Criteria for surgical decision-making in talocalcaneal tarsal coalitions

Abstract

Assessment and management of talocalcaneal middle facet tarsal coalitions present a complex orthopaedic challenge. Various studies have attempted to establish guidelines for surgical intervention based on coalition size and hindfoot alignment. Our paper reviews the historical focus on coalition size, suggesting instead that posterior facet health is a more appropriate consideration for surgical decision making. Additionally, we challenge the traditional method for evaluating hindfoot alignment and propose a more accurate evaluation method. This critical review intends to highlight flaws in historical literature, aiming to trigger a reevaluation of the criteria for surgical intervention in talocalcaneal tarsal coalitions and promote future research studies driven by data and scientifically validated methodologies.

Key concepts: (1)This paper challenges conventional criteria for surgical decision-making in talocalcaneal tarsal coalitions.(2)The authors advocate for a shift in focus, proposing that posterior facet health, rather than coalition size, should be the determinant for resection.(3)Wilde's method for evaluating hindfoot alignment is challenged as being subjective and susceptible to influence by the height/vertical length of the calcaneus visible on individual coronal CT scan slices.(4)The authors propose a more precise assessment of hindfoot alignment using the anatomic axis of the calcaneus, acknowledging the need for further validation.(5)Establishing scientifically tested criteria for posterior facet health/thickness and hindfoot valgus deformity through research will improve consistency in surgical decision making and, thereby, improve patient outcomes.

Level of evidence: V.

Keywords: Adolescents; Foot; Reconstruction; Resection; Talocalcaneal coalition; Tarsal coalition.

Figure 1

Wilde et al. criteria for a resectable and unresectable subtalar tarsal coalitions.

Figure 2

Measuring the width of a middle facet subtalar (ST) tarsal coalition. (A) A rare horizontal middle facet coalition. The width of the coalition (red line) and the width of the middle facet (black line) are approximately equal. (B) A typical down sloping coalition. The length of the coalition (red line) is longer than the middle facet is wide (black line). The dashed red line is the length of the coalition rotated and brought up to demonstrate the difference in lengths. (C) The width of the coalition in this foot can be measured, but an ossified coalition has no length and no surface area.

Figure 3

Thickness/health of the posterior facet in feet with middle facet tarsal coalitions. (A) The thickness of the articular cartilage in the posterior facet is equal to that in the ankle joint. This implies healthy cartilage in both joints. The coalition is not seen in this coronal CT scan slice of a foot with a fibrocartilaginous middle facet coalition, but the image is shown because the thicknesses were measured in PACS. (B-C) The thickness of the articular cartilage in the posterior facets is slightly less than that in the ankle joints in these feet with fibrocartilaginous coalitions. (D-E) The thickness of the articular cartilage in the posterior facets is 50% or less than that in the ankle joints in these feet with osseous coalitions. This is the radiographic, but not clinical, definition of arthritis, a.k.a. degenerative joint disease. (F) The articular cartilage is almost non-existent in this foot with a solid, osseous middle facet coalition that appears to be encroaching upon the posterior facet. PACS; picture archiving and communication system.

Figure 4

Measurement technique of the hindfoot (A) According to Wilde et al. , and (B) according to the anatomic axis of the calcaneus.

Figure 5

The Wilde et al. line and angle vs the anatomic axis line and angle on 2 different coronal CT scan slices in the same foot. The Wilde angle is affected by the length/height of the ossified calcaneus on the image, whereas the anatomic angle is not.