Knee Research Center, Yagi Orthopaedic Hospital, 1-35, Nishino-3-5, Nishi-ku, Sapporo, Hokkaido, 063-0033, Japan.
Centre for Sports Medicine, Hokkaido University Hospital, Kita-14, Nishi-5, Kita-ku, Sapporo, Hokkaido, 060-8648, Japan.
BMC Musculoskelet Disord. 2024 Jun 5;25(1):441. doi: 10.1186/s12891-024-07533-8.
An ideal synthetic spacer for medial opening wedge high tibial osteotomy (MOWHTO) has not yet been developed. The authors have developed a new β-tricalcium phosphate (β-TCP) spacer with 60% porosity (N-CP60) by modifying the micro- and macro-pore structures of a conventional β-TCP spacer (CP60) that is widely used in clinical practice. The purpose of this study was to compare the absorbability, osteoconductivity, and in vivo strength of the N-CP60 spacer with those of the CP60 spacer, when used in MOWHTO.
First, the porosity, diameter distribution of macro- and micropores, and compressive strength of each β-TCP block were examined using methodology of biomaterial science. Secondly, a clinical study was performed using a total of 106 patients (106 knees) with MOWHTO, who were followed up for 18 months after surgery. In these knees, the N-CP60 and CP-60 spacers were implanted into 49 tibias and 57 tibias, respectively. The absorbability and osteoconductivity were radiologically evaluated by measuring the area of the implanted spacer remaining unabsorbed and assessing with the Hemert's score, respectively. The incidence of cracking in the implanted spacers was determined using computed radiography. Statistical comparisons were made with non-parametric tests. The significance level was set at p = 0.05.
The N-CP60 and CP60 blocks had almost the same porosity (mean, 61.0% and 58.7%, respectively). The diameter of macropores was significantly larger (p < 0.0001) in the N-CP60 block than in the CP60 block, while the diameter of micropores was significantly smaller (p = 0.019) in the N-CP60 block. The ultimate strength of the N-CP60 block (median, 36.8 MPa) was significantly greater (p < 0.01) than that of the CP60 block (31.6 MPa). As for the clinical evaluations, the absorption rate of the N-CP60 spacer at 18 months after implantation (mean, 48.0%) was significantly greater (p < 0.001) than that of the CP60 spacer (29.0%). The osteoconductivity of the N-CP60 spacer was slightly but significantly higher (p = 0.0408) than that of the CP60 spacer only in zone 1. The incidence of in vivo cracking of the posteriorly located N-CP60 spacer at one month (mean, 75.5%) was significantly lower (p = 0.0035) than that of the CP60 spacer (91.2%).
The absorbability, osteoconductivity, and compressive strength of the new N-CP60 spacer were significantly improved by modifying the macro- and micro-pore structures, compared with the conventional CP60 spacer. The N-CP60 spacer is more clinically useful than the CP60 spacer.
H29-0002.
目前还没有开发出用于内侧开口楔形胫骨高位截骨术（MOWHTO）的理想合成间隔物。作者通过修改传统β-磷酸三钙（β-TCP）间隔物（CP60）的微孔和大孔结构，开发了一种新的 60%孔隙率（N-CP60）的β-磷酸三钙（β-TCP）间隔物。CP60 在临床实践中广泛使用。本研究旨在比较 N-CP60 间隔物与 CP60 间隔物在 MOWHTO 中的吸收能力、骨诱导性和体内强度。
首先，使用生物材料科学的方法检查每个β-TCP 块的孔隙率、大孔和微孔直径分布以及抗压强度。其次，对 106 例（106 膝）MOWHTO 患者进行了一项临床研究，术后随访 18 个月。在这些膝关节中，将 N-CP60 和 CP-60 间隔物分别植入 49 个胫骨和 57 个胫骨中。通过测量植入的间隔物未吸收的区域面积并使用 Hemert 评分进行评估，分别对吸收能力和骨诱导性进行影像学评估。使用计算机放射摄影术确定植入间隔物的开裂发生率。使用非参数检验进行统计比较。显著性水平设为 p = 0.05。
N-CP60 和 CP60 块的孔隙率几乎相同（平均值分别为 61.0%和 58.7%）。N-CP60 块的大孔直径明显更大（p < 0.0001），而 N-CP60 块的微孔直径明显更小（p = 0.019）。N-CP60 块的极限强度（中位数为 36.8 MPa）明显大于 CP60 块（31.6 MPa）（p < 0.01）。至于临床评估，植入后 18 个月 N-CP60 间隔物的吸收率（平均值为 48.0%）明显高于 CP60 间隔物（29.0%）（p < 0.001）。N-CP60 间隔物的骨诱导性仅在第 1 区略高（p = 0.0408），但明显高于 CP60 间隔物。植入后 1 个月时，位于后位的 N-CP60 间隔物的体内开裂发生率（平均值为 75.5%）明显低于 CP60 间隔物（91.2%）（p = 0.0035）。
通过修改大孔和微孔结构，新型 N-CP60 间隔物的吸收能力、骨诱导性和抗压强度均得到显著提高，与传统 CP60 间隔物相比。N-CP60 间隔物比 CP60 间隔物更具临床应用价值。
H29-0002。
