During the period 1986-1987, a study of the use of break-away bases to reduce sliding injuries was conducted in Ann Arbor, Michigan (1). The break-away base that was used in the study is anchored by rubber grommets to a rubber mat that is flush with the infield surface. The mat is anchored to the ground by a metal post similar to that used with standard stationary bases. Seven hundred foot-pounds of force, or one-fifth the force needed to dislodge a stationary base from its mooring, is required to release the break-away portion of the base. The study evaluated injuries sustained during 633 games on two fields with break-away bases and 627 games on six fields with stationary bases. The players were college students, laborers, executives, physicians, and others ranging from 18 to 55 years of age. Players were assigned to one of four leagues on the basis of skill level and experience. Teams were assigned to playing fields on a random and rotating basis. All fields were maintained in the same manner. All injuries requiring a player to leave the game were documented by the umpires. Local hospital emergency rooms, the University of Michigan Student Health Service, and private practice orthopedic surgeons were asked to keep logs of patients seen with softball-related injuries. All persons identified by these three surveillance systems were contacted to see whether their injuries had occurred while sliding. Patients who had been playing on the study fields were included in the analysis. During the study period, there were 45 sliding injuries on the fields with stationary bases (7.2/100 games) and two sliding injuries on the fields with break-away bases (0.3/100 games) (rate ratio = 22.7; 95% confidence intervals, 5.6 to 71.4). Forty-three of the 45 injuries to players sliding into stationary bases involved the dead foot or hand. Twenty-four of the 45 injuries were ankle injuries; five were skin abrasions; five were knee injuries; three were finger fractures; and eight were from other causes. Medical charges for these 45 players were approximately $55,050 ($2njury). The two injuries involving break-away bases comprised a nondisplaced medial malleolar ankle fracture and an ankle sprain. The total medical expense for these two players medical expense for these two play was approximately $700 ($350/injury). APR 14 1988 U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES / PUBLIC HEALTH SERVICE UNITED STATES OF AMERICA T Reported by: DH Janda, MD, EM Wojtys, MD, FM Hankin, MD, ME Benedict, MA, Univ of Michigan, Ann Arbor, Michigan. Epidemiology Br, Div of Injury Epidemiology and Control, Center for Environmental Health and Injury Control, CDC. Editorial Note: In 1986, the National Electronic Injury Surveillance System of the U.S. Consumer Product Safety Commission estimated that 361,552 baseball-related injuries were treated in emergency rooms in the United States (2). This figure probably underestimates the actual number of injuries. The Amateur Softball Association of America estimates that 32 million individuals participate in softball leagues and that teams consist of an average of 15 persons and play approximately 22 games per year (unpublished data). Based on these data, it may be further estimated that about 23 million softball games are played annually in the United States. Studies of recreational softball injuries have found that base sliding is responsible for 35% to 71% of injuries occurring during play, including abrasions, sprains, ligament strains, and fractures (3,4). These injuries are caused by the impact of rapid deceleration against stationary bases. Methods suggested to reduce base-sliding injuries have included prohibiting sliding, offering better instruction on sliding techniques, using recessed bases, and using quick-release bases (4,5). Prohibiting base sliding would be effective but might be met with resistance from some fans and participants. Holding instructional clinics on proper sliding techniques is a possibility for school-related organizations; however, this method might be impractical for community-based teams. The prospective study in Michigan suggests that modifying the bases can alter the pattern and frequency of sliding injuries. If the stationary-base sliding injury rate of 7.2/100 games and the cost per injury of $1,223 reported in the study are representative, then approximately 1.7 million sliding injuries occur annually at a cost of over $2 billion. Similar calculations indicate that exclusive use of break-away bases would reduce injuries to just over 70,000 (a 96% reduction) and medical costs to $24 million (a 99% reduction). The umpires indicated that break-away bases did not significantly delay play, even though sliding players dislodged the bases up to six times per game. Properly seated bases did not detach during routine base running, and the umpires did not have difficulty with judgment calls when the bases released. The bases were durable and easy to replace and lasted both seasons. The use of break-away bases in recreational softball leagues might provide a significant, cost-effective reduction in softball injuries from sliding. However, injuries may still occur from runners' errors in judgment, improper sliding technique, poor timing, inadequate physical conditioning, and alcohol consumption. References 1. Janda DH, Wojtys EM, Hankin FM, Benedict ME. Softball sliding injuries: a prospective study comparing standard and modified bases. JAMA 1988;259:1848-50. 2. US Consumer Product Safety Commission. The National Electronic Injury Surveillance System: January-December 1986. NEISS Data Highlights 1988;10. 3. Wheeler BR. Ankle fractures in slow-pitch softball: the Army experience. Milit Med 1987;152:626-8. 4. Janda DH, Hankin FM, Wojtys EM. Softball injuries: cost, cause and prevention. Am Fam Physician 1986;33:143-4. 5. Wheeler BR. Slow-pitch softball injuries. Am J Sports Med 1984;12:237-40. Current Trends Birth Defects Caused by Isotretinoin New Jersey Between June 1983 and January 1987, four infants with isotretinoin embryopathy were born in New Jersey. Isotretinoin embryopathy consists of severe birth defects associated with first-trimester exposure to the synthetic retinoid isotretinoin (Accutane TM*, Roche Laboratories, A Division of Hoffmann-La Roche, Inc.), which is used to treat severe, recalcitrant cystic acne. Two of the cases were reported to the New Jersey Birth Defects Registry. A third case was described in the pediatric literature (1). The fourth was identified through a teratologist currently investigating cases of isotretinoin embryopathy in the United States (Massachusetts General Hospital, unpublished data). These cases are similar to a larger number of cases that have been reported to the Food and Drug Administration (FDA) from all areas of the United States. Case 1: In June 1983, a 1,260 g female infant of 30 weeks gestation was born to a 22-year-old woman with no previous pregnancies. The woman had taken isotretinoin for 8 days when she was 4 to 6 weeks pregnant. Isotretinoin treatment had been stopped when the woman learned that she was pregnant. At birth, the infant had microcephaly, bilateral microphthalmia, and bilateral rudimentary pinnae. She died on the 28th day of life. Postmortem examination revealed lissencephaly, rudimentary pinnae, atrial septal defect, ventricular septal defect, patent ductus arteriosus, and interrupted aortic arch (1). Case 2: In June 1985, a full-term male infant weighing 2,760 g was born to a 22-year-old woman who had taken isotretinoin during the first weeks of gestation. She had been counseled about the risk of drug-induced birth defects and had elected to carry the pregnancy to term. The infant had micrognathia, facial dysmorphism, missing ear lobes, Dandy-Walker malformation, and hearing and visual impairment. He now has severe mental retardation and developmental delay and requires institutional care. Case 3: In September 1986, a male infant of 27 weeks gestation was born to a woman who had taken isotretinoin during the second month of gestation. The infant had dysplastic external ears and hydrocephalus, which was treated with a ventriculoperitoneal shunt. This abnormality is thought to be secondary to an intraventricular hemorrhage during the early neonatal period. Case 4: In January 1987, a full-term male infant weighing 3,558 g was born with dysplastic ears and hearing loss. His mother had been treated with isotretinoin during the first trimester of pregnancy. Reported by: M Knapp, MSN, RN, Special Child Health Svcs and New Jersey Birth Defects Registry; New Jersey State Dept of Health. Birth Defects and Genetic Diseases Br, Div of Birth Defects and Developmental Disabilities, Center for Environmental Health and Injury Control, CDC. Editorial Note: Isotretinoin was recognized as an animal teratogen before it was first marketed in September 1982. It was, therefore, classified by FDA as Category X, contraindicated for use during pregnancy. A statement to that effect was included in the package insert. *Use of trade names is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services or the Public Health Service. In June 1983, human teratogenicity was reported to FDA and to the public (2). Subsequent reports have documented a strong association between a characteristic group of birth defects and exposure to isotretinoin during the first weeks of gestation (3,4). These defects include external ear malformations, cleft palate, micrognathia, conotruncal heart defects, ventricular septal defects, aortic-arch malformations, and certain brain malformations (3). In one prospective follow-up study, eight of 36 pregnancies that were exposed to isotretinoin resulted in spontaneous abortions during the first trimester; four resulted in live-born infants with at least one major malformation; one, in a malformed stillborn infant; and 23, in infants without major malformations (3). This study found a relative risk of 25.6 (95% confidence interval, 11.4 to 57.5) for the defects associated with isotretinoin embryopathy. TABLE II. Notifiable diseases of low frequency, United States *Four of the 57 reported cases for this week were imported from a foreign country or can be directly traceable to a known internationally imported case within two generations. |