Cubitus Varus After a Childhood Elbow Fracture: Causes and Treatment

Cubitus varus is an inward angulation of the elbow in which, with the arm straight, the forearm points towards the body instead of angling slightly away from it. It most often develops when a supracondylar fracture, the commonest elbow fracture in children, heals in a tilted position, and because this type of deformity remodels poorly, it usually does not correct itself with growth. Whether it needs treatment depends on its severity, any symptoms and the child's and family's concerns, assessed through examination and imaging.

In this article we explain how supracondylar fractures are treated, which signs need urgent attention, and what can be done if cubitus varus develops. For an overview of how children's bones differ from adults', see our paediatric orthopaedics page.

What is a supracondylar fracture and how does it happen?

Just above the elbow, the humerus (upper arm bone) is very thin because of hollows on its front and back surfaces. When a child falls onto an outstretched hand with the arm straight, the force concentrates at this weak point and the bone breaks. The large majority of fractures occur through this "extension-type" mechanism; "flexion-type" fractures, from a fall onto a bent elbow, are less common. These injuries are seen most often in children of nursery and primary school age.

The most common signs are:

• marked pain at the elbow with rapidly increasing swelling
• the child refusing to move the arm and holding it against the body
• in some cases, visible deformity or bruising around the elbow

The Gartland classification and treatment options

Supracondylar fractures are usually graded with the Gartland classification, according to how far the fragments have moved on X-ray. Treatment depends on this grade, on the blood supply and nerve examination and on the child's overall condition:

When wires are used, they are usually removed in clinic after a few weeks, once the fracture has started to knit, in a short procedure. Some stiffness after the cast comes off is normal, and in most children movement returns over weeks to months through everyday play.

X-rays in the first days after treatment matter, because they confirm that the fracture has not slipped within the cast or wires. Careful checking of the elbow's angles during reduction, and attending follow-up appointments, both help to lower the chance of a deformity developing later.

While your child is in a cast or splint, it helps at home to:

• keep the arm raised on a pillow, slightly above heart level, for the first few days
• encourage your child to open and close the fingers often
• keep the cast dry and never push objects inside it to scratch
• check the colour, warmth and movement of the fingers several times a day

Our article on common fractures in children covers other injuries in this age group.

Which signs after an elbow fracture are urgent?

A supracondylar fracture lies close to the main artery and nerves at the front of the elbow, so the circulation and nerve function of the hand are checked carefully from the start. Seek urgent assessment if:

• the hand looks pale, cold or bluish
• there is numbness or tingling, or the child cannot move the fingers (for example, cannot make an "OK" sign with the thumb and index finger)
• pain keeps increasing despite pain relief
• pain rises sharply when the fingers are gently straightened, with a tight feeling in the forearm

The last two signs are important because they can point to compartment syndrome, a dangerous rise in pressure within the muscle compartments. Most nerve symptoms that accompany these fractures improve with time, but they should always be assessed by a doctor.

What is cubitus varus and why does it develop?

When the arm is straight with the palm facing forwards, the forearm normally angles slightly away from the body; this is called the carrying angle. In cubitus varus this angle is reversed, and the forearm points towards the body. Because of its shape it is sometimes called a "gunstock deformity". It is often first noticed after the cast has come off and the elbow begins to straighten fully, when the child holds the arm out or the two arms are compared side by side.

The commonest cause is a supracondylar fracture healing tilted inwards, rotated inwards and slightly over-extended. In other words, it is mainly a malunion problem; damage to the growth plate is a less frequent cause. The lower end of the humerus contributes relatively little to the growth in length of the arm, and sideways and rotational deformities at the elbow remodel poorly, so cubitus varus usually does not resolve on its own. By contrast, fractures of the outer part of the elbow (the lateral condyle) can lead to the opposite deformity, cubitus valgus, and years later to nerve symptoms on the little-finger side of the hand.

Can cubitus varus be prevented?

It cannot always be prevented, but several steps reduce the risk: aligning the fracture accurately at the first treatment, checking that alignment with imaging during surgery, fixing the bone securely, attending the early follow-up X-rays and keeping the cast on for the full period advised. The fracture type and the severity of the injury also influence the outcome.

Is cubitus varus only a cosmetic problem?

In many children elbow movement and everyday function remain good, so cubitus varus is often seen mainly as a cosmetic issue. Even so, some children and teenagers develop:

• a sense of looseness or giving way in the elbow over time
• clicking or snapping at the back of the elbow as a muscle or nerve slips
• numbness in the little and ring fingers (ulnar nerve irritation)
• pain with push-ups, throwing or lifting weights
• a higher risk of fracturing the outer part of the elbow in later falls

Concerns about appearance can also affect a young person's confidence, especially in adolescence, and are taken into account when deciding on treatment.

How is cubitus varus assessed and treated?

Assessment compares the carrying angle and range of movement of both arms, and X-rays of both elbows are taken. CT scanning and three-dimensional planning can help to understand the rotational and extension components of the deformity.

Mild deformity that causes no symptoms may simply be observed. For marked deformity or functional problems, treatment is a corrective osteotomy, in which the lower humerus is cut in a controlled way and realigned. Techniques include removing a wedge of bone from the outer side, a dome-shaped cut, or osteotomies planned in 3D with patient-specific guides. The bone is then fixed with wires, a plate or, in selected cases, an external fixator. Surgery is usually planned once the fracture has fully healed and elbow movement has returned. Our pages on malunion surgery and upper limb deformity correction explain the wider principles.

After surgery the arm is protected for a few weeks before movement exercises begin, and a return to full activities usually happens gradually over the following months. Possible problems, such as nerve irritation, stiffness or a correction that differs from the target, are discussed with the family beforehand. Prof. Dr. Halil İbrahim Balcı has received national and international congress awards for his work on humeral (upper arm) lengthening.

When should you see a doctor?

• After a fall, the elbow is swollen or misshapen, or your child will not use the arm
• In a cast, pain is increasing, or the fingers feel numb, cold or change colour
• Several months after the cast has come off, elbow movement is still not improving
• With the arm straight, the elbow looks different from the other side and angled inwards
• The elbow catches or gives way, or your child reports tingling in the little finger

Key points

• Cubitus varus is an inward angulation of the elbow that usually follows a supracondylar fracture healing in a tilted position.
• Supracondylar fractures are treated according to their Gartland type, from a cast to wire fixation, with careful checks of circulation and nerves.
• Because this deformity remodels poorly, it usually does not straighten with growth.
• Corrective osteotomy is an option for marked deformity or symptoms; the decision follows examination and imaging.