title: Anatomic suture anchor versus the Broström technique for anterior talofibular ligament repair: a biomechanical comparison.
abstract: BACKGROUND
  Despite the popularity of the Broström procedure for secondary repair of chronic lateral ankle instability, there have been no biomechanical studies reporting on the strength of this secondary repair method, whether using suture fixation or suture anchors.
  
  
  OBJECTIVE
  The purpose of our study was to perform a biomechanical comparison of the ultimate load to failure and stiffness of the traditional Broström technique using only a suture repair compared with a suture anchor repair of the anterior talofibular ligament (ATFL) at time zero. We believed that fixation strength of the suture anchor repair would be closer to the strength of the native ligament and allow more aggressive rehabilitation.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twenty-four fresh-frozen cadaveric ankles were randomly divided into 4 groups of 6 specimens. One group was an intact control group, and the other groups consisted of the traditional Broström and 2 suture anchor modifications (suture anchors in talus or fibula) of the Broström procedure. The specimens were loaded to failure to determine the strength and stiffness of each construct.
  
  
  RESULTS
  In load-to-failure testing, ultimate failure loads of the Broström (68.2 ± 27.8 N; P = .013), suture anchor fibula (79.2 ± 34.3 N; P = .037), and suture anchor talus (75.3 ± 45.6 N; P = .027) repairs were significantly lower than that of the intact (160.9 ± 72.2 N) ATFL group. Stiffness of the Broström (6.0 ± 2.5 N/mm; P = .02), suture anchor fibula (6.8 N/mm ± 2.7; P = .05), and suture anchor talus (6.6 N/mm ± 4.0; P = .04) repairs were significantly lower than that of the intact (12.4 N/mm ± 4.1 N/mm) ATFL group. The 3 repair groups were not significantly different from each other, but all 3 were substantially lower in strength and stiffness when compared to the intact ATFL.
  
  
  CONCLUSIONS
  The use of suture anchors to repair the ATFL produces a repair that can withstand loads to failure similar to the suture-only Broström repair. However, all 3 repair groups were much weaker than the intact, uninjured ATFL.
  
  
  CONCLUSIONS
  Biomechanically, the results show that both suture anchor and direct suture repair of the ATFL provide similar strength and stiffness. Unfortunately, these methods provide less than half the strength and stiffness of the native ATFL at time zero. As a result, regardless of the repair method, it is necessary to sufficiently protect the repair to avoid premature failure.
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, Vail, Colorado, USA.
authors.forename: Norman E
authors.initials: NE
authors.lastname: Waldrop
authors.forename: Coen A
authors.initials: CA
authors.lastname: Wijdicks
authors.forename: Kyle S
authors.initials: KS
authors.lastname: Jansson
authors.forename: Robert F
authors.initials: RF
authors.lastname: LaPrade
authors.forename: Thomas O
authors.initials: TO
authors.lastname: Clanton
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000601:surgery*; D017844:Lateral Ligament, Ankle / Q000293:injuries / Q000503:physiopathology / Q000601:surgery*; D008875:Middle Aged; D053441:Suture Anchors; D013536:Suture Techniques