Dou Yiming, Xiao Jianlin, Wen Xinggui, Gao Jianpeng, Tian Hao, Zuo Jianlin
Department of Orthopaedics, China-Japan Union Hospital of Jilin University, No. 126, Xiantai Street, Changchun, 130033, Jilin Province, China.
Arthroplasty. 2020 May 19;2(1):14. doi: 10.1186/s42836-020-00032-w.
To study the segmental uncoverage ratio (UCR) of a 44-mm cup model placed in a true acetabulum of Crowe type-IV developmental dysplasia of the hip via 3-Dimensional (3D) implantation simulation.
Qualified CT imaging data of 26 patients (involving 30 hips) with Crowe type-IV DDH were imported into Mimics software for reconstruction. Then a 44-mm eggshell cup model was placed in a true acetabulum. First, total uncoverage ratio (TUCR) was measured. Then the virtual cup was divided into 4 segments according to the quadrant setting of the true acetabulum, i.e., anterior-superior (A-S) segment, anterior-inferior (A-I) segment, posterior-superior (P-S) segment and posterior-inferior (P-I) segment. The UCRs of the aforementioned segments were measured, i.e., anterior-superior uncoverage ratio (A-SUCR), anterior-inferior uncoverage ratio (A-IUCR), posterior-superior uncoverage ratio (P-SUCR) and posterior-inferior uncoverage ratio (P-IUCR). The acetabular height and anterior-posterior diameter on the 3-D model were also calculated. Statistic analyses were performed by using SPSS software package.
TUCR was 0.2958 ± 0.1003 (95% [CI], 0.1020 to 0.5400) in this cohort of Crowe Type-IV hips. P-SUCR had the greatest value among all the segmental UCRs (0.1012 ± 0.0435, 95% confidence interval [CI],0.0152 to 0.1914) and the most significant positive correlation with TUCR (Pearson correlation = 0.889, p < 0.01. Linear regression R = 0.791). Similarly, P-IUCR and A-SUCR showed a significant positive correlation with TUCR. However, A-IUCR exhibited no correlation with either total or other segmental UCRs. P-SUCR was found to bear significant positive correlation with P-IUCR (pearson correlation = 0.644, p < 0.01. Linear regression R = 0.415). Acetabular height and A-P diameter were not correlated with TUCR.
Implantation of a 44-mm cup into Crowe type IV acetabulum is feasible and could achieve acceptable host bone coverage in most of the cases. P-SUCR contributed most to TUCR. TUCR had no linear relationship with the size of the host acetabulum, suggesting that the pre-operative plan should be individualized.
通过三维（3D）植入模拟研究置于Crowe IV型发育性髋关节发育不良真性髋臼中的44毫米杯状模型的节段性覆盖不足率（UCR）。
将26例（涉及30髋）Crowe IV型发育性髋关节发育不良患者的合格CT影像数据导入Mimics软件进行重建。然后将一个44毫米的蛋壳杯状模型置于真性髋臼中。首先，测量总覆盖不足率（TUCR）。然后根据真性髋臼的象限设置将虚拟杯状模型分为4个节段，即前上（A-S）节段、前下（A-I）节段、后上（P-S）节段和后下（P-I）节段。测量上述节段的UCR，即前上覆盖不足率（A-SUCR）、前下覆盖不足率（A-IUCR）、后上覆盖不足率（P-SUCR）和后下覆盖不足率（P-IUCR）。还计算了三维模型上的髋臼高度和前后径。使用SPSS软件包进行统计分析。
在这组Crowe IV型髋关节中，TUCR为0.2958±0.1003（95%[CI]，0.1020至0.5400）。P-SUCR在所有节段性UCR中值最大（0.1012±0.0435，95%置信区间[CI]，0.0152至0.1914），且与TUCR的正相关性最显著（Pearson相关性=0.889，p<0.01。线性回归R=0.791）。同样，P-IUCR和A-SUCR与TUCR呈显著正相关。然而，A-IUCR与总UCR或其他节段性UCR均无相关性。发现P-SUCR与P-IUCR呈显著正相关（Pearson相关性=0.644，p<0.01。线性回归R=0.415）。髋臼高度和前后径与TUCR无关。
将44毫米杯状假体植入Crowe IV型髋臼是可行的，且在大多数情况下可实现可接受的宿主骨覆盖。P-SUCR对TUCR的贡献最大。TUCR与宿主髋臼大小无线性关系，提示术前计划应个体化。
