Tibiopedal Motion Following Tendo-Achilles Lengthening or Gastrocnemius Recession in Total Ankle Replacement: A Comparative Cohort Study

Background: End-stage ankle arthritis is a debilitating condition often necessitating total ankle replacement (TAR). Tendo-Achilles lengthening (TAL) and gastrocnemius recession (GR) are commonly performed with TAR to improve ankle dorsiflexion (DF). No studies to date have radiographically analyzed tibiopedal motion to guide surgical management. The purpose of this study is to determine the effect of a TAL or GR during TAR on radiographic tibiopedal range of motion (ROM). Methods: A retrospective review of a prospectively maintained database was conducted followed by a propensity score-matched analysis of 110 patients who underwent TAL (n = 26), GR (n = 29), or no lengthening procedure (n = 55) with TAR. Minimum of 1-year ROM radiographic follow-up was required. Exclusion criteria included (1) calcaneal osteotomies, (2) simultaneous or previous hindfoot or midfoot arthrodesis, (3) prior ankle arthrodesis, or (4) revision TAR. Demographic data were extracted from the TAR database. Radiographic assessment included tibiopedal dorsiflexion (DF) and plantarflexion (PF). Results: DF improved by 2.8 degrees (P = .0286) and by 6.0 degrees (P < .0001) in the TAL and GR cohorts, respectively, with no difference in the control group (+0.7 degrees, P = .3764). PF was decreased by 4.5 degrees (P = .0152) and by 7.2 degrees (P = .0002) in the TAL and GR cohorts, respectively, with no difference in the control group (-0.2 degrees, P = .8546). Minimal differences were observed for total arc of motion for all 3 groups (control 0.5 degrees, GR -1.2 degrees, TAL -1.7 degrees), all of which were nonsignificant (all P > .05). There was no between-group difference in the change in overall arc of motion between the groups (P = .3599). GR resulted in a greater increase in DF (6.0 vs 2.8 degrees; P = .1074), with a reciprocal greater decrease in PF (7.2 vs 4.5 degrees; P = .2416) compared with the TAL cohort. Conclusion: Both TAL and GR increased postoperative DF; however, this was accompanied by a reciprocal loss in PF. Minimal differences were observed for total arc of motion. Patients should be counseled that concomitant procedures performed to increase DF will do so at the expense of PF.