Hui Catherine, Pi Yeli, Swami Vimarsha, Mabee Myles, Jaremko Jacob L
Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.
Department of Radiology/Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada.
Orthop J Sports Med. 2016 Dec 7;4(12):2325967116673797. doi: 10.1177/2325967116673797. eCollection 2016 Dec.
Anatomic single bundle anterior cruciate ligament (ACL) reconstruction is the current gold standard in ACL reconstructive surgery. However, placement of femoral and tibial tunnels at the anatomic center of the ACL insertion sites can be difficult intraoperatively. We developed a "virtual arthroscopy" program that allows users to identify ACL insertions on preoperative knee magnetic resonance images (MRIs) and generates a 3-dimensional (3D) bone model that matches the arthroscopic view to help guide intraoperative tunnel placement.
To test the validity of the ACL insertion sites identified using our 3D modeling program and to determine the accuracy of arthroscopic ACL reconstruction guided by our "virtual arthroscopic" model.
Descriptive laboratory study.
Sixteen cadaveric knees were prescanned using routine MRI sequences. A trained, blinded observer then identified the center of the ACL insertions using our program. Eight knees were dissected, and the centers of the ACL footprints were marked with a screw. In the remaining 8 knees, arthroscopic ACL tunnels were drilled into the center of the ACL footprints based on landmarks identified using our virtual arthroscopic model. Postprocedural MRI was performed on all 16 knees. The 3D distance between pre- and postoperative 3D centers of the ACL were calculated by 2 trained, blinded observers and a musculoskeletal radiologist.
With 2 outliers removed, the postoperative femoral and tibial tunnel placements in the open specimens differed by 2.5 ± 0.9 mm and 2.9 ± 0.7 mm from preoperative centers identified on MRI. Postoperative femoral and tibial tunnel centers in the arthroscopic specimens differed by 3.2 ± 0.9 mm and 2.9 ± 0.7 mm, respectively.
Our results show that MRI-based 3D localization of the ACL and our virtual arthroscopic modeling program is feasible and does not show a statistically significant difference to an open arthrotomy approach. However, additional refinements will be required to improve the accuracy and consistency of our model to make this an effective tool for surgeons performing anatomic single-bundle ACL reconstructions.
Arthroscopic anatomic single-bundle ACL reconstruction is the current gold standard for ACL reconstruction; however, the center of the ACL footprint can be difficult to identify arthroscopically. Our novel modeling can improve the identification of this important landmark intraoperatively and decrease the risk of graft malposition and subsequent graft failure.
解剖单束前交叉韧带（ACL）重建是目前ACL重建手术的金标准。然而，在手术中，将股骨和胫骨隧道放置在ACL插入部位的解剖中心可能具有挑战性。我们开发了一个“虚拟关节镜检查”程序，该程序允许用户在术前膝关节磁共振成像（MRI）上识别ACL插入点，并生成一个与关节镜视图相匹配的三维（3D）骨模型，以帮助指导术中隧道放置。
测试使用我们的3D建模程序识别的ACL插入点的有效性，并确定由我们的“虚拟关节镜”模型引导的关节镜下ACL重建的准确性。
描述性实验室研究。
使用常规MRI序列对16个尸体膝关节进行预扫描。然后，一名经过培训的不知情观察者使用我们的程序识别ACL插入的中心。解剖8个膝关节，并用螺钉标记ACL足迹的中心。在其余8个膝关节中，根据使用我们的虚拟关节镜模型识别的标志，在ACL足迹的中心钻关节镜下ACL隧道。对所有16个膝关节进行术后MRI检查。由两名经过培训的不知情观察者和一名肌肉骨骼放射科医生计算术前和术后ACL的3D中心之间的3D距离。
去除2个异常值后，开放标本中术后股骨和胫骨隧道的放置与MRI上术前确定的中心相差2.5±0.9mm和2.9±0.7mm。关节镜检查标本中术后股骨和胫骨隧道中心分别相差3.2±0.9mm和2.9±0.7mm。
我们的结果表明，基于MRI的ACL 3D定位和我们的虚拟关节镜建模程序是可行的，与开放关节切开术方法相比，没有显示出统计学上的显著差异。然而，需要进一步改进以提高我们模型的准确性和一致性，使其成为进行解剖单束ACL重建的外科医生的有效工具。
关节镜下解剖单束ACL重建是目前ACL重建的金标准；然而，ACL足迹的中心在关节镜下可能难以识别。我们的新型建模可以改善术中对这一重要标志的识别，并降低移植物位置不当和随后移植物失败的风险。
