• Orthopaedics Clinical Trials
• Foot & Ankle Conditions
• Orthopaedic Procedures

• Orthopaedics
• Orthopaedics Clinical Trials
• Foot & Ankle Conditions
• Orthopaedic Procedures

Total ankle arthroplasty (TAA) has gained greater acceptance as an alternative surgical treatment to ankle arthrodesis for end-stage ankle arthritis. Implant design and techniques have improved over the last few decades, with increased implant survival and equivalent pain relief and functional outcomes compared with ankle arthrodesis. Coronal malalignment remains a challenge for successful TAA. Previous study results suggest that a 10° to 15° varus alignment is a relative contraindication and a 20° varus alignment is an absolute contraindication for TAA [Valderrabano V et al. J Bone Joint Surg Br. 2005; Wood PL, Deakin S. J Bone Joint Surg Br. 2003]. More recent studies reported good TAA outcomes in patients with varus, including those with > 20° varus alignment [Sung KS et al. Foot Ankle Int. 2014; Trajkovski T et al. J Bone Joint Surg Am. 2013].

The objective of this study, presented by Alan Y. Yan, MD, Duke University Medical Center, Durham, North Carolina, USA, was to compare outcomes of TAA in patients with varus vs neutral (< 5° [valgus]) alignment. A total of 230 TAAs were prospectively followed from October 2007 to October 2011. The varus alignment group included 100 ankles (96 patients) and the neutral alignment group included 130 ankles (129 patients). The patients received the STAR ankle, the Salto Talaris, or the INBONE I or II. The preoperative and postoperative outcome measures included the Short Form-36 (SF-36), the Short Musculoskeletal Function Assessment Questionnaire (SMFA), Visual Analog Scale (VAS), Foot and Ankle Disability Index (FADI), and American Orthopaedic Foot & Ankle Society (AOFAS) hind foot-ankle scores. The mean follow-up was 43.2 months for the varus group and 45.0 months for the neutral group.

Analysis of the outcome measures showed no significant difference in preoperative, postoperative, or mean improvement in the SF-36, SMFA, VAS, FADI, or AOFAS scores (Table 1). The mean changes from baseline for the varus vs neutral group were as follows: SF-36, 23.6 vs 24.7; SMFA, 20.8 vs 21.6; VAS, 62.4 vs 56.8; FADI, 0.41 vs 0.37; and AOFAS score, 41.1 vs 37.3.

Most varus ankles (97%) were corrected to neutral (mean 0.5°; −3.9° to 4.1°), all of which maintained neutral at the last follow-up (mean 0.7°; −4.3° to 4.3°).

The varus group required significantly more procedures than the neutral group for soft tissue balancing and osteotomy at index procedures, the most common of which was medial deltoid ligament release (75% vs 4%). Kaplan-Meier estimates (revision end point) projected implant survival of 96.6% (95% CI, 85.8 to 99.2) in the varus group and 96.5% (95% CI, 91.1 to 98.7) in the neutral group over 60 months (Figure 1).

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Figure 1.

Kaplan-Meier Curve With Revision End Point

Reproduced with permission from AY Yan, MD.

This study demonstrated no significant difference in outcomes after TAA was performed for end-stage arthritis in patients with moderate to severe varus alignment vs neutral alignment. The outcomes of TAA for end-stage ankle arthritis were similar in patients with preoperative varus deformity > 20°. The contraindicated limits of varus deformity may need to be redefined based on current evidence.

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