by Sue Black
There is a tendency to be swayed initially by circumstantial evidence when a body is found—particularly when it is skeletonized. The recovery of female clothing and a handbag quite understandably suggested to investigators that this was most likely to be the body of a woman. However, such linear thinking can take an inquiry in completely the wrong direction if we are not careful. Assumption is the mother of all mistakes.
As I started to examine the skeleton with this bias in mind, I quickly began to get very confused. The skull appeared to be more masculine than feminine, and so did the pelvis.
When investigating skeletal remains, anthropologists usually start with sex determination, as that tends to be the easiest aspect of identity to establish with reasonable accuracy and it automatically rules out missing persons of the opposite sex. It is not uncommon for bones to display traits that are neither strongly masculine nor strongly feminine, but when the conflicting information is coming from the skull and the pelvis it is troubling, as these bones normally give us our best opportunity to get it right. I set sex determination to one side for the moment and turned to age estimation. I was much happier with the accuracy of my assessment here. The woman was somewhere between thirty-five and forty-five years old, most likely at the lower end of that range.
It was when I asked for a routine X-ray of the chest plate that the mists began to part. The way in which the costal cartilages start to ossify is dictated by the prevalence of either the male hormone testosterone or the female hormone oestrogen circulating in the vascular system. In ageing males, the bone in the cartilages is laid down along the upper and lower borders of the cartilage bar and can eventually fuse on to the front end of the rib, resulting in rib ends that look a bit like crab claws. On an X-ray, this new bone mimics the structure of the rib, with a thicker outer shell and a honeycomb appearance on the inside. This is the effect of testosterone on ossification of hyaline cartilage, which forms the costal cartilages.
If the dominant hormone is oestrogen, bone is laid down very differently in the costal cartilages. We will see dense, sclerotic nodules, mainly along the central core of the cartilage. So, from the cartilages alone, we might be able to proffer an opinion on sex with some confidence: do we have crab claws or a string of bony pearls? As ossification becomes more progressive with age, we are also able to provide a very broad age range (young, middle-aged or elderly) just from looking at an X-ray of the plastron.
So far, so good, but of course hormone levels can be changed artificially by medication or by disease. It is therefore logical that if you are biologically male but take regular doses of oestrogen, or biologically female taking regular doses of testosterone, the cartilages are likely to show both types of bone formation—crab claws and pearls. But before we get too excited about this, it is worth remembering that males naturally produce oestrogen and females testosterone. That means there is often a mix of both types of bone formation in both sexes. It is the proportion of one to the other that is important. In the costal cartilages of our woodland body, I could see quite extensive crab-claw ossification overlaid by dense, sclerotic nodules in the centre of the cartilages. Both were very pronounced. This required the kind of discussion that anthropologists need to have with each other first of all, when nobody else is listening. It is amazing how useful a toilet break can be when you want to talk to a colleague, out of earshot, to rehearse how to carefully phrase what you think you might want to say. What is said is not always what is heard, and what is offered as a theory has a habit of suddenly becoming gospel. Remember that Japanese wood saw.
After a sotto voce conversation with Lucina, I summoned the courage of our joint conviction and suggested to the police that the victim might be transgender. Given that they were wearing female clothes and that the skull and pelvis were so masculine, I believed it was possible we had someone transitioning from male to female.
While this probably wouldn’t raise any eyebrows nowadays, twenty years ago it was quite a radical theory, and I suspect the police thought I was off my rocker. I was proposing that this person may have been born a biological male, had taken oestrogen supplements and had latterly been living as a female. The pathologist shrugged his shoulders and said that it was possible, but none of them seemed too convinced. However, once the DNA results came back, the presence of Y chromosome genes confirmed my early suspicions and the anthropologist’s status was suddenly elevated from lunatic to miracle-worker. The victim was traced to a community that kept its distance from the police and consequently nobody had alerted the authorities that she was missing, if indeed anyone had noticed or cared. DNA from a relative confirmed her identity. Yvonne, whose birth name had been Martin, was a prostitute who worked the red-light district picking up gay men—a specialist known by the clients in those days, rather crudely and offensively, as a “chick with a dick.” She had apparently been a heavy heroin-user and substance abuse had indeed been suggested by the evidence visible on her rib ends.
One of the most common clinical complications for heroin addicts is infection, which can manifest itself in the chest wall, where the junction between the ribs and their cartilages becomes inflamed. The most common culprit is Pseudomonas aeruginosa. We found evidence of previous infection at the front end of Yvonne’s ribs but there was no clear indication of what had caused her death. Drug-related paraphernalia had been found all over the area where her body had been discovered, and it was known to be a place where addicts congregated to share needles. Had she taken an overdose, or shot up heroin from a bad batch? Perhaps that was what had happened, and her body had just been thrown into the undergrowth and forgotten. The bones in her chest told us some of her story, guided the police down the right track to find out who she was and allowed her to be buried with both her names, old and new.
Like the sternum, the ribs are susceptible to fracture because the layer of covering bone is relatively thin. Being curved, and connected at both front and back, they tend to snap either just in front of where they form a joint with the vertebra at the back (posterior angle), or towards the front (anterior angle), just behind where cartilage and rib meet.
At birth, our ribs are almost horizontal, which is why, when you watch a baby breathe, it is not their chest that moves but their abdomen. They are using the diaphragm, the sheet of muscle that separates the chest cavity from the abdominal cavity, like a set of bellows, to draw in air through the mouth and nose as the diaphragm contracts and blow it back out again when it relaxes. The ribs only start to take on the oblique angle we see in the adult at around two to three years of age. By this time, the pelvis has grown enough to allow the viscera in the abdomen to drop down and the little pot-bellied baby you’ve had for a couple of years appears, almost overnight, to turn into a scrawny little string bean who is now using their chest muscles to breathe.
Whether the ribs are horizontal or oblique allows the forensic anthropologist to narrow down a possible age for a child which can be confirmed by other parts of the skeleton, because our bones age as a collective, rarely in isolation. Each part of our anatomy talks to all the other parts so that they hum a similar tune and stay in harmony. It would be most unusual for one bone or organ to indicate that a person is in their fifties while another is suggesting they may be in their twenties. We don’t have old chests and young legs. If that is what we are seeing, we are probably looking at two bodies.
So we use what one part is telling us to corroborate what others are also whispering. This system of constant checks and balances enables us to establish an age range and then decide whether the person is more likely to be at the top or the bottom of it. Age determination cannot be definitive. If any forensic anthropologist were to specify that an individual was twenty-three years of age, the police ought to be getting themselves another anthropologist, because that degree of precision is simply not possible.
Providing a range with an inbuilt margin for error also helps families to acknowledge that a body may be their missing loved one. If you give an age of t
wenty-three and their relative is twenty-five, it can be hard for them to accept that you may be two years out. A range of between twenty and thirty, with the suggestion that the person is likely to be somewhere in the middle, encompasses all the possibilities.
While ribs have some value in the determination of sex and age, they provide little if any information about ethnicity or height. It is when they have been subjected to trauma that they become particularly helpful to us in trying to establish a pattern or sequence of events before, during or after death.
The analysis of rib fractures in children has long been dogged by elements of controversy, especially in relation to the type of case often referred to as “shaken baby syndrome.” All child deaths are emotive, and the dangers inherent in distinguishing between SIDS (sudden infant death syndrome) and intentional harm are starkly illustrated by the historical cases of Sally Clark, Trupti Patel and Angela Cannings, all of whom were convicted of killing their children and subsequently had their convictions quashed. Such miscarriages of justice, together with high-profile cases of shaken baby deaths, have, quite rightly, made paediatricians, pathologists and anthropologists cautious about how they interpret what they see when it comes to rib pattern fracturing.
Ribs tend to be a first port of call for investigators who suspect child abuse. However, a child’s rib can fracture easily, and the explanation may well be innocent. Even multiple fractures can be due to one of several clinical conditions that can lead to brittle bones. In cases of SIDS, they can also be caused by attempts at resuscitation. It is vital that the fractures are viewed in the light of the general health of the rest of the skeleton, and the circumstances surrounding the child’s life and death, before anyone jumps to the wrong conclusion.
The rationale for treating rib injuries as suspicious is that fractures may result from a child being grabbed by the chest and shaken violently, at the point where the hands of the person doing the shaking come into contact with the chest wall on either side. Breaks will generally heal within a few months in small children, often without leaving much evidence that they have ever happened. But where there is repeated child abuse, an X-ray can reveal fractures at different stages of healing: some from the past, which may be barely visible, others from a few months before, clearly still healing, and recent injuries showing little or no sign of callous formation.
A callous is new bone that grows around a break, acting a bit like a very big sticking plaster, to hold the two separated ends together and give them a chance to heal. Within a few hours, a haematoma, a large blood clot, will form around the site of fracture, producing a temporary soft-tissue callous (a bridge). This inflammatory response induces bone formation as new cells stream into the area to begin to repair the damage. Around seven to nine days after the trauma, the haematoma will have visibly been converted into a cartilage callous where bone can start to generate. Within three weeks, a bony callous has begun to form. Over time, several months, or years in some cases, the bone will be remodelled back into something close to its original shape.
When a child is being physically abused, there might well be other injuries in addition to fractures. In some of the worst cases, there can be little doubt that abuse has taken place, although it may be harder to prove who is responsible when there is more than one potential suspect. In one distressing case, there was no shortage of evidence on either count, but where forensic anthropology was able to help was in providing a detailed picture of what might have happened and when.
Harry was five years old when he died in hospital. His father had summoned the emergency services, telling them that he had found his son in bed, cold and unresponsive. Emergency staff were immediately suspicious when they registered the child’s black eye and what looked like a deep bite mark on his cheek. On removing the child’s clothes to administer CPR, their fears were confirmed. His body was covered in bruises and little circular marks that looked like cigarette burns. As they lifted Harry from his bed, they noticed a head wound. Police were of course quickly alerted. The full extent of Harry’s prolonged misery was revealed at postmortem and following a radiological assessment of his injuries. It is terrifying reading the list, let alone trying to imagine what he lived through. These bare facts paint a picture of a truly horrendous short existence for a scared little boy.
The images from the PM and CT scans of his body were brought to my team in the hope that we could establish a chronological time-line for some of his injuries. Starting at the top, he had recent fractures to his skull which, we were informed, were the likely cause of death. Hair and blood found in the plaster of the bathroom wall suggested that his head had been banged repeatedly against it. On his face were four bite marks and a cut to his chin; his nose had been broken not long before he died, part of his earlobe was missing and he had two black eyes.
There were cuts and bruises to his legs and arms and numerous burns, some probably inflicted by lit cigarettes and others perhaps by an iron. His right arm had been broken recently, as had both bones of his right forearm. His left arm had been fractured in the past, and now showed quite extensive healing. Two breaks in his left forearm and fractures to the left thumb and fingers, and bones in his left foot, were new injuries.
The torso bore bruises and burns and he had been repeatedly punched in the abdomen and genitals. On the right-hand side, there were fractures to ribs 7 and 8—two to the latter, one older than the other, which suggested recurrent abuse. On the left, he had fractures of ribs 7, 8, 10 and 11, and again, two temporally distinct periods of fracture and repair could be seen on rib 11.
It is not within the forensic anthropologist’s area of expertise to date soft-tissue injury. We work with hard tissues and, more specifically, bone. Focusing on the bones, we were able to determine from the images that the healed fracture to the left arm was probably up to a year old. Hospital records confirmed that Harry had attended to have a plaster cast applied. It was claimed that he had fallen in the playground. At least two of the rib fractures had been sustained about two to four months before he died. All the other skeletal injuries appeared to be recent, coinciding roughly with the time of his death. We could conclude that there had been at least three periods of repeated skeletal trauma. It was the fractures to his ribs that gave the clearest indication of the persistent nature of these events.
Harry had lived alone with his father since his mother departed the country, perhaps to escape the violence of her husband. But she had left her little boy behind to suffer this awful catalogue of abuse. The father pleaded a mental disorder, but the court did not accept this, and he was sentenced to life, and to serve a minimum of nineteen years before being considered for parole.
Child deaths are the hardest for every member of any medical or forensic team to deal with, but at the same time they instil a renewed sense of purpose and a drive to find the truth for the sake of justice.
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The ribs run from the vertebral column at the back to the sternum at the front, where the bones are replaced by cartilage. We need the thoracic cage to retain as much flexibility as possible to assist us with breathing. The muscles that sit between the ribs, the intercostals, are responsible for raising one rib against the other. Because, in the adult, the ribs are not horizontal around the chest but at a curved angle, when they are raised, they work like bucket handles. This is why, when you take a deep breath, your chest swells not only at the front but also at the sides. This is caused by each intercostal muscle contracting and pulling up the rib below it, thereby altering internal thoracic pressure and drawing air through the nose and mouth into the lungs.
While the human normally has twelve pairs of ribs, this can vary. Some people have twenty-six, or even more in total. Cervical ribs (in the neck) can, if they grow too big, cause problems with circulation, pain and paraesthesia (loss of sensation) in the upper limbs. They can be surgically removed if they give too much trouble, with no ill effect on the patient.
These anomalies can naturally be a help in mak
ing identifications if their presence in skeletonized remains can be matched to a previous X-ray as their incidence is not frequent. And anyone with extra ribs that brought them discomfort is likely to have been referred at some point to a hospital.
Ribs in the lumbar region are more unusual, and arguably of limited value for identification purposes as they tend to be very small, almost vestigial, and generally produce no symptoms. Many people who have them are blissfully unaware of their presence.
Additional ribs may create some initial confusion when remains are discovered, especially if they are fully skeletonized. You might be down on your hands and knees in a muddy field, the horizontal rain of Scotland freezing your ears off, when you find an extra little bit of bone. You have to pay careful attention to where you found it, of course, but a lot of rain can move small pieces of bone around so the ribs aren’t necessarily going to be located where you expect them to be. They might also have been disturbed by animals, of course. Since the calorie-rich viscera are a magnet to many scavenging creatures, parts of the torso may be dragged away from the site of the body for consumption and ribs can often show quite extensive damage caused by chewing or gnawing.
Sometimes it may be only ribs that we find, and then it can be tricky to establish whether they are actually human, especially if they are fragmented. Because in anatomy, form follows function, if a part of the body is doing the same job in one animal as it is in another, it may look very similar in different species of a similar size. This is particularly true of the ribs of humans and pigs. If you think about how often a police search includes a dump or landfill site, and the quantities of spare ribs sold in our restaurants and takeaways, it will give you some idea of how often forensic anthropologists are called upon to distinguish between them.