Chapter 24 Single-Stage Free Tendon Grafting for Flexor Tendon Injury in Fingers
Outline
Indications
Single-stage free tendon graft is carried out as an initial procedure in selective cases including:
Flexor tendon injuries with segmental tendon loss.
Delay in repair of more than 3 weeks that compromises primary repair.
Preoperative prerequisites include the following:
The wound should be healed, the joints should be free of contracture, and maximum passive motion should have been obtained.
There is no extensive scarring.
Passive movements are full, or nearly full.
The circulation is satisfactory.
Contraindications to single-stage free tendon grafting are:
The best indication for single-stage free tendon graft for flexor tendon injury is the grade 1 hand according to Boyes’ classification (Table 24-1)1 or according to Merle and Dautel’s classification (Table 24-2).2 For grade 2 or 3 hands, staged tendon grafting is preferred.
Table 24-1 Boyes’ Preoperative Classification1
| Grade | Preoperative Condition |
|---|---|
| 1 | Good: Minimal scar with mobile joints and no trophic changes |
| 2 | Cicatrix: Heavy skin scarring because of injury or prior surgery; deep scarring because of failed primary repair or infection |
| 3 | Joint damage: Injury to joint with restricted range of motion |
| 4 | Nerve damage: Injury to digital nerves resulting in trophic changes in finger |
| 5 | Multiple damages: Involvement of multiple fingers with combination of above problems |
Table 24-2 Preoperative Classification Based on Modified Grading of Merle and Dautel2
| Grade | Preoperative Condition |
|---|---|
| 1 | Minimal or mild scar without major damages to digital vascular bundles and nerves |
| 2 | Extensive scar in the digit causing or together with: |
| 3 | Serious scar in the digit with: |
Place only one graft in each finger.
Use a graft of a suitable caliber to fit into the finger.
Place the proximal junction outside the tendon sheath.
Avoid damage to the fingernail or fingertip, in making the distal junction.
In cases with an intact or functioning FDS tendon, the following additional principles apply:
Operative Methods
Injuries to Both FDP and FDS Tendons
Dissection of the Flexor Tendons
The neurovascular bundles are preserved throughout the dissection. The tendon sheath is explored and protected as much as possible. Approximately 1 cm of the distal FDP tendon is preserved. The remainder of the damaged FDP tendon is excised distal to the lumbrical origin in the palm. The FDS tendon is resected, leaving 1 or 2 cm of the insertion of the FDS tendon to provide stability and avoid hyperextension deformity of the interphalangeal joint (Figure 24-1).
