Ankle Range of Motion Following 3-Component Total Ankle Arthroplasty

BACKGROUND: Although surgeons have argued that preserving motion at the level of the ankle joint may be crucial for the long-term success in the treatment of end-stage ankle osteoarthritis, there is little evidence regarding the potential of total ankle arthroplasty (TAA) to increase ankle range of motion (ROM). In addition, the effect of a percutaneous heel cord lengthening (HCL) during TAA on ankle motion is poorly understood.

METHODS: A total of 357 primary TAAs treated with a 3-component device (336 patients, mean age 62.6 [24-85] years) performed between May 2003 and November 2017 were retrospectively analyzed. Sagittal ankle ROM was assessed according to a previously published protocol preoperatively (PreOP), 1 year postoperatively (PostOP), and at the last available follow-up (LastFU). Pain assessed on a visual analog scale (VAS) was assessed at the same time points. The effect of a percutaneous HCL on ankle ROM and VAS for pain was also evaluated.

RESULTS: Preoperative ankle ROM increased from mean 31.3 (0-69) to 33.9 (5-65) degrees 1 year postoperatively (P = .0002) and decreased to 31.9 (5-70) degrees at the LastFU (P = .007). Percutaneous HCL showed no effect on ankle ROM development after TAA (P = .141). Ankle ROM improvement after TAA (PreOP to LastFU) was higher in ankles with lower preoperative ankle motion (P < .0001). A lower ankle ROM at the last follow-up tended to be associated with a higher pain level (P = .056).

CONCLUSION: Although ankles with a lower preoperative sagittal ROM gained motion, the current data suggest that TAA has little potential to increase the preoperative available ankle motion. In some patients with a high preoperative ankle ROM, a slight decrease of ankle motion was observed postoperatively. Patients with limited ankle motion at long-term follow-up tended toward experiencing higher pain levels. The short- and long-term effect of a percutaneous HCL on ankle ROM following TAA was minimal.

LEVEL OF EVIDENCE: Level III, retrospective comparative series.