A calcaneal spur (also known as a heel spur) is a bony outgrowth from the calcaneal tuberosity (heel bone). Calcaneal spurs are typically detected by x-ray examination. It is a form of exostosis. When a foot is exposed to constant stress, calcium deposits build up on the bottom of the heel bone. Generally, this has no effect on a persons daily life. However, repeated damage can cause these deposits to pile up on each other, causing a spur-shaped deformity, called a calcaneal (or heel) spur.An inferior calcaneal spur is located on the inferior aspect of the calcaneus and is typically a response to plantar fasciitis over a period, but may also be associated with ankylosing spondylitis (typically in children). A posterior calcaneal spur develops on the back of the heel at the insertion of the Achilles tendon.An inferior calcaneal spur consists of a calcification of the calcaneus, which lies superior to the plantar fascia at the insertion of the plantar fascia. A posterior calcaneal spur is often large and palpable through the skin and may need to be removed as part of the treatment of insertional Achilles tendonitis. Signs and symptoms
Major symptoms consist of pain in the region surrounding the spur, which typically increases in intensity after prolonged periods of rest. Patients may report heel pain to be more severe when waking up in the morning. Patients may not be able to bear weight on the affected heel comfortably. Running, walking, or lifting heavy weight may exacerbate the issue.
In some fetuses, this process does not occur completely between all fingers or toes and some residual webbing remains. Genetics
Five types of syndactyly have been identified in humans. The corresponding loci associated with these types and their common phenotypical expression are as follows:

type I:  2q34-q36; webbing occurs between middle and ring fingers and/or second and third toes. type II:  2q31; also involves long and ring fingers, but has a sixth finger merged in between. type III:  6q21-q23; small finger is merged into the ring finger. type IV:  7q36; involves all fingers and/or toes. type V:  2q31-q32; similar to type I, but the metacarpals and metatarsals may also be fused. Management
Syndactyly of the border digits (thumb/index finger or ring/small fingers) is treated at early age to prevent the larger digit from curving towards the smaller digit with growth. Typically, syndactyly of these digits is treated at six months of age. The treatment of syndactyly of the other digits is elective and is more commonly performed when the digits have grown, at 18–24 months of age. Techniques
Because the circumference of the conjoined fingers is smaller than the circumference of the two separated fingers, there is not enough skin to cover both digits once they are separated at the time of surgery. Therefore, the surgeon must bring new skin into the area at the time of surgery. This is most commonly done with a skin graft (from groin or anterior elbow).