Purpose

Timely repair of tendon injuries followed by early postoperative active range of motion has improved outcomes of flexor tendon repairs compared to passive range of motion, but places increased strain on the repair.  It has been established that Fiberwire can withstand the early increased forces placed on a tendon.  A novel suture, Fiberloop, has been developed as a double stranded looped, double-armed suture of fiberwire, but has not been previously studied.   This study was a comparison study of Fiberloop, Fiberwire, and Ethibond.

Methods

Bovine superficial extensor tendons were size matched to 5mm in diameter and randomly sorted for testing.  They were lacerated and repaired using one of three different suture types (Fiberwire, Fiberloop, and Ethibond) with two different repair techniques (Tajima and Modified Krackow).  A single surgeon used 4-0 suture and an epitendinous 6-0 prolene in all repairs.  Thirteen tendons were included in six total groups and each repair was tested to failure using an INSTRON 8871 testing machine.  A one-way analysis of variance (ANOVA) was used to evaluate the data of the 3 suture types.

Results

Both FiberLoop and Fiberwire were significantly stronger than Ethibond regardless of repair technique used.  Fiberloop and Fiberwire sustained sufficient force to tolerate early rehabilitation protocols.  The Fiberwire was significantly stronger (p<0.001) than Ethibond in both repair techniques by 48.4% and 67.9% with the Tajima and modified Krackow repair, respectively.  Fiberloop tolerated a significantly larger force (p<0.001) than Ethibond at maximum capacity, by 32.3% and 50.9% with the Tajima and modified Krackow repair, respectively.  The mean ultimate load tolerated by the Fiberloop suture was 82 ± 13N with the Tajima repair and 80 ± 17N with the Modified Krackow repair.  In this study, there was no difference between the locking modified Krackow and non-locking Tajima repair technique in any of the suture groups. The technique of tying the fiberloop strands individually was important for adequate strength in the repair.  Finally, there was a trend toward decreased repair time with the Fiberloop suture.

Conclusions

Biomechanical testing revealed that the novel Fiberloop suture and the Fiberwire suture were significantly stronger than the Ethibond suture.  In addition, this study shows that 4-0 suture is of adequate strength to repair a tendon injury.  Furthermore, the value of the double armed Fiberloop may translate into quicker tendon repairs.

Figure 1: Rendition of FiberLoop suture untied

Figure 2: