前交叉韧带股骨止点的放射学研究

Radiographic Study of the Femoral Footprints of the Anterior Cruciate Ligament

目的：通过分析前交叉韧带（ACL）股骨止点的X线影像学位置与特点,为ACL双束重建时股骨骨道定位及术后评估提供依据。方法：30例成人膝关节标本,屈膝60°,根据纤维张力的不同将ACL分成前内束（anteromedial band,AMB）和后外束（posterolateral band,PLB）,将两束自股骨止点切除,用金属丝标记ACL股骨止点边缘及两束交界线,用金属钉标记两束股骨止点中心点;同时标记模拟ACL重建术AMB股骨骨道的中心点。测量膝关节髁间窝位X线片及侧位片中的上述标记位置。结果：在髁间窝位X线平片上：AMB股骨止点范围是9∶55±16.52′~11∶20±4.50′（右膝）,0∶42±6.12′~2∶08±14.50′（左膝）,其中心点位于10∶18±12′（右膝）,1∶40±10′（左膝）;PLB股骨止点的范围是8∶55±7.17′~10∶23±21.17′（右膝）,1∶38±17.5′~2∶08±5.70′（左膝）,其中心点位于9∶30±16.32′（右膝）,2∶32±14.12′（左膝）;模拟ACL重建中AMB股骨骨道中心点位置是10∶55±5′（右膝）,1∶03±8′（左膝）;AMB、PLB股骨止点分界线的位置在9∶55±16.52′~10∶23±21.17′（右膝）,1∶38±17.15′~2∶08±14.50′（左膝）。在侧位X线平片上：AMB股骨止点范围在股骨外髁长度的7.23±4.09%~38.66±8.06%,股骨外髁高度的3.99±4.48%~41.38±10.44%,其中心点位于股骨外髁长度的22.0±4.43%、高度的27.1±8.08%;PLB股骨止点范围在股骨外髁长度的13.05±6.37%~46.22±12.88%,股骨外髁高度的38.32±22.37%~65.41±14.25%,其中心点位于股骨外髁长度的32.7±6.20%、高度的51.2±9.65%;模拟ACL重建中AMB股骨骨道中心点位置为股骨外髁长度的16.0±6.57%、高度的14.97±6.36%。结论：AMB股骨等长重建点与AMB止点解剖中心点不重合。ACL股骨止点X线影像学研究可以为ACL双束重建术中的股骨骨道定位及术后骨道位置评估提供实验依据。

Objective To provide evidence on the femoral tunnels placement of the anteromedial bundle （AMB） and posterolateral bundle （PLB） for anterior cruciate ligament （ACL） double bundle reconstruction, the femoral footprints of the two bundles were analyzed by radiography. Methods The natural ACL was divided into AMB and PLB according to their different tension at 60° knee flexion. Footprints of the anteromedial and posterolateral bundles of the anterior cruciate ligament were preserved on 15 matched pairs of fresh-frozen human cadaveric femurs （30 femurs total）. The borderline and the centers of AMB and PLB were then marked. The point T, which referred to the center of the tunnel of AMB, was also marked when simulating reconstruction. The data described above were analyzed on a notch and lateral view of radiograph. Results On notch views, AMB was located at 9：55±16.52′-11：20±4.50′ （right） ,0：42±6.12′-2-2：08±14.50′ （left）, the center of AMB was lo- cated at 10： 18±12′ （right）, 1 ： 40±10′（left）. PLB was located at 8′ 55±7.17′ -- 10： 23±21.17′ （right）, 1：38±17.15′--2：08±5.70′ （left）, and its center was at 9：30±16.32′ （right）,2：32±14. 12′ （left）. The borderline between AMB and PLB ranged from 9 ： 55±16.52′ to 10：23 ±21.17′ （right）, from 1：38±17.15′ to 2 ： 08±14.50′ （left）. The point T was located at 10′55±5′（right）, l：03±8′（left）. On the lateral view, the centeral AMB was located at 22.0±4.43% from the posterior margin in the anteroposterior and 27.1±8.08% from the roof in the proximal to distal direction. The borderline of AMB ranged from 7.23±4.09 % to 38.66±8.06 % from the posterior margin, and ranged from 3.99±4.48 % to 41.38±10.44 from the roof. The center of the center of PLB was located at 32.7±6.20% from the posterior margin and 51.2±9.65% from the roof. The borderline of PLB ranged from 13.05 ± 6.37% to 46.22 ± 12.88% from the posterior margin, and ranged from 38.32±22.37% to 65.41±14.25% from the roof. The point T was located at 16.0±6.57% from the posterior margin, 14.97±6.36% from the roof. Conclusion Radiographic study of the femoral footprints of the AMB and PLB of the ACL might be helpful in drilling correct bone tunnels of these two bundles and evaluating their postoperative positions. The position of T was different from the center of AMB attachment.