title: Flexor tendon repair with a knotless barbed suture: a comparative biomechanical study.
abstract: OBJECTIVE
  To test the hypothesis that a flexor tendon repair with only a knotless barbed suture technique provides a repair with a greater maximal load to failure and 2-mm gapping resistance than a traditional technique using a 4-strand core plus a running-locking epitendinous suture.
  
  
  METHODS
  We assigned 41 fresh-frozen cadaveric flexor digitorum profundus tendons for repair by either a traditional technique using a 4-strand core (Tajima and horizontal mattress) plus a running-locking epitendinous suture (n = 20) or a bidirectional barbed suture technique using a knotless, 4-strand core secured with 3 transverse passes (n = 21). A biomechanical study was performed on each tendon-suture construct and the tendons were linearly distracted to failure at 100 mm/min. The maximal tensile load to failure, 2-mm gapping tensile load, and mode of failure were determined and statistically compared.
  
  
  RESULTS
  The average maximal load to failure was not significantly different between the traditional repair (48 ± 12 N) and the barbed suture repair (50 ± 14 N). The average 2-mm gapping load was also insignificantly different between the traditional repair (42 ± 12 N) and the barbed suture repair (32 ± 9 N). The traditional repair failed by knot unraveling and suture rupture 35% and 65% of the time, respectively. The barbed suture repair failed by suture pull-out and rupture 67% and 33% of the time, respectively. The average load to failure by suture rupture was insignificantly different between the traditional repair (51 ± 13 N) and the barbed suture repair (63 ± 16 N). The average load to failure by knot unraveling using the traditional repair was 43 ± 11 N, whereas the average load to failure by suture pull-out using the barbed suture repair was 43 ± 8 N.
  
  
  CONCLUSIONS
  The barbed suture repair did not demonstrate a significant difference in maximal load to failure and 2-mm gapping resistance compared with the traditional method of repair.
  
  
  CONCLUSIONS
  This study examines the biomechanical differences between 2 types of flexor-tendon repair, which can help guide the surgical management for these injuries.
authors.affiliation: Indiana Hand to Shoulder Center, Indianapolis, IN, USA.
authors.forename: Ian C
authors.initials: IC
authors.lastname: Marrero-Amadeo
authors.forename: Aakash
authors.initials: A
authors.lastname: Chauhan
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Warden
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Merrell
mesh_terms: D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D019651:Plastic Surgery Procedures / Q000379:methods*; D012680:Sensitivity and Specificity; D013536:Suture Techniques; D013537:Sutures; D013708:Tendon Injuries / Q000601:surgery; D013718:Tensile Strength