Objective: To investigate the effectiveness of three-dimensional (3D)-printed hemi-pelvic prosthesis for revision of aseptic loosening or screw fracture of modular hemi-pelvic prosthesis.
Methods: Between February 2017 and January 2020, 11 patients with aseptic loosening or screw fracture of modular hemi-pelvic prosthesis were revised using 3D-printed hemi-pelvic prostheses. There were 7 males and 4 females with an average age of 44 years (range, 25-60 years). In the first operation, all patients underwent total tumor resection, modular hemi-pelvic prosthesis reconstruction, and autologous femoral head transplantation. According to the Enneking pelvic partition system, 8 cases were resected in zones Ⅰ+Ⅱ and 3 cases in zones Ⅰ+Ⅱ+Ⅲ. The interval from the initial operation to this revision ranged from 14.3-66.2 months, with an average of 35.8 months. The operation time, the amount of intraoperative bleeding, and the occurrence of complications were recorded. At 6 months after the first operation, before revision, and at last follow-up, the American Musculoskeletal Tumor Society (MSTS) score and Harris score were used to evaluate the recovery of lower limb function. The pain-free walking distance of patients without brace assistance was recorded at last follow-up. X-ray films were taken at 1 month after the first operation, before revision, and at 1 month after revision, the acetabulum position was assessed by the differences in weight arm and cup height between bilateral hip joints. At last follow-up, the digital X-ray tomography was taken to evaluate the prosthesis-bone integration and the occurrence of aseptic loosening.
Results: The operation time was 182.6-238.0 minutes (mean, 197.4 minutes). The amount of intraoperative bleeding was 400-860 mL (mean, 550.0 mL). All incisions healed by first intention with no infection, hip dislocation, nerve damage, or vascular-related adverse events. The MSTS score and Harris score at last follow-up were significantly higher than those at 6 months after the first operation and before revision ( P<0.05), while the score before revision was significantly lower than that at 6 months after the first operation ( P<0.05). At last follow-up, the patients were able to walk more than 1 000 meters painlessly without brace assistance. Imaging review showed that the difference of cup height at 1 month after revision was significantly lower than that at 1 month after the first operation and before revision, and at 1 month after the first operation than before revision operation, and the differences were significant ( P<0.05). There was no significant difference in the difference of weight arm among three time points ( P>0.05). All prostheses were well integrated, and no aseptic loosening of the prosthesis or screw fracture occurred.
Conclusion: Revision with 3D-printed hemi-pelvic prostheses benefited in reconstructing stable pelvic ring and natural bodyweight transmission for patients encountering the aseptic loosening or screw fracture of modular hemi-pelvic prosthesis. Early postoperative rehabilitation training can maximize the recovery of patient limb function, reduce pain during walking, and reduce the incidence of complications.
目的: 探讨组配式半骨盆假体无菌性松动或螺钉断裂患者采用3D打印定制半骨盆假体进行翻修的有效性。.
方法: 2017年2月—2020年1月，对11例组配式半骨盆假体无菌性松动或螺钉断裂患者，采用3D打印定制半骨盆假体进行翻修术。男7例，女4例；年龄25～60岁，平均44岁。初次手术均为肿瘤整块切除并采用组配式半骨盆假体重建、自体股骨头移植。根据Enneking骨盆分区系统，Ⅰ+Ⅱ区切除8例，Ⅰ+Ⅱ+Ⅲ区切除3例。初次手术至该次翻修手术间隔14.3～66.2个月，平均35.8个月。记录手术时间、术中出血量以及并发症发生情况；初次术后6个月、翻修术前以及末次随访时，采用美国骨与软组织肿瘤协会（MSTS）评分及Harris评分评价下肢功能恢复情况；末次随访时记录患者无支具辅助下无痛步行距离。初次术后1个月、翻修术前和翻修术后1个月摄X线片，测算健患侧体质量力臂差值和髋臼杯高度差值，以评估髋臼位置；末次随访时，以数字化X线体层摄影评估假体-骨整合情况及有无无菌性松动发生。.
结果: 手术时间182.6～238.4 min，平均197.4 min；术中出血量400～860 mL，平均550.0 mL。术后切口均Ⅰ期愈合，无深部感染、髋关节脱位、神经损伤及血管相关不良事件等并发症发生。末次随访时，MSTS评分及Harris评分较初次术后6个月及翻修术前均提高，而翻修术前较初次术后6个月降低，差异均有统计学意义（ P<0.05）；患者均能在无支具辅助下无痛步行1 000 m以上。影像学复查示，翻修术后1个月髋臼杯高度差值低于初次术后1个月及翻修术前，初次术后1个月低于翻修术前，差异有统计学意义（ P<0.05）。初次术后1个月及翻修手术前后体质量力臂差值差异均无统计学意义（ P>0.05）。所有假体与骨整合良好，无假体无菌性松动或螺钉断裂发生。.
结论: 组配式半骨盆假体置换术后发生假体无菌性松动或螺钉断裂患者，采用3D打印定制半骨盆假体翻修能重建骨盆环完整性，恢复正常力学传导。术后早期行恰当康复训练能够最大限度恢复患者肢体功能、减轻行走时疼痛、降低并发症发生率。.
Keywords: Pelvic tumor; modular hemi-pelvic prosthesis; revision; three-dimesional-printed hemi-pelvic prosthesis.