Penn State College of Medicine, Penn State Department of Orthopaedics and Rehabilitation, Penn State Health Milton S. Hershey Medical Center, Hershey, Pennsylvania, U.S.A..
Penn State College of Medicine, Penn State Department of Orthopaedics and Rehabilitation, Penn State Health Milton S. Hershey Medical Center, Hershey, Pennsylvania, U.S.A.
Arthroscopy. 2021 Oct;37(10):3016-3021. doi: 10.1016/j.arthro.2021.03.085. Epub 2021 Apr 23.
To compare the biomechanical characteristics of a single radially expanding all-suture anchor with an interference screw for open subpectoral long head of biceps tendon (LHBT) tenodesis.
Eighteen fresh-frozen matched-pair human cadaveric humeri were used for this biomechanical study. The matched pair humeri were randomly assigned into 2 experimental biceps tenodesis groups: conventional interference screw (CIS) or all-suture suture anchor (ASSA). Open subpectoral LHBT tenodesis was then performed and biomechanical testing was performed using a servohydraulic test frame. A preload of 5 N was applied for 2 minutes before cyclic loading. Displacement was recorded at cycle 300 (D300) and cycle 500 (D500) and at ultimate failure. Data recorded included displacement, load to failure, displacement at failure. Paired t test was used for analysis.
Decreased displacement was observed for the CIS group at D300 (1.67 ± 0.57 mm vs 3.35 ± 2.24 mm; P = .04), D500 (2.00 ± 0.76 mm vs 3.87 ± 2.20 mm; P = .04), and at failure (5.17 ± 3.05 mm vs 10.76 ± 2.66 mm; P < .001). Load to failure was lower in CIS specimens (170 ± 24.5 N vs 217.8 ± 51.54 N; P = .02). Failure in each case was tendon pullout for all CIS specimens; in ASSA 6 specimens failed as the suture pulled through the tendon, 2 specimens failed by suture breakage. No difference in stiffness was observed between the 2 groups (CIS = 98.33 ± 22.98 N/m vs ASSA = 75.94 ± 44.83 N/m; P = .20).
Our study found that open subpectoral biceps tenodesis performed with an ASSA construct results in increased load to failure as compared with CIS. However, the CIS did demonstrate decreased displacement as compared to ASSA in this cadaveric biomechanical study.
ASSA and CIS at time zero provide fixation as indicated by the provider intraoperatively for LHBT tenodesis. ASSA, however, does remove less cortical bone than does CIS and therefore produces a smaller stress riser in the proximal humerus. Further testing as to the integrity of ASSA is warranted to determine the integrity of the tenodesis with cyclical loading.
比较单根放射状扩张全缝线锚钉与干扰螺钉在开放式胸肌下长头肱二头肌肌腱（LHBT）固定中的生物力学特性。
本生物力学研究使用了 18 个新鲜冷冻的配对人肱骨。将配对肱骨随机分为 2 个实验性肱二头肌固定组：常规干扰螺钉（CIS）或全缝线锚钉（ASSA）。然后进行开放式胸肌下 LHBT 固定，并使用伺服液压测试框架进行生物力学测试。在循环加载前施加 5 N 的预载 2 分钟。记录循环 300 次（D300）和循环 500 次（D500）以及最终失效时的位移。使用配对 t 检验进行分析。
CIS 组在 D300（1.67 ± 0.57mm 比 3.35 ± 2.24mm；P =.04）、D500（2.00 ± 0.76mm 比 3.87 ± 2.20mm；P =.04）和失效时（5.17 ± 3.05mm 比 10.76 ± 2.66mm；P <.001）的位移减少。CIS 标本的失效负荷较低（170 ± 24.5N 比 217.8 ± 51.54N；P =.02）。在每种情况下，CIS 标本的失效都是肌腱拔出；在 ASSA 中，有 6 个标本因缝线穿过肌腱而失效，2 个标本因缝线断裂而失效。两组之间的刚度无差异（CIS = 98.33 ± 22.98N/m 比 ASSA = 75.94 ± 44.83N/m；P =.20）。
我们的研究发现，与 CIS 相比，开放式胸肌下肱二头肌固定采用 ASSA 构建可增加失效负荷。然而，在这项尸体生物力学研究中，CIS 与 ASSA 相比，位移减少。
ASSA 和 CIS 在手术时为 LHBT 固定提供固定，如术者所指示。然而，ASSA 去除的皮质骨比 CIS 少，因此在肱骨头近端产生较小的应力集中。需要进一步测试 ASSA 的完整性，以确定周期性加载时的固定完整性。
