title: The sagittal plane angle and tunnel-related complications in double-bundle anterior cruciate ligament reconstruction using the transportal technique: an in vivo imaging study.
abstract: OBJECTIVE
  To evaluate the relation between the tunnel angle in the 3 orthogonal planes, especially the sagittal plane, which can be influenced by knee flexion during drilling, and the incidence of complications from the transportal technique using in vivo imaging data.
  
  
  METHODS
  Fifty-one patients who underwent anatomic double-bundle anterior cruciate ligament reconstruction by the transportal technique were evaluated retrospectively. A 3-dimensional surface model was made using an axial computed tomography scan obtained after anterior cruciate ligament reconstruction. The tunnel length, posterior cortical damage, proximity between the outer orifice of the tunnel and lateral collateral ligament (LCL) origin, and medial femoral condyle cartilage damage were evaluated on a 3-dimensional computed tomography scan and 3-T magnetic resonance imaging. Correlations between those parameters and the tunnel angle in the coronal, axial, and sagittal planes were analyzed.
  
  
  RESULTS
  A tunnel length of less than 30 mm developed in 4 cases (8%) in the anteromedial tunnel and in 1 case (2%) in the posterolateral (PL) tunnel. Posterior cortical damage developed in 12 cases (23%). A distance from the outer orifice of the tunnel to the LCL origin of less than 3 mm occurred in 18 cases (35.2%) in the PL tunnel. Medial femoral condyle cartilage damage was detected in 3 cases (6%). A positive correlation was observed between the sagittal angle and anteromedial tunnel length (P = .002, r = 0.547). The sagittal angle in the group with posterior cortical damage was lower than that in the group with no posterior cortical damage (P = .002). A negative correlation was observed between the distance from the outer orifice of the PL tunnel to the LCL origin and the sagittal angle (P = .002, r = -0.55).
  
  
  CONCLUSIONS
  Drilling at a higher angle in the sagittal plane decreased the incidence of posterior cortical damage and a short anteromedial tunnel. However, drilling at a higher angle shortened the distance to the LCL origin for the PL tunnel.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Department of Orthopaedic Surgery, Soonchunhyang University School of Medicine, Bucheon Hospital, Bucheon, South Korea.
authors.forename: Sin Hyung
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Orthopaedic Surgery, Inje University School of Medicine, Haeundae Paik Hospital, Busan, South Korea.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Moon
authors.affiliation: Department of Orthopaedic Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, South Korea.
authors.forename: Byung Hoon
authors.initials: BH
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, South Korea.
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Chae
authors.affiliation: Department of Orthopaedic Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, South Korea.
authors.forename: Jin Hwan
authors.initials: JH
authors.lastname: Ahn
authors.affiliation: School of Mechanical Engineering, Korea University, Seoul, South Korea.
authors.forename: Minho
authors.initials: M
authors.lastname: Chang
authors.affiliation: Department of Orthopaedic Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, South Korea. Electronic address: mdwang88@gmail.com.
authors.forename: Joon Ho
authors.initials: JH
authors.lastname: Wang
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007718:Knee Injuries / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult