In addition, the rest of the cellular components are composed of chondrocytes, synovial cells, vascular cells, ...