Amongst the long bones, fracture of the shaft of humerus is less common. The impact of injury strikes more around the shoulder leading to dislocation or fracture of the upper end of humerus thereby sparing the shaft in many cases.
MECAHNISM OF INJURY
- Violence- Direct violence is the commonest cause producing transverse or comminuted fractures. Indirect injury after a fall on an outstretched hand will usually produce a spiral fracture. A twisting injury will lead to a similar lesion as above.
- Pathological fracture- The shaft of the humerus is a common site for malignant metastasis. This takes place mainly from the breast and lung. Fracture may be the earliest manifestation of a malignant condition at a distant place.
TYPES OF FRACTURE
Fractures of the shaft mostly happens in the mid- third region. This may be of transverse, spiral, oblique or comminuted variety.
There is pain, swelling and deformity at the fracture site. Abnormal mobility can be observed. Radial nerve injury must be excluded by asking the patient to extend the fingers and the wrist joints.
X-ray: The type of fracture and nature of displacement are observed from the x-ray.
Most shaft fractures unite satisfactorily. Development of non- union especially in the shaft of humerus is a serious condition. This develops mainly following distraction of the fractured segments. Excessive weight of plaster can interfere with the apposition of broken ends. Checkup x-ray at regular intervals must be taken to see if the union is satisfactorily. Spiral and comminuted types of lesions usually do not provide any problem. A minor degree of angulation does not interfere with the process of union.
U- shaped plaster immobilization- “U” plaster is applied with the patient in sitting position. No anaesthesia is required. About 10 c.m. (4”) wide and six layers of thick plaster slab is applied directly on the skin. This extends from under the axilla, medial surface of arm, around the elbow, over the outer side of the arm, extending over the shoulder up to the acromioclavicular joint. Crepe bandage is applied round the “U” slab.
Triangular Bandage. This has the advantage that when firmly tied, it elevates the elbow and keeps the fractured ends compressed together.
After Care. Finger and wrist movements are advised. Immobilization is maintained for a period of 4-6 weeks.
MANAGEMENT OF DISPLACED FRACTURE
Displaced fractures are seen in transverse and short oblique lesions.
Reduction: General anaesthesia is not necessary. Infiltration of a local anaesthetic solution at the site of fracture is sufficient but, in most cases, reduction can be done without any anaesthesia. Patient sits on the chair; the assistant firmly holds the upper part of the arm proximal to the fracture. The surgeon applies traction on the distal segment with both hands. Patient’s elbow joint is kept at 90⁰ flexed position. By manipulation the segments is to press the elbow upward while the assistant process down over the shoulder. Resistance is felt when the segments are in contact. Rotational and angulatory deformity is corrected. “U” slab is applied along with cuff and collar sling.
Check x-ray: Check x-ray is taken immediately, and further x-ray is taken every week till 3rd week. If any distraction is noted at the site of fracture, this is corrected by pressing the elbow upwards by applying a firm bandage over the “U” slab. Angulatory deformity can be corrected similarly. Exercise of fingers, wrist, elbow and shoulder is instituted from the beginning.
OTHER METHODS OF TREATMENT TRACTION
Reduction and immobilization can be done by continuous traction, but this can distract the fracture ends; therefore, this technique is not usually advocated.
Shoulder spica may be suitable in non- cooperative patents, especially in children or in some unstable fractures.
Internal fixation by rush nail is advocated in unstable fractures. This method can be ideal in cases of failure to reduce the fracture by conservative means and in pathological fractures.
The common complications are radial nerve injury and non-union of the fracture which are discussed below.
RADIAL NERVE INJURY
Injury to the radial nerve in the spiral groove can take place producing wrist drop. In most cases the nerve is contused and not severed. Incomplete paralysis holds a better prognosis.
- Conservative treatment: Cock- up splint with the wrist joint in hyperextension, electric muscle stimulation, physiotherapy are instituted. After a few weeks if no improvement is observed, exploration of the nerve is done.
- Muscle transplant: Transplantation of flexor muscles to extensors of forearm is done in case of failure of nerve injury.
This condition can be preserved by proper management. In established cases, internal fixation with bone graft is performed. The limb is immobilized in a shoulder spica.
This article is edited by Siora Surgicals team for the knowledge purpose. Siora Surgicals Pvt. Ltd. is an orthopedic implants exporter in Indonesia and other country too. Our company manufacturers high- quality orthopaedic medical implants and instruments.