title: Biomechanical comparison of double-loaded suture anchors using arthroscopic Mason-Allen stitches versus traditional transosseous suture technique and modified Mason-Allen stitches for rotator cuff repair.
abstract: BACKGROUND
  In recent studies objective evaluations have demonstrated that arthroscopic rotator cuff repairs can have higher failure rates than open repairs. Thus, there is a need for a stronger tissue-holding stitch for arthroscopical repair. The purpose of this study was to compare the biomechanical properties of traditional open transosseous suture technique and modified Mason-Allen stitches versus double-loaded suture anchors and arthroscopic Mason-Allen stitches in rotator cuff repair.
  
  
  METHODS
  In 20 sheep shoulders the infraspinatus tendons were dissected from their insertion and were randomized to 2 repair groups: (1) repair with transosseous suture and modified Mason-Allen stitches, (2) repair with double loaded bioabsorbable suture anchors and arthroscopic Mason-Allen stitches: Both groups were coupled with braided, nonabsorbable polyester (Ethibond) suture sized USP No. 2. All repairs were cyclically loaded from 10 to 180N with the use of a materials testing machine. The number of cycles to gap formation of 5 and 10mm at the repair site and the mode of failure were recorded.
  
  
  RESULTS
  The number of cycles to 5-mm gap was mean 634 (SD 106) for group 1 and mean 750 (SD 107) for group 2 (P<0.026). The corresponding values to 10-mm gap were mean 1573 (SD 161) for group 1, and mean 1789 (SD 183 cycles) for group 2 (P<0.012). In group 2 the mode of failure occurred by tissue pull-out, whereas in group 1 the failure occurred by a mixture of suture breakage and pull-out.
  
  
  CONCLUSIONS
  This time-zero study demonstrates that the combination of bioabsorbable suture anchors and arthroscopic Mason-Allen stitches provides strength superior to that of the modified Mason-Allen transosseous suture technique under isometric cyclic loading conditions. However, additional evaluation is needed to examine the effects on the sustained strength of the repair throughout the healing process.
authors.affiliation: Department of Orthopaedic Surgery, Georg-August-University of Göttingen, Robert-Koch-Strasse 40, D-37075 Göttingen, Germany. michael.klinger@med.uni-goettingen.de
authors.forename: Hans-Michael
authors.initials: HM
authors.lastname: Klinger
authors.forename: Hanno
authors.initials: H
authors.lastname: Steckel
authors.forename: Gunter
authors.initials: G
authors.lastname: Spahn
authors.forename: Gottfried H
authors.initials: GH
authors.lastname: Buchhorn
authors.forename: Mike H
authors.initials: MH
authors.lastname: Baums
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001182:Arthroscopy / Q000379:methods*; D001696:Biomechanical Phenomena / Q000379:methods*; D019637:Orthopedic Procedures; D011897:Random Allocation; D017006:Rotator Cuff / Q000033:anatomy & histology*; D012756:Sheep; D013314:Stress, Mechanical; D053441:Suture Anchors; D013536:Suture Techniques / Q000534:rehabilitation; D013708:Tendon Injuries / Q000601:surgery*; D013718:Tensile Strength; D013997:Time Factors; D016474:Weight-Bearing; D014945:Wound Healing