Orthopaedic Department of Aristotle University of Thessaloniki, George Papanikolaou Hospital Thessaloniki, Thessaloniki, Greece.
Research Centre ELPEN, Director of Experimental, Thessaloniki, Greece.
Biomed Mater. 2020 Sep 26;15(6):065011. doi: 10.1088/1748-605X/aba326.
Hardware removal after complete fracture healing is a laborious and traumatic procedure that bears the risks of refracture, infection, and soft tissue damage. Absorbable materials for fracture fixation have the advantage of eliminating the need for removal; however, they may stimulate a considerable inflammatory response. For that reason, we compared in a prospective randomized experimental animal model study the incidence of foreign-body reactions between Inion OTPS absorbable plate implants, consisting of carbon trimethylene, L-polylactic acid, and D, L-polylactic acid, and conventional titanium plates. Seventy rabbits were equally divided into two groups. Titanium (Group A) or absorbable (Group B) plates and screws were implanted in the femoral shaft of the rabbits. Wound reaction and laboratory tests including white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) values were measured and compared at different time points. Radiographs and histological analysis of tissue samples from all animals were also used to identify potential foreign-body reactions. WBC showed normal values in both groups. In Group A, ESR levels were higher at all time points but CRP values were normalized at 3 weeks postoperatively. In Group B, ESR and CRP levels reached a peak at 3 weeks and were above normal values throughout the whole experiment (p < 0.001). Radiologic examination revealed periosteal thickening and surrounding sclerosis in 23 out of 35 animals of Group B (66%). All Group A animals had normal radiographic findings. Histopathology showed a typical non-specific foreign-body reaction in all animals in Group B (100%) but none in Group A. However, only four of them (11.8%) developed non-infected wound complications and showed significantly elevated CRP and ESR values (p = 0.054). Although Inion OTPS Biodegradable Plating System stimulates a foreign-body reaction, only a small but not negligible percentage of almost 12% may lead to wound problems. However, this difference compared to titanium plates was of borderline not statistically significant. Future studies should focus on the development of absorbable implants with improved biocompatibility aiming to further decrease the potential of foreign-body reaction and eliminate the need for additional reoperative procedures.
在完全骨折愈合后进行内固定物取出是一项费力且具创伤性的操作，会增加再骨折、感染和软组织损伤的风险。骨折固定用可吸收材料具有无需取出的优势，但可能会引起相当大的炎症反应。出于这个原因，我们在一项前瞻性随机实验动物模型研究中比较了由碳三亚甲基、L-聚乳酸和 D、L-聚乳酸组成的 Inion OTPS 可吸收板植入物和传统钛板之间的异物反应发生率。将 70 只兔子平均分为两组。在兔子的股骨干中分别植入钛板（A 组）或可吸收板（B 组）和螺钉。在不同时间点测量并比较伤口反应和实验室检查，包括白细胞计数（WBC）、红细胞沉降率（ESR）和 C 反应蛋白（CRP）值。还对所有动物的组织样本进行 X 线片和组织学分析，以确定潜在的异物反应。两组的 WBC 均处于正常值。在 A 组中，所有时间点的 ESR 水平均较高，但 CRP 值在术后 3 周时恢复正常。在 B 组中，ESR 和 CRP 值在 3 周时达到峰值，并在整个实验过程中均高于正常值（p<0.001）。放射学检查显示 B 组 35 只动物中有 23 只（66%）出现骨膜增厚和周围硬化。所有 A 组动物的放射学检查结果均正常。组织病理学显示 B 组所有动物均存在典型的非特异性异物反应（100%），而 A 组则没有。然而，只有其中 4 只（11.8%）发生无感染性伤口并发症，且 CRP 和 ESR 值显著升高（p=0.054）。尽管 Inion OTPS 可生物降解接骨板系统会引起异物反应，但只有很小但并非微不足道的 12%左右的比例可能会导致伤口问题。然而，与钛板相比，这种差异具有统计学意义上的边界性。未来的研究应集中于开发具有更好生物相容性的可吸收植入物，以进一步降低异物反应的可能性，并消除再次手术的需要。
