Comparison of zone II flexor tendon repairs using an in vitro linear cyclic testing protocol

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Materials science

Background:

• Evaluating suture techniques for tendon repair is crucial for successful rehabilitation.
• Modified Kessler and Savage core suture techniques with varying epitenon repairs were assessed.
• Understanding dynamic properties under cyclic loading is key to predicting repair integrity.

Purpose of the Study:

• To compare the dynamic properties and survivorship of three different suture configurations.
• To assess the risk of gap formation in modified Kessler and Savage repairs under simulated early rehabilitation loads.

Main Methods:

• In vitro cyclic testing protocol simulating early rehabilitation (20 N and 33 N, 500 cycles).
• Survivorship analysis using dynamic mechanical testing.
• Gap formation measured electronically every 100 cycles; analyzed using log-rank test and relative risk.

Main Results:

• No increased gap formation risk for cross-stitched epitenon Kessler repair versus standard Kessler.
• Savage repair showed significantly lower risk of gap formation (>10-fold for standard, >7-fold for cross-stitched Kessler).
• The Savage repair demonstrated superior performance under dynamic loading conditions.

Conclusions:

• The Savage repair technique is superior to modified Kessler repairs for tendon repair under dynamic loading.
• Survivorship curves and relative risk analysis offer valuable insights into the mechanical behavior of surgical repairs.
• This study provides evidence for improved clinical outcomes with the Savage repair technique.