Ankle Arthritis: To Fuse Or Not To Fuse?

Jeffrey Bowman DPM MS

Given that our current political leaders cannot seem to agree on much, let us look at what has divided podiatry into two parties: the “Fusion” party and the “Replacement” party.

Today, a debate exists whether to fuse or replace an ankle joint. Both procedures are indicated for arthritis that occurs from normal joint degeneration, a traumatic event or inflammatory arthritis.

Prior to 1882, treatment for arthritis of any joint was bracing or amputation. Fusion originated in Germany and became the standard treatment. In the 1960s, Charnley developed joint replacement, which became the standard of care for arthritis in the hip.1 Joint replacement subsequently followed in the knee. Surgeons introduced arthroplasty in the ankle in the 1970s but early complications eliminated it as a standard procedure internationally. Successes in other joint replacements have led to researchers’ pursuit of refining the total ankle replacement systems.

Understanding when it is appropriate to fuse versus replace depends on numerous factors.

Age. Several reports have suggested that the survivorship of implants and functional outcomes are less favorable in younger patients. One study shows five-year survivorship is 74 percent in patients younger than 54 and 89 percent in those over 54.2,3

Deformity. Severely deformed ankle joints in any plane are contraindicated for total ankle replacements and better suited for fusion. When surgeons perform arthrodesis osteotomies appropriately, they can correct the planal deformity.4

Design. When comparing historical implant designs with their modern counterparts, we can see numerous improvements. Previously, practitioners used larger, two-part, cemented and constrained implants that required major bone resection. Older two-part implants have high bone-implant interface stresses, incongruent metal-polyethylene articulation and failed to dissipate transverse rotation. The newer three-part systems report less bone resection (10 to 12 mm), which can lead to better outcomes if a fusion is later indicated. Today, non-cemented designs have a porous interface for ingrowth of bone. In comparison to fixed bearing designs, mobile designs allow multiple planes of motion (more similar to ankle motion) and reduce shearing and torque forces, which can lead to loosening at the bone-metal interface. These changes in design should improve outcomes for total ankle replacement in comparison with arthrodesis.4

The literature debating fusion versus replacement is messier than the arguments being made on Capitol Hill these days. One side vehemently argues its point as the other retorts with its arguments. Haddad, for example, found that intermediate outcomes of total ankle arthroplasty were similar to arthrodesis.5 Krause concluded that complication rates were higher in total ankle replacement.6 However, the literature defending total ankle replacement is slowly increasing.

Given the success that joint replacement has had in the hip and knee, one may assume that advances in implant design and surgical technique will eventually place total ankle replacement ahead of ankle arthrodesis as a means of treating ankle arthritis.

For now, in my experience, the gold standard remains ankle fusion. It is too bad C-Span does not cover the American College of Foot and Ankle Surgeons (ACFAS) or American Podiatric Medical Association (APMA) meetings. Given the coming changes to healthcare and the lifestyle our political leaders have, I should have gotten into politics.

For more information on total ankle joint fusion/arthrodesis, please feel to contact me at www.houstonfootspecialists.com .

References

1. Charnley J. Present status of total hip replacement. Ann Rheum Dis. 1971; 30(6):560-4.

2. Saltzman CL, Zimmerman MB, O’Rourke M, Brown TD, Buckwalter JA, Johnson R, et al. Impact of comorbidities on the measurement of health in patients with ankle osteoarthritis. J Bone Joint Surg Am. 2006; 88(11):2366-2372.

3. Nunley JA, Caputo AM, Easley ME, Cook C. Intermediate to long-term outcomes of the star total ankle replacement: the patient perspective. J Bone Joint Surg Am. 2012; 94(1):43-48.

4. Easley ME, Adams SB Jr., Hembree WC, DeOrio JK. Results of total ankle arthroplasty. J Bone Joint Surg Am. 2011; 93(15):1455-1468.

5. Haddad SL, Coetzee JC, Estok R, 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; 89(9):1899-905.

6. Krause FG, Windolf M, Bora B. Impact of complications in total ankle replacement and ankle arthrodesis analyzed with a validated outcome measurement. J Bone Joint Surg Am. 2011; 93(9):830-839.

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