JAAOS, Volume 13, No. 7

Acute compartment syndrome in lower extremity musculoskeletal trauma.

Acute compartment syndrome is a potentially devastating condition in which the pressure within an osseofascial compartment rises to a level that decreases the perfusion gradient across tissue capillary beds, leading to cellular anoxia, muscle ischemia, and death. A variety of injuries and medical conditions may initiate acute compartment syndrome, including fractures, contusions, bleeding disorders, burns, trauma, postischemic swelling, and gunshot wounds. Diagnosis is primarily clinical, supplemented by compartment pressure measurements. Certain anesthetic techniques, such as nerve blocks and other forms of regional and epidural anesthesia, reportedly contribute to a delay in diagnosis. Basic science data suggest that the ischemic threshold of normal muscle is reached when pressure within the compartment is elevated to 20 mm Hg below the diastolic pressure or 30 mm Hg below the mean arterial blood pressure. On diagnosis of impending or true compartment syndrome, immediate measures must be taken. Complete fasciotomy of all compartments involved is required to reliably normalize compartment pressures and restore perfusion to the affected tissues. Recognizing compartment syndromes requires having and maintaining a high index of suspicion, performing serial examinations in patients at risk, and carefully documenting changes over time.

    • Keywords:
    • Compartment Syndromes|Humans|Ischemia|Lower Extremity|Musculoskeletal System|Treatment Outcome

    • Subspecialty:
    • Trauma

    • Basic Science

Direct catastrophic injury in sports.

Catastrophic sports injuries are rare but tragic events. Direct (traumatic) catastrophic injury results from participating in the skills of a sport, such as a collision in football. Football is associated with the greatest number of direct catastrophic injuries for all major team sports in the United States. Pole vaulting, gymnastics, ice hockey, and football have the highest incidence of direct catastrophic injuries for sports in which males participate. In most sports, the rate of catastrophic injury is higher at the collegiate than at the high school level. Cheerleading is associated with the highest number of direct catastrophic injuries for all sports in which females participate. Indirect (nontraumatic) injury is caused by systemic failure as a result of exertion while participating in a sport. Cardiovascular conditions, heat illness, exertional hyponatremia, and dehydration can cause indirect catastrophic injury. Understanding the common mechanisms of injury and prevention strategies for direct catastrophic injuries is critical in caring for athletes.

    • Keywords:
    • Athletic Injuries|Female|Humans|Male

    • Subspecialty:
    • Sports Medicine

Preoperative planning for primary total hip arthroplasty.

Preoperative planning is of paramount importance in obtaining reproducible results in modern hip arthroplasty. Planning helps the surgeon visualize the operation after careful review of the clinical and radiographic findings. A standardized radiograph with a known magnification should be used for templating. The cup template should be placed relative to the ilioischial line, the teardrop, and the superolateral acetabular margin, so that the removal of the supportive subchondral bone is minimal and the center of rotation of the hip is restored. When acetabular abnormalities are encountered, additional measures are necessary to optimize cup coverage and minimize the risk of malposition. Templating the femoral side for cemented and cementless implants should aim to optimize limb length and femoral offset, thereby improving the biomechanics of the hip joint. Meticulous preoperative planning allows the surgeon to perform the procedure expediently and precisely, anticipate potential intraoperative complications, and achieve reproducible results.

    • Keywords:
    • Arthroplasty

    • Replacement

    • Hip|Hip Joint|Humans|Joint Diseases|Preoperative Care

    • Subspecialty:
    • Adult Reconstruction

Rheumatoid arthritis in the cervical spine.

The cervical spine often becomes involved early in the course of rheumatoid arthritis, leading to three different patterns of instability: atlantoaxial subluxation, atlantoaxial impaction, and subaxial subluxation. Although radiographic changes are common, the prevalence of neurologic injury is relatively low. The primary goal of treatment is to prevent permanent neurologic injury while avoiding potentially dangerous and unnecessary surgery. Strategies include patient education, lifestyle modification, regular radiographic follow-up, and early surgical intervention, when indicated. Magnetic resonance imaging is indicated when neurologic deficit (myelopathy) occurs or when plain radiographs show atlantoaxial subluxation with a posterior atlantodental interval < or =14 mm, any degree of atlantoaxial impaction, or subaxial stenosis with a canal diameter < or =14 mm. Surgery should be considered promptly for any of the following: progressive neurologic deficit, chronic neck pain in the setting of radiographic instability that does not respond to nonnarcotic pain medication, any degree of atlantoaxial impaction or cord stenosis, a posterior atlantodental interval < or =14 mm, atlantoaxial impaction represented by odontoid migration > or =5 mm rostral to McGregor's line, sagittal canal diameter <14 mm, or a cervicomedullary angle <135 degrees.

    • Keywords:
    • Arthritis

    • Rheumatoid|Cervical Vertebrae|Humans

    • Subspecialty:
    • Pain Management

    • Spine

Secondary osteoporosis.

Secondary osteoporosis occurs as a consequence of various lifestyle factors (eg, eating disorders, smoking, alcoholism), disease processes (eg, endocrinopathies, gastrointestinal tract disease, hepatobiliary disease), and treatment regimens that comprise corticosteroids or chemotherapeutic agents. Some of the disease entities underlying secondary osteoporosis may be clinically silent and identified only during evaluation for documented osteoporosis. The pathogenesis of osteoporosis in these settings is typically multifactorial. The loss of bone may be direct or indirect but ultimately is related to altered osteoblast or osteoclast function. Causes of secondary osteoporosis should especially be investigated in men at all ages and in premenopausal women with atraumatic fractures. In addition, patients with known risk factors should be evaluated. Early recognition and intervention are essential to prevent further loss of bone mass and to prevent fragility fractures.

    • Keywords:
    • Bone and Bones|Female|Homeostasis|Humans|Male|Osteoporosis

    • Subspecialty:
    • Spine

    • General Orthopaedics