- Congenital, non progressive limitation of movement due to soft tissue contractures affecting two or more joints
- Usually secondary to an underlying neuromuscular disorder
- Some patients who have the clinical picture of arthrogryposis are found to have chromosomal abnormalities
- Onset is during fetal development
- A primary alteration in one of the components of the final common pathway (anterior horn cell, roots, peripheral nerves, motor end plates or muscles)
- Greater than 1/3 may be associated with amyoplasia, characterised by absence of limb muscles which may be replaced by fibrous and fatty tissue
- Associated with
- Low set ears
- Wide flat nose
- Microganthia
- Short neck
- Congenital heart disease
- High arched palate
- Hypoplastic lungs
- Cryptorchidism
- Amyoplasia
- Multiple congenital contractures
- Typical and symmetrical positioning of the limbs
- Decreased girth in the muscular areas of the limbs
- Sporadic occurrence with no hereditary patten
Aetiology
- Variety of conditions affecting neural and muscular elements may be contributory to the condition
- Defect occurs during the 8 – 12 week of development stage
Incidence
1 / 3000
Clinically
- Usually all four limbs are involved symmetrically with normal intelligence and sensation
- Shoulder is in adduction and internal rotation
- Elbow is in extension contracture (flexion contracture is less common), with loss of the normal flexion crease
- Wrist is in flexion, ulnar deviation and pronation deformity, with the fingers partially flexed (hook like wrist-hand-digit unit)
- Hip is in flexion, abduction, and external rotation
- Hip contractures are most common and approximately 1/3 of patient have unilateral or bilateral hip dislocation
- Knee is in flexion contracture (extension contracture is less common)
- Foot and Ankle are rigid and resistant
- Some have talipes equinovarus which is universally resistant to non-operative treatment
- Spine : scoliosis is present in approximately 1/3 of patients
Investigations
EMG shows mixed myopathic and neuropathic features
Treatment
- Early passive range of motion exercises and casts should be avoided
- Treat unilateral dislocated hips which usually require open reduction
- Bilateral dislocation probably do not need treatment, as patients get around well
- Severe spinal deformity (scoliosis > 50) should be treated operatively
- Talectomy indicated for badly deformed equino varus foot in patients with arthrogryposis or spina bifida where deformity mals standing difficult