Biomechanical Study of Modified Massachusetts General Hospital Flexor Tendon Repair Using Looped Sutures

Background: Massachusetts General Hospital (MGH) repair is one of the widely used 4-strand flexor tendon repair techniques. However, it uses two single strand sutures that are each passed twice across the repair site. This is time consuming and may cause imbalance of the load across the repair. We modified the MGH repair by using a looped suture and call it the looped MGH repair. The aim of this study is to compare the strength of the looped MGH repair performed with three different looped sutures against the strength of original MGH repair. Methods: Forty porcine flexors were used for the study. The original MGH repair was performed with Prolene^® 4-0. Looped MGH repair was performed with three different loop sutures, Supramid^® 4-0, Tendo-Loop^® 4-0 and FiberLoop^® 4-0. Mechanism of failure, ultimate tensile strength, stiffness, load to 2-mm gap formation and repair time were recorded for comparison. Results: There was no significant difference between the original MGH repair and the looped repair using Supramid^® regarding their biomechanical performance. Looped MGH repair using Tendo-Loop^® and FiberLoop^® showed significantly higher ultimate tensile strength and FiberLoop^® had highest 2-mm gap force. All looped MGH repairs required significant less time compared to original MGH repair. Conclusions: Our modification of the MGH repair using a looped Supramid^® 4-0 suture took significantly lesser time to perform while providing the same strength as the original MGH repair using Prolene^® 4-0. The use of the FiberLoop^® 4-0 provided significantly greater strength while taking lesser time.