forensic nurse - Clinical Update - Knee-Chest Positions for Child Exams Revisited

I am responding to the article by Gretchen Overstolz and Elizabeth Baker-Gibbs in the October/November issue of forensic nurse magazine, regarding the use of the prone knee-chest position for examining children who may have been sexually abused. As a pediatrician who has been involved in the care of children with suspected sexual abuse since , and as one of the researchers whose publications were referenced in the article and as a member of the International Association of Forensic Nurses, I have some comments to make.

The prone knee-chest examination position is one of the various methods that can be used to help examiners assess the integrity of the posterior rim of the hymen. It is not often used in infants or toddlers and is usually not necessary in adolescent patients, but it can be very helpful when an examiner thinks the hymen looks abnormal in the supine position and needs to verify whether in fact an abnormality is present. I disagree with the authors' statement that the position "provides little, if any objective data by which to formulate a medical diagnosis of inflicted genital trauma that cannot be gained by other ... methods." If the use of the prone knee-chest position allows better visualization of the hymenal rim so that it is found to be normal, this is very important information and can avoid the mis-diagnosis of "old trauma."

The most common mistake of newly trained examiners, both physicians and nurses, is to call something abnormal in the genital examination because adequate methods were not used to visualize the entire rim of the hymen. The misdiagnosis of abuse can be extremely damaging to a child and family, so uncertain or questionable findings must be confirmed using multiple techniques.

The hymen is a floppy, sticky piece of tissue in both pre-pubertal girls and adolescent girls, and it is often impossible to tell with only the separation and labial traction technique whether a perceived irregularity in the hymenal rim is real or an artifact of the examination. The hymen can fold up on itself, flop outward, fold inward and stick together. In infants and toddlers, using water to "float" the hymenal edges will often make what looks like a notch or cleft disappear so that the smooth, uninterrupted edge is clearly visible. In adolescents, a moist cotton swab can be used to stretch out the rim, or a Foley catheter can be used. I also like the idea of using a colored cotton swab to help define notches or clefts in the hymen of an adolescent. With a pre-pubertal girl, however, a swab should not be used because of the extreme sensitivity of the hymen. In cases where neither labial traction nor the use of water provides a clear view of the posterior hymen, the knee-chest position is often very helpful.

Two recent research studies have documented the extremely low frequency of abnormal genital or anal examination findings in children who describe vaginal penetration or anal penetration. Berenson¹ and colleagues did a case-control study where they compared the genital findings (documented on magnified photographs) between two groups of girls age 3 to 8 years. One group was recruited from a well-child clinic and each child was carefully screened and found to have no suspicion of abuse. The other group of girls all gave clear histories of either digital or penile-vaginal penetration. Less than 5 percent of the girls in the abused group had abnormal genital examinations. Likewise, a review of 2,384 children referred for suspected sexual abuse over a five-year period were found by Heger and colleagues² to have abnormal genital findings in only 4 percent of cases. Even when vaginal penetration was highly suspected, only 5.5 percent of girls had abnormal examinations.

Therefore, if an examiner suspects an abnormality, it is essential to not only use additional techniques to demonstrate the abnormality, but to obtain photographic or video documentation so the finding can be reviewed by a more experienced clinician, such as an expert who has examined 1,000 children or more. Examiners who have completed a CD course on child sexual abuse medical evaluation, offered on the Web site: http://child-abuseCME.ucsd.edu, can access an online directory of clinicians who are experts in sexual abuse evaluation and who have indicated their availability to assist other examiners who may have a question about a particular finding in a child.

When I first began my training in adolescent medicine 20-some years ago, I was very uncomfortable doing genital examinations on young men. My teachers had me do as many examinations as I could to overcome my discomfort and become matter-of-fact in my approach to the patients. When I became comfortable, my patients became comfortable. I think the same thing applies to using the prone knee-chest position to examine children who may have been abused. If the examiner is convinced that the exam will be uncomfortable, "demeaning" and "disempowering" to the child, the child will almost certainly also be uncomfortable. If it is done as a routine part of the check-up, if the child's cooperation is elicited, if it is made to be "not a big deal" and kind of a funny way to "pretend you're a kitty cat," the child will be agreeable 99 times out of 100. That has been my experience in the 2,000 or so examinations I've done in my career and my colleagues have similar experiences. Two nurse practitioners I've worked with, who have probably conducted 13,000 child sexual abuse examinations between them, also can get just about any girl in knee-chest, and the children don't appear in the least bit traumatized. Of course if a child is resistant or begins to become upset, the prone knee-chest examination is not done, and the examination is either postponed, or other supplemental techniques are attempted, such as using water to 'float' the hymen.

Everyone who works with children who have been, or may have been, sexually abused must be sensitive to the child's needs. However, we need to be careful not to let our own prejudices regarding a particular examination method interfere with our job, which is to obtain the very best examination of the child, in a gentle and careful manner which helps the child feel better at the conclusion of the examination, and to assess the significance of any medical findings using published research of abused and non-abused children.