Flexor Tendon Repair                                

- Anatomy:
      - on volar aspect of finger, FDP passes through FDS to insert on distal phalanx;
      - both long flexor tendons are tightly enclosed in common tendon sheath which corresponds to zone II;
      - anatomical proximity explains the development of adhesions between FDS & FDP tendons & digital
               fibrous sheaths following injury;
      - excursion of tendons
      - tendon sheath anatomy

- Partial Laceration of Flexor Tendons

- Primary Tendon Repair:
     - tendon injuries are usually repair primarily, esp in clean wounds;
     - surgical approach and statedgy are dependent on location of tear:
             - FDS Laceration
             - FDP Laceration  (FDP avulsion)
             - Zone I Injuries
             - Zone II injuries
             - Zone III injuries
             - Zone IV and Zone V
     - Tendon Repair Technique:
             - core suture techniques
             - optimizing tension in flexor tendon repair:

- Primary Flexor Tendon Grafting
- Staged Flexor Tendon Repair:
     - optimizing tension in flexor tendon repair
     - prosthetic Grafts
     - pulley reconstruction
     - complications:
            - delayed primary repair is complicated by enlargement of proximal tendon end, which contracts into palm and thus cannot be
                      passed back through narrow digital sheath;
            - adhesions will also restrict tendon from entering the tendon sheath;
            - if these conditions are encountered then consider a tendon graft;

- Pulley Reconstruction:
    - Tendon Sheath Anatomy

- Post Operative Care

- Complications:
    - tendon rupture
    - adhesion formation: (see: flexor tenolysis)
           - adhesions form if part is immobilized because the wound in sheath and wound in the tendon grow together;
                  - if part is kept mobile, they heal separately, and function is more likely to be restored;
                  - collagen tensile strength across the repair is not sufficient to permit active loading for 4-5 weeks
           - on exam, patient will demonstrate loss of active flexion, but relative maintenance of active extension and maintenance of
                  passive flexion;
           - severe adhesion formation is managed with tenolysis
           - ref: Effects of Nonsteroidal Anti-Inflammatory Drugs on Flexor Tendon Adhesion 
    - flexion contracture:
           - may occur in up to 20%;
           - distinguish between true flexion contracture (loss of both active and passive ROM) and flexor tendon adhesions (loss of active
                   ROM only);      
           - occurs as a result of holding finger in the flexed position;
    - swan neck deformity:
           - especially likely to happen, in pts w/ hyperextensible PIP joint;
           - can occur after primary repair of FDP or free tendon grafting;
           - may result from complete excision of FDS;
                  - see: swan neck deformity following FDS harvest;
                  - when FDS is exised at its insertion, the vinculum is also excised, which damages the checkrein of PIP allowing to fall into
                  - as extensor apparatus becomes lengthened from PIP hyperextension, the terminal phalanx will sag into flexion;
                  - lateral bands displace dorsally;
           - to prevent swan neck deformities:
                  - avoid excision of FDS farther distally than neck of middle phalanx or just proximal to the vinculum
    - references:    
           - Treatment of unfavourable results of flexor tendon surgery: Ruptured repairs, tethered repairs and pulley incompetence.


Bridge flexor tendon grafts.

Angiogenesis in healing autogenous flexor-tendon grafts.

Autogenous flexor-tendon grafts. A biomechanical and morphological study in dogs.

Work of flexion after flexor tendon repair according to the placement of sutures.

Practice patterns in flexor tendon repair.

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, June 17, 2016 1:41 pm