The hind- and midfoot alignment computed after a medializing calcaneal osteotomy using a 3D weightbearing CT

Int J Comput Assist Radiol Surg. 2019 Aug;14(8):1439-1447. doi: 10.1007/s11548-019-01949-7. Epub 2019 Mar 26.

Abstract

Purpose: A medializing calcaneal osteotomy (MCO) is a surgical procedure frequently performed to correct an adult acquired flatfoot (AAFD) deformity. However, most studies are limited to a 2D analysis of 3D deformity. Therefore, the aim is to perform a 3D assessment of the hind- and midfoot alignment using a weightbearing CT (WBCT) preoperatively as well as postoperatively.

Methods: Eighteen patients with a mean age of 49.4 years (range 18-67) were prospectively included in a pre-post-study design. A MCO was performed and a WBCT was obtained pre- and postoperative. Images were converted into 3D models to compute linear and angular measurements, respectively, in millimeters (mm) and degrees (°), based on previously reported landmarks of the hind- and midfoot alignment. A regression analysis was performed between the displacement of a MCO and the obtained postoperative correction.

Results: The mean 3D hindfoot angle improved significantly preoperative compared to postoperative (p < 0.001). This appeared according to a linear relation with the amount of medial translation in a MCO (R2 = 0.84, p < 0.001). The axes of the tibia showed significant coronal as well as axial changes (p < 0.05). Analysis of the midfoot showed significant changes in the navicular height and rotation as well as the Méary angle (p < 0.05). Additionally, a linear trend between the midfoot measurements and amount of medial translation in a MCO was observed, but not significant (p > 0.05).

Conclusion: This study demonstrates an effective 3D correction of an AAFD by a MCO according to a linear relationship. The concomitant formula can be used to perform a preoperative planning. The novelty is the comparative 3D weightbearing CT assessment of both the computed hind- and midfoot alignment after a medializing calcaneus osteotomy. This could improve accuracy of the currently performed preoperative planning in clinical practice.

Keywords: Adult acquired flatfoot deformity; Computed pre- and postoperative assessment; Medializing calcaneal osteotomy; Weightbearing CT.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Calcaneus / surgery
  • Female
  • Flatfoot / diagnostic imaging*
  • Humans
  • Imaging, Three-Dimensional*
  • Male
  • Middle Aged
  • Osteotomy / methods*
  • Postoperative Period
  • Prospective Studies
  • Radiography
  • Regression Analysis
  • Reproducibility of Results
  • Research Design
  • Rotation
  • Tibia / diagnostic imaging
  • Tomography, X-Ray Computed*
  • Weight-Bearing*
  • Young Adult