The influence of sequential debridement in total knee arthroplasty on the flexion axis of the knee using computer-aided navigation.

The effects of osteophyte debridement, bony cuts, and soft tissue releases on the functional flexion axis of the knee can be assessed by evaluating 3D kinematics following each step of a total knee arthroplasty. Using a navigated knee system with dedicated software, the functional flexion axis (helical axis) can be determined after each step. Five paired fresh-frozen cadaveric knees were used with a CT scan performed on each specimen identifying implanted fiducial markers.

Fatigue performance of composite analogue femur constructs under high activity loading.

Synthetic mechanical analogue bone models are valuable tools for consistent analysis of implant performance in both equilibrium and fatigue biomechanical testing. Use of these models has previously been limited by the poor fatigue performance when tested under realistic service loads. An objective was to determine whether a new analogue bone model (Fourth-Generation) using enhanced analogue cortical bone provides significantly improved resistance to high load fracture and fatigue as compared to the current (Third-Generation) bone models in clinically relevant in situ type testing of total hip implants.