title: A biomechanical investigation of a knotless tension band in medial malleolar fracture models in composite Sawbones®.
abstract: The present study introduces a knotless tension band construct and compares its biomechanical behavior with that of a traditional stainless steel tension band construct. Fourth-generation composite tibial Sawbones(®) were used in the present study. Fracture models were created to mimic Orthopaedic Trauma Association type 44-B2.2 ankle fractures. A total of 20 specimens were randomized evenly into a stainless steel tension band group (control group); or a knotless tension band group. The fixation constructs were mechanically tested, and the stiffness and failure strengths were calculated. Two failure strengths were determined: the engineering-based failure strength, defined as the greatest tensile load tolerated by the construct; and the clinical failure strength, defined as the force required to displace the fracture by 2 mm. We used 2-tailed independent samples t tests to compare and identify significant differences. The knotless tension band construct was 7.7% stronger and 33.2% stiffer and required a 36.7% greater force to displace the fracture by 2 mm. Independent sample t tests confirmed that differences in mean stiffness (p = .003) and clinical failure strength (p = .003) were statistically significant. Although the mean engineering strength for the knotless group was greater than that for the stainless steel group, this difference was not statistically significant (p = .170). This knotless tension band construct could potentially offer both clinical and biomechanical advantages compared with the current stainless steel standard.
authors.affiliation: Department of Orthopaedic Surgery, John Peter Smith Hospital, Tarrant County Hospital District, Fort Worth, TX.
authors.forename: John
authors.initials: J
authors.lastname: Clyde
authors.forename: Victor
authors.initials: V
authors.lastname: Kosmopoulos
authors.forename: Brian
authors.initials: B
authors.lastname: Carpenter
mesh_terms: D016512:Ankle Injuries / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D008422:Materials Testing; D008954:Models, Biological; D009984:Orthopedic Fixation Devices; D011897:Random Allocation; D053441:Suture Anchors; D013718:Tensile Strength; D016474:Weight-Bearing