壓電刺激在骨科植入物上的影響

Abstract

在臨床上，骨骼系統有自我癒合能力，一般只要骨折部位密合固定，就能夠期待病患自身的骨癒合能力完成自體癒合。即便骨折手術本身是個風險相對低、治癒率相對高的療程，仍然有大於5%的病患出現術後骨折不癒合的情形由於骨折術後的觀察期較長，骨折不癒合的診斷經常會延遲至術後9個月才能確認並轉診給專門處理不癒合的骨科醫師[1]。目前臨床上使用的骨折醫材，包括骨釘、骨板和骨填充物等，都只有定位與固定功能而無法在植入後持續幫助骨折斷面進行骨癒合。我們近期在壓電刺激對骨髓幹細胞和軟骨細胞的研究顯示，壓電刺激能夠有效增進骨髓幹細胞的遷移、增生與分化，並能幫助軟骨細胞在平面培養環境下維持軟骨特性[2, 3]。由於這些生理過程都是骨癒合中重要的元素，因此我們假設壓電刺激可以增進骨癒合，基於這個假設，如果我們能將現行骨折醫材加入壓電材料特性，就能在骨釘植入後不斷對骨折部位進行壓電刺激，藉以促進骨癒合並且避免骨折不癒合的情形出現。 基於我們先前的研究揭示了壓電刺激在增強骨髓幹細胞的遷移、增殖和分化，以及保護軟骨細胞軟骨特性方面的反應[2, 3]，本研究探討了將壓電特性整合到傳統的骨折植入物中的可能性。我們假設這種整合可以加速骨骼癒合並預防骨折的不癒合。通過兩次進行的小鼠脛骨骨折實驗，結果一致並且壓電組達顯著差異；而這樣的結果也在大鼠股骨骨折實驗中得到了兩次，故可將本研究作為概念驗證。通過在目前的臨床骨釘或骨板中引入壓電材料，我們的目標是為骨折部位提供額外的壓電刺激，以減少骨癒合的時間。這項研究的結果為推進現有骨材開闢了前景，該技術已在美國和臺灣申請專利。我們希望能儘快將其應用於臨床用途。

In clinical practice, the skeletal system possesses an intrinsic self-healing capability. Typically, if the fractured site is properly aligned and stabilized, the patient's own bone healing capacity can achieve self-repair. Although bone fracture surgeries are generally low-risk procedures with high healing rates, over 5% of patients still experience nonunion post-surgery. Due to the extended observation period required after fracture surgeries, diagnosing nonunion often gets delayed until nine months post-operation, necessitating referral to orthopedic specialists who handle nonunion cases. Current clinical fracture fixation materials, including bone screws, plates, and fillers, primarily serve positioning and stabilization functions without promoting continuous bone healing post-implantation. Our recent research on piezoelectric stimulation demonstrated its efficacy in enhancing the migration, proliferation, and differentiation of bone marrow stem cells and in maintaining chondrocyte characteristics in planar cultures. Given the critical roles of these physiological processes in bone healing, we hypothesized that piezoelectric stimulation could enhance bone healing. Building upon our prior research revealing the efficacy of piezoelectric stimulation in enhancing the migration, proliferation, and differentiation of bone marrow stem cells, as well as preserving chondrocyte cartilage characteristics, this study explores the potential integration of piezoelectric properties into conventional bone fracture implants. Our hypothesis posits that such integration can expedite bone healing and prevent nonunion of fractures. Leveraging mouse tibia fracture experiments, conducted twice with consistently significant results, and rat femur fracture experiments, similarly yielding significant outcomes in two separate trials, this study serves as a proof of concept. By introducing piezoelectric elements into current clinical bone screws or plates, our goal is to provide VI additional post-surgery stimulation to the fracture site, aiming to assess the impact on bone healing time. The results of this investigation may offer a promising avenue for advancing fracture treatment modalities, with potential implications for improving patient outcomes and minimizing complications associated with nonunion of fractures. The technology has already been patent pending in the US and Taiwan, and we hope it could be applied to clinical use as soon as possible.