What is the recommended technique for performing a modified Kessler flexor tendon repair, including suture material, core construct, epitendinous stitch, and postoperative immobilization?

Modified Kessler Technique for Flexor Tendon Repair

The modified Kessler technique should be performed as a 4-strand core suture using 3-0 or 4-0 non-absorbable monofilament suture (Prolene or FiberLoop), augmented with an epitendinous running suture, followed by early active mobilization protocols starting within the first week postoperatively.

Core Suture Configuration

The 4-strand modified Kessler is the preferred configuration over the traditional 2-strand approach. A 4-strand repair provides significantly greater tensile strength and lower rupture rates (2.3%) while achieving 91.4% good-to-excellent functional outcomes 1. The 4-strand technique is now considered the minimum standard for optimal results, as it provides sufficient strength to withstand early active mobilization 2, 3.

Technical Execution

• Suture Material: Use 3-0 or 4-0 non-absorbable monofilament suture

  • Prolene is the most widely used (89.3% of practitioners) 2
  • 4-0 FiberLoop demonstrates superior biomechanical performance with higher maximum force and 2mm gap force values 4
  • 4-0 suture size is preferred by 54.1% of surgeons 2

• Knot Placement: Position the core suture knot on the dorsal surface of the tendon, not between the lacerated ends

  • The knot occupies approximately 24% of the tendon's cross-sectional area 5
  • Dorsal embedding increases load for 2mm gap formation and ultimate load compared to volar, radial, or central placement 5
  • This positioning reduces gliding resistance and facilitates early mobilization 5

Epitendinous Suture

Always incorporate an epitendinous running suture to augment the core repair - this is universally practiced (100% of surveyed surgeons use it) 6. The epitendinous suture provides critical additional strength that significantly impacts biomechanical performance 7. Use a continuous interlocking pattern with fine monofilament suture.

Postoperative Rehabilitation

Initiate early active mobilization within the first week postoperatively - this is the preferred approach for 56.9% of practitioners 2. The evidence strongly supports this:

• Early active mobilization prevents extrinsic adhesions and large tendon calluses that occur with immobilization 3
• Actively mobilized tendons demonstrate significantly greater gap and ultimate strength throughout the 42-day healing period compared to immobilized tendons 3
• The 4-strand modified Kessler has sufficient tensile strength to withstand early active motion without rupture 3

Mobilization Protocol Options

• Modified Kleinert protocol: Dorsal blocking splint with controlled passive flexion and active extension
• Early active motion: Supervised active flexion and extension exercises
• Age-specific modifications 8:
  • <5 years: Boxing glove immobilization
  • 5-10 years: Dorsal blocking splint with cage

  • 10 years: Dorsal blocking splint ± cage

Critical Timing Consideration

Perform the repair within 24 hours of injury when an experienced surgeon is available 1. Repair timing significantly affects functional outcomes - delayed repairs yield inferior Strickland scores. This is one of the most important factors affecting results.

Common Pitfalls

• Avoid 2-strand repairs: Only 11.7% of practitioners still use 2-strand techniques 2, and they provide inadequate strength for early mobilization
• Don't place the knot between tendon ends: This impedes contact and hinders healing 5
• Don't immobilize routinely: Only 14.8% of practitioners use strict immobilization 2, and it leads to worse adhesion formation 3
• Watch for PIP contractures: Occur in approximately 10% of cases 1

The modified Kessler remains the most practiced technique globally (33.1% preference) 2 and in Israel (58.3%) 6, reflecting its technical feasibility and reliable outcomes when executed properly with 4-strand configuration and early mobilization.