What is the difference between swan neck deformity and boutonniere deformity?
What is the difference between swan neck deformity and boutonniere deformity?
A swan-neck deformity is characterized by hyperextension of the proximal interphalangeal (PIP) joint with flexion of the distal interphalangeal (DIP) joint. The boutonniere deformity is characterized by the inverse posture.
What is swan neck and boutonniere deformities?
Abstract. Acute and chronic injuries to the finger extensor mechanism can result in swan neck and boutonniere deformities. Loss of coordination between the multiple, specialized components of the extensor mechanism results in tendon imbalances leading to altered interphalangeal joint flexion and extension forces.
What is swan neck deformity associated with?
The usual cause of a swan neck deformity is weakness or tearing of a ligament on the palm side of the middle joint of the finger. Sometimes it is caused by tearing of the tendon that flexes the middle joint. In other cases, injury of the tendon that straightens the end joint is the cause.
What is heberden and Bouchard nodes?
Bony bumps on the finger joint closest to the fingernail are called Heberden’s nodes. Bony bumps on the middle joint of the finger are known as Bouchard’s nodes. Bony bumps are also common at the base of the thumb. These bumps do not have a nickname, but the joint is called the CMC or carpometacarpal joint.
What is boutonniere deformity?
Boutonnière deformity is the result of an injury to the tendons that straightens the middle joint of your finger. The result is that the middle joint of the injured finger will not straighten, while the fingertip bends back.
What causes boutonniere deformity?
Boutonnière deformity is generally caused by a forceful blow to the top (dorsal) side of a bent (flexed) middle joint of a finger. It also can be caused by a cut on the top of the finger, which can sever the central slip (tendon) from its attachment to the bone.
Is boutonniere deformity hereditary?
Causes of boutonniere deformity Severe cut — a severe cut to the top of the finger can cause the tendon to be severed from the bone. In some severe cases, the bone may come out through the cut. Genetic conditions — genetic conditions such as Ehlers-Danlos syndrome can cause a boutonniere deformity.
Why is it called swan neck deformity?
Swan neck deformity is the result of ligament and joint damage. Hyperextension of the middle finger joint forms a shallow “V” shape, while a flexion in the joint farthest from the palm points the fingertip downward. The resulting shape may resemble that of a swan’s neck.
