Long-lasting reconstruction after extensive resection involving peri-knee metaphysis is a challenging problem in orthopedic oncology. Various reconstruction methods have been proposed, but they are characterized by a high complication rate. The purposes of this study were to (1) assess osseointegration at the bone implant interface and correlated incidence of aseptic loosening; (2) identify complications including infection, endoprosthesis fracture, periprosthetic fracture, leg length discrepancy, and wound healing problem in this case series; and (3) evaluate the short-term function of the patient who received this personalized reconstruction system. Between September 2016 and June 2018, our center treated 15 patients with malignancies arising in the femur or tibia shaft using endoprosthesis with a 3D-printed custom-made stem. Osseointegration and aseptic loosening were assessed with digital tomosynthesis. Complications were recorded by reviewing the patients’ records. The function was evaluated with the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score at a median of 42 (range, 34 to 54) months after reconstruction. One patient who experienced early aseptic loosening was managed with immobilization and bisphosphonates infusion. All implants were well osseointegrated at the final follow-up examination. There are two periprosthetic fractures intraoperatively. The wire was applied to assist fixation, and the fracture healed at the latest follow-up. Two patients experienced significant leg length discrepancies. The median MSTS-93 score was 26 (range, 23 to 30). A 3D-printed custom-made ultra-short stem with a porous structure provides acceptable early outcomes in patients who received peri-knee metaphyseal reconstruction. With detailed preoperative design and precise intraoperative techniques, the reasonable initial stability benefits osseointegration to osteoconductive porous titanium, and therefore ensures short- and possibly long-term durability. Personalized adaptive endoprosthesis, careful intraoperative operation, and strict follow-up management enable effective prevention and treatment of complications. The functional results in our series were acceptable thanks to reliable fixation in the bone-endoprosthesis interface and an individualized rehabilitation program. These positive results indicate this device series can be a feasible alternative for critical bone defect reconstruction. Nevertheless, longer follow-up is required to determine whether this technique is superior to other forms of fixation.

中文翻译：

---

具有多孔结构的 3D 打印定制超短柄是否是膝周干骺端肿瘤骨缺损可接受的重建替代方案？

涉及膝周干骺端的广泛切除后的持久重建是骨科肿瘤学中的一个具有挑战性的问题。已经提出了各种重建方法，但它们的特点是并发症发生率高。本研究的目的是 (1) 评估骨植入物界面的骨整合和相关的无菌松动发生率；(2) 确定本病例系列中的并发症，包括感染、假体内骨折、假体周围骨折、腿长差异和伤口愈合问题；(3) 评估接受该个性化重建系统的患者的短期功能。2016 年 9 月至 2018 年 6 月期间，我们的中心使用带有 3D 打印定制柄的内置假体治疗了 15 名患有股骨或胫骨干恶性肿瘤的患者。用数字断层合成评估骨整合和无菌松动。通过查看患者的病历记录并发症。在重建后中位数为 42（范围，34 至 54）个月时，使用 1993 版肌肉骨骼肿瘤学会 (MSTS-93) 评分评估该功能。一名经历过早期无菌性松动的患者通过固定和双膦酸盐输注进行治疗。在最后的随访检查中，所有种植体都具有良好的骨整合。术中有两处假体周围骨折。使用钢丝辅助固定，最后一次随访时骨折愈合。两名患者经历了显着的腿长差异。MSTS-93 得分中位数为 26（范围，23 至 30）。具有多孔结构的 3D 打印定制超短柄可为接受膝周干骺端重建的患者提供可接受的早期结果。通过详细的术前设计和精确的术中技术，合理的初始稳定性有利于骨传导性多孔钛的骨整合，从而确保短期和可能的长期耐久性。个性化的适应性假体，精心的术中操作，严格的随访管理，有效预防和治疗并发症。由于骨内假体接口的可靠固定和个性化的康复计划，我们系列中的功能结果是可以接受的。这些积极的结果表明该设备系列可以成为关键骨缺损重建的可行替代方案。尽管如此，