Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A.
Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A..
Arthroscopy. 2018 Mar;34(3):806-813. doi: 10.1016/j.arthro.2017.09.012. Epub 2017 Dec 26.
To quantify the torsional load to fracture for subpectoral biceps tenodesis with interference screw fixation.
We randomized 28 specimens from 14 matched-pair full-length humeri (mean age, 55.3 years) into 3 groups: (1) empty ream group (ERG), (2) screw-only group (SOG), and (3) screw-plus-biceps tendon group (SBG). In each group, 1 humerus of each matched pair was prepared according to group allocation and the contralateral humerus remained intact as a control. In the ERG, an 8-mm unicortical hole was reamed 1 cm proximal to the inferior border of the pectoralis major tendon insertion; in the SOG, the humerus was filled with an 8-mm × 12-mm PEEK (polyether ether ketone) screw; and in the SBG, the humerus was filled with a PEEK screw and the cadaveric long head of the biceps tendon. Humeri were tested under torsional displacement at a rate of 1°/s until fracture. Maximum torque, energy to maximum torque, and linear stiffness were used to assess humerus strength.
Compared with contralateral intact specimens, the maximum torque to fracture was reduced by 28% in the ERG (P = .005), 30% in the SOG (P = .014), and 20% in the SBG (P = .046). Energy to maximum torque was similarly reduced in the ERG (P = .007), SOG (P = .023), and SBG (P = .049). Stiffness was increased by 4% in the ERG (P = .498), 9% in the SOG (P = .030), and 4% in the SBG (P = .439).
Drilling an 8-mm unicortical hole in zone 3 of the bicipital tunnel for open subpectoral biceps tenodesis reduces the torsional load to humeral fracture up to 28% at time 0. The addition of a PEEK tenodesis screw alone reduced the maximum torque by 30%, and the addition of a screw with the long head of the biceps tendon reduced the maximum torque by 20%. The total load to fracture was reduced in all settings. Stiffness was not significantly different for the ERG and SBG, but stiffness was significantly higher for the SOG compared with the intact matched humeri at time 0.
When performing a biceps tenodesis, humeral fracture susceptibility is increased with an applied torsional load at time 0. Thus providers must be aware of this reduced integrity when a subpectoral biceps tenodesis is used.
量化经三角肌下入路肱二头肌肌腱止点重建中使用骨-肌腱界面螺钉固定时的扭转断裂载荷。
我们将 14 对匹配的全长肱骨（平均年龄 55.3 岁）中的 28 个标本随机分为 3 组：（1）空扩组（ERG）、（2）螺钉组（SOG）和（3）螺钉加肱二头肌肌腱组（SBG）。每组中，每对匹配肱骨的 1 侧按分组进行准备，而对侧肱骨保持完整作为对照。在 ERG 中，在距胸大肌肌腱插入处下边界 1cm 处进行 8mm 单皮质骨扩孔；在 SOG 中，肱骨内填充 8mm×12mm PEEK（聚醚醚酮）螺钉；在 SBG 中，肱骨内填充 PEEK 螺钉和尸体肱二头肌长头。肱骨在 1°/s 的扭转位移率下进行测试，直至发生骨折。最大扭矩、最大扭矩能量和线性刚度用于评估肱骨强度。
与对侧完整标本相比，ERG 组的骨折最大扭矩降低了 28%（P=0.005），SOG 组降低了 30%（P=0.014），SBG 组降低了 20%（P=0.046）。ERG 组（P=0.007）、SOG 组（P=0.023）和 SBG 组（P=0.049）的最大扭矩能量也类似降低。ERG 组的刚度增加了 4%（P=0.498），SOG 组增加了 9%（P=0.030），SBG 组增加了 4%（P=0.439）。
在肱二头肌隧道的 3 区进行 8mm 单皮质骨扩孔进行开放式三角肌下入路肱二头肌肌腱止点重建，可使 0 时刻的肱骨扭转断裂载荷降低 28%。单独增加 PEEK 肌腱固定螺钉会使最大扭矩降低 30%，而增加螺钉和肱二头肌长头会使最大扭矩降低 20%。所有情况下的骨折总载荷均降低。ERG 和 SBG 的刚度没有显著差异，但与 0 时刻的完整匹配肱骨相比，SOG 的刚度显著更高。
在进行肱二头肌肌腱止点重建时，施加扭转负荷会增加肱骨骨折的易感性。因此，当使用三角肌下入路肱二头肌肌腱止点重建时，术者必须意识到这种完整性的降低。
