Biomechanical Comparison of Dual Interlocking Single Loop and Double Loop Tension Band Techniques to the Classic AO Tension Band Technique for Repair of Olecranon Osteotomies in Dogs

Abstract

The DL construct is easy to perform, less bulky, and provides comparable fragment stability to standard TBW techniques at functional loads. Surgical method is important for optimal performance of all TBW constructs.

Influence of wire configuration on resistance to fragment distraction of tension bands placed in a greater trochanteric osteotomy model

“…The failure load was highly correlated with and scaled with the initial tension by a factor of 2.3, so creating more tension in a TB construct during tying means that it will resist greater loads before it begins to loosen. Our results are in line with previous studies in which the double loop generated greater static tension and a higher yield load and resisted higher loads at 2 mm of displacement compared with single loop or twist constructs. In the study reported here, the figure‐of‐eight TB construct with two twists resisted distraction of the trochanter fragment better than the one with one twist and thus was able to achieve a 21% higher force before failure at 2 mm (199 vs 165 N).…”

“…Because the knot or fold is the weak point of the system, more force is required to unbend two arms (DL) than to untwist two wires wrapped around each other, as is present in the other three constructs. We found the following factors important for producing the most secure construct and maximizing TB performance: (1) forming small loops to reduce the impact of loop elongation under load (DL, DISL), (2) pressing the wire flat to the trochanter fragment and minimizing laxity as it is looped around, and (3) maintaining wire tension throughout tying by applying continual pressure on wire tightener cranks while bending over the wire for DL or pulling up during the twist‐and‐lay technique for OT and TT.…”

“…Four TB configurations were tested (Figure ) including the figure‐of‐eight with one twist (OT), a figure‐of‐eight with two twists (TT), the dual interlocking single loop (DISL) construct, and a double loop (DL) construct modified from one previously described . All constructs were formed with 316L 1.0‐mm orthopedic wire (18 gauge; IMEX Veterinary, Longview, Texas) and tied by a third‐year surgery resident.…”

“…In a polymer model, larger pin diameter and thicker wire resulted in stronger constructs, and the figure‐of‐eight configuration was stronger than a single wire loop . In an ulna osteotomy model, a double loop configuration resisted greater load at 2 mm of displacement compared with the standard figure‐of‐eight with two twists . A dual interlocking single loop configuration resisted similar loads to the standard figure‐of‐eight constructs.…”

“…Previous TB studies have incorporated a variety of configurations in the presence of K‐wires with or without other securing devices, such as lag screws or bone staples, to determine the most effective (ie, strongest, most stable) wire construct . However, the load resistance of the wire portion alone without the confounding influence of K‐wire stabilization has not been evaluated and may inform improved TB wire designs to mitigate the persisting complications with TB fixation.…”