April 11, 2024

Cubitus Varus is called when the forearm has deviated inwards with respect to the arm at the elbow resulting in medial angulation in full extension.

Any reduction in physiological valgus is called cubitus varus (Even cubitus rectus is cubitus varus)

Normal Values: 8°-15°

Higher in females

Lower in males

Causes:

  • Progressive Varus
    • Congenital (Progressive)
    • Mal-united lateral condyle fracture ( Progressive if due to hyperemia and overgrowth)
  • Static Varus
    • Supracondylar fracture malunited
    • Trochlear osteonecrosis
    • Malunited intercondylar fractures
    • Malunited medial condyle fractures

Why is supracondylar fracture so common?

  1. Thin bone
  2. Olecranon impinges at the fossa with leverage and delivers point stress
  3. Lax soft tissue: amount for possible hyperextension
  4. Bone actively undergoing modeling at the site during 6 – 10 years of age
  5. A large number of actively growing physis in the vicinity account for increased vascularity in the region and resultant relative hyperemia
  6. Periosteal attachment to olecranon fossa (result in constant trans-condylar failure), the capsule is tight anteriorly and hinges tip against the fossa

Displacements in Cubital Varus

  1. Medial displacement
  2. Medial tilt
  3. Internal rotation
  4. Posterior displacement
  5. Posterior tilt
  6. Proximal migration

Complications following Supracondylar fracture

Early Complications

Late Complications

  • Malunion
  • Myositic ossificans
  • Cubitus varus
  • Cubitus valgus
  • Tardy ulnar nerve palsy
  • Chronic nerve entrapment in healed callus (METEV’S SIGH= Median nerve gets entrapped in fracture callus)

Puckering: Button holing of the fragment through anterior muscles particularly brachialis

Nerve Injury in supracondylar fracture according to displacement

Posterior-medial typeRadial nerve
Postero-lateral typeMedian nerve
Flexion typeUlnar nerve
Nerve injury in fracture type

Adequacy of reduction

Coronal plane: True AP view of the elbow is evaluated and compared with the normal side for Baumann’s angle and intact olecranon fossa

Change in 5° of Baumann’s angle -> 2° cubitus varus with malunion

Other is

  • Homero-Ulnar-wrist alignment
  • Metaphyseal diaphyseal angle

For rotational alignment

  • Deformation in teardrop
  • Anterior humeral line must transect capitullum
Fishtail sign

Gun – stock deformity

Associated deformities with cubitus varus

  1. Internal rotation
  2. Extension of distal fragment (Can get corrected with time)
  3. Shortening
  4. Medial shift

Difference between Supracondylar fracture and lateral condyle fracture

ContentsLateral condyle fractureSupracondylar fractures
3-point relationshipDisturbedMaintained
Arm lengthNormalMay be reduced
Thickening of supra-condylar ridgesLateral onlyBoth sides
InstabilityTo varus stressNone
Fixed flexion deformityPresentAbsent
MovementsRestriction of rotation or flexion/extension is often seenNone ofter decrease ER in the shoulder due to bony deformity at the elbow
HyperextensionRestrictedSeen
ComplicationsDelayed by months to yearsUsually immediate and neurovascular
Long termArthrosis commonVery rare
Difference between the lateral condyle and supracondylar fracture

Treatment

French Osteotomy (Modified)

  • Lateral Closing wedge osteotomy
French OsteotomyModified French Osteotomy
Posterior longitudinal approachPostero-lateral incision
Detach the lateral half of the tricepThe whole tricep detached
Ulnar nerve- exposedNot explained
Medial periosteal hingeMedial periosteal and bony hinge

Rotational Correction:

  • The proximal lateral screw is posterior to the coronal plane
  • Distal -> Slightly anterior= Distal slightly anterior = Leads to external rotation of distal fragment after wires are tightened
French osteotomy

Other Osteotomy Names:

  1. Dome osteotomy
  2. Oblique osteotomy with derotation
  3. Three-dimensional osteotomy
  4. Step cut osteotomy
  5. Medial opening wedge osteotomy with bone graft

Osteotomy is done at least 1 year following fracture (adequate duration for remodeling of bone and tissue equilibrium to gain)

No functional benefits after osteotomy only cosmetic

Complications:

  • Stiffness
  • Nerve Injury
  • Under-correction
  • Non-union
  • Lazy- S- deformity

Pseudo cubitus varus deformity

Lateral condyle fracture: lateral spur formation, due to lateral elevation of periosteum by displaced fragment. No real change in angle but lateral prominence produces the appearance of cubitus varus

See also: Cubitus Valgus

See also: The Unstable Elbow

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