title: The lasso-loop, lasso-mattress and simple-cinch stitch for arthroscopic rotator cuff repair: are there biomechanical differences?
abstract: OBJECTIVE
  Various stitching techniques have been described to facilitate arthroscopic repair of rotator cuff tears. The aim of the present study was to compare the biomechanical properties of the lasso-loop, lasso-mattress and simple-cinch stitch for rotator cuff repair.
  
  
  METHODS
  Twelve infraspinatus tendons were harvested from sheep and split in half. The tendons were randomized into three different stitch configuration groups for biomechanical testing: lasso-loop, lasso-mattress and simple-cinch stitch. Each specimen was first cyclically loaded on a universal materials testing machine under force control from 5 to 30 N at 0.25 Hz for twenty cycles. Then, each specimen was loaded to failure under displacement control at a rate of 1 mm/s. Cyclic elongation, peak-to-peak displacement and ultimate tensile load were reported as mean ± standard error and compared using one way analysis of variance. The type of failure was recorded.
  
  
  RESULTS
  No differences in cyclic elongation (1.31 ± 0.09 mm for the simple-cinch vs. 1.49 ± 0.07 mm for the lasso-mattress vs. 1.61 ± 0.09 mm for the lasso-loop stitch, p = 0.063) or peak-to-peak displacement (0.58 ± 0.04 mm for the simple-cinch, 0.50 ± 0.03 mm for the lasso-mattress and 0.62 ± 0.06 mm for the lasso-loop stitch, p = 0.141) were seen between all tested stitch configurations. In the load-to-failure test, the simple cinch stitch (149.38 ± 11.89 N) and the lasso-mattress (149.38 ± 10.33 N) stitch demonstrated significantly higher ultimate load than the lasso-loop stitch (65.88 ± 4.75 N, p < 0.001). All stitch configurations failed with suture pull out.
  
  
  CONCLUSIONS
  The lasso-mattress and the simple-cinch stitch showed similar biomechanical properties with significant higher tensile loads needed for failure than the lasso-loop stitch.
authors: Trauma Department, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625, Hannover, Germany. liodakis.emmanouil@mh-hannover.de.
authors: Emmanouil
authors: E
authors: Liodakis
authors: Trauma Department, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors: Antonios
authors: A
authors: Dratzidis
authors: Laboratory for Biomechanics and Biomaterials, Department of Orthopaedic Surgery, Hannover Medical School (MHH), Hannover, Germany.
authors: Manuel
authors: M
authors: Kraemer
authors: Laboratory for Biomechanics and Biomaterials, Department of Orthopaedic Surgery, Hannover Medical School (MHH), Hannover, Germany.
authors: Christof
authors: C
authors: Hurschler
authors: Trauma Department, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors: Christian
authors: C
authors: Krettek
authors: Orthopaedic and Surgical Clinic Braunschweig (OCP), Brunswick, Germany.
authors: Ahmed
authors: A
authors: Hawi
authors: Trauma Department, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors: Mohamed
authors: M
authors: Omar
authors: Trauma Department, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors: Rupert
authors: R
authors: Meller
authors: Trauma Department, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors: Nael
authors: N
authors: Hawi
mesh_terms: D000818:Animals; D001182:Arthroscopy / Q000379:methods*; D001696:Biomechanical Phenomena; D004195:Disease Models, Animal; D017006:Rotator Cuff / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D000070636:Rotator Cuff Injuries / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D012756:Sheep; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures
keywords: Biomechanical evaluation; Lasso-loop stitch; Lasso-mattress stitch; Rotator cuff; Rotator cuff repair; Simple-cinch stitch