Which is more important for achieving superior stability in a massive rotator cuff tear? The spacer effect (static) vs. concavity compression (dynamic): a biomechanical cadaveric study

IF 2.9 2区医学 Q1 ORTHOPEDICS Journal of Shoulder and Elbow Surgery Pub Date : 2025-10-01 Epub Date: 2025-02-14 DOI:10.1016/j.jse.2024.12.051

Yoon Sang Jeon MD , Sang Hyun Ko MD , Yoon Cheol Nam MD , Gi Cheol Bae MD , Dong Jin Ryu MD , Yeop Na MD , Dong Seok Kang MD , Sungwook Jung MS , Aaron Hui , Michelle H. McGarry MS , Thay Q. Lee PhD

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Abstract

Background

This study aimed to investigate the biomechanical effect of subacromial spacer (physically depressing the humeral head) and magnets (concavity compression restoration) in massive rotator cuff tear (MRCT). We assessed the influence on superior stability by employing the subacromial spacer (the spacer effect) and magnets (concavity compression effect) separately or in combination in MRCT.

Methods

A customized shoulder testing system tested 7 fresh-frozen cadaveric shoulders. The prosthesis implantation was performed prior to all experimental conditions. Each specimen underwent the following conditions: (1) intact rotator cuff without magnets, (2) MRCT without magnets, (3) MRCT with magnets, (4) MRCT with a spacer, and (5) MRCT with magnets and a spacer. For each condition, superior migration and subacromial contact pressure were measured at 0°, 30°, and 60° abduction angles.

Results

Condition 2 resulted in a significant increase in both superior migration and subacromial contact pressure compared to condition 1. Condition 3 exhibited no significant differences in both parameters compared to condition 2 (P > .05). In condition 4, both parameters significantly decreased (P < .05), and in condition 5, levels were restored to those of the intact condition with no significant difference. Neither parameter between conditions 4 and 5 differed significantly (P > .05).

Conclusion

The combination of the static (spacer) and dynamic (concavity compression) effect demonstrated restoration of superior migration and subacromial contact pressure after MRCT to levels comparable to the intact condition. However, the subacromial spacer alone also showed positive results, and the influence of concavity compression was minimal. To achieve superior stability in MRCT, the static role (spacer) as superior restraint is more critical for rotator cuff function than the dynamic role (concavity compression).

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在大规模肩袖撕裂中，哪一个更重要？间隔器效应（静态）与凹性压缩（动态）：一项生物力学尸体研究。

背景：本研究旨在探讨肩峰下间隔器（物理抑制肱骨头）和磁体（凹压缩修复）在大规模肩袖撕裂（MRCT）中的生物力学效果。我们通过在MRCT中单独或联合使用肩峰下间隔器（间隔器效应）和磁体（凹性压缩效应）来评估对优越稳定性的影响。方法：采用定制的肩部检测系统对7具新鲜冷冻尸体的肩部进行检测。在所有实验条件之前进行假体植入。每个标本接受以下条件：(1)完整的肩袖，不带磁铁；(2)不带磁铁的MRCT；(3)带磁铁的MRCT，(4)带间隔片的MRCT，(5)带磁铁和间隔片的MRCT。对于每种情况，在0°，30°和60°外展角下测量上移和肩峰下接触压。结果：与条件1相比，条件2导致上移和肩峰下接触压力显著增加。条件3与条件2相比，两项指标均无显著差异（p < 0.05）。在条件4中，两项参数均显著降低（p < 0.05），在条件5中，水平恢复到原状，但无显著差异。条件4和条件5间无显著差异（p < 0.05）。结论：静态（间隔）和动态（凹压缩）效果的结合表明，MRCT后上移和肩峰下接触压力恢复到与完整状态相当的水平。然而，单独的肩峰下间隔器也显示出积极的结果，凹性压缩的影响是最小的。为了在MRCT中获得更好的稳定性，作为更好约束的静态作用（间隔器）比动态作用（凹性压缩）对肩袖功能更重要。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Shoulder and Elbow Surgery 医学-外科

CiteScore

6.50

自引率

23.30%

发文量

604

审稿时长

11.2 weeks

期刊介绍： The official publication for eight leading specialty organizations, this authoritative journal is the only publication to focus exclusively on medical, surgical, and physical techniques for treating injury/disease of the upper extremity, including the shoulder girdle, arm, and elbow. Clinically oriented and peer-reviewed, the Journal provides an international forum for the exchange of information on new techniques, instruments, and materials. Journal of Shoulder and Elbow Surgery features vivid photos, professional illustrations, and explicit diagrams that demonstrate surgical approaches and depict implant devices. Topics covered include fractures, dislocations, diseases and injuries of the rotator cuff, imaging techniques, arthritis, arthroscopy, arthroplasty, and rehabilitation.