ABSTRACT
PURPOSE: To biomechanically compare No. 2 polyblend suture with 2-mm polyblend tape in a bovine rotator cuff model as well as in isolation. METHODS: Ten paired bovine infraspinatus specimens were randomly assigned to simple suture fixation with either No. 2 polyblend suture or 2-mm polyblend tape. Each specimen was subjected to cyclic testing followed by load-to-failure testing. Elongation, ultimate tensile load, and stiffness were determined. The failure method was recorded. Isolated suture specimens were also cycled and tested with the same protocol. RESULTS: For tendon-suture specimens, testing showed no significant difference for elongation (1.44 ± 0.41 mm v 1.90 ± 1.15 mm, P = .192) or stiffness (67 ± 13 N/mm v 66 ± 11 N/mm, P = .757). Statistical significance was found for ultimate tensile load (168 ± 73 N v 184 ± 83 N, P = .046). The most common mode of failure for both groups of specimens was disruption of the tendon by the suture. Isolated suture specimens showed significant differences for ultimate tensile load (349 ± 7 N v 937 ± 93 N, P = .001) and stiffness (85 ± 12 N/mm v 218 ± 20 N/mm, P = .002) but not for elongation (0.26 ± 0.05 mm v 0.19 ± 0.04 mm, P = .124). CONCLUSIONS: Using the described testing method in bovine rotator cuff specimens, we found no difference in ultimate tensile load, stiffness, or elongation between the 2 tested sutures. Testing of the sutures in isolation showed that the 2-mm tape was approximately 3 times as stiff as the No. 2 suture and failed at 3 times the loads of the No. 2 suture. CLINICAL RELEVANCE: The larger 2-mm tape does not diminish the biomechanical performance of rotator cuff-suture specimens in comparison to No. 2 suture. Although the effect of tape on the vascularity of the rotator cuff is not known, the larger tape does not negatively affect elongation, ultimate tensile load, or stiffness in this in vitro animal model.
Subject(s)
Rotator Cuff/surgery , Stress, Mechanical , Sutures , Tensile Strength , Animals , Biomechanical Phenomena , Cattle , Models, Animal , Sensitivity and Specificity , Shoulder Joint/surgery , Suture Techniques , Tendons/surgeryABSTRACT
BACKGROUND: Several biomechanical studies comparing open and arthroscopic rotator cuff repair methods have shown inferior performance of arthroscopic repairs. Suture anchor-augmented transosseous repairs and suture bridge repairs have shown superior biomechanical performance when compared with other methods, but these 2 repair methods have not been directly compared. HYPOTHESIS: There will be no difference in the biomechanical performance of the transosseous-suture anchor and suture bridge techniques. STUDY DESIGN: Controlled laboratory study. METHODS: Eight paired cadaveric shoulder specimens (16 specimens) had creation followed by repair of a complete tear of the supraspinatus, with the first member of each pair undergoing repair by a transosseous-suture anchor technique and the second member undergoing repair by the suture bridge technique. Specimens were then cycled from 10 to 180 N for 200 cycles, followed by testing to failure at 33 mm/s. Elongation was measured during cyclic testing, and failure load and stiffness were obtained during load-to-failure testing. Failure method was recorded. RESULTS: There was no significant difference between transosseous-suture anchor repairs and suture bridge repairs for elongation (4.0 +/- 1.60 mm vs 3.5 +/- 1.1 mm, P = .31), failure load (408 +/- 93 N vs 419 +/- 62 N, P = .70), or stiffness (58 +/- 10 N/mm vs 58 +/- 14 N/mm, P = .94). The most common mode of failure with each method was suture cutting through tendon. CONCLUSION: The suture bridge repair exhibited similar biomechanical performance during cyclic and load-to-failure testing as a transosseous-suture anchor repair, which historically has been performed in open or mini-open fashion. CLINICAL RELEVANCE: Arthroscopic rotator cuff repairs can be performed that are as strong as open or mini-open repairs.
Subject(s)
Arthroscopy , Rotator Cuff/surgery , Suture Anchors , Aged , Aged, 80 and over , Biomechanical Phenomena , Female , Humans , Male , Middle Aged , Rotator Cuff Injuries , Weight-BearingABSTRACT
BACKGROUND: Despite technical advances in rotator cuff surgery, recurrent or persistent defects in the repaired tendon continue to occur. Improved strength of sutures and suture anchors has resulted in the most common site of failure being the suture-tendon interface. HYPOTHESIS: The type of suture material used has a significant effect on the biomechanics of the suture-tendon interface. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-two bovine infraspinatus specimens were randomly assigned to simple suture fixation using No. 2 Fiberwire, Ultrabraid, Orthocord, or Ethibond. Each specimen was subjected to cyclic testing from 5 to 30 N for 30 cycles, followed by load-to-failure testing. RESULTS: Cyclic testing revealed significantly greater elongation with Ultrabraid, whereas peak-to-peak displacements were lowest for Fiberwire and greatest for Orthocord. Load-to-failure testing revealed no significant differences between any suture material for ultimate tensile load. Fiberwire and Orthocord repairs had the highest stiffness. The most common failure mode during load-to-failure testing was suture breakage in Ethibond specimens and suture cutting through the tendon in the polyblend suture specimens. CONCLUSION: The type of suture material has a significant effect on the biomechanical behavior of the suture-tendon interface. CLINICAL RELEVANCE: The type of suture may influence early gap formation and ultimate healing of rotator cuff repairs.
