Raina Deepak Bushan, Markevičiūtė Vetra, Stravinskas Mindaugas, Kok Joeri, Jacobson Ida, Liu Yang, Sezgin Erdem Aras, Isaksson Hanna, Zwingenberger Stefan, Tägil Magnus, Tarasevičius Šarūnas, Lidgren Lars
Department of Clinical Sciences Lund, Orthopedics, The Faculty of Medicine, Lund University, Lund, Sweden.
Department of Orthopedics and Traumatology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Front Bioeng Biotechnol. 2022 Mar 2;10:816250. doi: 10.3389/fbioe.2022.816250. eCollection 2022.
Pertrochanteric fractures (TF) due to osteoporosis constitute nearly half of all proximal femur fractures. TFs are treated with a surgical approach and fracture fixation is achieved using metallic fixation devices. Poor quality cancellous bone in osteoporotic patients makes anchorage of a fixation device challenging, which can lead to failure of the fracture fixation. Methods to reinforce the bone-implant interface using bone cement (PMMA) and other calcium phosphate cements in TFs have been described earlier but a clear evidence on the advantage of using such biomaterials for augmentation is weak. Furthermore, there is no standardized technique for delivering these biomaterials at the bone-implant interface. In this study, we firstly describe a method to deliver a calcium sulphate/hydroxyapatite (CaS/HA) based biomaterial for the augmentation of a lag-screw commonly used for TF fixation. We then used an osteoporotic Sawbones model to study the consequence of CaS/HA augmentation on the immediate mechanical anchorage of the lag-screw to osteoporotic bone. Finally, as a proof-of-concept, the method of delivering the CaS/HA biomaterial at the bone-implant interface as well as spreading of the CaS/HA material at this interface was tested in patients undergoing treatment for TF as well as in donated femoral heads. The mechanical testing results indicated that the CaS/HA based biomaterial increased the peak extraction force of the lag-screw by 4 times compared with un-augmented lag-screws and the results were at par with PMMA. The X-ray images from the patient series showed that it was possible to inject the CaS/HA material at the bone-implant interface without applying additional pressure and the CaS/HA material spreading was observed at the interface of the lag-screw threads and the bone. Finally, the spreading of the CaS/HA material was also verified on donated femoral heads and micro-CT imaging indicated that the entire length of the lag-screw threads was covered with the CaS/HA biomaterial. In conclusion, we present a novel method for augmenting a lag-screw in TFs, which could potentially reduce the risk of fracture fixation failure and reoperation in fragile osteoporotic patients.
骨质疏松性转子周围骨折（TF）占所有股骨近端骨折的近一半。TF采用手术方法治疗，使用金属固定装置实现骨折固定。骨质疏松患者的松质骨质量差，使得固定装置的锚固具有挑战性，这可能导致骨折固定失败。早期已描述了在TF中使用骨水泥（PMMA）和其他磷酸钙骨水泥增强骨-植入物界面的方法，但关于使用此类生物材料进行增强的优势的明确证据不足。此外，在骨-植入物界面输送这些生物材料尚无标准化技术。在本研究中，我们首先描述了一种输送硫酸钙/羟基磷灰石（CaS/HA）基生物材料以增强常用于TF固定的拉力螺钉的方法。然后，我们使用骨质疏松的Sawbones模型研究CaS/HA增强对拉力螺钉与骨质疏松骨的即时机械锚固的影响。最后，作为概念验证，在接受TF治疗的患者以及捐赠的股骨头中测试了在骨-植入物界面输送CaS/HA生物材料以及该材料在该界面扩散的方法。力学测试结果表明，与未增强的拉力螺钉相比，CaS/HA基生物材料使拉力螺钉的峰值拔出力增加了4倍，结果与PMMA相当。患者系列的X射线图像显示，无需施加额外压力即可在骨-植入物界面注射CaS/HA材料，并且在拉力螺钉螺纹与骨的界面处观察到CaS/HA材料扩散。最后，在捐赠的股骨头上也验证了CaS/HA材料的扩散，微CT成像表明拉力螺钉螺纹的整个长度都被CaS/HA生物材料覆盖。总之，我们提出了一种在TF中增强拉力螺钉的新方法，这可能会降低脆弱骨质疏松患者骨折固定失败和再次手术的风险。
