The article by Hendy et al. is an important observational study that enables physicians to advise patients with respect to their recovery time course after total ankle arthroplasty. Most experienced foot and ankle surgeons know, and will advise their patients, that the recovery after foot and ankle surgery can be lengthy. One of my patients informed me 7 years after surgery that his ankle was amazing—he wished he’d had surgery years before he did—but it took a year and a half for his ankle to get better. This paper provides a scientific basis for recovery up to 6 months out. It is not clear why foot and ankle outcomes take so long to improve, and many patients get despondent waiting to see the improvement. This paper helps surgeons, physiotherapists, and other members of the care team to correctly advise patients in response to the question that they pose frequently during their first 6 months after surgery: “Is it going to get better?” The answer is “yes.”
The authors prospectively review 134 total ankle arthroplasties performed with a single fixed-bearing design (Salto Talaris) by a single surgeon. Patient age averaged 65 years, and 2 patients had a bilateral procedure. Many patients underwent concomitant procedures, and these are documented. The age range and the demographics as well as the concomitant procedures are all similar to those in the Canadian series1.
The range of motion was measured on a lateral radiograph as described by Coetzee and Castro2. In addition to a visual analogue scale (VAS) for pain, validated outcome measures (the Foot and Ankle Ability Measure [FAAM] and Short Form-12 [SF-12]) were used. Range of motion can be difficult to measure after total ankle arthroplasty. The method of Coetzee et al. is accurate but requires radiographs and a willing x-ray department. The method described by Thornton et al. and the TARVA (Total Ankle Replacement Versus Arthrodesis) group in the United Kingdom is simpler3. A standardized technique is required if ankle range of motion is going to be reliably measured. The authors validated the Coetzee measurement method and demonstrated a high interclass correlation of 0.9.
Hendy and colleagues show that the range of motion improves after total ankle arthroplasty, from 21° preoperatively to 28° at 3 months, increasing to 34° at 6 months and 33.3° at 1 and 2 years. Most patients are advised that the range of motion is unlikely to increase much after replacement, but this study showed that this is clearly not the case. A better range of motion also correlated with less pain both before and 1 year after surgery and with a better FAAM Activities of Daily Living (ADL) score at 3 months, 1 year, and 2 years postoperatively. In their discussion, Hendy et al. attribute some of the increased motion to the concomitant heel cord lengthening (Strayer procedure) performed.
The outcomes also improved with time. The VAS pain score decreased from 74 of 100 preoperatively to 30 at 3 months, 18 at 6 months, 18 at 1 year, and 15 at 2 years. The FAAM ADL and SF-12 Physical Component Summary (PCS) scores also incrementally improved with time. The SF-12 Mental Component Summary (MCS) score did not change with time.
Also observed was a broad range of results after surgery and a range of recovery times. Some patients had a rapid recovery and regained maximum function, and others had slower recovery. This is indicated by the standard deviations for the outcomes of this study.
The authors use the reporting guidelines by Vander Griend et al. and the editorial board of Foot & Ankle International4. These were derived after the inconsistency in terminology of adverse events in the literature was documented5. It is encouraging to see standard terminology being used to report adverse events, allowing different series of total ankle arthroplasties to be compared with respect to aseptic loosening, wound complications, etc.
The authors reported revision of 2 prostheses—1 because of infection and 1 because of implant failure. There were, in total, 3 infection-related revision surgical procedures, 2 of which resulted in retention of the components.
This article further documents the trend of improved outcomes of ankle replacement surgery, indicating that modern ankle replacement designs are performing well provided the surgery is done well, and that additional procedures such as the Strayer procedure may be required.
This paper adds to the evidence that total ankle arthroplasty is a valuable alternative to arthrodesis for end-stage ankle arthritis.
1. Daniels TR, Younger AS, Penner M, Wing K, Dryden PJ, Wong H, Glazebrook M. Intermediate-term results of total ankle replacement and ankle arthrodesis: a COFAS multicenter study. J Bone Joint Surg Am. 2014 Jan 15;96(2):135-42.
2. Coetzee JC, Castro MD. Accurate measurement of ankle range of motion after total ankle arthroplasty. Clin Orthop Relat Res. 2004 Jul;424:27-31.
3. Thornton J, Sabah S, Segaren N, Cullen N, Singh D, Goldberg A. Validated method for measuring functional range of motion in patients with ankle arthritis. Foot Ankle Int. 2016 Aug;37(8):868-73. Epub 2016 Apr 25.
4. Vander Griend RA, Younger ASE, Buedts K, Chiodo CP, Coetzee JC, Ledoux WR, Pinzur MS, Prasad KSRK, Queen RM, Saltzman CL, Thordarson DB. Total ankle arthroplasty: minimum follow-up policy for reporting results and guidelines for reporting problems and complications resulting in reoperations. Foot Ankle Int. 2017 Jul;38(7):703-4.
5. Mercer J, Penner M, Wing K, Younger AS. Inconsistency in the reporting of adverse events in total ankle arthroplasty: a systematic review of the literature. Foot Ankle Int. 2016 Feb;37(2):127-36. Epub 2015 Oct 7.