What is the recommended technique for performing a modified tenorrhaphy, including suture selection, repair steps, and postoperative protocol?

Modified Tenorrhaphy Technique

For flexor tendon repair, use a 6-strand core suture technique with a running peripheral epitendinous suture, prioritizing materials that minimize repair site bulk while maximizing tensile strength to enable early active mobilization. For Achilles tendon repair, limited open or percutaneous techniques are preferred over traditional open repair to reduce wound complications while maintaining structural integrity 1.

Suture Selection and Configuration

Flexor Tendon Repair

The strongest evidence supports 6-strand core suture configurations over traditional 4-strand repairs:

• 6-strand barbed suture repair achieved 88 ± 4 N load to failure compared to 29 ± 7 N for 4-strand cruciate repairs (p < 0.001), with significantly less repair-site bunching (cross-sectional area ratio 1.2 vs 1.5, p = 0.005) 2
• The helical 6-strand cruciate tenorrhaphy demonstrated superior ultimate tensile strength (65.5 N) compared to Adelaide (46 N) and modified Kessler (36 N) techniques (p < 0.001), with greater load to 2-mm gap force and less stiffness 3
• Modified 4-strand core suture with FiberLoop® showed only 2.1% rupture rate with 93% excellent Strickland scores at 34-month follow-up 4

Key technical points:

• Barbed sutures eliminate knots (which are the primary failure point in traditional repairs) and fail by suture breakage rather than knot rupture or pullout 2
• Maintain repair site cross-sectional area as close to native tendon as possible to facilitate gliding through pulleys
• Combine core sutures with running peripheral epitendinous suture for optimal strength

Achilles Tendon Repair

Three surgical approaches are viable options 1:

1. Percutaneous repair: Significantly less wound breakdown/delayed healing and fewer scar adhesions compared to open repair, with comparable rerupture rates and higher SF-12 physical/mental component scores 1

   • Caveat: Higher incidence of wound puckering and potential sural nerve injury without direct visualization

2. Limited open repair: Faster return to normal walking, stair climbing, and sports compared to standard open repair, with significantly fewer severe wound infections, superficial infections, and minor surgical site infections 1

3. Open repair: Traditional extended incision with direct visualization

   • Higher wound complication rates but allows precise suture placement

Modified giftbox technique with nonabsorbable suture loops represents a contemporary mini-open approach with no reruptures at 1-year follow-up and mean return to unrestricted activity at 24.3 weeks 5.

Repair Steps

Core Suture Placement

1. For 6-strand repairs: Place three separate 2-strand passes or use helical configuration to distribute tension evenly
2. Suture purchase: Minimum 1 cm from tendon edge for adequate holding strength
3. Tension distribution: Modified Kessler tension-reducing suturing can redistribute forces and improve healing environment 6

Peripheral Suture

• Running epitendinous suture increases repair strength by 10-50%
• Smooth repair contour to minimize triggering through pulleys

Postoperative Protocol

Achilles Tendon

Early protected weight-bearing (≤2 weeks) is recommended over traditional 6-week non-weight-bearing protocols 1:

• Allows quicker return to activities during first 6 months
• Use dorsiflexion-limiting splint/boot to protect repair
• Ultimate functional outcomes equivalent at 12 months regardless of protocol
• Critical caveat: Two reruptures occurred in early weight-bearing group due to documented noncompliance with splint use 1

Specific timeline:

• Immediate to 2 weeks: Begin protected weight-bearing with dorsiflexion limitation
• 2-4 weeks: Continue protection in splint/boot
• 4-6 weeks: Progress to full weight-bearing
• Return to sports: Typically 6+ months

Flexor Tendon

Early active mobilization protocol is essential for modern high-strength repairs:

• Initiate controlled active motion within first week postoperatively
• 6-strand repairs provide sufficient strength (>60 N) to withstand early mobilization forces
• Mean return to work: 3-4 months depending on occupational demands 4
• Expect 93% excellent functional outcomes with appropriate rehabilitation 4

Common Pitfalls

1. Inadequate suture purchase: Less than 1 cm from tendon edge increases pullout risk
2. Excessive repair bulk: Impedes tendon gliding and increases triggering risk
3. Knot placement: Traditional knots are the weakest link—consider knotless barbed suture alternatives
4. Premature unprotected weight-bearing: Ensure patient compliance with dorsiflexion-limiting devices for Achilles repairs
5. Delayed mobilization: Modern high-strength repairs require early motion to prevent adhesions

The evidence strongly favors multi-strand repairs with materials that minimize bulk while maximizing strength, combined with early protected mobilization protocols tailored to the specific tendon repaired.