Department of Orthopedics and Orthopedic Oncology, University of Padova, Via Giustiniani, 235128, Padova, Italy.
Department of Orthopedics, Traumatology and Orthopedic Oncology, Pomeranian Medical University, Szczecin, Poland.
Int Orthop. 2020 May;44(5):829-837. doi: 10.1007/s00264-020-04523-y. Epub 2020 Mar 13.
Three-dimensional (3D) printing is an emerging technology used in numerous medical fields. Reconstruction of large bone defects after tumor resections or complex revision surgeries is challenging especially in specific sites where modular prostheses are not available. The possibility to realize custom-made 3D-printed prostheses improves their application in surgical field despite the complication rate, gaining a lot of attention for potential benefits.
We asked: (1) What are the emerging indications and designs of 3D-printed prostheses for complex bone reconstructions? (2) What complications occur with the use of custom implants considering site?
We performed a retrospective analysis of every patient in whom a custom-made 3D-printed prosthesis was used to reconstruct a bone defect after resection for a bone tumour or challenging revision surgery from 2009 to 2018 in two referral centres. Forty-one patients (11 males [27%], 30 females [73%]) with a mean age of 41 years (range, 10-78 years) were included. Our general indications for using these implants were complex reconstructions of massive bone defects, in the absence of available modular prostheses. Seven were non-oncologic patients, whereas 24 patients were mainly treated for their malignant bone tumours. Custom-made 3D-printed prostheses were used in pelvis (29), forearm (6), scapula (2), distal tibia (2), calcaneus (1), and femoral diaphysis (1). The reconstruction included complete articular replacement in 24 cases (58%) whereas a combined spinopelvic implant has been used in two cases. Flaps were used in 25 cases (61%). Statistical analyses include Kaplan-Meier curves of survival.
The mean follow-up was 20 months. In the oncologic group, overall survival was 89% at five year follow-up and only three patients died of disease. Only one patient required implant removal due to deep infection. Overall major and minor complication rate was 22% (14 complications in 9/41 patients), mainly wound-related problems. One patient reported a periprosthetic fracture, one had hip dislocation, and four (12% [4/34 cases]) had local recurrence. Mean MSTS functional outcome score at follow-up was 73% (range, 23-100%), with a full weight bearing at an average time of 73 days from surgery of lower limbs.
Custom-made 3D-printed prostheses represent at today a promising reconstructive technique, maintaining however the correct indications for their use in musculoskeletal oncology and challenging revision surgery. Complication rate is acceptable, with infection and wound healing problems relatively common after complex pelvic reconstructions. We will continue to follow our patients over the longer term to ascertain the role of these implants; however, larger studies will need to confirm indications and control for prognostic factors.
三维（3D）打印是一种新兴技术，已应用于众多医学领域。肿瘤切除或复杂翻修手术后的大骨缺损重建极具挑战性，尤其是在特定部位，此时无法使用模块化假体。尽管存在并发症发生率，但定制 3D 打印假体的可能性提高了它们在外科领域的应用，因为其具有潜在益处，因此受到了广泛关注。
我们提出以下问题：（1）用于复杂骨重建的 3D 打印假体的新兴适应证和设计有哪些？（2）考虑到部位，使用定制植入物会出现哪些并发症？
我们对 2009 年至 2018 年期间在两个转诊中心因骨肿瘤切除或复杂翻修手术而接受定制 3D 打印假体重建骨缺损的每位患者进行了回顾性分析。共纳入 41 例患者（11 例男性[27%]，30 例女性[73%]），平均年龄为 41 岁（10-78 岁）。我们使用这些植入物的一般适应证是复杂的大块骨缺损重建，此时无法使用模块化假体。其中 7 例为非肿瘤患者，24 例患者主要因恶性骨肿瘤而接受治疗。定制 3D 打印假体用于骨盆（29 例）、前臂（6 例）、肩胛骨（2 例）、胫骨远端（2 例）、跟骨（1 例）和股骨干（1 例）。重建包括 24 例（58%）完全关节置换，2 例采用联合脊柱骨盆植入物。25 例（61%）采用了皮瓣。统计分析包括生存的 Kaplan-Meier 曲线。
平均随访时间为 20 个月。在肿瘤组中，5 年随访时的总生存率为 89%，仅有 3 例患者因疾病死亡。仅有 1 例患者因深部感染而需要取出植入物。总体严重和轻微并发症发生率为 22%（9/41 例患者中有 14 例并发症），主要与伤口相关。1 例患者报告发生假体周围骨折，1 例患者发生髋关节脱位，4 例（12%[34 例中的 4 例]）患者发生局部复发。随访时的平均 MSTS 功能评分（范围，23-100%）为 73%，下肢手术平均 73 天后可完全负重。
定制 3D 打印假体目前是一种很有前途的重建技术，但在肌肉骨骼肿瘤学和复杂翻修手术中仍需正确把握其适应证。并发症发生率可以接受，复杂骨盆重建后感染和伤口愈合问题相对常见。我们将继续对患者进行长期随访，以确定这些植入物的作用；但是，需要更大的研究来证实适应证并控制预后因素。
