A Novel Vector-Based Computer Tomography Alignment Measurement Protocol for Total Knee Arthroplasty.

Introduction: Component position and overall limb alignment following total knee arthroplasty (TKA) have been shown to influence implant survivorships and clinical outcomes. While most surgeons utilize standard x-ray imaging for preoperative joint assessments, computer tomography scans (CT), coupled with automated digital analyses have been shown to provide additional surgical and clinical benefits. However, to date, a postoperative CT measurement protocol has not been reported for robotic-arm assisted TKA (RATKA).

Robotic-Arm Assisted Total Knee Arthroplasty Demonstrated Soft Tissue Protection.

Introduction: While total knee arthroplasty (TKA) procedures have demonstrated clinical success, occasionally intraoperative complications can occur. Collateral or posterior cruciate ligament injury, instability, extensor mechanism disruption, and tibiofemoral or patellofemoral dislocation are among a few of the intraoperatively driven adverse events prevalently ranked by The Knee Society. Robotic-arm assisted TKA (RATKA) provides a surgeon the ability to three-dimensionally plan a TKA and use intraoperative visual, auditory, and tactile feedback to ensure that only the desired bone cuts are made.

In vivo kinematics of a robot-assisted uni- and multi-compartmental knee arthroplasty.

Background: There is great interest in providing reliable and durable treatments for one- and two-compartment arthritic degeneration of the cruciate-ligament intact knee. One approach is to resurface only the diseased compartments with discrete unicompartmental components, retaining the undamaged compartment(s). However, placing multiple small implants into the knee presents a greater surgical challenge than total knee arthroplasty, so it is not certain that the natural knee mechanics can be maintained or restored.

Kinematic and contact stress analysis of posterior malleolus fractures of the ankle.

Objective: To determine if there are measurable dynamic contact stress aberrations and kinematic abnormalities (instability) that have not been observed in conventional static loading studies of posterior malleolar ankle fractures.

Design: Cadaveric fracture model.

Setting: Biomechanics laboratory.

Gait cycle finite element comparison of rotating-platform total knee designs.

Functional load transmission and kinematic performance were compared for standard versus posterior-stabilized versions of a rotating-platform total knee implant, over a standardized loading cycle, using three-dimensional contact finite element analysis. These two design variants differ primarily in terms of the latter's polyethylene insert having a cam that engages with the femoral component during appreciable flexion, thereby inducing femoral component rollback. The finite element model, previously validated experimentally, afforded direct comparisons of anterior lift-off of the insert from the tibial tray, of bearing mobility (insert rotation about the pivot post), of femoral rollback, and of metal-on-polyethylene contact stresses at the bearing and backside surfaces of the insert.