Trauma is a major health disrupter and responsible for the morbidity of a large number of people in addition to being a leading killer.
Trauma can injure any organ but in this article, we would concentrate on musculoskeletal parts only. From the this point of view, the major orthopedic complications of trauma are
- Acute respiratory distress syndrome (Fat embolism syndrome)
- Multisystem organ failure
- Thromboembolic disease
- Compartment syndrome
- Ectopic bone formation.
Some of these complications of trauma, especially pulmonary complications may have serious consequences.
Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome can occur in severe trauma. The trauma causes the release of inflammatory mediators. The release of these mediators causes disruption of the microvessels of the pulmonary system and may cause ARDS as a complication of trauma
This causes the following changes
- Pulmonary edema
- Decreased partial pressures of oxygen
- Decrease in arterial oxygen saturation
- Increased carbon dioxide levels
Acute respiratory distress syndrome usually occurs within 24 h after trauma.
Fat embolism also is also caused by factors other than bone trauma like when the medullary canal of a long bone is pressurized during total knee replacement.
The clinical diagnosis is confirmed by
- A decrease in arterial oxygen pressure
- Increase pressure of carbon dioxide
- Infiltrates on chest radiograph
- Presence of petechiae
- Mental confusion in a patient at risk.
Relatively minor injuries can result in this syndrome in patients with limited pulmonary reserve.
Treatment is directed toward minimizing hypoxemia with ventilatory support as needed. Prevention is enhanced by early mobilization of the patient, which often implies early fracture fixation.
Atelectasis refers to a localized collapse of alveoli. It is often seen as a postoperative complication in patients who undergo surgery. But it can also occur as complications of trauma because of the required immobilization.
Atelectasis can result in low levels of oxygen in blood [hypoxemia] rapidly.
X-rays may show the collapse of areas of the lung.
The condition responds rapidly to the treatment that may consist of encouraging coughing, deep breathing, and spirometry. Severe cases may require further respiratory therapy.
Trauma patients especially those with spinal cord injury have risk of pulmonary embolism.
The risk is more in
- Oral contraceptive
- Deep vein thrombosis in the lower extremities
The patient would have difficulty in breathing around 4-5 days after the trauma. In contrast, fat embolism occurs sooner, around 48-72 hours.
The patient frequently reports chest pain and can often point to the painful area. Blood in sputum or hemoptysis may also be present.
On physical examination, there is an increased heart rate [tachycardia], cyanosis, and pleural friction rub.
A pulmonary angiogram and perfusion-ventilation scan help to confirm or refute the diagnosis.
Spiral CT is also becoming useful in the diagnosis of pulmonary embolism.
Treatment involves pulmonary support and heparin therapy.
The compartment syndrome refers to pathologic pressure build-up in a closed compartment circumscribed by fascia and incorporates one or more bones. For example, the leg has four compartments.
The increased pressure is because of intracompartmental bleeding and edema in the tissue as a result of the injury. The built-up pressure compromises circulation to the tissues of the compartment causing compression of the muscle and damage to nerves.
Compartment syndrome may result from
- Soft-tissue injury
- Arterial injury
- External compression from mobilization
The pain of compartment syndrome is often not responsive to pain medication.
Other features are
- Absent pulse [very late feature]
- An increase in compartmental pressure
- Clinical measurement [not very reliable as tissue hardness does not reflect the pressure
- Measurement by measuring gadgets
- Intracompartmental pressures within 30 mm Hg of the diastolic blood pressure require fasciotomy.
Mild compartment syndromes can be managed by observation and other supportive treatments. Severe clinical findings or highly raised intracompartmental pressure readings require fasciotomy.
Fasciotomy is a surgery where the compartment is split open so that intracompartmental pressure build-up decreases.
Any bony or arterial injury is treated after the fasciotomy, often in the same setting.
Two most common locations for compartment syndromes are the forearm and calf.
Heterotopic Bone Formation
Bone formation after trauma is called heterotropic ossification. This is a unique orthopedic complication of trauma where bone forms in the soft tissue after an injury. Heterotopic ossification occurs in about 10 percent of trauma cases.
It often occurs near the joints and reduces joint motion even to the extent of the ankylosis.
It is quite common in patients with a head injury. An ossification hampering the motion may require surgical removal but can recur after removal.
The resection may have to wait for about 18 months as that is the period bone takes to mature.