injuries poisoning
Overview of Dislocations
Complications
Serious complications of dislocations are unusual but may threaten life or limb viability or cause permanent limb dysfunction. Risk of complications is high with open dislocations (which predispose to infection) and with dislocations that disrupt blood vessels, tissue perfusion, and/or nerves. Dislocations, particularly if not rapidly reduced, tend to have a higher risk of vascular and nerve injuries than do fractures. Closed dislocations that do not involve blood vessels or nerves, particularly those that are quickly reduced, are least likely to result in serious complications. Acute complications (associated injuries)of dislocations include the following: Fractures:Fractures may accompany a dislocation (eg, shoulder dislocation and fracture of the greater tuberosity). Bleeding:Bleeding accompanies all significant soft-tissue injuries. Vascular injuries:Some closed dislocations, particularly knee or hip dislocations, disrupt the vascular supply sufficiently to cause distal limb ischemia; this vascular disruption may be clinically occult for hours after the injury. Nerve injuries:Nerves may be injured when stretched by a dislocated joint. Depending on the cause of the dislocation, nerves may be bruised, crushed, or torn. When nerves are bruised (called neurapraxia), nerve conduction is blocked, but the nerve is not torn. Neurapraxia causes temporary motor and/or sensory deficits; neurologic function returns completely in about 6 to 8 weeks. When nerves are crushed (called axonotmesis), the axon is injured, but the myelin sheath is not. This injury is more severe than neurapraxia. Depending on the extent of the damage, the nerve can regenerate over weeks to years. Usually, nerves are torn (called neurotmesis) only in open dislocations. Torn nerves do not heal spontaneously and may have to be repaired surgically. Any injury can become infected, but risk is highest with those that are open or surgically treated. Acute infection can lead to Osteomyelitis , which is a bone infection that can be difficult to cure. Long-term complicationsof dislocations include the following: Instability:Various dislocations can lead to joint instability. Instability can be disabling and increases the risk of osteoarthritis. Stiffness and impaired range of motion:Stiffness is more likely if a joint needs prolonged immobilization. The knee, elbow, and shoulder are particularly prone to posttraumatic stiffness, especially in older patients. Osteonecrosis (ON) : Osteoarthritis (OA) : 