Comparative Study of Four- and Six-Strand Flexor Tendon Repair in Zone II (FLEXSTRAND)

Comparison of Six Strand and Four Strand Techniques on the Repair of Injured Flexor Tendons of Zone II of the Hand

Flexor tendon injuries in Zone 2 of the hand remain challenging because of the need to achieve optimal tendon healing while allowing early mobilization and minimizing complications such as rupture and adhesions. Various tendon repair techniques have been described, including four-strand and six-strand core suture methods.

This study aims to compare the functional outcomes and complication rates between four-strand and six-strand flexor tendon repair techniques in patients with Zone 2 flexor tendon injuries.

Study Overview

• Status: Completed
• Conditions: Hand Tendon Injury
• Intervention / Treatment: Procedure: Four strand Repair technique; Procedure: Six Strand Repair Technique

Detailed Description

Flexor tendon injuries of Zone 2 are among the most difficult hand injuries to manage because of the complex anatomy and the tendency for adhesion formation and tendon rupture. Advances in tendon repair techniques have focused on increasing repair strength to permit early active mobilization while maintaining tendon gliding.

Four-strand repair techniques have been widely used and provide acceptable tensile strength and clinical outcomes. However, six-strand repair techniques may provide greater biomechanical stability and potentially allow safer early mobilization with lower rupture rates. Despite these theoretical advantages, there remains ongoing debate regarding the superiority of one technique over the other in terms of functional recovery and complication profile.

This prospective comparative study will be conducted in patients presenting with acute Zone 2 flexor tendon injuries of the hand. Eligible patients will undergo tendon repair using either four-strand or six-strand core suture techniques according to study allocation. All patients will follow a standardized postoperative rehabilitation protocol.

Primary outcomes will include functional assessment using total active motion and tendon rupture rates.

The findings of this study may help determine the optimal repair technique for improving functional outcomes in Zone 2 flexor tendon injuries while minimizing complications.

• Study Type: Interventional
• Enrollment (Actual): 136
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Pakistan
  • Punjab Province
    • Faisalabad, Punjab Province, Pakistan, 00000
      • Allied Hospital, Faisalabad Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Male or female participants.
• Age 18 to 50 years.
• Zone II flexor tendon injury of the hand.
• Presentation within one week of injury.
• Willingness to participate and provide informed consent.
• Ability to comply with the postoperative rehabilitation protocol.

Exclusion Criteria:

• Injuries that interfere with postoperative rehabilitation.
• Extensive soft tissue damage associated with the tendon injury.
• Previous tendon injury in the same digit or hand region.
• Previous surgery in the same affected area.
• Non-compliance or anticipated inability to comply with the postoperative rehabilitation protocol.
• Evidence of a psychological or personality disorder that may affect participation or outcome assessment.
• Systemic illness that may compromise wound or tendon healing (e.g., uncontrolled diabetes mellitus, connective tissue disorders, severe vascular disease).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Four strand repair group; Participants in this group will undergo repair of Zone 2 flexor tendon injuries using the four-strand core suture tendon repair technique followed by standardized postoperative rehabilitation.	Procedure: Four strand Repair technique; Repair of Zone 2 flexor tendon injuries using a four-strand core suture tendon repair technique performed under standard operative protocol followed by postoperative rehabilitation.
Experimental: Six strand repair group; Participants in this group will undergo repair of Zone 2 flexor tendon injuries using the six-strand core suture tendon repair technique followed by standardized postoperative rehabilitation.	Procedure: Six Strand Repair Technique; Repair of Zone 2 flexor tendon injuries using a six-strand core suture tendon repair technique performed under standard operative protocol followed by postoperative rehabilitation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Functional Outcome according to Tang Criteria	Functional outcome assessed using the Tang classification (Excellent, Good, Fair, Poor) based on total active motion of the injured finger. The higher the Tang score, the better functional outcome.	Three months after Tendon repair

Collaborators and Investigators

• Sponsor: Allied Hospital Faisalabad

Study record dates

Study Major Dates

• Study Start (Actual): January 27, 2026
• Primary Completion (Actual): April 15, 2026
• Study Completion (Actual): April 26, 2026

Study Registration Dates

• First Submitted: May 28, 2026
• First Submitted That Met QC Criteria: June 2, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Zone 2 Flexor tendon injuries
• Other Study ID Numbers: No.48.ERC/FMU/2025-26/106

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No, individual participant data will not be shared.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No