title: Intertunnel relationships in combined anterior cruciate ligament and posterolateral corner reconstruction: an in vivo 3-dimensional anatomic study.
abstract: BACKGROUND
  Combined anterior cruciate ligament (ACL) and posterolateral corner (PLC) injuries are relatively common, and tunnel convergence could occur in combined ACL and PLC reconstruction.
  
  
  OBJECTIVE
  This study sought to elucidate the ranges of angles and distances of lateral collateral ligament (LCL) and popliteus tendon (PT) femoral tunnels that do not violate the intercondylar notch distally and ACL tunnels proximally during combined ACL and PLC reconstruction.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  Three-dimensional anatomic knee models were developed using customized software from computed tomography images of 14 patients at 0°, 90°, and 120° of flexion. Single-bundle (SB) and double-bundle (DB) ACL tunnels using the transtibial method for anteromedial bundles and the anteromedial portal method for posterolateral bundles were created. The ranges of safe angles and distances were measured at 10° and 20° posterior, neutral (0°), and 10° and 20° anterior on the horizontal plane relative to the transepicondylar axis from the isometric LCL and PT femoral insertions. The SB ACL reconstruction using the accessory medial portal and LCL reconstruction using the anatomic footprint were also analyzed.
  
  
  RESULTS
  Distal and proximal angles from insertions of the LCL and PT, not violating the intercondylar notch or the ACL tunnels, increased as the LCL or PT headed from a posterior to anterior direction. Safe distances from the LCL and PT femoral insertions were approximately over 35 mm distally and 30 mm proximally. For SB ACL reconstruction using the accessory medial portal, safe angles were larger proximally than those of SB ACL reconstruction using the transtibial technique. For LCL reconstruction using the anatomic footprint, proximal angles were significantly smaller than those of the isometric LCL.
  
  
  CONCLUSIONS
  Considering the relationship between the LCL and PT tunnels and fixation strength, tunneling will be safe when the LCL and PT are positioned at an angle of approximately 20° anterior and 10° proximal to the transepicondylar axis.
  
  
  CONCLUSIONS
  These results will help to reduce the incidence of tunnel convergence in combined ACL and PLC reconstructions.
authors: Arthroscopy and Joint Research Institute, College of Medicine, Yonsei University, Seoul, Korea.
authors: Sung-Jae
authors: SJ
authors: Kim
authors: Chong Bum
authors: CB
authors: Chang
authors: Chong Hyuk
authors: CH
authors: Choi
authors: Yon-Sik
authors: YS
authors: Yoo
authors: Sung-Hwan
authors: SH
authors: Kim
authors: Jae Han
authors: JH
authors: Ko
authors: Kwan Kyu
authors: KK
authors: Park
mesh_terms: D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction; D006801:Humans; D021621:Imaging, Three-Dimensional; D007718:Knee Injuries / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D011859:Radiography; D055815:Young Adult