Joint contractures can be due to a variety of conditions.
These include inherited disease (syndromes such as arthrogryposis with contractures present from birth) through to conditions where contractures develop with time (such as genetic conditions including some forms of mucopolysaccharidoses [MPS]), skeletal dysplasias (such as progressive pseudorheumatoid dysplasia), and inherited myopathies (such as Duchenne Muscular Dystrophy) or cerebral palsy (with changes being symmetrical or more commonly asymmetrical with other features of increased tone). There may be other features such as abnormality of growth (short stature or short limbs), bone deformity or malalignment (e.g., bow legs), developmental delay or a significant family history with risk increase with consanguinity.
Careful clinical assessments (history and examination including birth history and family history) are important.
Investigations in the context of joint contractures will be determined by the clinical assessment and suspected diagnoses. It is important to consider specialist referral as often a diagnosis is determined by a combination of investigations. Tests may include:
- Blood tests including full [complete] blood count, inflammatory markers (ESR, CRP).
- Muscle enzymes for muscle disease (inflammatory or inherited).
- Urine for glycosaminoglycans (GAGs) to help exclude MPS (Urine GAGS can be normal in MPS so if concerned, further specialist advice is needed).
- Imaging of joints, bone skeleton or muscle (such as ultrasound or MRI).
- Biopsy of skin, joint or muscle.
- Genetic tests for muscle tests or MPS disorders or other syndromes.
- Thermography and capillaroscopy for investigation for morphoea or JDM.