Background:Rotator cuff tears have been repaired using the transosseous method for decades. The direct suture (DS) technique has been widely used for rotator cuff tears; however, the retear rate is relatively high. Suture anchors are now used frequently for rotator cuff repair (RCR) in accordance with recent developments in materials. However, polyether ether ketone (PEEK) may still cause complications such as the formation of cysts and osteophytes. Some studies have developed the inlay suture (IS) technique for RCR.Purpose/Hypothesis:To compare how 3 different surgical techniques—namely, the DS, IS, and PEEK suture anchor (PSA)—affect tendon-bone healing after RCR. We hypothesized that the IS technique would lead to better tendon-to-bone healing and that the repaired structure would be similar to the normal enthesis.Study Design:Controlled laboratory study.Methods:Acute infraspinatus tendon tears were created in 36 six-month-old male rabbits, which were divided into 3 groups based on the technique used for RCR: DS, IS, and PSA. Animals were euthanized at 6 and 12 weeks postoperatively and underwent a histological assessment and imaging. The expression of related proteins was demonstrated by immunohistochemistry and immunofluorescence staining. Mechanical properties were evaluated by biomechanical testing.Results:At 12 weeks, regeneration of the enthesis was observed in the 3 groups. However, the DS group showed a lower type I collagen content than the PSA and IS groups, which was similar to the results for scleraxis. The DS group displayed a significantly inferior type II collagen expression and proteoglycan deposition after safranin O/fast green and sirius red staining. With regard to runt-related transcription factor 2 and alkaline phosphatase, the IS group showed upregulated expression levels compared with the other 2 groups.Conclusion:Compared with the DS technique, the PSA and IS techniques contributed to the improved maturation of tendons and fibrocartilage regeneration, while the IS technique particularly promoted osteogenesis at the enthesis.Clinical Relevance:The IS and PSA techniques may be more beneficial for tendon-bone healing after RCR.

中文翻译：

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兔模型修复肩袖的 3 种不同手术技术的比较：直接缝合、嵌体缝合和聚醚醚酮 (PEEK) 缝合锚钉

背景：几十年来，人们一直使用经骨方法修复肩袖撕裂。直接缝合（DS）技术已广泛用于肩袖撕裂；然而，延迟率相对较高。根据材料的最新发展，缝合锚钉现在经常用于肩袖修复（RCR）。然而，聚醚醚酮（PEEK）仍可能引起并发症，例如囊肿和骨赘的形成。一些研究开发了用于 RCR 的镶嵌缝合 (IS) 技术。目的/假设：比较 3 种不同的手术技术（即 DS、IS 和 PEEK 缝合锚钉 (PSA)）如何影响 RCR 后肌腱骨愈合。我们假设 IS 技术将导致更好的肌腱到骨骼的愈合，并且修复后的结构将类似于正常的附着点。研究设计：对照实验室研究。方法：在 36 名六个月的患者中发生急性冈下肌腱撕裂。老年雄性兔子，根据 RCR 所用技术分为 3 组：DS、IS 和 PSA。术后6周和12周对动物实施安乐死，并进行组织学评估和成像。通过免疫组织化学和免疫荧光染色证明相关蛋白的表达。通过生物力学测试评估力学性能。结果：12周时，3组均观察到附着点再生。然而，DS 组显示出比 PSA 和 IS 组更低的 I 型胶原蛋白含量，这与 scleaxis 的结果相似。 DS 组在番红 O/固绿和天狼星红染色后显示出明显较差的 II 型胶原蛋白表达和蛋白聚糖沉积。在runt相关转录因子2和碱性磷酸酶方面，IS组与其他2组相比表达水平上调。结论：与DS技术相比，PSA和IS技术有助于促进肌腱成熟和纤维软骨再生。临床意义：IS和PSA技术可能更有利于RCR后腱骨的愈合。