title: Volume and contact surface area analysis of bony tunnels in single and double bundle anterior cruciate ligament reconstruction using autograft tendons: in vivo three-dimensional imaging analysis.
abstract: BACKGROUND
  Regarding reconstruction surgery of the anterior cruciate ligament (ACL), there is still a debate whether to perform a single bundle (SB) or double bundle (DB) reconstruction. The purpose of this study was to analyze and compare the volume and surface area of femoral and tibial tunnels during transtibial SB versus transportal DB ACL reconstruction.
  
  
  METHODS
  A consecutive series of 26 patients who underwent trantibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft from January 2010 to October 2010 were included in this study. Three-dimensional computed tomography (3D-CT) was taken within one week after operation. The CT bone images were segmented with use of Mimics software v14.0. The obtained digital images were then imported in the commercial package Geomagic Studio v10.0 and SketchUp Pro v8.0 for processing. The femoral and tibial tunnel lengths, diameters, volumes and surface areas were evaluated. A comparison between the two groups was performed using the independent-samples t-test. A p-value less than the significance value of 5% (p < 0.05) was considered statistically significant.
  
  
  RESULTS
  Regarding femur tunnels, a significant difference was not found between the tunnel volume for SB technique (1,496.51 ± 396.72 mm(3)) and the total tunnel volume for DB technique (1,593.81 ± 469.42 mm(3); p = 0.366). However, the total surface area for femoral tunnels was larger in DB technique (919.65 ± 201.79 mm(2)) compared to SB technique (810.02 ± 117.98 mm(2); p = 0.004). For tibia tunnels, there was a significant difference between tunnel volume for the SB technique (2,070.43 ± 565.07 mm(3)) and the total tunnel volume for the DB technique (2,681.93 ± 668.09 mm(3); p ≤ 0.001). The tibial tunnel surface area for the SB technique (958.84 ± 147.50 mm(2)) was smaller than the total tunnel surface area for the DB technique (1,493.31 ± 220.79 mm(2); p ≤ 0.001).
  
  
  CONCLUSIONS
  Although the total femoral tunnel volume was similar between two techniques, the total surface area was larger in the DB technique. For the tibia, both total tunnel volume and the surface area were larger in DB technique.
authors.affiliation: Department of Orthopedic Surgery, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Yang
authors.affiliation: Department of Mechanical Engineering, Korea University, Seoul, Korea.
authors.forename: Minho
authors.initials: M
authors.lastname: Chang
authors.affiliation: Catholic Institute for Applied Anatomy, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Dai-Soon
authors.initials: DS
authors.lastname: Kwak
authors.affiliation: Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
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 / Q000379:methods*; D064592:Autografts; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D011859:Radiography; D013708:Tendon Injuries / Q000000981:diagnostic imaging* / Q000534:rehabilitation / Q000601:surgery; D013710:Tendons / Q000637:transplantation; D013977:Tibia / Q000000981:diagnostic imaging* / Q000601:surgery
keywords: Anterior cruciate ligament reconstruction; Double bundle; Single bundle; Surface area; Tunnel; Volume