Extensor tendon reconstruction for zones II and IV using local tendon flap: a cadaver study

Area of Science:

• Orthopedic surgery
• Hand surgery
• Reconstructive surgery

Background:

• Extensor tendon injuries in zones II and IV present reconstructive challenges.
• Traditional methods like distant tendon grafts (DTGs) have limitations, including donor site morbidity.
• Local tendon flaps (LTFs) offer a potential alternative for tendon reconstruction.

Purpose of the Study:

• To evaluate the feasibility of using local tendon flaps (LTFs) for extensor tendon defects in zones II and IV.
• To identify anatomical constraints limiting LTF use and determine maximum reconstructable defect size.
• To compare LTF reconstruction with distant tendon grafts (DTGs) for similar defect sizes.

Main Methods:

• Dissection of 33 fresh-frozen cadaver extensor tendons.
• Creation of 0.5-cm and 1.0-cm defects in zones II and IV.
• Reconstruction using either LTFs harvested from proximal tendons or palmaris longus DTGs.
• Limited kinematic analysis of repaired tendons.

Main Results:

• LTFs were feasible for 0.5-cm defects in zone II (all 9) and zone IV (6/8 and 9/9).
• LTFs successfully repaired 1.0-cm defects in zone IV (all 9).
• Maximum reconstructable defect size with LTFs varied by finger and zone (0.5 cm to 1.0 cm).
• DTGs were feasible for all tested defect sizes in zones II and IV.

Conclusions:

• Both LTFs and DTGs are anatomically feasible and technically straightforward for extensor tendon reconstruction in zones II and IV.
• LTFs offer advantages by avoiding a distant donor site and associated morbidity.
• The application of LTFs in this study was limited to zones II and IV of the extensor tendon.