Inoue Yu, Fukui Tomoaki, Oe Keisuke, Hayashi Shinya, Kawamoto Teruya, Kuroda Ryosuke, Niikura Takahiro
Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Case Rep Orthop. 2021 Oct 6;2021:6668006. doi: 10.1155/2021/6668006. eCollection 2021.
Tumor-induced osteomalacia (TIO) is a rare skeletal disease caused by hypersecretion of fibroblast growth factor 23 (FGF-23) from neoplasms of mesenchymal origin; patients with TIO present with insufficiency fractures, progressive bone pain, and delayed fracture unions. Herein, we report the case of a 48-year-old man with an insufficiency fracture in his left femoral neck associated with TIO. The causative tumor located in the patient's maxillary sinus had been resected; however, complete resection was impossible due to the location of the tumor. Therefore, the patient's osteomalacia persisted, and he experienced a left femoral neck fracture in the absence of severe trauma. Because delayed fracture union was anticipated in this patient, we performed an internal fixation using an implant with a lateral plate for angular stability and multiple screws for rotational stability. Although fracture union took 15 months, the patient's postoperative course was uneventful, and he could walk without any symptoms or assistance at his most recent follow-up 30 months after surgery. In TIO, hypersecretion of FGF-23 leads to increased renal excretion of phosphorus, increased bone resorption of calcium and phosphorus, decreased osteoblastic bone mineralization, and decreased gastrointestinal absorption of calcium and phosphorus, leading to insufficiency fractures and delayed fracture unions. Diagnosis of TIO is often delayed due to its rarity and vague symptoms. Total resection of the causative tumor is the optimal treatment; however, in cases wherein complete tumor resection is impossible, drug therapy may be insufficient, and the underlying TIO pathology, including bone fragility, may persist. Early diagnosis of TIO is important for preventing insufficiency fractures; however, when fractures are unavoidable, the surgical treatment of femoral neck fractures in patients with osteomalacia should account for a longer time frame for complete fracture union and therefore utilize implants with sufficient stability.
肿瘤诱导的骨软化症（TIO）是一种罕见的骨骼疾病，由间充质来源的肿瘤过度分泌成纤维细胞生长因子23（FGF-23）引起；TIO患者表现为不全骨折、进行性骨痛和骨折愈合延迟。在此，我们报告一例48岁男性，其左股骨颈不全骨折与TIO相关。导致该疾病的肿瘤位于患者上颌窦，已被切除；然而，由于肿瘤位置原因无法完全切除。因此，患者的骨软化症持续存在，且在无严重创伤的情况下发生了左股骨颈骨折。由于预计该患者骨折愈合延迟，我们使用带有侧板以提供角度稳定性和多根螺钉以提供旋转稳定性的植入物进行了内固定。尽管骨折愈合耗时15个月，但患者术后恢复过程平稳，在术后30个月的最近一次随访中，他无需任何症状或辅助即可行走。在TIO中，FGF-23的过度分泌导致肾脏磷排泄增加、钙和磷的骨吸收增加、成骨细胞骨矿化减少以及胃肠道钙和磷吸收减少，从而导致不全骨折和骨折愈合延迟。由于TIO罕见且症状不明确，其诊断往往延迟。导致该疾病的肿瘤完全切除是最佳治疗方法；然而，在无法完全切除肿瘤的情况下，药物治疗可能不足，且潜在的TIO病理状况（包括骨脆性）可能持续存在。TIO的早期诊断对于预防不全骨折很重要；然而，当骨折不可避免时，骨软化症患者股骨颈骨折的手术治疗应考虑到骨折完全愈合需要更长时间，因此应使用具有足够稳定性的植入物。
