Melbourne Orthopaedic Group, Melbourne, Australia.
Hand and Wrist Biomechanics Laboratory, O'Brien Institute / St Vincent's Institute, Fitzroy, Australia.
Am J Sports Med. 2023 Jun;51(7):1895-1903. doi: 10.1177/03635465231171131. Epub 2023 May 15.
Extracortical single-button (SB) inlay repair is a commonly used distal biceps tendon technique. However, complications (eg, neurovascular injury) and nonanatomic repairs have led to the development of intracortical fixation techniques.
To compare the biomechanical stability of extracortical SB repair with an anatomic intracortical double-button (DB) repair technique.
Controlled laboratory study.
The distal biceps tendon was transected in 18 cadaveric elbows from 9 donors. One elbow of each donor was randomly assigned to the extracortical SB or anatomic DB group. Both groups were cyclically loaded with 60 N over 1000 cycles between 90° of flexion and full extension. The elbow was then fixed in 90° of flexion and the repair construct loaded to failure. Gap formation and construct stiffness during cyclic loading and ultimate load to failure were analyzed.
When compared with the extracortical SB technique after 1000 cycles, the anatomic DB technique showed significantly less gap formation (mean ± SD, 2.7 ± 0.8 vs 1.5 ± 0.9 mm; = .017) and significantly more construct stiffness (87.4 ± 32.7 vs 119.9 ± 31.6 N/mm; = .023). Ultimate load to failure was not significantly different between the groups (277 ± 93 vs 285 ± 135 N; = .859). The failure mode in the anatomic DB group was significantly different from that of the extracortical SB technique ( = .002) and was due to fracture avulsion of the cortical button in 7 of 9 specimens (vs none in the SB group).
Our study shows that the intracortical DB technique produces equivalent or superior biomechanical performance to that of the SB technique. The DB technique may offer a clinically viable alternative to the SB repair technique.
This study suggests, at worst, an equivalent and, at best, a superior biomechanical performance of intracortical anatomic DB footprint repair at the time of surgery. However, the mode of failure suggests that this technique should not be used in patients with poor bone quality.
皮质外单按钮（SB）嵌体修复是一种常用的肱二头肌远端肌腱技术。然而，并发症（如神经血管损伤）和非解剖修复导致了皮质内固定技术的发展。
比较皮质外 SB 修复与解剖学皮质内双按钮（DB）修复技术的生物力学稳定性。
对照实验室研究。
从 9 名供体的 18 具尸体肘部切断肱二头肌远端肌腱。每位供体的一只肘部随机分配到皮质外 SB 或解剖学 DB 组。两组均在 90°屈曲至完全伸展之间以 60 N 的循环加载 1000 次。然后将肘部固定在 90°屈曲位，并对修复结构进行失效加载。分析循环加载和失效负载过程中的间隙形成和结构刚度。
与 1000 次循环后的皮质外 SB 技术相比，解剖学 DB 技术的间隙形成明显减少（平均 ± SD，2.7 ± 0.8 比 1.5 ± 0.9 mm； =.017），结构刚度明显增加（87.4 ± 32.7 比 119.9 ± 31.6 N/mm； =.023）。两组的最终失效负载无显著差异（277 ± 93 比 285 ± 135 N； =.859）。解剖学 DB 组的失效模式与皮质外 SB 技术明显不同（ =.002），7 个标本的皮质按钮发生骨折撕脱（SB 组无）。
我们的研究表明，皮质内 DB 技术的生物力学性能与 SB 技术相当或更优。DB 技术可能是 SB 修复技术的一种可行的临床替代方案。
本研究表明，在手术时，皮质内解剖学 DB 足印修复的生物力学性能至少与 SB 技术相当，最好则更优。但失败模式表明，该技术不应在骨质较差的患者中使用。
