How to get the most out of bone densitometry. Results can help assess fracture risk and guide therapy.

Bone densitometry has well-established usefulness in assessing fracture risk. Anyone with a condition that might reduce bone mass or accelerate bone loss should undergo testing, as should postmenopausal women and perimenopausal women who are undecided about starting estrogen replacement therapy. When stratifying a patient's risk of fracture, clinicians should consider not only BMD but also age, lifestyle, concurrent illness, and family history. Almost all patients with BMD in the osteoporotic range on densitometry should be considered for pharmacologic therapy, and so should many of those with values in the osteopenic range. Periodic retesting with bone densitometry is appropriate to monitor the progress of age-related bone loss and response to therapy. There are differences among skeletal sites used in BMD measurement, particularly regarding response to therapy. In addition, there are differences in calibration among densitometry machines, so whenever possible, serial studies should be done on the same machine and by the same technologist.

Morbidity and mortality in the wilderness.

The medical literature is limited regarding current wilderness morbidity and mortality statistics. Available studies concentrate on selected wilderness activities. This study retrospectively examines wilderness injuries, illnesses, and mortality based on case incident report files from eight National Park Service parks within California over a three-year period. Data were extracted regarding type of illness or injury, body area affected, age, gender, month in which the event occurred, and activity in which the victim was involved at the time of the event. The overall occurrence of nonfatal events was 9.2 people per 100,000 visits. More than 70% of all nonfatal events were related to musculoskeletal or soft-tissue injury. The most frequently involved body area was the lower limbs (38%). Seventy-eight mortalities occurred during the three years studied, resulting in an overall mortality rate of 0.26 deaths per 100,000 visits. Men accounted for 78% of the deaths. Heart disease, drowning and falls were the most common causes of death. The information and statistics on morbidity and mortality in California wilderness areas that this study provides may be used to guide future wilderness use, education, and management. A standardized, computerized database would greatly facilitate future evaluations, decisions, and policies.

Risk factors associated with stress reactions in female Marines.

Women have a higher stress fracture rate than men in military studies, although the exact cause of this is not clear. Hyperpronation has been implicated as a potential risk factor for injury. In this prospective observational study, we measured subtalar joint range of motion in 101 women (ages 20-27 years) enrolled in Marine Corps Officer Candidate School in June 1994. The purpose of this study was to identify risk factors for injury in female Marine Corps officer candidates. The primary area of interest was the association between the amount of subtalar joint range of motion and stress reactions. Questionnaires were administered that explored previous physical activities, sports participation, and menstrual history. Anthropometric measurements were performed, including subtalar joint range of motion. During the 10 weeks of physical training, 11.5% of the women (N = 12) had stress reactions compared with 7% of the men (N = 10). There was no statistically significant difference in the means of subtalar joint range of motion in the stress reaction group compared with the non-stress reaction group. Differences in stress reaction rate across quartiles of subtalar joint range of motion were not significant. Those women who ran fewer miles (< or = 2.8 miles per session) before training had a higher rate of stress reactions (p < 0.04). Younger individuals (< 23 years) had a higher rate of stress reactions (p < 0.01). Women with fewer menstrual periods (< 10 per year) had a higher rate of stress reactions (p < 0.02). A narrow pelvis (< or = 26 cm) was associated with a higher rate of stress reactions (p < 0.09). We conclude that an increased subtalar joint range of motion is not a risk factor for stress reactions in women. However, further studies with a larger study population should be performed to confirm these findings.

The numb arm and hand.

Trauma and compression along the course of the median, ulnar or radial nerve from the brachial plexus to the fingers may cause pain, weakness, numbness or tingling of the upper extremity. Diabetes, smoking, alcohol consumption, rheumatoid arthritis and hypothyroidism are risk factors for nerve entrapment, although these disorders typically produce bilateral symptoms. Carpal tunnel syndrome, the most common nerve entrapment condition, results from median nerve compression at the wrist. The diagnosis is suggested by decreased pain sensation and numbness in the thumb and index and middle fingers; symptoms are reproduced by wrist hyperflexion and median nerve percussion. Volar splinting and steroid injection often ameliorate symptoms. Decreased sensation of the little finger and the ulnar aspect of the ring finger, along with intrinsic muscle weakness, may be caused by cervical radiculopathy, thoracic outlet syndrome or compression of the ulnar nerve above the elbow (cubital tunnel syndrome) or at the wrist (ulnar tunnel syndrome). Electromyography and radiography may help differentiate these conditions. Radial tunnel syndrome occasionally accompanies inflammation of the common wrist extensors and lateral epicondylitis ("tennis elbow"). A radial nerve block can help exclude concomitant radial tunnel syndrome in patients with symptoms of lateral epicondylitis.

Spinal bone loss in postmenopausal women supplemented with calcium and trace minerals.

The effects of calcium supplementation (as calcium citrate malate, 1000 mg elemental Ca/d) with and without the addition of zinc (15.0 mg/d), manganese (5.0 mg/d) and copper (2.5 mg/d) on spinal bone loss (L2-L4 vertebrae) was evaluated in healthy older postmenopausal women (n = 59, mean age 66 y) in a 2-y, double-blind, placebo-controlled trial. Changes (mean +/- SEM) in bone density were -3.53 +/- 1.24% (placebo), -1.89 +/- 1.40% (trace minerals only), -1.25 +/- 1.46% (calcium only) and 1.48 +/- 1.40% (calcium plus trace minerals). Bone loss relative to base-line value was significant (P = 0.0061) in the placebo group but not in the groups receiving trace minerals alone, calcium alone, or calcium plus trace minerals. The only significant group difference occurred between the placebo group and the group receiving calcium plus trace minerals (P = 0.0099). These data suggest that bone loss in calcium-supplemented, older postmenopausal women can be further arrested by concomitant increases in trace mineral intake.

Coagulopathy presenting as calf pain in a racquetball player.

Most cases of lower leg pain in athletes result from musculoskeletal injury. Occasionally these patients do not respond to treatment in a timely fashion. This should alert the clinician to rethink the original diagnosis and consider more unusual causes of leg pain. Deep venous thrombosis must be considered in a young athletic person experiencing unexplained persistent calf pain after exercise. Further investigation may be necessary to rule out a hereditary or acquired hypercoagulable state.

Acute injuries from mountain biking.

We questioned members of 2 southern California off-road bicycling organizations about injuries associated with the use of all-terrain bicycles. Cyclists were asked about riding and safety habits, the kind(s) of injury sustained with their most recent accident and whether they sought medical treatment, and the circumstances of the accident. Of 459 mailed surveys, 268 (58.4%) were returned. Respondents (82.8% of whom were male) ranged in age from 14 to 68 years. Of these, 225 (84%) had been injured while riding all-terrain bicycles, 51% in the past year. Although most injuries were characterized as minor, 26% required professional medical care, and 4.4% of those injured were admitted to hospital. Extremity injuries--abrasions, lacerations, contusions--occurred in 201 (90%) cyclists with 27 (12%) sustaining a fracture or dislocation. High levels of helmet use (88%) may explain the low occurrence of head and neck trauma (12%). Frequent riding and riding on paved terrain were associated with increased severity of injury, although most accidents--197 (87.6%)--occurred off paved roads. These results suggest that, compared with regular bicyclists, all-terrain cyclists have more, but not necessarily more severe, injuries. Clinicians and emergency medical personnel should be aware that the increasing popularity of off-road cycling may change the frequency and nature of bicycling injuries.

Effects of a preventive cardiology curriculum on behavioral cardiovascular risk factors and knowledge of medical students.

We evaluated a Preventive Cardiology Academic Award (PCAA) program designed to integrate preventive cardiology concepts into the medical school curriculum. Diet, preventive cardiology knowledge, preventive cardiology attitudes, exercise behavior, and body mass index were compared at entrance to medical school and during the graduation year. Complete data were available on 94 students (65 men and 29 women). Similar data from students who graduated in 1987, prior to the introduction of the PCAA curriculum, served as a control. Women showed a significant enhancement in attitude towards cardiovascular disease (CVD) prevention, while both men and women significantly increased their knowledge about CVD prevention. The frequency of planned physical activity decreased significantly in both sexes and men showed a significant increase in body mass index. Men significantly reduced total calories, percent of calories from fat and saturated fat and dietary cholesterol and increased fiber intake. In women, the only significant reduction was in total calories. In comparison to the control class that did not have the program, men receiving the PCAA curriculum reduced dietary cholesterol, dietary fat, saturated fat and monounsaturated fat. Changes in these dietary parameters were nonsignificant for women in comparison to the control class women. Additional analyses showed no systematic secular trends in dietary or other variables in classes entering from 1986 to 1990. We conclude that the PCAA curriculum changes have favorably affected the preventive cardiology knowledge, attitudes and diet of medical students.

Cardiovascular risk factor assessment of medical students as an educational tool.

For three consecutive years, beginning in 1986, we evaluated cardiovascular disease (CVD) risk factors of medical students as part of the teaching program in a Preventive Cardiology Academic Award. Entering students in three consecutive classes were screened on the first day of orientation to medical school. The first year, we evaluated 108 students (71 men and 37 women), the second year, 99 students (75 men, 24 women), and the third year 108 students (67 men and 41 women). During the single four-hour period, we obtained data on personal and family history of CVD risk factors, type A behavior, knowledge of CVD, attitudes toward CVD prevention, measures of depression and anger, blood pressure, blood pressure reactivity, physical activity, and diet. Blood was drawn for lipid analysis. Height and weight were measured, and a physical fitness step test was administered. Pulmonary function was measured during the third year. We used a four-tiered approach to preventive cardiology education. During the assessment session, abnormalities, such as elevated blood pressure or abnormal pulse, were discussed with the student. In the second tier, the data were analyzed and returned to all students during teaching sessions, enabling them to compare their levels with the class and the national averages. For the third tier, students with high-risk values, defined as low-density lipoprotein cholesterol level > or = 150 mg/dL, a total cholesterol or triglyceride level > or = 200 mg/dL, or blood pressure > or = 140/90 mmHg, were seen by faculty physicians who suggested remedial interventions in separate sessions.(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental and thermal injury.

The environment can have a profound impact on human performance. Over the past decade there has been considerable interest in the scientific study of the human ability of to protect oneself against heat and cold. This new knowledge has led to a better understanding of physiology and resulted in better prevention, recognition, and treatment of hyperthermia, hypothermia, and frostbite. This article reviews the pathophysiology of extreme environmental exposure and discusses current strategies for prevention and treatment.

Spinal bone density and calcium intake in healthy postmenopausal women.

Dietary calcium intake and bone mineral density (BMD) of the lumbar spine (L2-L4) were determined in 131 healthy free-living postmenopausal women (aged 64.7 +/- 7.6 y, means +/- SD). The calcium consumption for the total population was 606 +/- 302 mg/d. Subjects consuming less than the population mean of dietary calcium had significantly lower BMDs than did subjects with intakes above the mean (P less than 0.009); these two groups did not differ in basic demographic characteristics. Additional analyses using a stepwise univariate regression model demonstrated that BMD was significantly associated with body weight (P less than 0.001) and dietary calcium intake (P less than 0.02). These data support the hypothesis that dietary calcium intake is a determinant of skeletal health in postmenopausal women.

Long-term estrogen replacement therapy in postmenopausal women sustains vertebral bone mineral density.

The cross-sectional relationship between long-term estrogen use and vertebral (L2-4) bone mineral density (BMD) was determined in 65 postmenopausal white women between 55 and 75 years who were at least 10 years from their menopause. Long-term estrogen users began therapy within 5 years of menopause and continued for a duration of at least 10 years. The mean duration of use was 19.8 years. Controls used estrogen for less than 1 year. There was a significant difference (p less than 0.02) in mean spinal BMD between estrogen users (1.219 g/cm2) and controls (1.092 g/cm2). There was no significant difference in age, height, weight, or dietary calcium (Ca) intake between the two groups. The statistical difference in BMD was retained when (1) 23 estrogen users were paired with age-matched controls, (2) only women with a natural menopause or history of bilateral oophorectomy were included, and (3) only women with a natural menopause were compared. A spinal BMD below the estimated fracture threshold of 0.965 g/cm2 was found in 11 of 40 controls and only 2 of 25 estrogen users. Comparison of estrogen users with a natural menopause to those with bilateral oophorectomy revealed no significant difference in BMD. These data confirm the salutary effect of long-term estrogen use in the maintenance of vertebral bone mass in postmenopausal women.

Chronic Shoulder Pain in a Volleyball Player.

In brief A high school girl had pain in her right shoulder when she played volleyball. X-rays revealed the cause: diffuse multiple loose calcifications throughout the synovium of the shoulder. The calcifications were removed arthroscopically, and a partial synovectomy of the shoulder joint was performed. The patient's prognosis was considered fair because this disorder can recur; however, it sometimes resolves with no further problems. This disorder-synovial chrondomatosis-is especially rare in young athletes, occurring primarily in middle-aged men, with 60% of cases occurring in the knee.

A comparison of quantitative dual-energy radiographic absorptiometry and dual photon absorptiometry of the lumbar spine in postmenopausal women.

Noninvasive bone densitometry is an important aspect in the detection and management of osteoporosis and other forms of metabolic disease of calcified tissue. A system using quantitative dual-energy digital projection radiography (QDR) of the lumbar spine was systematically tested against dual-photon absorptiometry (DPA) of the lumbar spine in 131 women over 55 years of age and free from major risk factors for osteoporosis. All subjects were scanned by both QDR and DPA under the same conditions. Measurements for a given subject were made within 15 minutes of each other. Bone mineral densities (BMD) were determined for four individual levels in the lumbar spine (L1-L4). Regression equations for BMD vs. age, height, and weight were calculated. The results of this investigation indicate that DPA- and QDR-derived BMD values are comparable. BMD values derived by QDR were consistently lower than those obtained by DPA (DPA = 1.115 QDR + 0.137, r = 0.942). The L2 lumbar region was the most strongly correlated determination.

Rattlesnakes: The Animal and the Venom (Part 1 of 2).

In brief: All rattlesnakes are venomous, but | they vary in degree of dangerousness. They also vary in length, color, and markings. Because they like warm weather, most of them live in the southern states, from California to Florida. Unfortunately, it is difficult to identify rattlesnakes, because harmless snakes share some of their characteristics. The primary purpose of the rattlesnake's venom is to obtain food; to a lesser extent it is used as a defensive tool. In offensive bites the volume of venom is well controlled, while in defensive bites it is not. Sometimes no venom is injected. Human reactions to envenomation include pain and swelling, hypotension, bleeding, and neurotoxicity.

First Aid and Management of Rattlesnake Bites (Part 2 of 2).

In brief: Rattlesnake bites are rarely fatal, but prevention is the best treatment. People who live in areas indigenous to rattlesnakes should take routine precautionary measures such as wearing boots and long pants. A person who encounters or is bitten by a snake should get away from it as soon as possible. First aid includes applying a constricting band and suction; incisions are not recommended. The victim should be transported to a medical facility as soon as possible. Medical management includes a history and physical examination and laboratory data, including blood coagulation studies and urinalysis. Intravenous antivenom is the mainstay of treatment.

Hyperthermia: New Thoughts on an Old Problem.

In brief: This article reviews the causes and treatment of the common heat illnesses-heat syncope, heat exhaustion, and exertional heatstroke. The authors discuss the effectiveness of cooling heatstroke victims in ice water vs water that has been cooled to a temperature of 15° C. The latter method is more practical and has been found as effective as cooling with ice water. The authors also present the energy depletion model, which shows the cycle that results in reduced exercise/heat tolerance and significant morbidity and mortality in victims of exercise-induced hyperthermia. This model predicts that cellular/metabolic processes and deficits operate for some time after hyperthermia has subsided with cooling.

Cluster Headache Among Athletes.

A group of experts met to discuss a case from the University of California, San Diego, School of Medicine. This case conference is part of a series featuring a variety of sports medicine topics.

High-Altitude Pulmonary Edema: The Disguised Killer.

In brief: High-altitude pulmonary edema afflicts 1% to 2% of sojourners above 10,000 to 11,000 ft. It is at the severe end of a spectrum of high-altitude illnesses; symptoms can be subtle or overt and can rapidly progress to coma and death. The best prevention is acclimatization-slow, gradual ascent that allows the body to adapt to a hypoxic environment. The author reviews the signs and symptoms and how to recognize them, the pathophysiology, and the prevention and management of this avoidable, but potentially fatal, condition.

Signs, Symptoms, and Management of Jellyfish Envenomation.

In brief: Millions of divers, swimmers, and other ocean-goers may encounter jellyfish. If they are stung, they may need either first aid if the case is mild, or extensive treatment if they suffer anaphylaxis, cardiorespiratory problems, or long-term reactions. Some severe cases may even be fatal. The author describes the mechanisms of envenomation and tissue reaction and discusses how to recognize and treat both the immediate and late sequelae.