JAAOS

JAAOS, Volume 6, No. 6


Exercise-induced loss of bone density in athletes.

In athletes, the rarely identified malady of osteoporosis differs from other chronic effects of exercise. The most obvious difference is that hormonal imbalance leads to compensatory mechanisms that in turn lead to osteoporosis and increased incidence of fracture. Most research on this subject has dealt with women, because hormonal imbalances in women are easier to detect than those in men. Endurance athletes are known to have decreased levels of sex hormones, which can cause physiologic changes that lead to bone loss. This may result in relative osteoporosis despite the loading of the bone during exercise, which would normally increase bone mineral density. Premature osteoporosis may be irreversible, causing young athletes to become osteoporotic at an earlier age and have an increased risk of fracture later in life.

    • Keywords:
    • Adolescent|Adult|Bone Density|Bone Remodeling|Calcium

    • Dietary|Exercise|Female|Gonadal Steroid Hormones|Humans|Male|Middle Aged|Nutritional Requirements|Osteoporosis|Risk Factors|Sports

    • Subspecialty:
    • Sports Medicine

    • Pediatric Orthopaedics

Lower-limb deficiencies and amputations in children.

Important differences exist in the management of child and adult amputees. Many factors, including the etiology of childhood limb deficiencies, expected skeletal growth, functional demand on the locomotor system and prosthesis, appositional bone stump overgrowth, and psychological challenges, make caring for these young patients particularly challenging. Adherence to the general principles of childhood amputation surgery will typically guide one to the optimal functional result. These principles can be summarized as follows: (1) Preserve length. (2) Preserve important growth plates. (3) Perform disarticulation rather than transosseous amputation whenever possible. (4) Preserve the knee joint whenever possible. (5) Stabilize and normalize the proximal portion of the limb. (6) Be prepared to deal with issues in addition to limb deficiency in children with other clinically important conditions. A large proportion of young amputees undergo a Syme disarticulation, modified Boyd amputation, or knee disarticulation. A modified Van Nes rotationplasty procedure is also useful in this age group. All these provide the child with a weight-bearing stump with good growth potential and no complications due to bone overgrowth. Appropriate timing of amputation procedures and prosthetic fittings is essential to maximize functional benefit to the patient.

    • Keywords:
    • Age Factors|Amputation|Child|Child Development|Child Psychology|Humans|Leg|Surgical Flaps

    • Subspecialty:
    • Foot and Ankle

    • Pediatric Orthopaedics

Surgical treatment of the unstable ankle.

Symptomatic ankle instability will develop in as many as 20% of patients after inversion sprain of the lateral ankle ligaments. Although most patients may be successfully treated with a rehabilitative exercise program and bracing, some will continue to sustain recurrent ankle sprains with activities of daily living, work on uneven terrain, or sports. The anterior talofibular ligament and the calcaneofibular ligament are the primary stabilizers of the lateral ankle, and surgical procedures should be aimed at restoring the normal function of these ligaments. Preoperative stress radiographs should be obtained to determine the degree of laxity and to differentiate between subtalar joint and ankle joint instability. Numerous surgical techniques have been described to correct ankle instability, most with an 80% to 90% success rate. Reconstructions using tendon grafts may restrict normal ankle and subtalar joint motion, depending on the placement of the graft. Direct repair of the anterior talofibular and calcaneofibular ligaments with shortening and reattachment to the fibula has a success rate similar to that for augmented reconstruction and avoids the increased morbidity associated with tendon graft procedures. Patients with severe laxity or with weak or deficient tissue for direct repair may require an augmented reconstruction. Osteotomy may be required in addition to ligament reconstruction in patients with severe ankle or hindfoot varus alignment, in order to prevent failure of the repair. Patients with paralysis or weakness of the peroneal musculature may require a nonanatomic procedure that limits subtalar motion.

    • Keywords:
    • Ankle Joint|Biomechanics|Humans|Joint Instability|Ligaments

    • Articular|Osteotomy|Patient Selection|Range of Motion

    • Articular|Risk Factors|Tendons

    • Subspecialty:
    • Foot and Ankle

    • Sports Medicine

The rotator cuff-deficient arthritic shoulder: diagnosis and surgical management.

The symptomatic rotator cuff-deficient, arthritic glenohumeral joint poses a complex problem for the orthopaedic surgeon. Surgical management can be facilitated by classifying the disorder in one of three diagnostic categories: (1) rotator cuff-tear arthropathy, (2) rheumatoid arthritic shoulder with cuff deficiency, or (3) degenerative arthritic (osteoarthritic) shoulder with cuff deficiency. If it is not possible to repair the cuff defect, surgical management may include prosthetic arthroplasty, with the recognition that only limited goals are attainable, particularly with respect to strength and active motion. Glenohumeral arthrodesis is a salvage procedure when other surgical measures have failed. Arthrodesis is also indicated in patients with deltoid muscle deficiency. Humeral hemiarthroplasty avoids the complications of glenoid loosening and is an attractive alternative to arthrodesis, resection arthroplasty, and total shoulder arthroplasty. The functionally intact coracoacromial arch should be preserved to reduce the risk of anterosuperior subluxation. Care should be taken not to "overstuff" the gleno-humeral joint with a prosthetic component. In cases of significant internal rotation contracture, subscapularis lengthening is necessary to restore anterior and posterior rotator cuff balance. If the less stringent criteria of Neer's "limited goals" rehabilitation are followed, approximately 80% to 90% of patients treated with humeral hemiarthroplasty can have satisfactory results.

    • Keywords:
    • Arthritis

    • Rheumatoid|Arthrodesis|Arthroplasty|Biomechanics|Diagnosis

    • Differential|Humans|Nutritional Status|Osteoarthritis|Patient Selection|Risk Factors|Rotator Cuff|Shoulder Joint

    • Subspecialty:
    • Shoulder and Elbow

Thromboembolism after hip and knee arthroplasty: diagnosis and treatment.

Postoperative thromboembolism is a potentially lethal complication. Its diagnosis may be difficult, as the classic clinical signs and symptoms are often absent, making a high index of suspicion imperative for diagnosis. Anticoagulant therapy is effective in reducing morbidity and mortality due to thromboembolism, but is associated with a substantial rate of bleeding complications in the immediate postoperative period. Inferior vena cava filters constitute an alternative to anticoagulant therapy, but are also associated with a substantial complication rate. The appropriate use of diagnostic tests combined with clinical suspicion can guide the orthopaedic surgeon in deciding which patients require treatment for thromboembolism.

    • Keywords:
    • Algorithms|Anticoagulants|Arthroplasty

    • Replacement

    • Hip|Arthroplasty

    • Knee|Decision Trees|Humans|Risk Factors|Thromboembolism|Vena Cava Filters

    • Subspecialty:
    • Adult Reconstruction

Uncommon nerve compression syndromes of the upper extremity.

Nerve compression syndromes are a common cause of pain, sensory disturbance, and motor weakness in both the upper and the lower extremities. Although carpal tunnel syndrome is frequently diagnosed and treated surgically with success, other compression syndromes are less common and are often best treated nonsurgically. Understanding the anatomy of the major peripheral nerves with respect to intermuscular septa, fibrous bands, muscle margins, and internervous planes is crucial to understanding how and where peripheral nerve compression can occur. Some conditions, such as anterior interosseous nerve syndrome, respond well to nonoperative treatment; others, such as posterior interosseous nerve syndrome, are better treated by surgical intervention. The authors discuss the anatomic and pathologic causes for compression syndromes, as well as guidelines for treatment and outcomes.

    • Keywords:
    • Arm|Axilla|Diagnosis

    • Differential|Humans|Median Nerve|Nerve Compression Syndromes|Radial Nerve|Scapula

    • Subspecialty:
    • Shoulder and Elbow

    • Hand and Wrist

    • Pain Management

    • Basic Science

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