These are the major complication found after arm fracture treatment as shown in the above picture.
(A) The elbow’s axis of rotation extends slightly, obliquely in a medial-lateral direction through the capitulum and the trochlea. Normal carrying angle of the elbow is shown with the forearm deviated laterally from the longitudinal axis of the humerus axis between 5° and 15°(In male it is found to be 5°to 10° and in Female is is usually 10° to 15°).
(B) Cubitus valgus is a medical deformity in which the forearm is angled away from the body to a greater degree than normal when fully extended. A small degree of cubitus valgus (known as the carrying angle) is acceptable and occurs in the general population.Excessive cubitus valgus deformity is shown with the forearm deviated laterally 30°.When present at birth, it can be an indication of Turner syndrome or Noonan syndrome. It can also be acquired through fracture or other trauma. The physiological cubitus valgus varies from 3° to 29°. Women usually have a more pronounced Cubitus valgus than men. The deformity can also occur as a complication of fracture of the lateral condyle of the humerus, which may lead to tardy/delayed ulnar nerve palsy.
(C) The opposite condition of Cubitus valgus is known as Cubitus varus deformity which is depicted with the forearm deviated medially −5°. It can be corrected via a corrective osteotomy of the humerus and either internal or external fixation of the bone until union. 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. A cubitus varus deformity is more cosmetic than limiting of any function, however internal rotation of the radius over the ulna may be limited due to the overgrowth of the humerus. This may be noticeable during an activity such as using a computer mouse.
(D) Gunstock deformity with −15° medial deviation. it is commonly known is the most common complication of displaced supracondylar fractures in children with an incidence ranging from 3% to 57% . The deformity involves not only loss of coronal alignment to make the distal forearm and hand deviate to the midline of the body ,but also has recurvatum deformation in the sagittal plane and internal rotation deformity in the axial plane.
Should we correct these deformities?
A person/child with cubitus varus is usually an unsightly deformity with a reasonably good range of movement at the elbow. Although some studies have reported asymmetrical flexion arc with limitation of elbow flexion range on affected side but functional arc was maintained. This led most authors to believe that the deformity has no functional implications. However studies have shown that long term follow up of children with cubitus varus may result in a problems such as increased chances of lateral condyle fractures or other secondary fractures, posterolateral elbow pain and instability, tardy ulnar nerve palsy. There are some reports of alteration in morphology and alignment of the elbow joint in cubitus varus, but the clinical significance of the same is still debatable.
Cosmetic appearance still is the most common cause why the parents bring their child to clinician. The above mentioned complications along with cosmetic concerns justify surgical management, although many times this deformity is neglected and patients are asymptomatic. Thus, although the decision making tips more in favour of surgical correction of deformity, the treatment should be individualized.
What are the Problems/Complications of Deformity correction?
The main complications are lateral prominence, incomplete correction, loss of correction, nerve palsies, infection and re-operations. Lateral prominence was reported in French osteotomy due to prominence of distal fragment laterally. An equal limb oblique osteotomy minimises this issues. Medialisation of the distal fragment may also reduce the lateral fragment prominence. In a recently published studies of French osteotomy it is pointed that the lateral prominence does remodel in younger children (less than 11 years of age). Dome and step cut osteotomies do not have issues of lateral prominence.
Incomplete Correction is generally a complication of incomplete planning and execution and is not a function of selecting the osteotomy. It is reported in 5.9% of patients. Loss of correction is a function of kind of osteotomy and type of fixation used. As mentioned earlier screws with tension loop wires will fail if the medial continued is compromised. Similarly fixation with smooth K wires have more chances of loss of fixation. Nerve palsies have been reported in about 2.5% of cases of cubitus varus correction osteotomies with decreasing frequencies of involvement of ulnar, radial and median nerves. Almost 78% of these palsies are temporary and recover. Nerve injuries are more commonly seen in dome osteotomies with minimal risk in distraction osteogenesis. Overall complication rate for osteotomies is reported to be 14.5% with poor results are seen around 12% cases. Most complications are seen in cases with K wire fixation and lowest overall complication rate is seen in external fixation. However external fixation patients have highest rate of infection. The complexity of osteotomy does not affect the overall complication rate but specific complications may be more with certain osteotomies, like nerve injuries in dome osteotomies.
Cubitus varus deformity requires surgical correction or may lead to various consequences like secondary fractures, lateral instability and nerve palsies. Lateral closed wedge osteotomy is a good method to correct the deformity. Appropriate stabilisation preferably with plate and screw will minimise complications. Surgeons should be aware of complications and should counsel the patients for the same. The lateral bump index post correction and the appearance and placement of the scar are the two variables which may affect the cosmetic aspect of the correction and should be considered while decision making.