Infection:
If debridement is not done or done incompletely in the case of open fracture, it may cause pyogenic infection, or esteomyelitis or hematosepsis in the severe cases; if it is an anaerobic infection, such as tetanus or gas gangrene, the condition will be more serious.

Injury of the lung:
The case of rib fracture may be complicated by injury of pulmonary parenchyma or rupture of intercostal blood vessels, which may result in hemathorax, or closed pneumothorax, open pneumothorax, tension pneumothorax, or hematopneumothorax.

Hepatic and splenic ruptures:
When the force acts on the lower part of the chest, besides rib fracture, it may result in hepatic rupture or splenic rupture, especially in the case of splenomegaly, serious internal bleeding and shock may appear.

Injury of the bladder, urethra and rectum:
When the pubic bone and ischium are broken simultaneously, posterior urethral injury may happen. If the bladder is full, it may be stabbed by the fractured and displaced end of bone. The case of sacrococcyx fracture may be complicated by injury of the rectum.

Injury of major arteries:
It usually occurs in the case of severe open fracture or closed fracture with great displacement. For example, extended supracondylar fracture of humerus may injury brachial artery. In the case of injury of a major artery, there is pain, numbness, coldness, pale or cyanosis in the distal limbs, or no pulse or weak pulse.

Spinal cord injury:
The severe displacement of spine fracture may be complicated by contusion or laceration of spinal cord, giving rise to paralysis below the injured level.

Peripheral nerve injury:
It may be caused by traction, compression, contusion or stimulation of nerve in the early stage of a fracture, or by compression from external fixation, encapsulation from callus or by traction from deformity of the limbs in the late stage of fracture. In the case of nerve injury, there will appear sensory disturbance or dyscinesia in the limb region controlled by the nerve and neuratrophia in the late stage.

Fat embolism:
It is a severe complication that is not commonly seen, but it is increasing recently. In adults’ fracture of the diaphysis, the fat droplet of bone marrow, in the case of too big a tension of hematoma in the marrow cavity, may enter the venous blood flow through the ruptured vein, forming fat emboli to block the vessels, resulting in ischemia of the vital organs like the lung and brain or tissues which consequently endangers the life.

Ischemic osteonecrosis:
Disturbance of blood supply for fractured segment may cause ischemic osteonecrosis. The common cases are fracture of neck of femur complicated by necrosis of femur head, and fracture of middle part of scaphoid bone complicated by necrosis of the proximal segment.

Delayed deformity:
Fracture of epiphysis in children may impair the growth and development of the joint, gradually (usually in several years) lead to deformity of the limb. For example, lateral condylar fracture of humerus may result in deformity of cubitus valgus or claw hand.

Ischomic muscular contracture:
It is a severe complication caused by compartment syndrome of fascia. In the upper limbs, it often happens in the case of supracondylar fracture of humerus or fracture of ulna and radius; in the lower limbs, it often happens in the case of supracondylar fracture of femur or fracture of the upper end of tibia. The muscle groups of the forearm or leg may undergo necrosis because of ischemia after the injury of the major arteries of the limbs in the case of insufficient blood supply due to injury of artery of the limb, or in the case of a tight bandage for a long period of time. Neuroparalysis or muscular necrosis can give rise to formation of scar tissue through organization of the necrosed tissues. The scar tissue may gradually contract and further cause special deformity of caw hand or caw foot, resulting in severe deformity.

Hypostatic pneumonia:
In the case of fracture of the lower limbs or spinal bone, the patient needs to stay in bed for a long time. It will lead to decrease of pulmonary function, accumulation of sputum difficult to cough up, resulting in respiratory infection. This case is often seen in old people, and often endangers the life. Therefore, in the period of bedtime, the patient should take more deep respiration, or tap the chest actively to help expectoration, and at the same time do more bed functional exercises on the presupposition but not influencing treatment of fracture.

Bed sore
In the patients with severe traumatic coma or spinal fracture complicated by paraplegia who need to keep in bed for a long time, compression of some parts with projecting bone may lead to necrosis of the tissue because of disturbance of local blood circulation, hence forming ulcer. So, the patient should be given strict nursing care for an early prevention. The parts subject to bed sore should be kept clean and dry, the patient’s position should be changed frequently, and the patient should be given massage, or cotton or air pad in the local region in order to reduce compression.

Urinary infect ion and calculus:
A long period of treatment of indwelling catheter for urinary dysfunction of a patient with spinal fracture complicated by paraplegia may cause retrograde urinary infection, giving rise to cystitis, pyelitis, etc. So, the catheter should be regularly changed, and the bladder be irrigated regularly. The bone of a patient long living in bed is decalcified, the kidney secretes a great deal of calcium salt. If the patient does little exercise and drinks less, he may get urinary calculus due to hypouresis. So, the patient should be encouraged to drink a lot in order to keep normal urination.

Traumatic ossification
It is also called ossifying myositis. In the case of intracapsular fracture or fracture around the joint, the trauma, poor emergency fixation, repeated rude reduction and passive exercise may make hematoma spread or bleeding repeat. The blood diffuses into the broken muscle fibers. After the organization of hematoma, it may gradually change into cartilage through induction of periosteal ossification nearby, and it may undergo calcification and ossification. There is ossification shadow in X-ray film. Clinically, it is a complication often seen in trauma of cubital articulation and may greatly influence the movement of the joint.

Traumatic arthritis
Malposition healing of intracapsular fracture due to improper reduction or angulation healing of diaphysial fracture may make the articular surface uneven, or lead to unbalanced force acting on the articular surface. A long period of abrasion with articular movement may cause damage and degeneration to the articular cartilage surface, hence traumatic arthritis.

Ankylosis
It may occur in the severe cases of intracapsular fracture. A long term of wide extra-articular arthrodesis may cause adhesion of soft tissues and contraction of muscle tendon around the joint, and then lead to disturbance of joint movement. Therefore, for the case of intracapsular fracture complicated with hematocele, the blood needs to be drawn out as thoroughly as possible. The time and range for the arthrodesis should be proper, and an early functional exercise of the joint is beneficial.