Comparison of Six-strand and Four-strand Techniques on the Repair of Injured Deep Flexor Tendons of Zone II of the Hand: A Randomized Controlled Clinical Trial

Hand zone II flexor tendon repair had been associated with many complications thereby it was previously called no man's land. Although there is some agreement on the primary repair of flexor tendons in this area, it is challenging due to certain complications. We compared the six and four-strand techniques in the repair of flexor digitorum profundus (FDP) tendons of zone II.

This randomized controlled clinical trial was registered with the Iranian Registry of Clinical Trials (IRCT20130812014333N139). Fifty patients with damaged FDP in zone II of the hand who were referred to Taleghani Hospital, Kermanshah, Iran in 2020 were included and divided into two groups (n=25). In group 1, the damaged tendons were repaired using the four-strand technique and prolene suture while in group 2, the six-strand technique was used. Postoperatively, the patients were examined every week for the first three weeks. In the second and third weeks, sutures were removed. At the end of 3rd month, the outcomes of surgery were compared in the groups.

Fifty patients (74% male) with 85 damaged fingers were investigated. Based on Buck-Gramcko criteria, the outcomes of surgery were excellent in 78%, good in 16%, fair in 4%, and bad in 2%. Complications after surgery were adhesion (8%) and 2 cases of rupture. There was no significant difference between 4 and 6-strand sutures regarding tendon adhesion and range of motion. 

Both 4 and 6-strand sutures were associated with favorable outcomes in patients with damaged FDP in zone II of the hand.