Total Ankle Arthroplasty: An Imaging Overview

Abstract

With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice.

Medium-term results of the HINTEGRA total ankle arthroplasty

“…It is important to note that medium-term follow-up of fixed-bearing and mobilebearing implants revealed no differences in functional tests or outcomes (5,6,(16)(17)(18)(19) . Patient satisfaction increased from 10% and 65% (in patients with first-and second-generation implants, respectively) to almost 90% with third-generation implants such as the HINTEGRA TAA (3,13,18,(20)(21)(22)(23)(24) .…”

“…Hintermann and colleagues described radiographic criteria for loosening of the implant: The tibial component should be considered loose if either its position has changed by more than 2° relative to the long axis of the tibia, or a progressive radiolucency of more than 2mm is detected around the implant on anteroposterior or lateral views. The criteria for a loose talar component are: subsidence greater than 5 mm or a change in position of more than 5° relative to the hindfoot axis (3,13,21) . Other studies have suggested possible implant loosening when components moved more than 5° or 5 mm in serial X-ray imaging (27)(28)33) .…”

“…This classification is currently widely used and has substituted previous classifications (1,2) . Secondary OA of the hip and knee joints accounts for only 9.8% and 1.6% of OA cases, respectively, whereas in the ankle it is reported to be as high as 65%-80% (3)(4)(5)(6) . This progressive destructive joint disease leads to severe pain, decreased quality of life, and limits the performance of activities of daily living.…”

Imaging of Total Ankle Arthroplasty: Normal Imaging Findings and Hardware Complications

“…97 Subsequent studies are performed with AP and lateral weightbearing technique depending on patient tolerance, and some institutions include lateral non-weightbearing maximally dorsiflexed and plantarflexed images to assess the range of motion. 98 The subsequent studies are used to evaluate for signs of osteointegration, determine osseous and prosthetic component alignment, and detect developing heterotopic ossification, in addition to evaluating range of motion.…”

“…Additionally, MRI may help assess adjacent soft tissue structures, such as the surrounding ligaments and tendons. 98 As with CT, MRI of metallic devices can produce significant artifacts that limit its ability to characterize the adjacent bone and soft tissues, and several techniques have been used to reduce the degree of artifact to detect areas of expansile periprosthetic osteolysis. These include orienting the long axis of the device along the long axis of the main magnetic field, imaging on lower field-strength magnets with strong gradients, using high bandwidth sequences, substituting short tau inversion recovery sequences for chemically selective, fat-suppressed, fluid-sensitive sequences, and using thin section imaging.…”