A biomechanical study of Tang's multiple locking techniques for flexor tendon repair

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Hand Surgery

Background:

• Flexor tendon injuries in the hand require robust repair techniques to ensure functional recovery.
• Various suture methods exist, but their biomechanical properties, particularly under tensile load, require rigorous comparison.

Purpose of the Study:

• To biomechanically compare the efficacy of Tang's multiple looped locking suture technique against traditional methods for flexor tendon repair in the hand.
• To evaluate key tensile properties including gap formation force and ultimate tensile strength.

Main Methods:

• Fifty flexor digitorum profundus tendons from pig toes were used as a model system.
• Tendons were repaired using five distinct techniques: modified Kessler, Tsuge's, double Kessler, modified Kessler plus Tsuge, and Tang's suture.
• Repaired tendons underwent tensile testing to measure 2 mm gap formation force, ultimate tensile strength, and maximal work to failure.

Main Results:

• Tang's suture technique demonstrated the highest gap formation force (41.4 N) and ultimate tensile strength (45.6 N).
• Double Kessler and Kessler plus Tsuge techniques showed significantly greater strength than basic Kessler or Tsuge methods.
• Tendons repaired with Tang's method withstood 133-198% higher tensile loads than other techniques.

Conclusions:

• Tang's multiple looped locking suture provides superior gap resistance and tensile strength for flexor tendon repair.
• This technique shows potential for enabling early active mobilization following primary flexor tendon repair.
• Biomechanical data supports Tang's suture as a strong option for hand flexor tendon injuries.