Objective: To analyze the occurrence of rod fracture after surgery for lumbosacral deformity associated sacral agenesis and discuss the relevant salvage methods. Methods: The clinical records of 19 patients who underwent surgical treatment for lumbosacral deformity associated sacral agenesis from January 2001 to January 2018 were retrospectively reviewed, including 11 boys and 8 girls. The average age was (9.6±5.2) years. The outcomes of surgical correction and internal fixation were evaluated by postoperative regular follow-up. We also recorded the time and position of rod fracture occurrence. The Cobb angle, coronal balance and sagittal balance were measured and compared to analyze the corresponding salvage methods and revision outcomes. Results: Three patients encountered rod fracture during follow-up, so the incidence of rod fracture after surgery for lumbosacral deformity associated sacral agenesis was 15.8%(3/19). Based on their own conditions, we formulated the individualized strategy and performed the revision surgery through the posterior-only approach. The most critical step was abundant bone-grafting and fusion in the defected sacroiliac joint. After revision, the scoliotic Cobb angle improved in two patients (91.5° vs 47.5°, 49.0° vs 28.0°) and coronal balance improved in one patient (40.3 mm vs 24.3 mm). No complication reoccurred during follow-up. Conclusion: The rod fracture after surgery for lumbosacral deformity associated sacral agenesis is quite common, which is probably correlated with its unique deformed structure and biomechanical characteristics. The individualized salvage methods and adequate bone-grafting and fusion for the defected sacroiliac joint will guarantee the reconstruction and maintenance of spine balance after revision.

目的： 分析合并骶骨发育不良的腰骶部畸形术后断棒的发生并探讨相应的翻修策略。 方法： 回顾性分析2001年1月至2018年1月期间在南京鼓楼医院手术治疗的19例合并骶骨发育不良的腰骶部畸形患儿的病历资料，其中男11例，女8例，年龄（9.6±5.2）岁，通过术后规律的随访评估患儿矫形效果、内固定在位情况，记录出现断棒的时间及位置，并测量侧凸Cobb角、冠状面平衡和矢状面平衡等指标，分析相应的翻修手术方案及效果。 结果： 在随访过程中共有3例患儿发生了断棒，因此合并骶骨发育不良的腰骶部畸形术后断棒的发生率为15.8%（3/19）。依据3例患儿各自的情况，制定了个性化的方案并行脊柱单纯后路翻修手术，其中，最关键的步骤为骶髂关节缺损处的充分植骨融合。在翻修手术后，有2例患儿的侧凸Cobb角得到改善（91.5°比47.5°，49.0°比28.0°），1例患儿的冠状面平衡得到改善（40.3 mm比24.3 mm），且均无并发症的再发生。 结论： 合并骶骨发育不良的腰骶部畸形患儿术后断棒的发生比较常见，这可能与其独特的畸形结构和生物力学特点有关，个性化的翻修策略和骶髂关节缺损处的充分植骨融合将保证翻修术后脊柱平衡的重建与维持。.