The diagnosis of radial head subluxation is a clinical diagnosis made on the basis of a compatible history and examination with a good response to manipulation. Due to the unusual age and mechanism of injury there is the possibility that the presentation was related to simple soft tissue injury. However, in light of the family history and the rapid resolution of symptoms following the manipulation, the likelihood of radial head subluxation being the underlying cause is high.
Hypermobility occurs in 5% of the population and children tend to have a greater range of joint movement than adults.5
Connective tissue disorders causing hypermobility such as Marfan and Ehlers Danlos syndromes are well known to have an association with joint dislocations including elbow, temporomandibular joint, patellae, fingers and hip dislocation.6
Benign joint hypermobility syndrome (BJHS) is described as the occurrence of musculoskeletal symptoms in hypermobile individuals in the absence of systemic rheumatologic disease.7
BJHS has been associated with a wide variety of musculoskeletal disorders in childhood, ranging from ‘growing pains’ to more serious problems such as chronic back pain and even spondylolysis.5
It is also associated with joint subluxation and dislocation. If detected early BJHS can be managed with advice, physiotherapy and occupational therapy input which are likely to improve the outcome.
BJHS can be diagnosed using the Brighton scoring system8
which is based on a series of major and minor criteria including arthralgia, recurrent subluxation or dislocation of joints. Alternatively a Beighton score9
is a simple assessment which is based on a sequence of manoeuvres assessing joint flexibility and is scored out of nine. A first degree relative who is unequivocally affected is also a determining factor. BJHS is excluded in the presence of Marfan or Ehlers-Danlos syndromes.
Although radial head subluxation has been reported in an adolescent9
and on two occasions in adults,10,11
the age range is usually stated as being between 1 and 3 years. In one study3
of 100 patients only three children with radial head subluxation were over 5 years of age and none were over 6. It can therefore be argued that in older individuals with radial head subluxation a predisposing pathology such as BJHS should be considered.
- Radial head subluxation, although rare in patients over the age of 5, should be considered in those with a compatible history and examination.
- If an older child is diagnosed with radial head subluxation, an underlying diagnosis of hypermobility or benign joint hypermobility syndrome (BJHS) should be considered.
- Early detection and appropriate management of these conditions is likely to improve the patient’s long term outcome.