deformity

(de-for′mĭt-ē)

[L. deformitas, ugliness, deformity]
Alteration in or distortion of the natural form of a part, organ, or the entire body. It may be acquired or congenital. If present after injury, deformity usually implies the presence of bone fracture, bone dislocation, or both. It may be due to extensive swelling, extravasation of blood, or rupture of muscles and severe contracture of scar tissue.

anterior deformity

Abnormal anterior convexity of the spine.
SYN: SEE: lordosis

Arnold-Chiari deformity

SEE: Arnold-Chiari deformity

bird's beak deformity

A sharply tapering loop of bowel seen on plain films of the abdomen in patients with a volvulus (twisting or torsion) of the sigmoid colon.

boutonnière deformity

A finger position marked by extension of the metacarpophalangeal and distal interphalangeal joints and flexion of the proximal interphalangeal joint. This condition outwardly resembles a pseudoboutonnière deformity.
SEE: pseudoboutonnière deformity

ETIOLOGY
A rupture of the central extensor tendon of the involved finger. The tendon then displaces palmarly relative to the proximal interphalangeal joint.

TREATMENT
The finger is splinted with the proximal and distal interphalangeal joints in extension. Surgery may be required for patients who do not respond to conservative treatment.

Chiari deformity

SEE: Arnold-Chiari deformity.

dinner-fork deformity

A radiologic sign seen in Colles fracture of the radius. The dorsal displacement and angulation of the distal fragment of the radius results in a contour, seen in the lateral projection, similar to the curve of a dinner fork.

gunstock deformity

A deformity in which the forearm, when extended, makes an angle with the arm because of displacement of the axis of the extended arm. It is caused by a condylar fracture at the elbow.

Haglund deformity

SEE: Haglund deformity

habit-tic deformity

Horizontal sharp grooving in a band across the tip of the nailbed. It is caused by biting or picking the proximal nail fold of the thumb with the index fingernail.

Madelung deformity

SEE: Madelung deformity

pencil-in-cup deformity

A form of osteolysis found in severe inflammatory arthritis, esp. in the finger and toe joints. The deformity is characterized by thinning of the phalangeal shaft and widening of its base proximal to the joint space.

pseudoboutonnière deformity

A finger posture marked by extension of the metacarpophalangeal and distal interphalangeal (DIP) joints and flexion of the proximal interphalangeal (PIP) joint. This condition outwardly resembles a boutonnière deformity. It can be diagnosed by performing the boutonnière deformity examination and asking the patient to flex the DIP joint extension of the PIP joint. If the patient cannot extend the PIP joint but can actively flex the DIP joint, a pseudoboutonnière deformity is indicated.
SEE: boutonnière deformity

ETIOLOGY
A rupture of the volar plate over the area of the proximal and middle phalanges causes the volar plate to displace dorsally relative to the PIP joint.

TREATMENT
The finger is splinted with the PIP and DIP joints in extension. Surgery may be required for patients who do not respond to conservative treatment.

seal fin deformity

An obsolete term for ulnar deviation of the fingers in rheumatoid arthritis.

silverfork deformity

The peculiar deformity seen in Colles fracture of the forearm, resembling the curve on the back of a fork.
SEE: Colles fracture

Sprengel deformity

SEE: Sprengel deformity

string-of-pearls deformity

Fusiform enlargement of the proximal and middle phalanges, seen in rickets.

swan-neck deformity

A finger deformity marked by flexion of the distal interphalangeal joints and hyperextension of the proximal interphalangeal joints, often seen in rheumatoid arthritis.

Velpeau deformity

SEE: Velpeau, Alfred

Volkmann deformity

SEE: Volkmann, Richard von