Abstract
Category:
Hindfoot; Midfoot/Forefoot
Introduction/Purpose:
Lateral column lengthening (LCL) is the cornerstone for flexible, progressive collapsing foot correction. Evans LCL (ELCL) and Hinterman LCL (HLCL) are the most used surgical techniques. ELCL is performed between the anterior and medial facets and endangers specific os-calcis subtypes (OSCT). HLCL passes in a safe zone between the posterior and medial facets and should be suitable for all OSCTs. However, both osteotomies are associated with increased subtalar osteoarthritis, indicating iatrogenic damage. Distance mapping (DM) enables visualization of the relative distance between two articular surfaces using color patterns. This study aims to measure the safe zones for LCL using DM.
Methods:
Using the Bruckner et al. classification, two raters categorized 134 patients and 200 feet into the four OSCTs. Four angles were measured. The proximal posterior safe zone (PSZ) and distal PSZ angles defined the safe zone for HLCLO; it was measured for all OSCTs. The proximal anterior safe zone (ASF) angle and the distal ASF defined the safe zone for ELCLO. They were measured only in cases where a discontinuity between the two facets exists or in the absence of anterior facet. A statistical comparison between the groups was made
Results:
The mean proximal PSZ angle was 68+/-7 degrees, the distal PSZ angle was 75+/-5, the Proximal ASZ angle was 89+/-6 degrees, and the distal ASZ angle was 95+/- 5 degrees. There were no statistically significant differences between the OSCTs. In five patients, the PSZ morphology did not allow planning for HLCLO.in 13 cases; the ASZ left insufficient bone stock between the ELCLO and the calcaneal cuboid joint.
Conclusion:
In this study, we used DM to determine the safe zone for LCL. The high OSCT and morphology variability call for patient-specific LCL preoperative planning. DM could be reliably used to tailor the optimal surgical solution.
