title: Double-bundle posterior cruciate ligament reconstruction: a biomechanical analysis of simulated early motion and partial and full weightbearing on common reconstruction grafts.
abstract: OBJECTIVE
  The purpose of this study was to determine the biomechanical effects of simulated immediate motion and weightbearing during rehabilitation on different double-bundle posterior cruciate ligament reconstruction (DB-PCLR) graft options.
  
  
  METHODS
  Nine each of commercially prepared (allograft) Achilles tendon allografts, fresh-frozen (autograft) bone-patellar tendon-bone grafts, and fresh-frozen quadriceps tendon grafts were paired with commercially prepared anterior tibialis allografts, fresh-frozen semitendinosus grafts, and fresh-frozen semitendinosus grafts, respectively. Graft pairs were loaded to simulate early range of motion on a stationary bicycle, partial weightbearing (30 %), and full weightbearing.
  
  
  RESULTS
  Acquired laxity (displacement, mm) between graft pairs was not significantly different during simulated early range of motion. However, during simulated partial weightbearing, the median acquired laxity of the patellar tendon/semitendinosus pair (1.06 mm) was significantly less than that of the quadriceps tendon/semitendinosus (1.50 mm, p = 0.01) and Achilles/anterior tibialis (1.44 mm, p = 0.003) graft pairs. During simulated full weightbearing, significantly less acquired laxity was observed for the patellar tendon/semitendinosus graft pair (2.38 mm) compared to the Achilles/anterior tibialis pair (4.85 mm, p = 0.04), but a significant difference was not observed compared to the QT/semitendinosus graft pair (3.91 mm, n.s.). There were no significant differences in the ultimate loads between any of the graft pairs.
  
  
  CONCLUSIONS
  Simulated early range of motion and early partial weightbearing did not result in clinically significant acquired graft laxity in common graft options utilized for DB-PCLR. However, simulated full weightbearing did result in clinically significant acquired graft laxity, and therefore, early rehabilitation protocols should avoid implementing full weightbearing that could contribute to graft failure.
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, 81657, USA.|The Steadman Clinic, 181 West Meadow Drive, Suite 400, Vail, CO, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Mook
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, 81657, USA.
authors.forename: David
authors.initials: D
authors.lastname: Civitarese
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, 81657, USA.
authors.forename: Travis Lee
authors.initials: TL
authors.lastname: Turnbull
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, 81657, USA.
authors.forename: Nicholas I
authors.initials: NI
authors.lastname: Kennedy
authors.affiliation: Howard Head Sports Medicine Center, Vail, CO, USA.
authors.forename: Luke
authors.initials: L
authors.lastname: O'Brien
authors.affiliation: The Steadman Clinic, 181 West Meadow Drive, Suite 400, Vail, CO, USA.
authors.forename: Jarod B
authors.initials: JB
authors.lastname: Schoeberl
authors.affiliation: Steadman Philippon Research Institute, Vail, CO, 81657, USA. drlaprade@sprivail.org.|The Steadman Clinic, 181 West Meadow Drive, Suite 400, Vail, CO, USA. drlaprade@sprivail.org.
authors.forename: Robert F
authors.initials: RF
authors.lastname: LaPrade
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D064594:Bone-Patellar Tendon-Bone Grafts; D004434:Early Ambulation; D005260:Female; D006801:Humans; D009068:Movement; D000072229:Posterior Cruciate Ligament Reconstruction / Q000379:methods* / Q000534:rehabilitation*; D016059:Range of Motion, Articular; D013710:Tendons / Q000637:transplantation; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous; D016474:Weight-Bearing
keywords: Allograft; Autograft; Double-bundle posterior cruciate ligament reconstruction; Range of motion; Rehabilitation; Weightbearing