Extensor tendon repair with and without central slip reattachment to bone: a biomechanical study

Area of Science:

• Orthopedic surgery
• Hand surgery
• Biomechanical analysis

Background:

• Swanson's technique for proximal interphalangeal (PIP) joint extensor tendon repair involves bony reattachment.
• A simpler, less invasive technique is proposed for PIP joint extensor tendon repair.

Purpose of the Study:

• To introduce and compare the biomechanical strength of a novel extensor tendon repair technique with Swanson's technique in a cadaver model.
• To evaluate the fixation strength and stiffness of the new side-to-side repair versus bony reattachment.

Main Methods:

• Fresh-frozen cadaver hands (24 digits) were used, with each technique applied to 12 digits.
• Tendon repairs were subjected to physiologic loading to measure fixation strength and stiffness.
• The new technique involves longitudinal incision and side-to-side suture approximation of the central slip.

Main Results:

• All tested tendon repairs withstood physiologic loading of 25 N.
• No statistically significant difference in stiffness was observed between the new technique and the Swanson technique (p >.05).

Conclusions:

• Simple side-to-side repair of the central slip preserves extensor mechanism function at the PIP joint.
• The proposed technique offers excellent visualization of the PIP joint and comparable strength to Swanson's method.