Cadence Total Ankle Replacement

49 Cadence Total Ankle Replacement


David I. Pedowitz, Selene G. Parekh, and Timothy R. Daniels


Abstract


The cadence total ankle replacement system is a fixed bearing condylar ankle replacement designed to take minimal talar bone and prevent fibular impingement. Inserted through a standard anterior approach, the system also allows for the correction of talar subluxation in the sagittal plane using anteriorly and posteriorly biased polyethylene inserts.


Keywords: total ankle replacement, arthroplasty, tibiotalar arthritis, posttraumatic arthritis


49.1 Indications and Pathology


• End-stage degenerative, posttraumatic, or inflammatory tibiotalar arthritis.


49.1.1 Clinical Evaluation


• Tenderness over tibiotalar joint line.


• Patients should have pain with weight-bearing activity.


• May present with, or without, significant ankle, midfoot, or hindfoot deformity.


• May have some decreased sagittal arc of motion at ankle joint.


49.1.2 Radiographic Evaluation


• Plain weight-bearing X-rays of the foot and ankle looking for the following:


image Tibiotalar congruence.


image Intra versus extra-articular deformity at the ankle.


image Hindfoot deformity and how, if at all, it affects ankle joint.


image Bone loss.


image Collapse or signs of avascular necrosis of the talus.


image Location of preexisting hardware as it affects placement of implant and impacts the need for removal at the time of arthroplasty.


image Anterior or posterior subluxation of the talus.


image Adjacent segment (subtalar and talonavicular) arthritic change.


image Talar dome anatomy.


• Magnetic resonance imaging (MRI):


image Used in the setting of suspected avascular necrosis of the talus that may be a contraindication for arthroplasty.


• Computed tomography (CT) scan:


image Used to assess bone stock when cysts or osteochondral lesions can be seen with plain radiography.


image Used to assess talar morphology in the setting of collapse or prior fracture that may affect choice of talus implant or helping to anticipate the need for bone grafting.


image Used to evaluate the presence of adjacent joint arthritis.


49.1.3 Nonoperative Options


• Brace immobilization.


• Activity modification.


• Rocker-bottom sole and cushioned heel to shoe; orthotic inserts.


• Medications: cortisone injection, hyaluronic acid injections, anti-inflammatory medications.


49.1.4 Contraindications


• Insufficient bone stock to support the implant, particularly on the talar side.


• Extensive avascular necrosis (AVN) of the talus. The authors’ recommendation is that arthroplasty should be highly cautioned when greater than 30% of talar AVN exists.


• Severe neuropathy.


• Active infection.


• Prior infection remains a relative contraindication and ankle replacement may be performed under select circumstances in which latent infection can largely be ruled out.


• Psychiatric or psychosocial conditions that may make a patient unable to follow the postoperative protocol.


• Smoking remains relative contraindication. The authors do not perform total ankle arthroplasty in smokers.


• Uncontrolled diabetes with an HgA1c greater than 6.5 brings with it an unusually high complication rate and those patients who have an elevated HbA1c should be cautioned about elective surgery.


• BMI (body mass index) greater than 40. This has been shown to lead to an increased rate of complications in hip and knee arthroplasty. To date, no hard recommendations have been set forth for the ankle. Some surgeons use this as a relative contraindication.


49.2 Goals of Surgical Procedure


• Painand brace-free ambulation.


• Plantigrade, balanced ankle with correction of any coronal plane deformity.


49.3 Advantages of Surgical Procedure


• Cutout in the tibial implant to match the natural incisura prevents fibular impingement (Fig. 49.1).


• Minimal talar resection preserves bone stock needed in case of revision.


• Anteriorly and posteriorly biased polyethylene inserts allow for restoration of sagittal alignment.


• Joint space evaluator allows one to estimate tibial resection and ensure cuts have taken enough bone for implantation of the components.


• Minimal violation of talus with pins in order to reduce vascular insult.


Jul 19, 2019 | Posted by in SPORT MEDICINE | Comments Off on Cadence Total Ankle Replacement

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