Case 24 A delayed walker
A female infant, Natalie, is born by normal vaginal delivery at term weighing 3.8 kg. Her mother, Clare, is 17 years old and a single parent. A neonatal examination is performed by the neonatal ST1, and Natalie is discharged home at 12 hours of age. She feeds well, and appears to be a content baby. At 6 weeks of age the neonatal examination is missed because Clare is visiting relatives in another part of the country, and the initial immunizations are also delayed by 5 weeks.
Initially Natalie makes normal developmental progress, but is reluctant to crawl and dislikes the prone position. At 13 months she is taken to her GP by her grandmother because of her reluctance to crawl. Natalie moves around the room in a sitting position, pushing herself with her feet.
What other information should you obtain? What is the differential diagnosis?
The GP takes a history, and is told by Natalie’s grandmother that Clare had also been reluctant to crawl as a baby. The GP makes a diagnosis of ‘bottom-shuffling’, and reassures the grandmother. He does not examine Natalie.
At 19 months of age, the GP refers Natalie to a paediatrician with a history of delayed walking.
What does this history suggest?
The paediatrician obtains a more detailed history and discovers that Natalie’s father had worn a splint as a baby because of ‘clicky hips’. On examination, she finds that Natalie has apparent shortening of her left leg by 2 cm, with reduced abduction and rotation of the hip. A pelvic X-ray is performed (Case Figure 24.1).
What do you think of the X-ray?
The X-ray reveals a dysplastic left acetabulum with complete dislocation of the left hip. A referral is made to a paediatric orthopaedic surgeon, and Natalie subsequently requires an open reduction of the hip, acetabuloplasty and a femoral shortening osteotomy.
What is the likely long-term prognosis?
A review of the neonatal and maternal notes reveals that the sections for paternal details and history were left blank.
Two years later Natalie’s grandmother complains that medical incompetence by the GP and at the hospital led to a delay in the diagnosis with all the resultant adverse sequelae.
Expert opinion
Screening for Developmental Dysplasia of the Hip (DDH) is part of the newborn and 6-weeks physical examination for infants. It is important that this examination is informed by an adequate family history as there is a 10-fold increased risk of DDH in the offspring of parents with DDH. In this case, the initial family history in the father was not recorded, the presence of DDH was not identified at the initial examination, and the second hip assessment at 6 weeks was missed. The UK National Screening Committee has set as a standard that 95% of babies with a normal hip examination but ‘a family history of a hip problem starting in infancy or as a young child’ should have a hip US performed by 6 weeks of age.
In order to perform a neonatal hip examination competently, it is important to understand the anatomy of the neonatal hip, and to practise the examination using clinical simulation with a model such as the ‘Baby Hippy’ (manufactured by Laerdal). Clinical practice should initially be supervised until it is clear that the technique has been mastered.
All screening procedures have a false negative rate, but an opportunistic hip examination at the time of the delayed immunization might have led to the diagnosis being made. The social history (young, single mother, missed appointments, grandmother (not mother) bringing the baby to clinic) is a clear indicator of added risk in this situation.
‘Bottom-shuffling‘ is common, and can run in families in an autosomal dominant fashion. It is a diagnosis of exclusion, and clinical examination to exclude neuromuscular disorders, cerebral palsy, spinal abnormalities and DDH is important. This opportunity was missed.
The purpose of an early diagnosis of DDH is the early institution of treatment by splintage (e.g. a Pavlik Harness). Natalie was denied this opportunity, required open surgery, and is now at risk of osteoarthritis of the hip as a young adult.
Legal comment
It seems that the neonatal trainee may have done an inadequate neonatal examination, and failed to diagnose DDH.
The hospital’s lawyers will want to take a statement from that doctor. They will want to know why the sections in the maternal and neonatal notes dealing with paternal history were left blank. Did the obstetric staff and the neonatal trainee make any attempt to get those details? Perhaps the mother was unable to provide them?
It is possible that the neonatal trainee will say that he had not had sufficient practice in hip examinations. In that case, his fault lies in not making this clear to his superiors and not ensuring that he was adequately supervised.
However, an expert considering the actions of the neonatal trainee may come to the view that, particularly in the absence of a paternal history, it was not negligent not to make the diagnosis on the first occasion. As stated above all screening procedures have a false negative rate.
Even if the expert view is that the diagnosis should have been made straightaway at birth, it seems very likely that the hospital can pass much of the liability for this case on to the GP practice which did not make a further appointment following the missed 6 week check and which had several opportunities to check again at subsequent appointments for immunizations and when Natalie was 13 months old.
The hospital would argue that if the GP practice had taken those opportunities to redo the examination, as it should have done, then the diagnosis would have been made while it was still possible to treat by splintage, rather than by open surgery. Therefore the GP should take full liability.
The argument would rely on the fact that there is a recognized false negative rate in hip examinations, which puts the GP under a legal duty to re-examine the hip. The failure to examine the patient at 13 months seems particularly indefensible by the GP.
