title: Tibiofemoral joint contact area and pressure after single- and double-bundle anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  The purpose of this study was to compare the tibiofemoral contact area and pressure after single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction by use of 2 femoral and 2 tibial tunnels in intact cadaveric knees.
  
  
  METHODS
  Tibiofemoral contact area and mean and maximum pressures were measured by pressure-sensitive film (Fujifilm, Valhalla, NY) inserted between the tibia and femur. The knee was subjected to a 1,000-N axial load by use of a uniaxial testing machine at 0 degrees , 15 degrees , 30 degrees , and 45 degrees of flexion. Three conditions were evaluated: (1) intact ACL, (2) SB ACL reconstruction (n = 10 knees), and (3) DB ACL reconstruction (n = 9 knees).
  
  
  RESULTS
  When compared with the intact knee, DB ACL reconstruction showed no significant difference in tibiofemoral contact area and mean and maximum pressures. SB ACL reconstruction had a significantly smaller contact area on the lateral and medial tibiofemoral joints at 30 degrees and 15 degrees of flexion. SB ACL reconstruction also had significantly higher mean pressures at 15 degrees of flexion on the medial tibiofemoral joint and at 0 degrees and 15 degrees of flexion on the lateral tibiofemoral joint, as well as significantly higher maximum pressures at 15 degrees of flexion on the lateral tibiofemoral joint.
  
  
  CONCLUSIONS
  SB ACL reconstruction resulted in a significantly smaller tibiofemoral contact area and higher pressures. DB ACL more closely restores the normal contact area and pressure mainly at low flexion angles.
  
  
  CONCLUSIONS
  Our findings suggest that the changes in the contact area and pressures after SB ACL reconstruction may be one of the causes of osteoarthritis on long-term follow-up. DB ACL reconstruction may reduce the incidence of osteoarthritis by closely restoring contact area and pressure.
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Mario
authors.initials: M
authors.lastname: Ferretti
authors.forename: Max
authors.initials: M
authors.lastname: Ekdahl
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000328:Adult; D000368:Aged; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D002102:Cadaver; D005269:Femur; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D011184:Postoperative Period; D011312:Pressure; D016059:Range of Motion, Articular; D019651:Plastic Surgery Procedures / Q000379:methods*; D013977:Tibia