Kinematics of meniscal- and ACL-transected mouse knees during controlled tibial compressive loading captured using...

Area of Science:

• Orthopaedic Research
• Biomechanical Engineering
• Osteoarthritis Pathogenesis

Background:

• Post-traumatic osteoarthritis (OA) research extensively studies morphological, molecular, and genetic pathways.
• The impact of surgical injury models like destabilization of the medial meniscus (DMM) and anterior cruciate ligament transection (ACLT) on joint kinematics remains undercharacterized.
• Understanding joint kinematics is vital for characterizing disease progression in OA models.

Purpose of the Study:

• To compare joint kinematics in DMM and ACLT models against intact joints under controlled tibial compressive loading.
• To investigate the hypothesis that DMM and ACLT models exhibit distinct joint instability patterns compared to intact joints.
• To elucidate the role of joint instability in OA initiation and severity within these pre-clinical models.

Main Methods:

• Utilized cadaver adult C57BL/6 mice with DMM or ACLT in one knee and intact contralateral controls.
• Applied roentgen stereophotogrammetry (RSA) with fiducial markers to analyze rigid body kinematics of the tibia and femur.
• Subjected all limbs to controlled compressive loads ranging from 0 to 9 N.

Main Results:

• ACLT joints exhibited dislocation even prior to load application, indicating significant instability.
• DMM and intact joints demonstrated comparable kinematics under compressive loading.
• Significant differences in joint instability were observed between ACLT, DMM, and intact joints.

Conclusions:

• Rigorous kinematic analysis is essential for defining the role of joint instability in animal models of OA.
• ACLT and DMM models display distinct joint instability profiles under mechanical loading.
• These findings highlight the importance of kinematic characterization for accurate OA model interpretation.