12-year survival analysis of 322 Hintegra total ankle arthroplasties from an independent center

Abstract

Background and purpose — Total ankle arthroplasties (TAAs) have larger revision rates than hip and knee implants. We examined the survival rates of our primary TAAs, and what different factors, including the cause of arthritis, affect the success and/or revision rate. Patients and methods — From 2004 to 2016, 322 primary Hintegra TAAs were implanted: the 2nd generation implant from 2004 until mid-2007 and the 3rd generation from late 2007 to 2016. A Cox proportional hazards model evaluated sex, age, primary diagnosis, and implant generation, pre- and postoperative angles and implant position as risk factors for revision. Results — 60 implants (19%) were revised, the majority (n = 34) due to loosening. The 5-year survival rate (95% CI) was 75% (69–82) and the 10-year survival rate was 68% (60–77). There was a reduced risk of revision, per degree of increased postoperative medial distal tibial angle at 0.84 (0.72–0.98) and preoperative talus angle at 0.95 (0.90–1.00), indicating that varus ankles may have a larger revision rate. Generation of implant, sex, primary diagnosis, and most pre- and postoperative radiological angles did not statistically affect revision risk. Interpretation — Our revision rates are slightly above registry rates and well above those of the developer. Most were revised due to loosening; no difference was demonstrated with the 2 generations of implant used. Learning curve and a low threshold for revision could explain the high revision rate.

Total Ankle Replacement Outcome in Patients With Inflammatory Versus Noninflammatory Arthritis: A Systematic Review and Meta-analysis

“…However, the learning curve and low threshold for revision were attributed to the higher revision rate in their series. 21…”

“…However, the learning curve and low threshold for revision were attributed to the higher revision rate in their series. 21 Unlike the initial reports in the 1970s that showed higher failure rates in patients with RA on long-term prednisone, 3 many recent studies showed no significantly increased risk of failure in patients with RA, which is partly due to newer anti-rheumatoid regimens as well as preoperative modification of the medications. 22,23 In the Hurowitz et al 17 series, 1 of 10 patients with RA developed a superficial wound infection that was the only patient taking both methotrexate and prednisone.…”

Evaluating and Managing the Painful Total Ankle Replacement

“…40 In large-scale, long-term studies from Europe, revision rates due to loosening were greater than 10%. 107,115 Although overall revision rates have declined with newer generations of implants, the proportion due to loosening has remained the same. 107 In a single-institution study of more than 500 TARs with 7-year follow-up, 6.4% were revised due to implant failure, with loosening and talar subsidence as the most common culprits, accounting for 21% and 41% of the failures, respectively.…”

“…76 Among mobile-bearing implants, increased implant failure was linked to increased varus position of the tibial component. 115 Implant malposition, especially involving the talar component, can reduce contact surface area, thereby increasing contact pressures, leading to increased risk of subsidence. 25,80 Anterior talar translation is often a culprit and may be due to preoperative deformity that was not adequately addressed, a tight heel cord or posterior capsule, overstuffing of the joint, or improper implant insertion.…”

“…76 Among mobile-bearing implants, increased implant failure was linked to increased varus position of the tibial component. 115…”