Changes in Relative Work of the Lower Extremity and Distal Foot Joints After Total Ankle Replacement: An Exploratory Study.

Ankle osteoarthritis does not only led to lower ankle power generation, but also results in compensatory gait mechanics at the hip and Chopart joints. Much of previous work explored the relative work distribution after total ankle replacement (TAR) either across the lower extremity joints where the foot was modelled as a single rigid unit or across the intrinsic foot joints without considering the more proximal lower limb joints. Therefore, this study aims, for the first time, to combine 3D kinetic lower limb and foot models together to assess changes in the relative joint work distribution across the foot and lower limb joints during level walking before and after patients undergo TAR.

Subtalar Arthrodesis in Patients With Prior Tibiotalar Arthrodesis for Posttraumatic Osteoarthritis.

Background: The tibiotalar arthrodesis for end-stage ankle osteoarthritis is a surgical procedure that leads to a modification of the kinematics of the adjacent joints and may result in the development of secondary osteoarthritic degeneration of the subtalar joint. It has previously been observed that subtalar arthrodesis in this context shows a lower fusion rate than isolated subtalar arthrodesis. This retrospective study reports the results of subtalar joint arthrodesis with previous ipsilateral tibiotalar arthrodesis and suggests some factors that may compromise the fusion of the joint.

Concomitant Triceps Surae Lengthening in Total Ankle Arthroplasty Affects the Mechanical Work at the Ankle Joint.

Background: Previous studies have examined the effect of concomitant triceps surae lengthening on ankle dorsiflexion motion at the time of total ankle arthroplasty (TAA). As plantarflexor muscle-tendon structures are important for producing positive ankle work during the propulsive phase of gait, caution should be exercised when lengthening triceps surae, as it may decrease plantarflexion strength. In order to develop an understanding of the work of the anatomical structures crossing the ankle during propulsion, joint work must be measured.

Early-Term Results of the Cadence Total Ankle Prosthesis: An European Noninventor Study.

Background: Although considerable literature can be found on the outcome of total ankle replacement (TAR), only a few studies have reported the results of the fixed-bearing Cadence prosthesis. This noninventor study reports a consecutive series of 60 Cadence TAR systems with a mean of 2.9 years' follow-up, focusing on clinical and radiographic outcomes and early complications.

Decreased Mechanical Work Demand in the Chopart Joint After Total Ankle Replacement.

Background: The success of total ankle replacement (TAR) must be based on restoring reasonable mechanical balance with anatomical structures that can produce mechanical joint work through elastic (eg, tendons, fascia) or viscoelastic (eg, heel pad) mechanisms, or by active muscle contractions. Yet, quantifying the work distribution across the affected joint and the neighboring foot joints after TAR is lacking. Therefore, the objective of this study was to investigate if there is a change in the joint work distribution across the Ankle, Chopart, Lisfranc and Metatarsophalangeal joints during level walking before and after patients undergo TAR.