Luenam Suriya, Bantuchai Theeraset, Kosiyatrakul Arkaphat, Chanpoo Malee, Phakdeewisetkul Kantapat, Puncreobutr Chedtha
Department of Orthopaedics, Phramongkutklao Hospital and College of Medicine, 315 Ratchawithi Road, Bangkok, 10400, Thailand.
Department of Anatomy, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
3D Print Med. 2021 Jan 28;7(1):3. doi: 10.1186/s41205-021-00093-w.
A prosthetic replacement is a standard treatment for an irreparable radial head fracture; however, the surface mismatch of the commercially available designs is concerned for the long-term cartilage wear. The patient-specific implant created from 3D printing technology could be favorable in replicating the normal anatomy and possibly reduce such sequela. Our study aimed to assess the precision of the computed tomography (CT) and cartilage-reproducing image reconstruction method (CIRM) in generating digital models for potentially use in manufacturing the patient-specific prosthesis from 3D printing.
Eight intact elbows (3 right and 5 left) from 7 formalin-embalmed cadavers (4 males and 3 females) with mean age of 83 years (range, 79-94 years) were used for this study. Computerized 3D models were generated from CT, and CIRM. The cartilage-reproducing image reconstruction method has compensated the cartilage profile based on the distance between the subchondral surfaces of the radial head and surrounding bones in CT images. The models of actual radial head geometry used as the gold standard was generated from CT arthrography (CTA). All models of each specimen were matched by registering the surface area of radial neck along with the tuberosity. The difference of head diameter, head thickness, and articular disc depth among three models was evaluated and analyzed by Friedman ANOVA and multiple comparison test using Bonferroni method for statistical correction. A p-value of less than 0.01 was considered statistically significant. The difference of overall 3D geometry was measured with the root mean square of adjacent point pairs.
The analysis displayed the difference of diameter, thickness, and disc depth across the models (p< 0.01). Pairwise comparisons revealed statistically significant difference of all parameters between CTA models and CT models (p< 0.01) whereas no difference was found between CTA models and CIRM models. The mean difference of overall 3D geometry between CTA models and CT models was 0.51±0.24 mm, and between CTA models and CIRM models was 0.24±0.10 mm.
CIRM demonstrated encouraging results in reestablish the normal anatomy and could be potentially used in production process of 3D printed patient-specific radial head prosthesis.
人工假体置换是不可修复的桡骨头骨折的标准治疗方法；然而，市售设计的表面不匹配问题令人担忧，因为这可能导致长期软骨磨损。利用3D打印技术制作的个体化植入物在复制正常解剖结构方面可能具有优势，并有可能减少此类后遗症。我们的研究旨在评估计算机断层扫描（CT）和软骨再现图像重建方法（CIRM）在生成数字模型方面的精度，这些数字模型可能用于通过3D打印制造个体化假体。
本研究使用了7具福尔马林固定尸体（4例男性，3例女性）的8个完整肘部（3个右侧，5个左侧），平均年龄83岁（范围79 - 94岁）。通过CT和CIRM生成计算机化3D模型。软骨再现图像重建方法基于CT图像中桡骨头与周围骨骼的软骨下表面之间的距离补偿了软骨轮廓。用作金标准的实际桡骨头几何模型由CT关节造影（CTA）生成。通过对齐桡骨颈连同结节的表面积，对每个标本的所有模型进行匹配。使用Friedman方差分析和采用Bonferroni方法进行统计校正的多重比较检验，评估并分析三种模型之间的头部直径、头部厚度和关节盘深度差异。p值小于0.01被认为具有统计学意义。用相邻点对的均方根测量整体3D几何形状的差异。
分析显示各模型之间在直径、厚度和盘深度方面存在差异（p < 0.01）。两两比较显示CTA模型与CT模型之间所有参数均存在统计学显著差异（p < 0.01），而CTA模型与CIRM模型之间未发现差异。CTA模型与CT模型之间整体3D几何形状的平均差异为0.51±0.24毫米，CTA模型与CIRM模型之间为0.24±0.10毫米。
CIRM在重建正常解剖结构方面显示出令人鼓舞的结果，并且有可能用于3D打印个体化桡骨头假体的生产过程。
