title: Value of additional acromioclavicular cerclage for horizontal stability in complete acromioclavicular separation: a biomechanical study.
abstract: OBJECTIVE
  To evaluate whether isolated anatomical coracoclavicular (CC) ligament reconstruction with two suture-button devices provides equal horizontal acromioclavicular joint (ACJ) stability compared to additional ACJ suture tape cerclage.
  
  
  METHODS
  A servohydraulic testing machine was used to assess horizontal ACJ translation in 12 fresh-frozen human shoulders during 5,000 cycles of dynamic anteroposterior directed loading (70 N). Horizontal ACJ stability was assessed for native specimen (n = 6) and compared to specimen with dissected AC ligaments but intact CC ligaments (n = 6). After complete AC/CC dissection, an anatomical CC reconstruction was performed with two suture-button devices (n = 6) and compared to the additional ACJ suture tape cerclage (n = 6).
  
  
  RESULTS
  Native specimen showed an mean horizontal amplitude of 10.8 mm [standard deviation (SD) 3.29]. After 5,000 cycles of horizontal loading (70 N), mean amplitude increased by 1.5 mm (SD 0.75, p = 0.005). Specimen with dissected AC ligaments started at an mean amplitude of 14.1 mm (SD 4.11), which was increased by 0.9 mm (SD 0.56, n.s.) after loading. Initially, amplitude of specimen with anatomical CC reconstruction was 13.2 mm (SD 2.75), which increased by 2.9 mm (SD 1.45, p = 0.001) after loading. The specimen with additional AC cerclage initially showed an amplitude of 10.6 mm (SD 2.35). After loading, translation was increased by 3.0 mm (SD 0.97, p = 0.001). There was no failure of any surgical reconstruction in the tests.
  
  
  CONCLUSIONS
  The results of this study suggest that only combined AC and CC reconstruction can adequately re-establish physiological horizontal ACJ stability. Therefore, it is likely that a combined surgical procedure with double suture-button devices and AC suture tape cerclage can adequately re-establish horizontal AC joint stability in case of an acute injury (≥type Rockwood IV and may allow superior clinical outcomes for patients, especially if early functional rehabilitation is intended).
authors.affiliation: Department for Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675, Munich, Germany.|Berufsgenossenschaftliche Unfallklinik Murnau, Prof.-Küntscher-Str. 8, 82418, Murnau, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Saier
authors.affiliation: Department for Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675, Munich, Germany.
authors.forename: Arne J
authors.initials: AJ
authors.lastname: Venjakob
authors.affiliation: Department for Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675, Munich, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Minzlaff
authors.affiliation: Department of Biomechanics, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675, Munich, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Föhr
authors.affiliation: Department of Biomechanics, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675, Munich, Germany.
authors.forename: Filip
authors.initials: F
authors.lastname: Lindell
authors.affiliation: Department for Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675, Munich, Germany. a.imhoff@lrz.tu-muenchen.de.
authors.forename: Andreas B
authors.initials: AB
authors.lastname: Imhoff
authors.affiliation: Department for Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675, Munich, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Vogt
authors.affiliation: Department for Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technische Universität München, Ismaningerstr. 22, 81675, Munich, Germany.
authors.forename: Sepp
authors.initials: S
authors.lastname: Braun
mesh_terms: D000173:Acromioclavicular Joint / Q000503:physiopathology / Q000601:surgery*; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D008023:Ligaments, Articular / Q000601:surgery*; D008875:Middle Aged; D019651:Plastic Surgery Procedures / Q000379:methods*; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures