Total Ankle Replacement

Educational Objectives

The goal of this program is to improve the management of injuries and arthritic disease requiring total ankle replacement. After hearing and assimilating this program, the clinician will be better able to:

1. Recognize the technical challenges of total ankle arthroplasty.

2. Compare the outcomes of total ankle arthroplasty with those of arthrodesis.

Summary

Background: ankle arthritis less common than hip or knee arthritis; about half of cases require surgical treatment result from trauma; potentially disabling; arthrodesis — historically, gold standard; high rate of transfer arthrosis among major problems; remains viable option

Anatomy of ankle: joint bears high loads over small surface area; high mechanical stresses lead to high stress to implant; distal tibial bone softer than proximal tibial bone; removal of 1 cm reduces strength by 30% to 50%; talus has limitations in blood supply; soft tissue very thin; complex interaction occurs between talus and mortis during flexion, extension, and rotation; exposed to forces of 5 to 7 times body weight; technical issues with ankle replacement create challenges

Implant design: consider congruence, constraint of implant, and bearing type (fixed vs mobile); ideal implant has high conformity associated with low wear and minimal constraint associated with decreased loosening

Developmental history of ankle implants: first generation (1960s and 1970s) — primarily cemented and constrained or semiconstrained; outcomes poor, with high rates of failure; second generation — showed improvement; third generation — implants have larger contact areas and patterns of wear similar to those of hip and knee implants; require smaller bone resections; implants thicker (allow surgeon to tension and rebalance ligaments); emphasis placed on mechanical alignment and soft-tissue balance; computed tomography-guided systems — patient-specific; allow better fit for tibial and talar components, minimized bone resection, and easier implantation

Results of clinical trials: interpretation difficult because of, eg, large amount of patient, selection, and surgeon bias, differences between implants; most approved for cemented use, but majority uncemented; fixed and mobile bearings available; most studies show comparable results regardless of implant

Learning curve: Haskell et al (2004) showed incidence of complications 3-fold higher for surgeon’s first 10 cases, compared with next 10; Saltzman et al (2003) showed type of initial training for ankle replacement (fellowship vs observing another surgeon vs surgical training course) had no effect on outcomes

Specific implants: Knecht et al (2004) found revision rate 15% with Agility implant but patient satisfaction rate 90% at mean follow-up of 9 yr; Kofoed et al (2004) showed survival rate 95% at mean follow-up of 9.4 yr for Scandinavian total ankle replacement (STAR); Buechel et al (2003) showed survival rate 93% at 10 yr with Buechel-Pappas implant

Arthrodesis vs total ankle arthroplasty: systematic review (Haddad et al [2007]) — found higher rate of revision in arthrodesis group; loosening was primary cause of revision in total ankles; nonunion was primary cause in arthrodesis; more below-knee amputations reported in arthrodesis group; Pedowitz et al (2016) — found more anatomic movement, better pain relief, and better patient-perceived outcomes with arthroplasties; fusion group had higher degree of motion emanating from talonavicular joint; Morash et al (2017) — found compensatory motion in talonavicular joint after arthrodesis; rate of reoperation higher in arthroplasty group, but survival rate good; authors concluded both surgeries effective; tailor choice to individual patients

Functional limitations with end-stage ankle arthritis: Segal et al (2012) — found patients with end-stage arthritis had reduced physical and patient-perceived function, compared with healthy individuals; high-intensity step count appeared better indicator of function compared with total steps per day; Shofer et al (2019) — showed surgical treatment of ankle arthritis significantly improved ambulatory activity, particularly at high activity levels; achieved more quickly in arthroplasty group compared with arthrodesis group, but no statistical difference at 3 yr

Intraoperative difficulties: include stiffness, alignment, ligament imbalance, and associated arthritis in midfoot or hindfoot; issues include management of complex deformities and balancing ligaments in coronal and sagittal plane

Readings

Buechel FF, Sr. et al: Ten-year evaluation of cementless Buechel-Pappas meniscal bearing total ankle replacement. Foot Ankle Int 2003 Jun;24(6):462-72; Haddad SL et al: Intermediate and long-term outcomes of total ankle arthroplasty and ankle arthrodesis. a systematic review of the literature. J Bone Joint Surg Am 2007 Sep;89(9):1899-905; Haskell A et al: Perioperative complication rate of total ankle replacement is reduced by surgeon experience. Foot Ankle Int 2004 May;25(5):283-9; Knecht SI et al: The Agility total ankle arthroplasty. seven to sixteen-year follow-up. J Bone Joint Surg Am 2004 Jun;86(6):1161-71; Kofoed H: Scandinavian total ankle replacement (STAR). Clin Orthop Relat Res 2004 Jul(424):73-9; Morash J et al: Ankle arthrodesis versus total ankle arthroplasty. Foot Ankle Clin 2017 Jun;22(2):251-66; Pedowitz DI et al: Total ankle arthroplasty versus ankle arthrodesis: a comparative analysis of arc of movement and functional outcomes. Bone Joint J 2016 May;98-B(5):634-40; Saltzman CL et al: Surgeon training and complications in total ankle arthroplasty. Foot Ankle Int 2003 Jun;24(6):514-8; Segal AD et al: Functional limitations associated with end-stage ankle arthritis. J Bone Joint Surg Am 2012 May 2;94(9):777-83; Shofer JB et al: Step activity after surgical treatment of ankle arthritis. J Bone Joint Surg Am 2019 Jul 3;101(13):1177-84.

Disclosures

For this program, the following has been disclosed: Dr. Anderson is a consultant and/or is on the Speakers’ Bureau for Bespa Global, Nextremity Solutions Inc, Paragon 28, Inc, Stryker, Wright Medical Group NV, and Zimmer Biomet. The planning committee reported nothing to disclose.

Acknowledgements

Dr. Anderson was recorded at the 20th Annual Chicago Orthopaedic Symposium, held August 15-18, 2019, in Chicago, IL, and presented by the Foundation for Education and Musculoskeletal Research. For information about upcoming dates for the Chicago Orthopaedic Symposium, please visit Chicagotraumasymposium.com. The Audio Digest Foundation thanks the speakers and the sponsors for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

OR431002

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.