HAPPY NEW YEAR!! LET’S CELEBRATE WITH THIS SUPER AWESOME CASE…
You are on placement in Paediatric A&E and you meet Rebecca, a 7-year old only child from the Maldives, who has been brought in by her mother. Rebecca has been complaining of severe left leg pain, from her knee up to her hip, which she rates as 10/10. This has been going on for 36 hours, but apart from this, she has no past medical history.
In your history, as well as on collateral history from her mother, neither one of them can remember any specific trauma to Rebecca’s leg. However, Rebecca tells you that the pain suddenly came on during a rainy walk in which she was jumping in lots of puddles.
A quick examination reveals a very tender left leg, with an almost totally restricted range of motion of the left hip and knee. Peripheral pulses and sensation is intact. You also notice a strange blue tinge to Rebecca’s eyes.
An X-ray promptly shows a fractured femur. Interestingly, from her notes, you notice that Rebecca has had many previous attendances to A&Es in her home country, and multiple previous X-rays have shown different fractures…
You present to your consultant, who asks for your differential diagnosis. She mentions there is something particularly important to not forget!
- Non-Accidental Injury
- Extremely important to remember, even if just to exclude before considering medical diagnoses
- Disorder of bone formation
- May include osteogenesis imperfecta, rickets or rarer osteochondrodysplasias
- Underlying bone cyst or malignancy (pathological bone)
- Simple trauma (less likely as the femur typically requires a very high force trauma to fracture)
Happily, on consultant review, you both agree that Rebecca is interacting well with her mother, seems happy, and there is no history or previous suspicion of child abuse. Rebecca is up to date with her immunisations, her parents have ensured she has attended any follow-up appointments, and her behaviour has been appropriate.
Your consultant suspects a certain diagnoses, and is satisfied that non-accidental injury can be excluded. That said, she praises you for being aware of the possibility.
Your consultant asks you what features of any presentation may raise suspicion of potential child abuse. She also asks which of these may have been applicable to Rebecca’s presentation.
Potential features which may apply here:
For a more thorough list of potential situations to suspect child abuse, please see the following from NICE: https://www.nice.org.uk/guidance/cg89/chapter/1-Guidance
- No suitable explanation for a serious or unusual injury
- Applicable, as a broken femur is a serious injury and the history has not presented a suitable explanation
- If a child has one or more fractures in the absence of a medical condition that predisposes to fragile bones or if the explanation is absent or unsuitable. Presentations include:
- Fractures of different ages
- X-ray evidence of occult fractures
- This is the case here, as Rebecca has evidence of multiple fractures of different ages, with no explanation and in the absence of a medical condition (for now)
- An unusual pattern of presentation to and contact with healthcare providers, or there are frequent presentations or reports of injuries
- Applicable here as you have identified frequent attendances at A&E and multiple fractures from this
- Delayed presentation to access medical care services
- More arguable, but depending on the extent and severity of Rebecca’s clinical presentation, 36 hours may be considered a delayed presentation to A&E. Note that this depends on other factors (such as the possibility that her condition has worsened, and so 36 hours ago, she may not have needed a visit to A&E)
Whilst she had been reviewing Rebecca, you consultant had done a more specific examination. During this, she had asked some questions and assessed some of Rebecca’s joints and calculated a Beighton Score.
Your consultant tells you that a Beighton Score can be used to assess for hypermobility, and that Rebecca was indeed hypermobile. In addition, she agrees with you that Rebecca’s sclerae had a blue tinge.
From this information, you consultant tells you that she suspects a diagnosis of osteogenesis imperfecta. She tells you that she’ll need to refer to Paediatric Rheumatology specialists to organise further investigations.
While she’s writing the referral, your consultant asks you if you’ve ever heard of osteogenesis imperfecta, and to tell her what you know.
Fortunately, you’ve just watched M. Night Shyamalan’s movie “Unbreakable” with Bruce Willis, in which Samuel L. Jackson’s character has OI, so you are a font of knowledge on this.
Osteogenesis imperfecta is a genetic condition that causes increased fragility of bone. It is present from birth, and the most common form is associated with mutations in the COL1A1 or COL1A2 genes. The primary features are widespread fractures caused my minimal impact, although other tissues containing type 1 collagen may be affected (ranging from bone to teeth to tendons to heart valves).
Type 1 osteogenesis imperfecta is by far the commonest form, and is an autosomal dominant condition causing a reduction in the amount of bone, alongside defective bone formation. In addition to fractures, patients may have slender, weak tendons (leading to hypermobility), thin heart valves (leading to aortic regurgitation or mitral valve prolapse) and aortic root widening. Teeth discolouration or erosion and hearing changes may also be seen. Bones may be deformed and joint or bone pain may be present in some cases. Finally, blue sclerae may be seen as defective collagen leads to scleral thinning, and as the choroidal veins are more visible, this gives the characteristic blue tinge.
Apart from Type 1, there are also Types 2-7. However, these will not be discussed in as much detail as they are seen more rarely.
Your consultant is blown away by your knowledge of OI. She is so impressed that when Rebecca’s mother asks what investigations and tests they will have to expect, your consultant lets you answer.
What investigations would be most relevant to help confirm a diagnosis of osteogenesis imperfecta?
No single test will give a definitive diagnosis of osteogenesis imperfecta. That said, certain investigations may be of use:
- X-rays (will show fractures, potentially of different ages)
- DEXA scan [aka bone densitometry] (will show decreased density of bone)
- Note that in a paediatric context, DEXA scans can be carried out in patients weighing more than 10kg
- There is insufficient data available to give accurate results for children under the age of five
- Genetic testing (for mutations seen in the different types of osteogenesis imperfecta)
Remember that whilst these investigations may help, osteogenesis imperfecta is a clinical diagnosis.
Before you leave, Rebecca’s mother asks you what treatment might be required for her daughter. In addition, Rebecca adds that she’s always wanted to have a pet pony and learn how to ride horses- will this still be possible?!
How would you answer Rebecca and her mother?
- Most patients with osteogenesis imperfecta that is mild or moderate can be managed with physiotherapy and management of symptoms as and when they occur
- Bisphosphonates (such as pamidronate or zoledronic acid) may be used to strengthen bones as they inhibit osteoclast activity and stimulate osteoblast activity to increase bone density
- Vitamin D supplements are recommended for all patients
- There is normal life expectancy in type 1
- For some more serious cases, a multidisciplinary approach involving physiotherapy, rehabilitation, bracing and surgical intervention (such as intramedullary rods or soft tissue surgery for contracture) may be advised
- That said, this would always be undertaken after discussion and joint decision making with the patient and carers
- With some adaptations, children and young people can have near-normal lifestyles, attending school/ college and doing certain sports
- According to GOSH’s guidance, horse-riding causes repetitive impact through the spine… that said, they said that it can be carried out, just with caution
- They advise to discuss with one’s medical team before taking part, so depending on the severity, Rebecca might be able to fulfil her dream after all! Now they just need to find someone to clean the stables!
NICELY DONE!! YOU SMASHED IT
We hope that you enjoyed this case – really interesting presentation!!
A HUUUUUGE shout out to Manu Ratnayake for putting so much time into writing this INCREDIBLE case!! x
See you all next month! 🙂