Diagnosis of TAR failure

• Clinical: pain, swelling, alignment, instability
• Radiographs
  • look for loosening, alignment, subsidence, cysts
  • weight-bearing radiographs (AP/mortice & lateral), Saltzman view
• CT or SPECT if loosening suspected but x-rays equivocal
• Inflammatory markers for consideration of infection
• Aspiration or biopsy (percutaneous or arthroscopic)

IDEALLY, CASES SHOULD BE DISCUSSED IN A MUTLIDISCIPLINARY TEAM MEETING FOR PATIENT MANAGEMENT AND SURGICAL PLANNING

 

Revision options

Revision arthroplasty

• larger units will have more experience
• limited implants currently available: Inbone, Invision, Salto XT
• bigger implants = more bone sacrificed = salvage options increasingly limited
• must address alignment and stability

*awaiting image upload*

FIgure 1 Examples of revision options: Inbone (left) is modular; Salto X (right)

Arthrodesis

• tibiotalar (ankle) or tibio-talo-calcaneal (TTC)
  • TTC indicated if insufficient bone stock or significant subtalar arthritis
• reasonable long-term results and patient satisfaction
• higher non-union rate than primary arthrodesis
• most require bone graft:
  • particulate cancellous graft
  • bulk graft (large bone loss):
    • tricortical iliac crest wedges
    • femoral head or distal tibial allograft
    • custom trabecular metal

Amputation

• final salvage option
• BKA allows good rehabilitation with well-fitting prosthesis

 

Prevention of failed TAR

Choose the optimal patient:

• older patient or one with lower physical demands
• other joint problems e.g. ipsilateral foot or knee or contralateral ankle arthritis
• good alignment and ligamentous stability

Avoid poor patient choice:

• neuromuscular deformity
• previous infection
• poor soft tissues / vascularity
• osteonecrosis / osteoporosis may cause problems with bony fixation

Choose the optimal surgeon:

• implant-trained, higher volumes
• supportive infrastructure and colleagues, research team
• access to complex case MDT
• regional network for revision cases

 

Conclusion

Most reported complications are preventable with good patient selection and surgical technique.

Failed TARs need appropriate investigation, work-up and team discussion before proceeding with appropriate revision / salvage options.

 

MCQ

What is NOT considered an inclusion criterion for TAR surgery?

• Fair hindfoot alignment
• Low demand patients older than 60 y/o
• Good bone quality patients with no significant co-morbidities
• Contralateral knee joint problems
• None of the above

 

References

Vickerstaff JA, Miles AW, Cunningham JL. A brief history of total ankle replacement and a review of the current status. Med Eng Phys. 2007 Dec;29(10):1056-64. doi: 10.1016/j.medengphy.2006.11.009. Epub 2007 Feb 14. PMID: 17300976

Saltzman CL. Total ankle arthroplasty: state of the art. Instr Course Lect. 1999;48:263-8. PMID: 10098052

Conti SF, Wong YS. Complications of Total Ankle Replacement. Clinical Orthopaedics and Related Research: October 2001 - Volume 391 - Issue - p 105-114

Henry JK, Rider C, Cody E, Ellis S, Demetracopoulos C. Evaluating and Managing the Painful Total Ankle Replacement. Foot Ankle Int 2021 Oct;42(10):1347-1361

https://www.orthobullets.com/foot-and-ankle/12133/total-ankle-arthroplasty