Fracture of the humeral shaft

Adults are more likely than children to sustain a shaft humerus fracture.

It can appear in any age group.

Transverse, oblique, spiral, comminuted, or segmental humerus fractures are all possible.

Mechanism of injury

Three important mechanisms:-

Direct force/direct injuries:
This may produce a transverse or comminuted fracture as in RTA, assault etc.
Indirect force/Indirect injuries:
This fracture caused by falling on an outstretched hand and this will produce oblique or spiral fractures.
Birth injuries:
This is the second most common birth fracture after the clavicle.

Anatomical Consideration –

The deformity is influenced by the muscles of the upper arm.
If the fracture is between the pectoralis major and deltoid, the proximal fragment is adducted by the pectoralis major, teres minor and latissimus dorsi, while the distal fragment is pulled upwards by the deltoid.
If the fracture is below the insertion of the deltoid, then the coracobrachialis, biceps and triceps pull the distal fragment upward.

Clinical features or signs and symptoms –

Pain
Swelling
Deformity
Abnormal mobility depending on the extent
The fracture’s severity.
Injuries to the radial nerve are common in spiral groove fractures or fractures of the lower one-third of the humerus and can result in a wrist drop.

Treatment –

Conservative methods –

1. Un-displaced fractures:-

Simple U-splint – In birth injuries
simple sling – young children
Chest arm bandage– The arm is strapped to the side of the chest with bandages. It can be considered for children less than five years of age.

2. Displaced fractures –

⁃Hanging cast:-

This is useful for older children and adolescents.
Gravity aids in the prevention of fractures.
They are not suitable if the level of fracture corresponds to the upper limit of the cast, because of the deforming effect of the proximal end of the cast.
It is indicated in comminuted fracture of the distal third.
If the cast is too heavy, it may cause destruction and consequent delay or non-union.

⁃ Plaster U-splint or Cast –

In most cases of proximal humerus fractures, the middle third of the humerus is sufficient.
The U-slab covers the following areas of the upper arm –
– Inner arm of the U: it supports the inner side of the arm just beneath the axilla.
– U-turn: it supports the medial epicondyle, olecranon tip and lateral epicondyle.
– Outer arm of the U: it supports the outer aspect of the arm, shoulder and extends up to the base of the neck.

Operative Treatment –

In a few cases with the following specific indications, the incidence of surgical treatment in the humerus fracture is reduced to a negligible number –

Failed conservative treatment.
Multiple fractures and unstable fractures.
Multi-system injuries.
Radial nerve palsy after closed reduction.
Segmental fracture.

Complications –

Radial nerve injury –

This is common in lower 1/3 fractures and is usually in a large variety.
It can also be damaged in the spiral grove.

Vascular injury –

Injury to the brachial vessels is unusual.
It requires repeated assessment and prompt treatment.

Malunion –

In humeral fracture, angular deformity of 20° is acceptable in the middle and distal one third, while in the proximal one third and 30° is acceptable.
The muscles in the upper arm usually conceal the malunion.

Non-union –

This is not very common but may be seen due to overweight hanging casts.
This requires open reduction, rigid planting and bone grafting.

Occupational therapy goals –

Restore the full shoulder range of motion on all planes.
Restore the full elbow range of motion.
Improve the strength of the following muscles –
– Pectoralis major
– Deltoid
– Biceps brachii
– Triceps brachii
Improve and restore the functions of the involved extremities in daily activities.

Occupational therapy management –

1. Day of injury to week one:-

Check the limb for the presence of a radial nerve injury.
Active range of motion (AROM) of the wrist and digits is started immediately to reduce oedema and stiffness.
If open reduction internal fixation (ORIF), gentle AROM and active assistive ROM (AAROM) to the shoulder and elbow.
If fixation is stable, pendulum exercises with gravity eliminated from the shoulder.
No weight bearing on the affected extremity.
There will be no strengthening exercises for the elbows or shoulders.

2. 2-3 weeks:-

AROM and AAROM are used to treat the shoulder, elbow, and wrist joints.
No strengthening exercises for the shoulder or elbow.
Isotonic exercises for the forearm muscles with wrist flexion and extension and ball squeezing exercises.
With a splint or brace, no abduction of the shoulder beyond 60°, only gentle pendulum exercise, may be started.
The uninvolved extremities may be used for the ADL.
In ORIF and external fixation, the involved extremities can be used for feeding, light grooming, and writing.
No weight-bearing on the affected extremity, limited weight-bearing with rodding.

3. 4 to 6 weeks –

AROM and AAROM of the shoulder, elbow, wrist, and digit motion.
Continue pendulum exercises.
Supination and pronation of the forearm are begun.
Continue strengthening exercises for the wrist and digits with isotonic exercises for the forearm muscles against resistance.
If a callus formation is present, gentle isometric exercises for the biceps and triceps begin at the end of six weeks.
Activities for 4 to 6 weeks –

– Bilateral sanding (inclined)
– Rope and Pulley
– Horizontal sanding
– Overhead pulley, unilateral sanding
Early weight-bearing is allowed with internal fixation.
No heavy lifting is allowed.
The patient may use the involved extremities for basic self-care and personal hygiene.
In the case of splints or braces, AROM and AAROM abduction up to 90° and then continue with pendulum exercises.

4. 6 to 12 weeks –

Complete range of motion in all planes of the shoulder and elbow.
Relaxed passive self-stretching of abduction – elevation and flexion – elevation and spine.
After 8 to 12 weeks, begin an active and gradually progress to a resistance regime using weighted dumbbells, weighted belts, pulleys, or weights.
Shoulder wheels, skates, and wands are all acceptable.
Light lifting is permitted.
The affected limbs can be used for self-care and personal hygiene.
Swinging should be completely integrated into the gait.
Full weight-bearing is allowed.
No heavy contact sports are allowed.