Injuries to the perineum can be classified as penetrating, non-penetrating, intentional, and accidental. Unintentional injuries of the perineum include straddle injuries (landing with the legs on either side of a bar), zipper entrapment, hair tourniquet, and even seat belt injury to the genitalia. The history in these unintentional injuries is the key to appropriate diagnosis.
Children with straddle and other accidental genital or anal injuries are usually brought to medical attention promptly, while child sexual abuse is often accompanied by a delay in disclosure and, thus, a delay in seeking medical care.
Straddle injuries, one of the most common injuries to the genitalia, rarely involves penetration. Straddle injuries typically result from a fall onto an object leading to soft tissue injury. The leading cause of such injuries involves objects such as bicycle bars, beds, fences, playground equipment, and walls. Straddle injuries can be differentiated from abuse since they are typically midline or unilateral, superficial, and involve the anterior portion of the external genitalia. Injury to the anus is extremely rare but can result due to penetrating injuries from a fall onto an upright object. In girls, the labia minora or urethra are most often affected. Injury to the hymen or anus is extremely rare but can result due to penetrating injuries from a fall onto an upright object. Among boys, the most common injury involves ecchymosis or minor laceration of the scrotum or penis.
The possibility of sexual abuse should be considered during evaluation. Increased suspicion of sexual abuse exists in cases of straddle injuries in non-ambulatory children, extensive trauma, associated physical trauma, and inconsistent history.