title: Tibiofemoral contact mechanics following posterior root of medial meniscus tear, repair, meniscectomy, and allograft transplantation.
abstract: OBJECTIVE
  The purposes of this study were to evaluate the effect on tibiofemoral contact mechanics of repair of the posterior root of the medial meniscus and the effect of meniscal allograft transplantation (MAT) with medial collateral ligament (MCL) release at different flexion angles.
  
  
  METHODS
  Ten fresh-frozen human cadaveric knees (five pairs) were used. A digital pressure sensor was inserted by capsulotomy, and experiments were performed serially under the following six conditions, that is, with an intact medial meniscus (normal controls), with a root tear, after root repair, after total meniscectomy, after MAT, and after MAT plus MCL release. During each experiment, knees were positioned at 0°, 30°, 60°, and 90° of flexion, and peak pressure (kPa) and contact area (cm2) were measured.
  
  
  RESULTS
  At 0° of flexion, contact pressure did not differ among the six experimental settings. However, at 30° and 60° of flexion, contact pressure differed significantly between root tear and root repair specimens (p = 0.04 and 0.03, respectively), and between total meniscectomy and MAT specimens (p = 0.02 and 0.03, respectively). On the other hand, mean contact pressures were different between normal (476.7 ± 473.1 and 573.3 ± 479.1 kPa) and root repair (575.7 ± 357.8 and 598.6 ± 415.8), and between normal and MAT (635.7 ± 437.4 and 674.3 ± 533.2). At 0°, 30°, 60°, and 90° of flexion, contact areas differed significantly between normal and total meniscectomy specimens (p = 0.02, 0.01, 0.02, and 0.02, respectively), and between MAT and total meniscectomy specimens (p = 0.03, 0.02, 0.02, and 0.03, respectively). Contact areas differed significantly between root tear and root repair specimens at 60° of flexion (p = 0.04), and between normal control and root repair specimens at 60° and 90° of flexion (p = 0.03 and 0.04, respectively). The effects of MAT plus MCL release on contact mechanics were not different from the effects of MAT alone (n.s.).
  
  
  CONCLUSIONS
  Both meniscal root repair and transplantation of meniscus improved contact mechanics, but it did not appear that repair of the meniscal root or transplantation of meniscus restores the biomechanical function back to normal level. The MAT plus MCL release was similar to those after MAT alone. Therefore, it is better to preserve meniscus and MCL release could be done during the MAT.
authors.affiliation: Department of Orthopedic Surgery, Seoul Paik Hospital, Inje University, Seoul, Korea.
authors.forename: Jin Goo
authors.initials: JG
authors.lastname: Kim
authors.forename: Yong Seuk
authors.initials: YS
authors.lastname: Lee
authors.forename: Tae Soo
authors.initials: TS
authors.lastname: Bae
authors.forename: Jeong Ku
authors.initials: JK
authors.lastname: Ha
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Lee
authors.forename: Young Jae
authors.initials: YJ
authors.lastname: Kim
authors.forename: Ho Jong
authors.initials: HJ
authors.lastname: Ra
mesh_terms: D000328:Adult; D064591:Allografts; D001696:Biomechanical Phenomena; D005260:Female; D005269:Femur / Q000502:physiology; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery* / Q000637:transplantation; D008875:Middle Aged; D012421:Rupture; D013977:Tibia / Q000502:physiology; D000070600:Tibial Meniscus Injuries