AAHS ASPN ASRM - 2013 Annual Meeting - American Association ...

Evaluation of Looped Suture and New Suture Material for Tendon Repair
Institution where the work was prepared: Loma Linda University, Loma Linda, CA, USA
Lawrence G. Sullivan, MD; Chad Brockardt; Montri D. Wongworawat, MD; Qiang Dai, PhD; Barry Watkins, MD; Loma Linda University
Purpose
Flexor tendon repair strength is proportional to the number of suture strands crossing the repair site. It has not been shown if each strand needs to result from
a separate pass through the tendon. Our purpose was to assess (1) whether one throw of looped suture across a flexor tendon repair site equals 2 separate
throws of suture, and (2) whether or not 2-stranded Fiberwire repair is equivalent to 4-stranded Supramid repair.
Methods
Seventy two Porcine flexor tendons were harvested and divided into 8 groups (n = 9). Transverse lacerations were created and repaired using simple Tajima
configuration, looped Tajima suture, double throw Tajima, and four-strand cruciate suture. Tendon repairs were fixed to clamps and distracted at a constant
rate of 10 mm/min (Instron), and the repair site was filmed with a digital video camera. The force at 2 mm gap, force at failure, and the gap at failure were
recorded. Statistical analysis was performed using ANOVA and Kruskal-Wallis Multiple-Comparison Test.
Results
The Supramid Tajima x 2 performed better than the Supramid Tajima-looped with respect to force applied to reach 2 mm gap (35 vs. 14 N) and gap at failure
(4.1 vs. 8.8 mm), p < 0.05. The 2-stranded Fiberwire Tajima performed similarly to the 4-stranded cruciate Supramid repair with respect to force at 2 mm
gap (17 vs. 22 N), force at failure (42 vs. 46 N), and gap at failure (6.9 vs. 5.6 mm). Twenty-seven of the 36 repairs using Supramid failed at the knot, whereas
18/36 repairs using Firberwire failed at the knot and the other 18 failed by pullout from the tendon. Overall, when measuring by the above parameters,
Fiberwire Tajima x 2 performed the best.
Force at 2mm (N) Force at failure (N) Gap at failure (mm) Mode of failure (suture:tendon)
Supramid Tajima 8 32 8 9:0
Tajima-looped 14 50 8.8 7:2
Tajima x 2 35* 50 4.1* 9:0
4-strand cruciate 22 46 5.6 2:7
Fiberwire Tajima 17 42 6.9 8:1
Tajima-looped 25 56* 7.6 2:7
Tajima x 2 43* 72* 4.6* 6:3
4-strand cruciate 36* 44 3.3* 2:7
* significantly superior values, p < 0.05.
Conclusions
With respect to force at 2mm and gap at failure, looped suture cannot substitute for 2 separate throws of suture. Two stranded Fiberwire Tajima repair equaled
4 stranded cruciate repair with Supramid for all tested parameters. Overall, Fiberwire Tajima x 2 provided the best biomechanical characteristics.
Biomechanical Analysis of a New Ultrasound Welded Knotless Tendon Repair
Institution where the work was prepared: University College Hospital, Galway, Ireland
Colin L. Riordan, MB, BCh, MRCS; Jeff Chan; Jack L Kelly; Padraic J Regan; University College Hospital Galway
Introduction:
Results of zone 2 flexor tendon repairs remain unsatisfactory despite numerous different repair techniques and suture materials. Complex suture knots are difficult
to master, are bulky, may lead to excessive foreign-body tissue reaction, knot impingement and, ultimately, may compromise the repair. In this study we
investigate the tensile properties of a novel ultrasonically welded knotless suture repair. Materials and
Methods:
The AxyaWeld? Suture Welding System uses ultrasonic energy in a small probe-like instrument to compress and weld the two limbs of the suture. Porcine flexor
tendons (n=20) were repaired using a core nylon suture welded using the AxyaWeld® Suture Welding System (n=10) or a conventional 4-0 Ethibond four
strand core suture (n=10). Repairs were pulled to failure using a Zwick® tensile testing apparatus. Load-elongation data, type and location of failure were
recorded for each sample.
Results:
The ultimate loads were significantly higher in the welded group (p