Decreased Postoperative Pain and Similar Biomechanical and Functional Outcomes of a Nondrilling Pull-Out Technique Compared to Bunnell's Technique in Flexor Digitorum Profundus Zone 1 Injuries.

PURPOSE: Zone 1 injuries of the flexor digitorum profundus (FDP) tendon pose technical and functional challenges due to the confined anatomy of the distal phalanx and the need for secure fixation. The classical Bunnell pull-out technique (BPT), although biomechanically reliable, is associated with nail deformities, postoperative pain, and bone-related complications. This study aimed to evaluate the biomechanical and clinical outcomes of a novel nondrilling pull-out technique (NDPT) designed to eliminate the need for bone drilling while maintaining repair strength.

METHODS

This study consisted of two parts: a cadaveric biomechanical analysis and a clinical comparative evaluation. In the cadaveric study, 15 FDP zone 1 repairs (8 BPT, 7 NDPT) were performed and tested for maximum tensile stress and pull-out force. In the clinical study, 37 patients with FDP zone 1a injuries were treated using either BPT (n = 20) or NDPT (n = 17). Pain was assessed using the visual analog scale at 24 hours, 3 days, and 7 days postoperatively. Functional outcomes were evaluated at 6 months using distal interphalangeal joint range of motion and Moiemen-Elliot criteria.

RESULTS

Biomechanical testing showed no significant differences in maximum tensile stress or pull-out force between BPT and NDPT (P > .05). Clinically, NDPT patients exhibited significantly lower median visual analog scale scores at 24 hours and 3 days postoperatively (P < .05). At 6 months, range of motion and the distribution of functional outcome categories were clinically comparable between the groups.

CONCLUSIONS

The NDPT provides biomechanical performance equivalent to the Bunnell technique while offering distinct clinical advantages, notably reduced early postoperative pain and enhanced patient comfort. By preserving bone integrity and eliminating the need for drilling, NDPT represents a bone-preserving and patient-friendly alternative for FDP zone 1 repairs.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.