title: New rabbit knee model of posttraumatic joint contracture: indirect capsular damage induces a severe contracture.
abstract: Reported models of joint contracture fail to result in severe motion loss. Our purpose was to develop a rabbit model of knee contracture and compare it to another well-accepted model to determine if more severe stiffness can be achieved. Sixteen skeletally mature New Zealand White female rabbits had their right knee operated to create 3-mm defects on the noncartilaginous portions of the femoral condyles, hyperextend the joint to disrupt the posterior capsule, and immobilize the joint in maximum flexion with a Kirschner-wire for 8 weeks (group I). Sixteen additional rabbits were operated on using an identical protocol except for the absence of capsular injury (group II). In each group, mechanical testing was performed at the time of Kirschner-wire release in eight animals, and 16 weeks after remobilization in eight animals. At immobilization release, the average contracture was 76 +/- 24 degrees in group I versus 20 +/- 10 degrees in group II (p < 0.001). Sixteen weeks after remobilization, the mean contracture was 49 +/- 15 degrees group I versus 11 +/- 10 degrees in group II (p < 0.001). When associated with bone perforations and immobilization in forced flexion, injury to the posterior capsule results in a severe contracture in the rabbit knee.
authors.affiliation: Department of Orthopedic Surgery and Orthopedic Biomechanics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA.
authors.forename: Sergiy
authors.initials: S
authors.lastname: Nesterenko
authors.forename: Mark E
authors.initials: ME
authors.lastname: Morrey
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Abdel
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.forename: Scott P
authors.initials: SP
authors.lastname: Steinmann
authors.forename: Bernard F
authors.initials: BF
authors.lastname: Morrey
authors.forename: Joaquin
authors.initials: J
authors.lastname: Sanchez-Sotelo
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003286:Contracture / Q000209:etiology*; D004195:Disease Models, Animal; D005260:Female; D007103:Immobilization / Q000009:adverse effects; D017746:Joint Capsule / Q000293:injuries*; D007593:Joint Instability / Q000209:etiology; D007718:Knee Injuries / Q000150:complications*; D007719:Knee Joint; D011817:Rabbits