Hindfoot Arthritis Progression and Arthrodesis Risk After Total Ankle Replacement

SLR - December 2017 - Samantha A. Luer

Reference: Dekker TJ, Walton D, Vinson EN, Hamid KS, Federer AE, Easley ME, DeOrio JK, Nunley JA, Adams SB Jr. Hindfoot Arthritis Progression and Arthrodesis Risk After Total Ankle Replacement. Foot Ankle Int. 2017 Aug 15; 00(0).

Scientific Literature Review

Reviewed By: Samantha A. Luer, DPM
Residency Program: Regions Hospital/HealthPartners Institute for Education & Research, Saint Paul, MN

Podiatric Relevance: Despite preservation of tibiotalar joint motion, patients with total ankle arthroplasty (TAA) continue to demonstrate supraphysiologic motion at the adjacent joints. A prior study from Dekker et al demonstrated that at least 30 percent of clinical motion observed after TAA comes through the subtalar and talonavicular joints. The purpose of this study was to determine the rate of radiographic adjacent joint degeneration following TAA.

Methods: One hundred forty patients met inclusion criteria of those who underwent TAA (Salto-Talaris, STAR or INBONE) from 2007 to 2011, had pre- and postoperative radiographs and a minimum follow-up of five years. Seventeen patients were excluded for prior arthrodesis of the talonavicular (8) or subtalar (9) joints. Mean follow-up was 6.5 years (range 5–8.9). Radiographs were analyzed for peritalar arthritic changes by extrapolating the modified Kellgren Lawrence (KL) grades of the knee to the subtalar and talonavicular joints. Preoperative x-rays were used to determine if there was preexisting arthritis. Two orthopaedic surgeons and one musculoskeletal radiologist reviewed all radiographs. Statistical analysis was then performed by a biostatistician.

Modified KL Score of the Hindfoot-Grade 0, no radiographic change of the joints; Grade 1, minor osteophyte formation with no joint space narrowing; Grade 2, increased osteophyte formation with preserved joint space; Grade 3, joint space narrowing and osteophyte formation; Grade 4, obliteration or severe sclerotic joint space changes.
 

Results:

  • Large number of patients had preexisting subtalar and talonavicular arthritis.
  • Majority of patients did not demonstrate radiographic progression of subtalar (60 percent) or talonavicular arthritis (66 percent).
  • Of patients who demonstrated progression in arthritis, only 27 percent demonstrated an increase in KL by 1 grade.
  • Subtalar arthritis
    • 27 percent INBONE, 29 percent Salto-Talaris and 22 percent STAR patients increased one grade (no statistical significance and arthritic progression did not correlate with prosthesis type)
    • 16 (11 percent) patients underwent subsequent subtalar arthrodesis secondary to pain (seven INBONE, five Salto-Talaris, four STAR)
  • Talonavicular arthritis
    • 29.5 percent INBONE, 38.5 percent Salto-Talaris and 23.1 percent STAR, increased one grade (no statistical significance and arthritic progression did not correlate with prosthesis type)
    • Two (1 percent) patients opted for subsequent talonavicular arthrodesis secondary to pain (one STAR, one Salto-Talaris) secondary to persistent pain.
Conclusions: TAA is thought to have the advantage of decreased adjacent joint stress as compared to ankle arthrodesis. However, this is the first study to assess the effect of ankle joint preservation on the contiguous joints. It demonstrated a moderate incidence of radiographic adjacent joint degeneration but a low incidence of clinically meaningful adjacent joint degeneration after TAA, documented as pain originating from or subsequent arthrodesis of the subtalar and/or talonavicular joints. Overall, this information is helpful when informing patients about risks of continued adjacent joint arthritis and subsequent procedures.