title: Initial repair strengths of two methods for acute medial collateral ligament injuries of the elbow.
abstract: The purposes of this study were to compare the initial repair strength of the medial collateral ligament (MCL) of the elbow using trans-osseous sutures and suture anchor methods and to determine the effect of repair pretensioning. Twelve, fresh-frozen upper extremities (66 +/- 5 years) were mounted in a valgus-loading system. MCL repairs were performed using trans-osseous suture and suture anchor methods with 20 N or 40 N pretensioning. A cyclic (0.5 Hz), valgus 40 N load was applied 12 cm distal to the elbow axis of flexion. The load was increased by 10 N every 200 cycles until a length increase of 5 mm or catastrophic failure of the repair occurred. Repairs pretensioned with 40 N endured a significantly higher number of cycles and failed at higher loads than those pretensioned with 20 N (p < 0.05). No difference was found in the cycles or load to failure between trans-osseous sutures and suture anchors (p > 0.05). A higher magnitude of pretensioning of MCL repairs was found to increase initial repair strength suggesting that pretensioning should be performed clinically. Despite the comparable failure loads of the trans-osseous suture and suture anchor methods, the failure mechanism differed between the two techniques. The suture anchors usually failed catastrophically when the sutures broke as they passed through the anchor eyelet, while the trans-osseous sutures gradually elongated to the defined failure length by stretching and sliding through the ligament. The use of different suture anchors, suture sizes, or suture materials would likely influence the findings of this study and should be considered when applying these findings clinically.
authors.affiliation: Bioengineering Research Laboratory, Hand and Upper Limb Centre, St. Joseph's Hospital, London, Ontario, Canada.
authors.forename: James E
authors.initials: JE
authors.lastname: Pichora
authors.forename: Keizo
authors.initials: K
authors.lastname: Furukawa
authors.forename: Louis M
authors.initials: LM
authors.lastname: Ferreira
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Faber
authors.forename: James A
authors.initials: JA
authors.lastname: Johnson
authors.forename: Graham J W
authors.initials: GJ
authors.lastname: King
mesh_terms: D000208:Acute Disease; D000368:Aged; D004551:Elbow Joint / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D066298:In Vitro Techniques; D008022:Ligaments / Q000293:injuries / Q000503:physiopathology / Q000601:surgery; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D013537:Sutures; D016474:Weight-Bearing; D000092464:Elbow Injuries