Flexor Tendon Reconstruction: Proximal Tendon Anchorage

- Discussion:
    - it is essenital to accurately determine the optimal tension to be applied to the motor unit;
    - use the relaxed natural cascade of the fingers to assist in determining the optimal tension;
    - most often the tendon graft is sutured to the proximal FDP in the mid palm, distal to the origin of the lumbrical;
    - consider using a Pulvertaft weave to join the tendons; (see tendon repair)
           - have fine misquito hemostat ready for this stage;

- Technique:
    - apply traction and test excursion and motion of IP joints are tested;
    - mid-palmar anastomosis:
          - indicated when the palm is free of substantial injury and scar and the proximal end of the profundus tendon remains in the palm;
          - advantages: palmaris longus is usually long enough (no need to additional graft harvest);
          - proximal tenorrhaphy is performed in the palm with a Pulvertaft weave technique with 4-0 Mersilene, keeping the lumbrical muscle free of the tenorrhaphy;
          - end to end or "button hole" suture is performed in palm proximal to origin of the lumbricals;
          - if proximal graft is placed distal to the origin of the lumbricals and if graft is placed slightly loose, the finger may develop a lumbrical plus deformity (where as overtightening can cause quadriga);
          - tendon graft is then sutured to the muscle belly, w/ muscle belly at half resting length & w/ wrist in neutral position;
          - alternatively, avoid the occurance of a lumbrical plus finger by dividing the lumbrical either in the palm or more distally at the radial band;
    - proximal (forearm) anastomosis:
          - indicated when the palm is heavily scarred and/or the proximal end of the profundus tendon is retracted proximal to the palm;
          - disadvantages:
                 - typically the palmaris longus is not long enough and surgeon may have to use plantaris or toe extensor for extra length;

- Complications:
    - tendon shortening:
            - in primary repair, musculotendinous unit can compensate for shortening as much as 1 cm;
    - excissive tendon lengthening:
            - a common complication is to leave the tendon too long;
            - this produces a lumbrical plus finger;
            - lumbrical plus finger can also be seen in unrepaired lacerations of flexor profundus and amputation of the distal phalanx;
            - this is manifested by intrinsic plus attitude in involved finger on attempted flexion w/ MP flexion there will be IP extension (Paradoxical Extension);
            - if several weeks have passed before this condition is noted, the radial lateral band may become adherent to the adjacent tissues;
                   - in this case, revision of the tendon repair will not correct the adherence of the lateral band;
                   - the adherent lateral band must be released in order to restore PIP flexion

Staged flexor tendon reconstruction fingertip to palm.

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

Last updated by Data Trace Staff on Tuesday, January 29, 2013 11:33 am