Bipartite medial cuneiform: magnetic resonance imaging findings and prevalence of this rare anatomical variant

Cubonavicular Coalition: Magnetic Resonance Imaging Findings and Associated Pathology of a Rarely Reported Condition in 27 Patients

RATIONALE AND OBJECTIVES

(1) Describe multimodality imaging of cubonavicular coalition (CNC) with magnetic resonance imaging (MRI) focus, (2) evaluate CNC associated foot and ankle pathology, (3) examine clinical presentation/symptoms associated with CNC, (4) record CNC treatment.

MATERIALS AND METHODS

Retrospective Institutional Review Board (IRB) approved study. Picture Archiving and Communication System (PACS) databases searched for CNC. Final study population: 34 cases in 27 patients. Each CNC was reviewed for: coalition type (osseous versus non-osseous- cartilaginous versus fibrous), tendon and ligament pathology, bone marrow edema at CNC and adjacent joints, presence and severity of degenerative changes at CNC and adjacent joints, fractures, additional coalitions, laterality, and pes planus. MRI planes and radiographic views on which coalitions were best identified were recorded. Each CNC EMR was reviewed for: symptoms, trauma, management, patient demographics. Inter-reader reliability was performed for type of non-osseous coalition.

RESULTS

Final cohort included 34 cases in 27 patients (average age: 34.7, range: 10-76; 71% female). No CNC was completely osseous. On MRI, 89.5% of coalitions were non-osseous and 5.3% were partially osseous. 76.5% of patients had referable symptoms including pain, limited motion, inability to bear weight. 23.5% of patients were surgically managed/pathologically proven. On MRI, 36.8% of patients had tendon pathology, 52.6% had ligamentous pathology, 100% had bone marrow edema-like signal abnormality about the CNC, and 88.2% had CNC degenerative changes. There was bone marrow edema-like signal abnormality at bones adjacent to the CNC in 52.6% and adjacent joint degenerative disease present in 50%. CNC was best identified on oblique radiographs and axial MRI. Inter-reader reliability for non-osseous coalition type was poor, Cronbach's alpha 0.554.

CONCLUSION

CNC is subtle and findings of osteoarthritis or bone marrow edema-like about the cubonavicular articulation should raise suspicion for underlying coalition.

Imaging of Bone Anatomical Variants Around the Foot and Ankle

Different anatomical variants can be found in the ankle and foot, generally as occasional findings, although they can be the cause of diagnostic pitfalls and difficulties, especially in radiographic interpretation in trauma. These variants include accessory bones, supernumerary sesamoid bones, and accessory muscles. In most cases, they represent developmental anomalies found in incidental radiographic findings. This review discusses the main bony anatomical variants, including accessory and sesamoid ossicles, most commonly found in the foot and ankle that can be a cause of diagnostic challenges.

A rare cause of foot pain in an adolescent due to os paracuneiforme: a case report and review of the literature

Os paracuneiforme is an extremely rare accessory ossicle located at the medial aspect of the medial cuneiform bone. Although foot pain secondary to accessory ossicles is well known, symptomatic os paracuneiforme that requires surgical excision is rarely reported in the current literature. Herein, a 12-year-old boy with symptomatic os paracuneiforme is presented, and its clinical and imaging findings as well as the treatment are discussed.