Total Ankle Arthroplasty

Original Editor - Sharon Schumacher, Carlos De Coster

Top Contributors - Jeremy Brady, Jorge Solorzano, Admin, Scott Buxton, Kim Jackson, Dana Williams, Shaimaa Eldib, Carlos De Coster, Neha Palsule, 127.0.0.1, Mariam Hashem, Simisola Ajeyalemi, Uchechukwu Chukwuemeka, Tony Lowe, George Prudden, Ryan De Laet, Rachael Lowe, Rucha Gadgil, Lucinda hampton, Sharon Schumacher, Jess Bell and Michael Kauffmann  

Search Strategy

PubMed (http://www.ncbi.nlm.nih.gov/pubmed)

MeSH terms:

• Complications
• Diagnosis
• Drug therapy
• Epidemiology
• Etiology
• Pathology
• Rehabilitation
• Surgery
• Therapy

Medline Plus

Used keyword:

• Ankle replacement
  

Definition/Description

Ankle replacement surgery has been available for over two decades however it is a far less common procedure than hip or knee arthroplasty owing to the less frequent incidence of osteoarthritis ankle pathology. The majority of ankle osteoarthritis is secondary to trauma.

Until relatively recently, ankle joint arthrodesis (fusion) was the gold standard of treatment, but this was not without its complications, e.g. non-union,Osteoarthritis in the other mid/hind foot joints and stiffness and loss of proprioception

     Total ankle replacement was developed in the 1970's but initially was plagued with high long term failure rates. The older prosthesis loosened or malfunctioned and frequently needed to be removed.  In the late 70's Dr. Frank G. Alvine an orthopedic surgeon from Sioux Falls, SD developed the Agility Ankle which was the first FDA approved total ankle implant in use in the United States. Since its introduction the Agility Ankle System has gone through several modifications. Currently the Agility Ankle System is the most widely used ankle prosthesis. With more than 20 years of experience it has the longest followup of any fixed bearing device.

On May 29, 2009 the medical news today announced the FDA approved the first mobile bearing device called the Scandinavian Total Ankle Replacement System (STAR). As a condition of FDA approval the company (Small Bone Innovations Inc.) must evaluate the safety and effectiveness of the device during the next eight years.

     In a systematic review of the literature published in the Journal of Bone and Joint Surgery in 2007, the intermediate outcome of total ankle arthroplasty appears to be similiar to that of ankle arthrodesis however data was sparse.  In a study comparing reoperation rates following ankle arthrodesis and total ankle arthroplasty SooHoo, Zingmond and Ko confirmed that ankle replacement is associated with a higher risk of complications as compared with ankle fusion, but also has potential advantages in terms of a decreased risk of the patient requiring subtalar joint fusion.  In a seven to sixteen year follow up on the Agility Total Ankle Arthroplasty, Knecht, Estin, Callagham et al concluded that the relatively low rates of radiographic hindfoot arthritis and revision procedures at an average of nine years after the arthroplasty are encouraging.

     Although interest in total ankle replacements is increasing, midterm clinical results to date are few and often have not been validated by independent pratitioners. In addition no level I or II studies have been published.

Indication for Procedure

There is no well-defined indication for a Total Ankle Arthroplasty. Surgery is considered only when conservative treatment has been attempted with no improvement. The operation is mainly being executed in patients who suffer from different types of arthrides. This cause advanced arthritic changes of disabling pain and loss of ankle motion. The ankle is most frequently affected by post-traumatic arthritis. Total ankle joint replacement is also indicated following unsuccessful ankle arthrodesis  the ‘ideal’ patient for ankle joint replacement is an elderly person with the low physical demands who has good bone stock, normal vascular status, no immune-suppression, and excellent hind foot-ankle alignment.

Surgical Procedure

To perfrom the procedure the patient is positined supine with the hip slightly elevated and a tourniquet on the proxinal thight to restrict blood flow during the procedure. Next a 10 cm incision is made over the centre of the joint line to expose the relevent anatomical structures. Once the structures have been exposed the crucial nerves and tendons are identified as to protect and ensure their intergrity to minimise operative complications, these include; peroneal nerves, tibialis anterior and extensor hallucis longus. This is also to achieve correct talocrural alignment and soft tissue balance to ensure the prosthesis can achieve plantar grade in standing. It is also important to debride and correct any osteophytes or any other structures that can contribute to malalignment. Depending on the natural angle of the talocrural joint (varus or valgus) more bone medially or laterally may have ot be removed, this also may occur if the joint is deep or shallow as it may need to be reduced or elevated.

Once the joints have been corrected and bones properly aligned the new components are trialled making sure rull ROM and stability is achieved. If dorsiflexion is limited and not due to malalignment then achilled tendon lengthening is required, the same goes for if there is instability in inversion or eversion the ligaments are reconstructed. Persistent malalignment can occure and may need seperate procedures to correct such as subtalar fusion depending on severity and correctability. 

Diagnostic Tests

add text here relating to diagnostic tests for the condition

Medical Management

add text here

Physical Therapy Management

As it will be explained in the Pre-Op and Post-Op the physician has a big role in making the arrangements before and after the surgery. Before the surgery the main job for the physician is to educate the patient about what will happen before, during and after the surgery. The physician will evaluate: the ROM from the patient, muscle strength, gait and deviations. For ergonomic reasons it is important that the patient learns how to walk with crutches so he still can perform ADL’s. After the surgery it is important that the patient keeps moving and performing his daily activities. However there is still discussion between physicians about when the patient should start again with exercising. There are some that allow exercise immediately after surgery. But some say it is considered best to wait until there is a satisfactory bony in growth as shown radio graphically. However it’s the job of the physician to try to improve:  the patient’s ROM of the ankle, maintain the ROM in the hip and knee, increase the muscle strength with exercise for the Gluteus Maximus, Quadriceps femoris muscles and the muscles that are responsible for dorsal flexion and the plantar flexion of the ankle. Postoperative mobilization begins early, with rapid progression to resumption of normal activities. The goal is to obtain 10° of dorsal flexion and 30° of plantar flexion. For patients who have almost no motion in their ankle is any motion an improvement. 

Pre-Op

Before the surgery, the most important role is intended for the physical therapist and the doctor. It is important that they orient the patient to the procedure and explain what they want to achieve with the treatment. The patient will be evaluated on his range of motion, muscle strength, ability to perform ADL, gait pattern and deviations. The patient will be given deep-breathing and coughing exercises. The physician will also give bilateral isometric contraction exercises for the Gluteus Maximus and the Quadriceps femoris muscles but also isotonic ankle exercise for planter flexion and dorsal flexion for not affected leg. For ergonomic reasons the patient needs to learn how to transfer from the bed to a chair without weight bearing on the affected ankle. He also needs to walk with Lofstrand crutches.

In early postoperative period it is important that the incision heals and the implant becomes solidly fixed to the bony bed to do this they will use a below knee non-weight bearing immobilization. This is maintained until there is satisfactory bony in growth. ^. The first 2 weeks the physician’s most important job is to help the patient maintain doing ADL activities, with crutches on a safe way. The second goal is to control the swelling and pain. It’s important that the patient rests and keeps his affected limb elevated above the heart.

After 2 weeks the cast will be replaced by a short leg boot. At this moment the patient goes back to the hospital for a first post-operative visit to the doctor.

The main goal for the physician is to increase the ROM of the ankle and maintain the hip and the knee ROM.

However there is still discussion between physicians about when the patient should start again with exercising. There are some that allow exercise immediately after surgery. But some say it is considered best to wait until there is a satisfactory bony in growth as shown radio graphically.

From here on it is important that the patient maintain his ROM from his ankle, knee and hip. He will be giving exercise to improve the strength of the Gluteus Maximus, Quadriceps and the muscles that are responsible for dorsal flexion and plantar flexion of the ankle.

After a few months the patient needs to make an appointment with the doctor. Here they will take X-ray scans to see if there are no complications like: joint debridement for osseous impingement; the next most common procedures were extra-articular procedures for axial misalignments and component replacements. 

Key Research

add links and reviews of high quality evidence here (case studies should be added on new pages using the case study template)

Clinical Bottom Line

add text here

Recent Related Research (from Pubmed)

Failed to load RSS feed from http://eutils.ncbi.nlm.nih.gov/entrez/eutils/erss.cgi?rss_guid=1lg0RU4SkRVBqMFj5d-bSyy2dkWVinKpajNeDAG9Bmj8Xqj5o|charset=UTF-8|short|max=10: Error parsing XML for RSS </div>