Clark Andrew R, Valerio Michael S, Kulwatno Jonathan, Kanovka Sergey S, Ferrer Andrew L, Dearth Christopher L, Goldman Stephen M
Extremity Trauma and Amputation Center of Excellence, Defense Health Agency, Falls Church, Virginia, USA.
Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.
Bone Joint Res. 2025 Jun 23;14(6):568-577. doi: 10.1302/2046-3758.146.BJR-2024-0334.R1.
Open fractures pose a substantial treatment challenge, with adjacent muscle loss being a major complication. The induced membrane (IM) technique has shown promise in treating complicated fractures. The aim of this study is to investigate the impact of adjacent muscle trauma on segmental fracture healing using recombinant human bone morphogenetic protein-2 (rhBMP-2) via the IM technique.
Skeletally mature male rats (n = 10 to 11 per group) underwent unilateral 3 mm segmental bone defects (SBD) of the tibial diaphysis or a composite tissue injury (CTI), which included a SBD along with volumetric muscle loss (VML). A polymethyl methacrylate (PMMA) spacer was formed within the SBD of each rat. After a four-week period, the PMMA spacer was removed, and the defect was treated with a rhBMP2-impregnated collagen sponge. Longitudinal micro-CT (µCT) imaging was conducted at baseline (Day 0) and at weeks 2, 4, 8, and 12 post-spacer removal to monitor fracture healing progress. At the 12-week postoperative mark, a comprehensive analysis was conducted, including endpoint µCT analysis, evaluation of neuromuscular function, tibia torsional testing, and histological examination.
Longitudinal µCT scans revealed no differences in bone formation or bone mineral density (BMD) at any timepoint between the SBD and CTI groups. High-resolution µCT analysis at the endpoint also showed no variations in bone quality. Torsion testing confirmed that VML did not affect bone strength. Notably, CTI animals exhibited an irreversible reduction in muscle mass and neuromuscular function, which was not observed in the SBD group.
Introducing the additional challenge of VML alongside SBD did not hinder the effectiveness of the induced membrane technique in healing a critical-sized defect.
开放性骨折带来了重大的治疗挑战，相邻肌肉缺失是主要并发症。诱导膜（IM）技术在治疗复杂骨折方面已显示出前景。本研究的目的是通过IM技术研究相邻肌肉创伤对使用重组人骨形态发生蛋白-2（rhBMP-2）的节段性骨折愈合的影响。
骨骼成熟的雄性大鼠（每组n = 10至11只）接受胫骨骨干单侧3毫米节段性骨缺损（SBD）或复合组织损伤（CTI），其中包括SBD以及体积性肌肉损失（VML）。在每只大鼠的SBD内形成聚甲基丙烯酸甲酯（PMMA）间隔物。四周后，取出PMMA间隔物，并用rhBMP2浸渍的胶原海绵治疗缺损。在基线（第0天）以及取出间隔物后的第2、4、8和12周进行纵向微计算机断层扫描（µCT）成像，以监测骨折愈合进展。在术后12周时，进行了全面分析，包括终点µCT分析、神经肌肉功能评估、胫骨扭转测试和组织学检查。
纵向µCT扫描显示，SBD组和CTI组在任何时间点的骨形成或骨矿物质密度（BMD）均无差异。终点处的高分辨率µCT分析也显示骨质量无变化。扭转测试证实VML不影响骨强度。值得注意的是，CTI组动物的肌肉质量和神经肌肉功能出现了不可逆的下降，而SBD组未观察到这种情况。
在SBD的基础上增加VML这一额外挑战并不妨碍诱导膜技术治愈临界尺寸缺损的有效性。
