Swan-neck deformity
What is it:
Deformity of the finger characterised by hyperextension of the middle finger joint and flexion of the fingertip.
Mechanism:
Initially caused by damage to the attachment of the finger extensor tendon which may be due to a traumatic laceration, avulsion fracture from a direct blow to the fingertip while finger is straight or due to weakening of the tendon caused by inflammatory disease e.g. rheumatoid arthritis.
Clinical presentation:
- Swelling and stiffness of finger joints
- A difficulty in flexion at the middle finger joint
- A snapping sensation may also occur during flexion.
Management:
Non surgical:
- A custom thermoplastic extension block splints to correct hyperextension at the middle finger joint.
- A progressive thermoplastic extension splint can help improve the fingertip flexion deformity.
- Passive stretching.
Surgical:
May be indicated for severe or long-standing deformities as these will not likely achieve true correction without surgery.
Prognosis:
Some degree of deformity or limitations in range of motion are common.
