June 20, 2024

Cubital Valgus is the condition in which the forearm has laterally deviated from normal anatomical deviation in full extension. A certain lateral deviation is acceptable in an elbow. Pathologically some of the causes are explained below;


  • Nonunited fracture lateral condyle
  • Malunited supracondylar fracture of humerus
  • Osteonecrosis of lateral trochlea
  • Malunited intercondylar fractures
  • Radial head fracture-dislocation
  • Medial epiphysis injury and growth stimulation

Non-Union of lateral condyle is called after 12 weeks / 3 months of fracture.

Cubital Valgus

Components of lateral condyle

  1. Lateral trochlear crista
  2. Lateral condylar physis and epicondyle
  3. Capitellum and lateral metaphyseal region

Lateral condylar fracture: Epiphyseal intraarticular fracture

Why non union is so common in lateral condyle fracture?

  1. Poor circulation to metaphyseal fragment
  2. Fragment bathed by synovial fluid
  3. Forces exerted by muscles arising from condylar fragment keeping it displaced
  4. Displaced fragment with the opposition of articular cartilage to the proximal fracture surface; In this scenario union is impossible


Jakob’s Classification

Stage IUndisplaced with the intact articular surface (Badelon modified displacement < 2 mm)
Stage IIComplete fracture through the articular surface
Stage IIIFragment rotated, displaced laterally and proximally allowing translocation of olecranon and radial head
Jakob’s classification

Fracture line runs between ECRB and Brachioradialis

Causes of cubitus valgus

Type I:

Fracture with healing there may be the development of bony bar or arrest of lateral growth due to injury to the ossification center

Type II:

Can’t be held securely in place with conservative methods being inherently unstable, so there is always a tendency toward lateral and proximal migration

In a united fracture, there could be the formation of the bony bar which tethers lateral growth

Cubitus valgus due to nonunion lateral condyle / united fractures is Progressive. It changes elbow mechanics and develops neurological complications, examples: Tardy Ulnar Nerve Palsy

Tardy Ulnar Nerve Palsy

Due to

  • Stretching of the nerve due to medial angulation and hence resulting lengthier course
  • Friction induced perineuritis
  • Adhesion causing entrapment of the nerve in the cubital tunnel


Surgical Management

Absolute Indications :

  • Progressive deformity
  • Associated tardy nerve palsy
  • Elbow instability

Symptomatic patient based on Flynn criteria

  1. Large metaphyseal fragment
  2. Displacement > 1 cm from joint space
  3. Open viable lateral condylar physis


Asymptomatic nonprogressive nonunion in an adult patient with tardy ulnar nerve palsy: Transposition of ulnar nerve

If articular cartilages oppose fracture surfaces-> Debridement of the fracture surface + Rigid fixation + Bone grafting + transposition of ulnar nerve

Patient with:

See also : Cubitus Varus

See also: The Stiff Elbow

See also: The Unstable Elbow

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