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Ankle replacement, or ankle arthroplasty.
Ankle replacement is becoming the treatment of choice for patients requiring arthroplasty, replacing arthrodesis, that is fusion of the bones.
The improvement the range of motion is the key feature in favor of ankle replacement.compared to arthrodesis.
For late-stage osteoarthritis of the ankle fusion has been considered the best option.
The dilemma between mobility and congruency must be addressed.
Most of the more recent designs feature three components, with a polyethylene meniscal bearing interposed between the two metal bone-anchored components.
The indications for ankle prosthesis:
patients with primary or posttraumatic osteoarthritis with relatively low functional demand
patients with severe ankle rheumatoid arthritis but not severe osteoporosis of the ankle
varus or valgus deformity greater than 15 degrees, severe bony erosion, severe talus subluxation
substantial osteoporosis or osteonecrosis particularly affecting the talus
previous or current infections of the foot, vascular disease or severe neurologic disorders
previous arthrodesis of the ipsilateral hip or knee or severe deformities of these joints.
patients suitable for arthrodesis but rejecting it.
The objectives of the prostheses for ankle joint replacements are:
to replicate original joint function, by restoring an appropriate kinematics at the replaced joint;
to permit a good fixation of the components, involving an appropriate load transfer to the bone and minimum risk of loosening;
to guarantee longevity of the implant,
to attain feasibility of implantation.
Contraindications to ankle prosthesis are:
varus or valgus deformity greater than 15 degrees,
severe bony erosion,
severe talus subluxation
substantial osteoporosis or osteonecrosis particularly affecting the talus
previous or current infections of the foot
vascular disease or severe neurologic disorders
previous arthrodesis of the ipsilateral hip or knee or severe deformities of these joints.
The survivorship of ankle prostheses is roughly 80 percent at eight years, compared with more than 95 percent at 10–15 years for hips and knees.
Outcome studies show a five-year implant survival rate between 67% and 94%, and ten-year survival rates around 75%.
Mobile bearing designs have enabled implant survival rates to continue to improve.
Ankle replacements have a 30-day readmission rate of 2.2%, which is similar to that of knee replacement but lower than that of total hip replacement.
6.6% of patients undergoing primary TAR require a reoperation within 12 months.
Outcome studies show a five-year implant survival rate between 67% and 94% and ten-year survival rates around 75%.
With Mobile bearing designs implant survival rates to continue to improve, reaching as high as 95% for five years and 90% for ten years.
Ankle replacements have a 30-day readmission rate of 2.2%.
30-day readmission rates are similar for ankle replacements and for knee replacements, but lower than that of total hip replacement.
Of patients undergoing primary total ankle replacement 6.6% require a reoperation within 12 months.
Complete recovery from surgery may take 4–9 months, but most individuals can resume their regular activities in 3–4 months.
Experts recommend gentle exercises that do not put stress on the ankle, such as:
walking
swimming
cycling
They also advise avoiding certain sports,: kickboxing and soccer, and limiting high impact activities, such as running or tennis.
Additionally, physical therapists can provide an individualized exercise program to increase the ankle’s range of motion, flexibility, and strength.