Cubitus varus is a

varus deformity A varus deformity is an excessive inward angulation ( medial angulation, that is, towards the body's midline) of the distal segment of a bone or joint. The opposite of varus is called valgus. The terms varus and valgus always refer to the direc ...

in which the extended forearm is deviated towards midline of the body. Cubitus varus is often referred to as "Gunstock deformity", due to the crooked nature of the healing. The "opposite" condition is cubitus valgus.

Signs and symptoms

Complications

Instances in which the medial epicondyle of the distal humerus is malformed due to the initial fracture at the humeral endplate may result in

subluxation A subluxation is an incomplete or partial dislocation of a joint or organ. According to the World Health Organization, a subluxation is a "significant structural displacement" and is therefore visible on static imaging studies, such as X-rays. ...

(snapping) of the

ulnar nerve The ulnar nerve is a nerve that runs near the ulna, one of the two long bones in the forearm. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or ...

over the medial epicondyle with active flexion and extension of the elbow. In such instances, conductance of the ulnar nerve may be compromised due to chronic irritation, potentially resulting in irreversible ulnar neuropathy.

Causes

A common cause is a supracondylar fracture of the humerus. It can be corrected via a corrective

osteotomy An osteotomy is a surgical operation whereby a bone is cut to shorten or lengthen it or to change its alignment. It is sometimes performed to correct a hallux valgus, or to straighten a bone that has healed crookedly following a fracture. It i ...

of the humerus and either internal or external fixation of the bone until union. Rüdiger Döhler: ''Suprakondyläre Korrekturosteotomie beim posttraumatischen Cubitus varus''. Unfallchirurg 105 (2002), p. 397-400

Diagnosis

Cubitus varus is not able to be diagnosed until after healing of the prior fracture, as the arm must be in full extension, not flexion, for the deformity to be noticed.

Prognosis

A cubitus varus deformity is more cosmetic than limiting of any function, however

internal rotation Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...

of the

radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

over the

ulna The ulna or ulnar bone (: ulnae or ulnas) is a long bone in the forearm stretching from the elbow to the wrist. It is on the same side of the forearm as the little finger, running parallel to the Radius (bone), radius, the forearm's other long ...

may be limited due to the overgrowth of the humerus. This may be noticeable during an activity such as using a

computer mouse A computer mouse (plural mice; also mouses) is a hand-held pointing device that detects Plane (mathematics), two-dimensional motion relative to a surface. This motion is typically translated into the motion of the Cursor (user interface)#Po ...

References

External links

{{Congenital malformations and deformations of musculoskeletal system Congenital disorders of musculoskeletal system Arthropathies