Kurz Sascha, Pieroh Philipp, Lenk Maximilian, Josten Christoph, Böhme Jörg
RG Numerical Simulation and Material Science, ZESBO - Center for Research on the Musculoskeletal System Department of Orthopedics, Trauma and Plastic Surgery, University of Leipzig, Leipzig Department of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
Medicine (Baltimore). 2017 Oct;96(42):e8136. doi: 10.1097/MD.0000000000008136.
Pelvic malunion is a rare complication and is technically challenging to correct owing to the complex three-dimensional (3D) geometry of the pelvic girdle. Hence, precise preoperative planning is required to ensure appropriate correction. Reconstructive surgery is generally a 2- or 3-stage procedure, with transiliac osteotomy serving as an alternative to address limb length discrepancy.
A 38-year-old female patient with a Mears type IV pelvic malunion with previous failed reconstructive surgery was admitted to our department due to progressive immobilization, increasing pain especially at the posterior pelvic arch and a leg length discrepancy. The leg discrepancy was approximately 4 cm and rotation of the right hip joint was associated with pain.
Radiography and computer tomography (CT) revealed a hypertrophic malunion at the site of the previous posterior osteotomy (Mears type IV) involving the anterior and middle column, according to the 3-column concept, as well as malunion of the left anterior arch (Mears type IV).
The surgery was planned virtually via 3D reconstruction, using the patient's CT, and subsequently performed via transiliac osteotomy and symphysiotomy. Finite element method (FEM) was used to plan the osteotomy and osteosynthesis as to include an estimation of the risk of implant failure.
There was not incidence of neurological injury or infection, and the remaining leg length discrepancy was ≤ 2 cm. The patient recovered independent, pain free, mobility. Virtual 3D planning provided a more precise measurement of correction parameters than radiographic-based measurements. FEM analysis identified the highest risk for implant failure at the symphyseal plate osteosynthesis and the parasymphyseal screws. No implant failure was observed.
Transiliac osteotomy, with additional osteotomy or symphysiotomy, was a suitable surgical procedure for the correction of pelvic malunion and provided adequate correction of leg length discrepancy. Virtual 3D planning enabled precise determination of correction parameters, with FEM analysis providing an appropriate method to predict areas of implant failure.
骨盆畸形愈合是一种罕见的并发症，由于骨盆环复杂的三维（3D）几何结构，在技术上矫正具有挑战性。因此，需要精确的术前规划以确保适当的矫正。重建手术通常是两阶段或三阶段手术，经髂骨截骨术可作为解决肢体长度差异的一种替代方法。
一名38岁女性患者，患有米尔斯IV型骨盆畸形愈合，之前的重建手术失败，因进行性活动受限、疼痛加剧（尤其是骨盆后弓处）以及肢体长度差异而入住我科。肢体长度差异约为4cm，右髋关节旋转伴有疼痛。
根据三柱概念，X线摄影和计算机断层扫描（CT）显示先前后方截骨部位（米尔斯IV型）存在肥大性畸形愈合，累及前柱和中柱，以及左前弓畸形愈合（米尔斯IV型）。
利用患者的CT通过3D重建进行虚拟手术规划，随后通过经髂骨截骨术和耻骨联合切开术进行手术。采用有限元方法（FEM）规划截骨术和骨固定，包括评估植入物失败的风险。
未发生神经损伤或感染，剩余肢体长度差异≤2cm。患者恢复了独立、无痛的活动能力。虚拟3D规划比基于X线摄影的测量提供了更精确的矫正参数测量。有限元分析确定耻骨联合钢板骨固定和耻骨联合旁螺钉处植入物失败风险最高。未观察到植入物失败。
经髂骨截骨术，辅以额外的截骨术或耻骨联合切开术，是矫正骨盆畸形愈合的合适手术方法，可充分矫正肢体长度差异。虚拟3D规划能够精确确定矫正参数，有限元分析提供了一种预测植入物失败区域的合适方法。
