Bone stress injuries in the presence of tarsal coalition as a cause of hindfoot pain in adolescents: case series of 6 patients with literature review

How accurate is MRI for diagnosing tarsal coalitions? A retrospective diagnostic accuracy study

OBJECTIVES

This study aimed to evaluate the diagnostic accuracy, inter-reader agreement, and associated pathologies on MR images of patients with confirmed TC.

METHODS AND MATERIALS

In this retrospective study, 168 ankle MRI exams were included, consisting of 56 patients with clinically or surgically confirmed TC and 112 controls without TC, matched for age and sex. Images were analyzed independently by three radiologists blinded to clinical information. The evaluation criteria included the presence, type, and location of TC, as well as associated pathologies. After calculating diagnostic accuracy and the odds ratio of demographic data and anatomic coalition type for associated pathologies, inter-reader agreement was assessed using kappa statistics.

RESULTS

The majority of TCs were non-osseous (91.1%) and located at the calcaneonavicular (33.9%) or talocalcaneal joint (66.1%). Associated pathologies included adjacent and distant bone marrow edema (57.1% and 25.0%), osteochondral defect of the talar dome (OCD, 19.6%), and joint effusion (10.7%) and accessory anterolateral talar facet (17.9%). Talar OCD was associated with increased patient age (p = 0.03). MRI exhibited a cumulative sensitivity and specificity of 95.8% and 94.3% with almost perfect inter-reader agreement (κ = 0.895).

CONCLUSION

MRI is a reliable method for detecting tarsal coalition and identifying commonly associated pathologies. Therefore, we recommend the routine use of MRI in the diagnostic workup of patients with foot pain and suspected tarsal coalition.

CLINICAL RELEVANCE STATEMENT

MRI is an accurate and reliable modality for diagnosing tarsal coalitions and detecting associated pathologies, while improving patient safety compared to computed tomography by avoiding radiation exposure.

KEY POINTS

• Despite the technological progress in magnetic resonance imaging (MRI), computed tomography (CT) is still regarded as the gold standard for diagnosing tarsal coalition (TC). • MRI had a cumulative sensitivity of 95.8% and specificity of 94.3% for detecting tarsal coalition with an almost perfect inter-reader agreement. • MRI demonstrates high accuracy and reliability in diagnosing tarsal coalitions and is useful for identifying associated pathologies, while also improving patient safety by avoiding radiation exposure.

Fracture through Pre-Existing Tarsal Coalition: A Narrative Review

Tarsal coalitions are abnormal fibrous or bony connections between the tarsal bones of the foot. While not always symptomatic, coalitions can cause pain, alterations in forefoot and hindfoot morphology, and alterations in foot and ankle biomechanics. Previous research has described the association of tarsal coalitions with fractures of the lower extremity. Multiple reports of acute fracture in the presence of tarsal coalition have been presented, as have reports of stress fractures of the foot and ankle with concomitant coalition, insidious in onset and thought to be related to aberrancies in foot and ankle biomechanics. The purpose of this review is to discuss the biomechanics seen in tarsal coalitions and to describe reports of fracture occurring concomitantly with tarsal coalitions. We will discuss diagnostic options and treatment approaches in the setting of fracture with preexisting tarsal coalition.