利用雙平面動態X光量測並比較反置式全人工肩關節置換術前術後在功能性動作下盂肱關節之三維運動與關節接觸

Abstract

肩關節，或稱盂肱關節，是人體最靈活的關節之一，但也是穩定性最差且最容易受傷的關節之一。肩關節穩定性多仰賴於周圍的肌肉、肌腱及韌帶，尤其是旋轉肌群。許多運動和日常活動都會要求肩關節進行重複動作或承受高壓力。由於過度使用和年齡的增長，容易使這些軟組織受到磨損、撕裂或其他病變，使得肩關節退化，嚴重影響生活品質，而這樣的病人通常需要接受全人工肩關節置換術。在過去幾十年中，人工肩關節置換術由最初的半人工肩關節置換到全人工肩關節置換，再到現在的反置式全人工肩關節置換。反置式全人工肩關節置換的獨特設計，在提供了病人更好的肩關節穩定性的同時，更降低了周圍軟組織的負擔，大大提升了病人的生活品質。然而，即使有這些技術，肩關節置換後的病人仍常面臨疼痛、關節活動範圍受限及肩關節功能下降等問題，即使有認真執行復健，仍有部分病人的恢復狀況不甚良好。在過去研究中，由於肩關節的複雜性及量測方法限制，有關反置式全人工肩關節置換術對於肩關節之影響尚未有完整研究。 本研究旨在利用雙平面動態X光系統結合斷層掃描重建之骨頭模型對位方法，量測反置式全人工肩關節置換術前術後在功能性動作下盂肱關節的三維運動和關節接觸模式。術前病人將特聚焦在旋轉肌斷裂引起的肩關節退化患者，比較其術前術後之生物力學變化，並與健康人數據進行比較。研究結果顯示，術後患者在屈曲、外翻和肩胛面抬舉等動作中的運動範圍顯著增加，關節接觸壓力分佈更為均勻，這有助於降低肩關節脫位和疼痛等併發症的風險。此外，由於盂肱關節在影像上的重疊區域會影響量測的準確性，本研究透過結合紅外線動作捕捉系統之試體研究進行量測方法的準確性評估。結果表明，本研究方法提供了一種精確評估術後恢復效果的手段，並能幫助臨床醫生更精確地制定個性化的術後康復計劃。這些發現對於臨床實踐和未來研究均具有重要參考價值，為優化反置式全人工肩關節置換術的設計和應用提供了科學依據。

The shoulder joint, also known as the glenohumeral joint, is one of the most flexible joints in the human body but also one of the least stable and most injury prone. The stability of the shoulder joint largely relies on surrounding muscles, tendons, and ligaments, especially the rotator cuff muscles. Many sports and daily activities require repetitive motions or high stress on the shoulder joint. Due to overuse and aging, these soft tissues are prone to wear, tear, or other pathologies, leading to shoulder joint degeneration and significantly affecting the quality of life. Patients with severe conditions often require total shoulder arthroplasty. Over the past decades, shoulder arthroplasty has evolved from hemiarthroplasty to total shoulder arthroplasty and now to reverse total shoulder arthroplasty (RSA). The unique design of RSA provides better joint stability and reduces the burden on surrounding soft tissues, greatly improving patients' quality of life. However, even with these advancements, patients undergoing shoulder arthroplasty still frequently experience pain, limited range of motion, and decreased shoulder function. Despite diligent rehabilitation, some patients do not recover satisfactorily. Previous studies, limited by the complexity of the shoulder joint and measurement techniques, have not comprehensively explored the impact of RSA on the shoulder joint. This study aims to measure the three-dimensional kinematics and joint contact patterns of the glenohumeral joint before and after RSA during functional movements using a dual-plane fluoroscopy system combined with CT-based bone model registration. The study focused on patients with shoulder degeneration due to rotator cuff tears, comparing biomechanical changes before and after surgery and with healthy individuals. The results indicated significant increases in range of motion in flexion, abduction, and scapular plane elevation postoperatively, with more uniform distribution of joint contact pressure, reducing the risk of dislocation and pain. Additionally, to address the overlapping areas in glenohumeral joint imaging that may affect measurement accuracy, this study evaluated the accuracy of the measurement method through a phantom study combining an infrared motion capture system. The findings demonstrate that our method provides a precise means of assessing postoperative recovery and aids clinicians in developing personalized rehabilitation plans. These results are valuable for clinical practice and future research, providing scientific evidence for optimizing the design and application of RSA.