前交叉韧带重建术后胫骨隧道的临床研究

目的通过双源cT（dual—source computed tomography，DSCT）三维重建前交叉韧带（anterior cruciate ligament，ACL）胫骨止点印迹及胫骨骨道，比较胫骨端单双束面积覆盖率以及自然印迹与骨道中心点相对位置，总结规律，为临床改进关节镜下ACL重建手术，实现解剖重建提供依据。方法对14例双束重建及20例单束重建术后患者双侧膝关节进行DSCT扫描。64排工作站（GE，Volume Share2-AW4．4版本软件）三维重建膝关节胫骨平台模型，再现胫骨平台ACL自然印迹及骨道。圈画、测量自然印迹、骨道面积等，比较单、双束骨道面积覆盖率及单、双束骨道中心点与自然印迹中心点相对位置。结果（1）术后面积覆盖率比较：单束（50．50±13．58）％，双束（61．07±11．53）％（t=2．370，P=0．024），双束面积覆盖率显著大于单束。（2）单束：矢状面上，骨道中心点相对位置（43．80±5．56）％，自然印迹中心点相对位置（44．90±6．69）％，无显著性差异（t=0．631，P=0．536）；冠状面上，骨道中心点相对位置（55．15±2．96）％，自然印迹中心点相对位置（51．85±2．80）％，有显著性差异（t=5．592，P=0．001）。（3）双束：矢状面上，前内束（anteromedial bundle，AMB）骨道中心点相对位置（37．00±6．00）％，自然印迹中心点相对位置（37．43±9．84）％，无显著性差异（t=0．120，P=0．908）；冠状面上，AMB骨道中心点位置（53．00±2．00）％，自然印迹中心点相对位置（51．14±1．83）％，有显著性差异（t=4．192，P=0．001）。矢状面上，后外束（posterolateral bundle，PLB）中心点相对位置（55．00±7．00）％，自然印迹中心点相对位置（40．79±6．42）％，有显著性差异（t=9．121，P=0．001）；冠状面上，PLB中心点相对位置（56．00±2．00）％，自然印迹中心点相对位置（51．64±2．12）％，有显著性差异（t=7．280，P=0．001）。结论（1）ACL胫骨骨道双束重建面积覆盖率大于单束重建，要实现ACL解剖重建需尽可能采用个体化双束重建技术。（2）双源CT三维重建可以帮助我们评估术后骨道与自然印迹相对位置关系，对改进关节镜下ACL重建手术有指导意义。

Clinical Research on Tibial Tunnel after Anterior Cruciate Ligament Reconstruction

Objective To provide basis for the improvement of arthroscopic reconstruction of the anterior cruciate ligament （ACL） through comparison of coverage rate and tunnel positions between single and double-bundle on tibial plateau by dual-source computed tomography （DSCT） three-dimensional imaging. Methods DSCT scans were performed on 14 pairs of double-bundle and 20 pairs of single-bundle reconstruction knees after aithroscopie reconstruction of ACL. ACL tibial footprints and tunnels were reconstructed on tibial plateau by 64-slice spiral CT workstation （ GE, Volume Share2-AW 4.4 version）. The area of ACL tibial footprint and tibial tunnel were marked and measured. The coverage rate of single and double-bundle on tibial plateau and the tunnels position were compared and calculated. Results （ 1 ） The coverage rate after surgery in single bundle was （50.50 ± 13.58） % while （61.07 ± 11.53） % in double bundle. There was significant difference （t = 2. 370,P = 0. 024） between the two groups. （2） The tunnel center in ACL single-bundle reconstruction was located at a mean of 43.80% in sagittal plane and 55.15% in frontal plane, whereas the natural footprint center located at 44.90% in sagittal plane and 51.85% in frontal plane. There was significant difference in frontal plane （t =5. 592,P =0. 001 ） but no significant difference in sagittal plane （t =0. 631 ,P =0. 536）. （3） In ACL double- bundle reconstruction, the center of AMB （ anteromedial bundle） tibial tunnel was located at a mean of 37.00% of anterior-to-posterior plane and 53.00% of lateral-to-medial plane. The center of natural footprint was located at 37.43% in sagittal plane and 51.14% in frontal plane. No significant difference was found in sagittal plane （t = 0. 120,P = 0. 908） while significant difference was observed in frontal plane （t =4. 192,P =0. 001 ）. The center of PLB （posterolateral bundle） tibial tunnel was located at a mean of 55.00% in sagittal plane and 56.00% in frontal plane while the center of natural footprint was located at 40.79% in sagittal plane and 51.64% in frontal plane. There was significant difference in sagittal plane （ t = 9. 121, P = 0. 001 ） and frontal plane （ t = 7. 280, P = 0. 001 ）.Conclusions The coverage rate of ACL on tibial tunnel was larger in double bundle reconstruction than in single bundle. In order to anatomically reconstruct ACL, individualized reconstruction technique should be adopted. Moreover, the dual-source three-dimensional computed tomography （DSCT） can help us to evaluate the relative location of tibial tunnel and ACL footprint which can provide meaningful guidance for arthroscopic reconstruction of the ACL.