BACKGROUND Calcitonin gene-related peptide (CGRP), which has been shown to play an important role in osteogenesis during fracture repair, is also widely distributed throughout the tendon and ligament. Few studies have focused on the role of CGRP in repair of the bone-tendon interface (BTI). PURPOSE To explore the effect of CGRP expression on BTI healing in a rabbit partial patellectomy model. STUDY DESIGN Controlled laboratory study. METHODS A total of 60 mature rabbits were subjected to a partial patellectomy and then randomly assigned to CGRP, CGRP-antagonist, and control groups. In the CGRP-antagonist group, the CGRP receptor antagonist BIBN4096BS was administered to block CGRP receptors. The patella-patellar tendon complex was harvested at 8 and 16 weeks postoperatively and subjected to radiographic, microlaser Raman spectroscopy, histologic, and biomechanical evaluation. RESULTS Radiographic data showed that local CGRP expression improved the growth parameters of newly formed bone, including area and volumetric bone mineral density (P < .05 for both). Raman spectroscopy revealed that the relative bone mineral composition increased in the CGRP group compared with in the control group and the CGRP-antagonist group (P < .05 for both). Histologic testing revealed that the CGRP group demonstrated better integration, characterized by well-developed trabecular bone expansion from the residual patella and marrow cavity formation, at the 8- and 16-week time points. Mechanical testing demonstrated that the failure load, ultimate strength, and stiffness in the CGRP group were significantly higher than those in the control group (P < .05 for all), whereas these parameters in the CGRP-antagonist group were significantly lower compared with those in the control group at 16 weeks after surgery (P < .05 for all). CONCLUSION Increasing the local concentration of CGRP in the early stages of BTI healing enhanced osteogenesis in a rabbit partial patellectomy model and promoted healing of the BTI injury, whereas treatment using a CGRP antagonist had the opposite effect. However, exogenous CGRP expression did not induce novel bone remolding. CLINICAL RELEVANCE CGRP may have potential as a new therapy for BTI injuries or may be added to postoperative regimens to facilitate healing.

中文翻译：

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降钙素基因相关肽通过成骨影响骨-肌腱界面愈合：兔部分髌骨切除模型的研究。

背景技术降钙素基因相关肽（CGRP）已被证明在骨折修复过程中在成骨中起重要作用，也广泛分布于肌腱和韧带中。很少有研究关注 CGRP 在修复骨-肌腱界面 (BTI) 中的作用。目的 探讨 CGRP 表达对兔髌骨部分切除模型 BTI 愈合的影响。研究设计 受控实验室研究。方法60只成年兔进行髌骨部分切除术，随机分为CGRP组、CGRP拮抗剂组和对照组。在CGRP拮抗剂组中，给予CGRP受体拮抗剂BIBN4096BS以阻断CGRP受体。髌骨-髌腱复合体在术后 8 周和 16 周采集并进行放射照相、微激光拉曼光谱、组织学和生物力学评估。结果 影像学数据显示，局部 CGRP 表达改善了新形成骨的生长参数，包括面积和体积骨矿物质密度（两者均 P < .05）。拉曼光谱显示，与对照组和 CGRP 拮抗剂组相比，CGRP 组的相对骨矿物质成分增加（两者均 P < .05）。组织学测试显示，CGRP 组在 8 周和 16 周的时间点表现出更好的整合，其特征在于残余髌骨和骨髓腔形成的发育良好的骨小梁扩张。机械测试表明，CGRP 组的破坏载荷、极限强度和刚度显着高于对照组（P < .05），而在术后 16 周，CGRP 拮抗剂组的这些参数显着低于对照组（P < .05）。结论在兔髌骨部分切除模型中增加BTI愈合早期CGRP的局部浓度可促进成骨，促进BTI损伤的愈合，而使用CGRP拮抗剂治疗具有相反的效果。然而，外源性 CGRP 表达并没有诱导新的骨重塑。临床相关性 CGRP 可能具有作为 BTI 损伤的新疗法的潜力，或者可能被添加到术后治疗方案中以促进愈合。结论在兔髌骨部分切除模型中增加BTI愈合早期CGRP的局部浓度可促进成骨，促进BTI损伤的愈合，而使用CGRP拮抗剂治疗具有相反的效果。然而，外源性 CGRP 表达并没有诱导新的骨重塑。临床相关性 CGRP 可能具有作为 BTI 损伤的新疗法的潜力，或者可能被添加到术后治疗方案中以促进愈合。结论在兔髌骨部分切除模型中增加BTI愈合早期CGRP的局部浓度可促进成骨，促进BTI损伤的愈合，而使用CGRP拮抗剂治疗具有相反的效果。然而，外源性 CGRP 表达并没有诱导新的骨重塑。临床相关性 CGRP 可能具有作为 BTI 损伤的新疗法的潜力，或者可能被添加到术后治疗方案中以促进愈合。