title: Biomechanics of single-tunnel double-bundle anterior cruciate ligament reconstruction using fixation with a unique expandable interference screw.
abstract: BACKGROUND
  Single-tunnel double-bundle (STDB) anterior cruciate ligament (ACL) reconstruction can restore biomechanical function and anatomic structure, but existing methods of graft fixation are not adequate. The aims of this study are to examine knee biomechanics after STDB reconstruction using a unique expandable interference screw for fixation.
  
  
  METHODS
  The biomechanical parameters of six pairs of human cadaveric knee specimens were measured with the ACL intact, after ACL removal, and after STDB reconstruction using the interference screw or single-tunnel single-bundle (STSB) reconstruction. Anterior tibial translation under 134 N anterior tibial load in a neutral position as well as in 15° and 30° internal and external knee rotation and the internal tibial rotation angle under the rotatory load (5 N·m internal tibial rotation) were measured.
  
  
  RESULTS
  Anterior tibial translations at each degree of knee flexion in the STDB group were significantly less than in the STSB group (all, P<0.05). The internal rotation angles in the STSB group at five flexion angles were significantly higher than in the ACL intact group, whereas there were significantly less than those of the ACL absent group (P<0.05). Under rotatory loads in the neutral position, the tibial internal rotation angles of the STDB group were significantly lower than in the STSB group at all flexion angles (all, P<0.05).
  
  
  CONCLUSIONS
  STDB ACL reconstruction with the expandable interference screw provides better anteroposterior and rotational stability than STSB reconstruction.
  
  
  CONCLUSIONS
  The technique provides the advantages of double-bundle reconstruction using a single-tunnel technique.
authors.affiliation: Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China.
authors.forename: Hua-yang
authors.initials: HY
authors.lastname: Huang
authors.affiliation: Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China; Bioenginering Laboratory, Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China.
authors.forename: Yong-liang
authors.initials: YL
authors.lastname: Ou
authors.affiliation: Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China.
authors.forename: Ping-yue
authors.initials: PY
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China; Bioenginering Laboratory, Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China.
authors.forename: Hong-yuan
authors.initials: HY
authors.lastname: Shen
authors.affiliation: Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, General Hospital of Guangzhou Military Command of PLA, Guangdong 510010, China. Electronic address: doctorzhengxiaofei@hotmail.com.
authors.forename: Xiao-fei
authors.initials: XF
authors.lastname: Zheng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation* / Q000379:methods*; D001863:Bone Screws; D002102:Cadaver; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D012399:Rotation; D013710:Tendons / Q000637:transplantation*; D013977:Tibia / Q000502:physiology; D014057:Tomography, X-Ray Computed; D019415:Torque; D016474:Weight-Bearing / Q000502:physiology*
keywords: Anterior cruciate ligament (ACL); Biomechanics; Expandable interference screw; Single-tunnel double-bundle ACL reconstruction