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Background: Surgical repair is advocated for flexor tendon lacerations deeper than 70%. Repair can be undertaken with different suturing techniques and using different materials. Different materials used for tendon repair will have a different gliding resistance (GR) at the joint. Previous studies have compared strength of repair and gliding resistance for various braided suture materials and for 100% laceration of flexor tendons. We directly compare the GR of two monofilament sutures when used for a peripheral running suture repair of partially lacerated tendons.

Methods: Sixteen flexor tendons and A2 pulleys were harvested from Turkey feet. They were prepared, partially lacerated to 50% depth, and then repaired with a core suture (modified Kessler technique with 4-0 Ethibond) as well as an additional superficial running suture of either 6-0 Prolene or Nylon (half randomised to each). Gliding resistance was measured for all tendons before and after repair, at different flexion angles (40 and 60 degrees) and for different loads (2N and 4N).

Results: After surgical repair, gliding resistance was increased for all tendons (P < 0.01). The tendons repaired with Prolene had a higher mean gliding resistance than those repaired with Nylon (P = 0.02). Increased flexion angle and load amplified the gliding resistance (both P < 0.01).

Conclusions: 6-0 Nylon was associated with a lower gliding resistance than 6-0 Prolene but the minor differences bare unknown clinical significance.

Background: This study evaluated the feasibility of using a low-profile titanium (Ti) plate implant, also known as the Ti-button, for Zone II flexor tendon repair. We hypothesize that the use of the Ti-button can distribute the tensile force on the digital flexor tendons to achieve better biomechanical performance.

Methods: Twenty lacerated porcine flexor tendons were randomly divided into two groups and repaired using Ti-button or 6-strand modified Lim-Tsai technique. Ultimate tensile strength, load to 2 mm gap force, and mode of failure were recorded during a single cycle loading test. We also harvested twelve fingers with lacerated flexor digitorum profundus tendons from six fresh-frozen cadaver hands and repaired the tendons using either Ti-button method or modified Lim-Tsai technique. A custom-made bio-friction measurement jig was used to measure the gliding resistance and coefficient of friction of the tendon sheath interface at the A2 pulley.

Results: The ultimate tensile strength, load to 2 mm gap force, stiffness, and gliding resistance of the Ti-button repairs were 101.5 N, 25.7 N, 7.8 N/mm, and 2.2 N respectively. Ti-button repairs had significantly higher ultimate tensile strength and stiffness than the modified Lim-Tsai repair. However, Ti-button also increased the gliding resistance and coefficient of friction but there was no significant difference between the two repair techniques.

Conclusions: Ti-button repair displayed comparable mechanical properties to the traditional repair in terms of 2-mm gap formation and gliding resistance, but with a stronger repair construct. Thus, this deepened our interest to further investigate the potential of using Ti-button implant in Zone II flexor tendon repair by studying both the mechanical and biochemical (tendon healing) properties in more in-depth.

Background: Early active motion protocols have shown better functional outcomes in zone II flexor tendon lacerations. Different techniques of tendon repair have different effects on gliding resistance, which can impact tendon excursion and adhesion formation. For successful initiation of early active mobilisation, the repair technique should have high breaking strength and low gliding resistance. Previous studies have shown the Modified Lim-Tsai technique demonstrates these characteristics. The Asymmetric repair has also shown superior ultimate tensile strength. This study aims to compare the gliding resistance between the two techniques.

Methods: FDP tendons from ten fresh frozen cadaveric fingers were randomly divided into two groups, transected completely distal to the sheath of the A2 pulley and repaired using either the Modified Lim-Tsai or Asymmetric technique. The core repair was performed with Supramid 4-0 looped sutures and circumferential epitendinous sutures were done with nylon monofilament Prolene 6-0 sutures. The gliding resistance and ultimate tensile strength were then tested.

Results: The gliding resistance of the Asymmetric and Modified Lim-Tsai repair techniques were 0.2 and 0.95 N respectively. This difference was significant (p = 0.008). The Modified Lim-Tsai technique had a higher ultimate tensile strength and load to 2 mm gap formation, though this was not significant.

Conclusions: Gliding resistance of the Asymmetric repair is significantly less than that of Modified Lim-Tsai. Ultimate tensile strength and load to 2 mm gap formation are comparable.