Brief summary of the case for the jury. Both parents are professionals-father is a radiologist and the mother is a medical malpractice lawyer. They have been married for 2 years, and this was their first child. Father accused of and charged with assault leading to the death of his 2 month old baby daughter. Cause of death found to be bilateral subdural haematomas and brain swelling. Charges against the defendant, what they mean and what is expected of the jury. Introduce QC for the defence. Witness has been qualified as an expert in child abuse.
Defense attorney (BH): Doctor, you are certainly an eminent expert in this field. I shall try to confine my questioning to your particular areas of expertise. 2 But first, for the benefit of the jury and to ensure that I have understood your evidence in chief I shall recap your findings in this case. In this 2 month old baby you have identified the following skeletal findings: multiple rib fractures,3 bilateral medial clavicle fractures, 4 a left acromion process fracture, a right 5 femoral shaft fracture and classic metaphysical lesions or CMLs of the distal right femur and distal left tibia and also periosteal new bone formation along the distal left tibial shaft. Are those your findings?
Expert (PK): Yes, by the way it’s metaphyseal not metaphysical
BH: Thank you for your clarification doctor! You have also very clearly stated how each fracture may have occurred and the amount and type of force necessary to produce each of them. I understand that in your opinion these were non-accidental injuries, in other words child abuse.
Doctor, you have testified regarding the fractures in this child. Is it true that you are not an orthopaedic surgeon?
PK: No, I am not an orthopaedic surgeon, but I…..
BH: And you do not treat patients with fractures?
PK: No, I do not treat them, but…
BH: So it is true that you are not able to diagnose fractures and determine their cause.
PK: No, that is not true. Radiologists regularly diagnose fractures and can make informed judgments regarding the types and magnitude of forces responsible for the injuries.
BH: But you are not a biomechanical engineer, correct?
PK: Correct.
BH: 6Regarding the rib fractures, could they have occurred at birth?
PK: No
BA: But rib fractures do occur with birth trauma, correct?
PK: Yes
BA: So how can you rule out that possibility in this infant?
PK: The rib fractures initially identified showed no signs of healing in this 2 month old infant.7
BH: But the fact that the rib fractures initially identified were in the mid posterior rib cage and this baby had what the father described as a very traumatic delivery would be in keeping with birth injuries, true?
PK: Yes but….
BH: 8 And what about the fact that additional rib fractures occurred when the infant was in the hospital?
Expert: They may have become evident in the hospital as callus became visible, but we know that acute fractures are often inconspicuous.
QC: So they MAY have occurred before the hospitalization, but you cannot rule out that they occurred after the child was admitted?
PK: Well, I guess that is theoretically possible, but…
PK: Let’s move on. I would now like to explore with you the possibility that an underlying medical condition may have been present, so that these fractures could have occurred as a result of normal, careful handling of the baby.
The police may not have informed you of some relevant background history in this case. It is recognised that the mother suffered from severe hyperemesis throughout pregnancy. Also, the baby was born prematurely at 34 weeks gestation and failed to establish feeding and needed naso-gastric feeding and one day of intravenous feeding before discharge at the age of one week.
Now let us consider the possibility that as a result of the hyperemesis, the mother and baby were deficient in certain nutrients. Would you tell us the X-ray findings you would expect to see if the baby were deficient in Vitamin C – in other words – was suffering from scurvy?
PK: 9 It is true that in scurvy there may be subphyseal lucency with metaphyseal fragmentation and fractures, but there is also relative increased density of the zone of provisional calcification and dense epiphyseal rings. Sub periosteal haemorrhage and mineralization is common.10 The hallmark of scurvy is severe demineralization.
BH: Just so we are clear – what do you mean by the term demineralization?
PK: Explains....
BH: I presume you are familiar with research that has been done identifying that X-rays are very imprecise in assessing bone density and that there can be a reduction of 30% of bone mineral content before this is apparent to radiologists?
PK: Well I am aware that that number has been thrown around, but I am not certain it applies in this setting.
BH: So, doctor, according to you, the classic findings of scurvy are metaphyseal fractures, periosteal reactions and possibly fractures as indeed we see in this baby, but you maintain the baby was not suffering from scurvy!
PK: But you have neglected the critical issue in scurvy of profound demineralization and other critical clinical and laboratory findings …..
BH: So let us move on. Another possibility given the hyperemesis, is that the baby was deficient in vitamin D – was suffering from congenital rickets. Would you tell us the X-ray findings you would expect to see in a case of rickets.
PK: 11 In rickets there is demineralization, loss of the zone of provisional calcification, widening of the physes with fraying and cupping of the metaphyses. With healing there may be periosteal reaction.
BH: You have identified metaphyseal fragmentation and periosteal changes with other fractures but you say the baby was not suffering from rickets! Were you aware that this patient had a vitamin D level of 32 and her mother showed clinical signs of vitamin D deficiency during her pregnancy presumably as a result of hyperemesis?
PK: Yes.
BH: Did this influence your thinking regarding the presence of rickets?
PK: Not really, since vitamin D deficiency is quite common, but rickets, particularly the congenital form is quite rare in otherwise normal infants. Fractures from dietary rickets in otherwise normal young infants are quite uncommon. 12This infant manifested vitamin D insufficiency, and a recent paper in Pediatrics from the Children’s Hospital of Philadelphia showed no increase in fracture risk with vitamin D insufficiency.
BH: Is it possible that this patient was suffering from rickets which was not apparent radiographically?
PK: Yes, it is possible that the patient might have metabolic alterations, but the absence of any gross rachitic changes and the pattern of injuries noted in this patient would not be consistent with fractures occurring purely from metabolic bone disease.
BH: But you would not be able to exclude rickets in this patient, correct?
PK: That is correct.
BH: And you cannot exclude the possibility that the patient's underlying metabolic bone disease could be contributing to the fractures, correct?
PK: Well, yes that is correct, however that cannot explain all of the findings that we are seeing in this case.
PK: Doctor, please restrict your response to a yes or no. Doctor, are you aware that there is an epidemic of confusion between child abuse and rickets?
PK: I am not aware of that.
BH: Doctor, is the journal Pediatric Radiology an authoritative publication.
PK: Yes it is but…
BH: 13Are you familiar with an article appearing in that respected journal, Pediatric Radiology that describes this epidemic of confusion between rickets and abuse?
PK: I am aware of the commentary which alleges that, but I am not in agreement.
BH: Are you suggesting that this journal publishes papers which are not correct?
PK: I do not believe everything I read.
BH: Would that include your own writings?
PK: I am afraid that would. But, I believe that at the time of publication, the editors of Pediatric Radiology indicated that this paper was published in order to stimulate conversation on the subject, which it certainly has. In the same journal issue, the editors found no scientific foundation for the authors’ allegations in this commentary. 14
Reads from paper: “we find that the connection made by Keller and Barnes between “rickets” and fractures they consider to be similar in appearance to those seen in child abuse is not based on any scientific data. Unfortunately, the current scenario is reminiscent of Patersons’ “ temporary brittle bone disease”. This concept has remained without proof and has been discredited. The work-up of child abuse considers a differential diagnosis including rickets but, unless there is reasonable evidence of rachitic bone disease, there is no scientific basis for confusing vitamin D insufficiency/deficiency with child abuse”
BH: This document is not in evidence and I move that the this testimony be struck. Now Doctor, I assume that your view that there is no scientific evidence to indicate that rickets is common in young infants is simply your opinion, and that there is no evidence-based research to support this, correct?
PK: No, that is not correct. A recent retrospective study examined approximately 100 infants dying of the sudden infant death syndrome with high-detail skeletal surveys. They found no cases with rickets.
BH: But is it possible that mild rickets may be present despite normal X-rays?
PK: To exclude that possibility, the authors reviewed the radiographs and also the microscopic findings in another group of 25 infants dying with multiple skeletal injuries detected at post-mortem imaging. Not only did they not find any radiologic evidence of rickets, a bone pathologist found no histologic evidence of rickets.
BH: Has this paper been published?
PK: No, not yet, but it was presented at the highly regarded International Pediatric Radiology meeting in London, a congress attended by the best and brightest minds in the field of pediatric radiology.
BH: So Doctor, are you saying that the vitamin D deficiency in this infant was not significant - in this infant who was breast fed and not supplemented with vitamin D?
PK: I cannot answer that with a simple yes or no.
BH: Well go on then.
PK: Would you please repeat the question?
BH: So Doctor, are you saying that the vitamin D deficiency in this infant was not significant - in this infant who was breast fed and not supplemented with vitamin D?
PK: I'm not sure I have the expertise to say whether it is significant or not, but we know that a low vitamin D level is common in this population. However, I can tell you to a reasonable medical certainty that there are no radiographic findings of rickets. Even if rickets was present, it would not explain all the imaging findings in this case.
BH: Doctor, did you consider copper deficiency? 15
PK: I did and ruled it out since this was an otherwise normal infant with no significant nutritional issues and there were no radiologic features to support that diagnosis
BH: What about osteopathy of prematurity?
PK: In an otherwise well infant born at 34 week, I don’t think so.
BH: Let me put this to you. Let us consider the possibility – given the unusual history in this case – that the baby was suffering from a combination of these problems but not quite sufficient for any one problem to be clinically evident – do you follow me? – so - a bit of deficiency of vitamins C and D and of copper and some prematurity. Is it not possible that this combination could account for the findings we have in this baby?
PK: Hmmm, a little bit of this and a little bit of that. That’s a novel thought—but since I saw no evidence of rickets, scurvy, copper deficiency or any other underlying condition, I cannot attribute the findings to a metabolic disorder, singly or in combination.
BH: Doctor, don’t you think you are being a bit dogmatic!
PK: Well, I would say……
BH: Let’s move on. Did you consider the possibility of osteogenesis imperfecta in this case? 16
PK: Yes I did.
BH: But you chose to ignore that possibility, correct?
PK: Well, not ignore it; I just saw no evidence of it.
BH: Doctor, have you already told us that you are not an orthopaedic surgeon?
PK: Yes I admitted that.
BH: And you are also not a medical geneticist
PK: No I am not, but I do play one on television!
BH: Doctor, kindly answer the question
PK: I saw no evidence of demineralization or other deformity or Wormian bones to suggest this condition.
BH: But Wormian bones are not always present, true?
PK: That is true. But the infant had metaphyseal corner fractures.
BH: Are you saying that metaphyseal corner fractures do not occur in OI.
PK: Ahhh, yes I am.
BH: 17Doctor don’t you recall publishing a case a number of years ago of Type 1 OI with a corner fracture pattern.
PK: Ahhhh yes, I do recollect that. I guess it slipped my mind.
BH: I wonder what else has slipped your mind doctor. Is it possible that this patient could still be suffering from osteogenesis imperfecta, even though the imaging findings are normal?
PK: Well yes it is possible, but….
BH: Please restrict your response to a yes or no. Is it possible that this infant could be suffering from OI?
PK: Yes, it is possible, but I would rely on a geneticist to make that determination.
BH: Then this patient could have OI and could have sustained these fractures as a consequence of that terrible disease?
Witness: No.
PK: We know that patients with osteogenesis imperfecta are susceptible to fractures and you said this patient could have this disease, therefore why couldn’t these fractures be explained by osteogenesis imperfecta?