Ortho Preferred Malpractice Insurance
Home » Joints » Wrist » Swan Neck Deformity following Excision of FDS

Swan Neck Deformity following Excision of FDS

- Discussion:
  - may result from complete excision of the flexor digitorum sublimis;
  - it is especially likely to occur in patients with a hyperextensible PIP joint;
  - major vinculum exists at the insertion of the sublimis tendon;
  - when tendon is exised to to its insertion, the vinculum is violated, creating major source of adhesion formation for reconstructed tendon; 
  - check rein effect on the joint is lost, allowing hyperextension;
        - this creates a relative lengthening of the extensor apparatus, causing terminal phalanx to drop into flexion;
        - lateral bands displace dorsally;

- Prevention:
  - do not excise sublimis distally farther than neck of middle phalanx or just proximal to vinculum;
       - if possible, the remaining sublimis should be left even longer