Basic Fucntion
Bursae contain synovial fluid and are usually located in locations that are subject to friction; they are closed sacs lined by a synovium-like membrane. Their function is to facilitate the motion that happens between bones and tendons, bones and skin, or tendons and ligaments and to mitigate friction.
The retrocalcaneal bursa is a horseshoe-shaped bursa found between the rounded superior bursal prominence of the os calcis and the Achilles tendon and is constant.
Position
Retrocalcaneal bursa is located amongst the superior tuberosity of the calcaneus and the Achilles tendon. Plantar flexion reduces the pressure in the retrocalcaneal bursa, while dorsi-flexion of the foot and ankle produces heightened pressure in the retrocalcaneal bursa.
Sructure
Anatomically, the posterior wall is identical from the thin epitenon of the Achilles tendon while, the retrocalcaneal bursa has an anterior bursal wall made up of fibrocartilage laid over the calcaneus. Setting like a cap over the calcaneus and having a concave aspect anteriorly, it is a disk-shaped construct lying over the posterior-superior aspect of the calcaneus.
Functions
- Its purpose is to reduce friction and thus to assist in the movement that takes place between bones and tendons, bones and skin, or tendons and ligaments.
- Between the axis of the ankle joint and the insertion of the Achilles tendon it sustains the relatively constant distance.
- There would be shortening of the distance of the ankle joint axis and the insertion of the Achilles tendon, if the posterior prominence were absent, during dorsiflexion.
Cinical Significance
It is a prospective site of inflammation and structural deformity. Retrocalcaneal bursa is subject to high stress daily.
Retrocalcaneal Bursitis
- Retrocalcaneal bursitis generally shows as posterior heel pain, tenderness, swelling, and warmth located proximal to the Achilles tendon insertion and anterior to the tendon.
- Retrocalcaneal bursitis is often connected with seronegative spondyloarthropathy. Irritation of the bursa may occur from a bony prominence (Haglund’s deformity); however, isolated bursitis without having such a prominence may occur.
- Patients with retrocalcaneal bursitis are generally older individuals with lower activity levels.
- The occurance is generally acute, between the Achilles and the calcaneus, with deep pain and recognizable inflammation in the posterior soft tissues. Interrelated warmth and increased pain with range of movement, particularly dorsiflexion, are usually present. This swelling may by quite obvious in the soft tissue medial and lateral to the tendon.
- Highest tenderness is found either medially or laterally or both, just anterior to the Achilles tendon.
- Treatment consists of rest, ice, a heel lift and an Achilles tendon extending program once acute symptoms have decreased. Due to the harmful effects on the biomechanical properties of the Achilles tendons leading to a rupture.A cortisone injection is not recommended.
- The procedure can be done as an open surgery or through an arthroscopic technique if the non-operative measures fail, surgery involving resection of the inflamed bursa may be considered.
Haglund Deformity
This entity often goes hand-in-hand with retrocalcaneal bursitis, and frequently there is an element of insertional tendinitis as well. Retrocalcaneal inflammation may also be associated with a protuberance of the posterosuperior lateral aspect of the calcaneus, causing irritation of the bursa, called a Haglund deformity or pump bump.
Retrocalcaneal Pain Syndrome
Retrocalcaneal pain syndrome is generally associated with the high-arched cavus foot and the varus heel. There is protuberance of the heel, which is more susceptible to enhanced pressure from the tendons and the counter of the shoe. The combination of these factors tends to produce a foot that does not dorsiflex as conveniently as a normal foot.