Clinical and radiographic evaluation of surgical reconstruction of finger flexion in tetraplegia.
PURPOSE: To define the order and frequency of elongation in tendon junctions in extensor carpi radialis longus (ECRL) to flexor digitorum profundus tendon transfer and its correlation to grip strength and lack of finger flexion. METHODS: Forty-seven tetraplegic patients had surgery involving the reconstruction of finger flexion with the transfer of the ECRL in a total of 62 arms. During surgery metal markers were placed on both sides of the tendon-to-tendon attachment site. After surgery the distance between the markers was measured on radiographs. Any increase in the distance between the markers was judged as elongation. The grip strength and mean pulp-to-palm distance were evaluated a minimum of 6 months after surgery. Three arms had a second surgery because of insufficient functional results. RESULTS: The average final elongation was 9 +/- 10 mm (mean +/- SD). The mean grip strength was 16 +/- 12 kPa (range, 0-50). The lack of flexion (mean value of pulp-to-distal palmar crease of 3 ulnar digits) was 0.8 +/- 1.2 cm on average. Elongation up to 15 to 20 mm still was compatible with good grasp. CONCLUSIONS: The tendon junction after a transfer of the ECRL to the finger flexors can be overloaded. Elongation therefore must be considered as one among several possible causes of an unsatisfactory result after this type of tendon transfer but elongation less than 15 mm usually is compatible with excellent function.