Consist of
- Ankylosing spondylitis
- commonest and is associated with the HLA- B27 genotype
- seen in 80– 98% of affected patients.
- Pathophysiology
- Systemic inflammatory processes lead to an enthesopathy (inflammation at the insertion of tendons and ligaments into the bone) with subsequent bridging syndesmophyte (bone spur) formation.
- Clinical features
- Stiffness from joint and ligament ossification
- kyphosis which when severe, manifests as a ‘chin-on- chest’ deformity.
- Radiology
- The chin- brow vertical angle is measured using standing whole spine radiographs and/ or clinical photographs to assess overall spinal deformity and balance.
- Treatment
- Correction of cervical deformity should only be entertained if concomitant abnormalities of the thoracolumbar spine and hip/ knee joints have been excluded.
- Osteopaenia occurs as part of the disease process and affects surgical planning involving instrumentation.
- Reiter’s syndrome
- Psoriatic arthritis
- Arthritis of inflammatory bowel disease
- Undifferentiated spondyloarthropathies