Department of Mechanical Engineering, University College London, London, UK.
Royal National Orthopaedic Hospital NHS Trust, Stanmore, UK.
J Orthop Res. 2024 Dec;42(12):2784-2795. doi: 10.1002/jor.25936. Epub 2024 Jul 11.
Large acetabular bone defects are challenging in hip revision surgery. Clinical assessment is crucial to evaluate modern technologies in surgical reconstruction. We aimed to better understand the bone remodeling that occurs following acetabular reconstruction. Our objectives were: (1) To characterize changes in the shape of the pelvis by studying sequential computed tomography (CT) scans collected immediately and 1-year postoperatively and (2) to identify which part of the pelvis is most susceptible to remodeling. We used the CT scans taken at two timepoints, of 24 patients with acetabular bone defects classified as Paprosky IIIB, treated with three-dimensional (3D)-printed custom-made acetabular implants. Segmented 3D models of the bony pelvis were co-registered using three different techniques. A global co-registration of the full pelvis was conducted, followed by the co-registration of the innominate bone and then ilium only, on the ipsilateral reconstructed side. The relative movements of the ilium, ischium, and pubis were analyzed from visual inspection and using co-registration metrics (root mean square error and intersection over union). No bone remodeling was found in 14/24 patients (58%). The co-registration of the innominate bone indicated bone remodeling in five cases (21%), while the remaining five cases (21%) presented remodeling in the global co-registration but not the innominate bone co-registration, suggestive of changes occurring at the sacroiliac joint. Changes in the pelvic shape were greatest at the pubis and ischium. Bone remodeling may occur in complex cases of Paprosky type IIIB defects, after acetabular reconstruction (occurrence of 21%, 5/24 cases). Surgeons and engineers should consider this when monitoring implant migration.
髋臼骨缺损在髋关节翻修手术中是一个挑战。临床评估对于评估手术重建中的现代技术至关重要。我们旨在更好地理解髋臼重建后发生的骨重塑。我们的目标是：（1）通过研究立即和术后 1 年采集的连续计算机断层扫描（CT）扫描来描述骨盆形状的变化，（2）确定骨盆的哪个部位最容易发生重塑。我们使用了 24 例髋臼骨缺损患者的 CT 扫描，这些患者的髋臼骨缺损分类为 Paprosky IIIB 型，采用三维（3D）打印定制髋臼植入物治疗。使用三种不同的技术对骨盆的三维模型进行分段配准。首先对整个骨盆进行全局配准，然后对患侧重建侧的骨盆进行坐骨和髂骨的配准，最后仅对髂骨进行配准。从视觉检查和配准指标（均方根误差和交并比）分析了髂骨、坐骨和耻骨的相对运动。在 24 例患者中，有 14 例（58%）未发现骨重塑。坐骨和髂骨的配准表明有 5 例（21%）存在骨重塑，而其余 5 例（21%）在全局配准中存在重塑，但在坐骨和髂骨配准中不存在，提示骶髂关节处发生了变化。骨盆形状的变化在耻骨和坐骨处最大。髋臼重建后（24 例中有 5 例，发生率为 21%），可能会发生复杂的 Paprosky ⅢB 型缺损病例的骨重塑。外科医生和工程师在监测植入物迁移时应考虑到这一点。
