A New Accessible Six-Strand Flexor Tendon Repair Technique: A Four-Group Comparative Study on a Porcine Model

Background: Six-strand flexor tendon repairs offer superior biomechanical strength, yet commonly used techniques often require looped sutures or proprietary materials that limit global accessibility. The Elsaftawy repair technique was developed as a six-strand construct using universally available braided polyester, aiming to provide high strength without reliance on specialty sutures. Methods: Sixty porcine digital flexor tendons were randomized into four groups: Elsaftawy 6-strand, Jin Bo Tang 6-strand, FiberLoop®, and modified Kessler 4-strand. Core repairs only were performed by a single experienced surgeon. Tendons were biomechanically tested for 2 mm gap formation force, ultimate tensile strength, suturing time, and failure mechanism. Results: All 60 tendons completed biomechanical testing without specimen loss. The Elsaftawy and Jin Bo Tang repairs demonstrated comparable biomechanical performance and significantly greater resistance to 2 mm gap formation and ultimate tensile strength than the Kessler repair (p < 0.05). FiberLoop® showed significantly lower gap resistance and ultimate load compared with both six-strand techniques but did not differ significantly from the Kessler repair. FiberLoop® was the fastest technique to perform (p < 0.05), whereas Elsaftawy and Jin Bo Tang repairs failed predominantly by suture rupture, in contrast to the pullout-dominant failure pattern observed with FiberLoop®. Conclusions: The Elsaftawy repair uses an accessible suture and showed no statistically significant differences in the measured biomechanical outcomes compared with the Jin Bo Tang technique. Its initial mechanical performance and use of standard non-looped sutures support further investigation, including assessment of reproducibility across surgeons and clinical outcomes.