Scientific Session 06 — Musculoskeletal - FootMonday, May 1, 2017
2832. Not One of the Usual Suspects: MRI Features of Insertional Lateral Cord Plantar Fasciitis
Umans H1,2, Newman E3*, Elsinger E1,4, Tobin K2 1. Albert Einstein College of Medicine, Bronx, NY; 2. Lenox Hill Radiology & Imaging Associates, PC, New York, NY; 3. Jacobi Medical Center, Bronx, NY; 4. Montefiore Medical Center, Bronx, NY
Address correspondence to H. Umans (email@example.com)
Objective: The purpose of this study was to report MRI findings of insertional lateral cord plantar fasciitis and review the presenting symptoms and suspected diagnoses.
Materials and Methods: Eighteen cases of lateral cord plantar fasciitis were identified in retrospective review of MRI performed from December 2014 to August 2016 using either 3-T (n = 9) or 1.5-T (n = 8) magnets. All 18 patients (12 female, six male; mean age, 55 years; range, 35–66 years) presented with lateral midfoot pain near the fifth metatarsal (MT) base. All imaging included axial, coronal, and sagittal T1-weighted and proton density– or T2-weighted fat-suppressed sequences. One outside MRI examination was performed using three planes of T1-weighted and STIR sequences 1 year before lateral foot ultrasound. Electronic medical records were reviewed for history and suspected diagnoses. MR images were reviewed to assess lateral cord plantar fascia (LCPF) thickness, signal, contour, insertional enthesophytes, and reactive bone marrow edema at the fifth MT base, peroneal tendinosis, tear and tenosynovitis, and osseous or articular abnormality within the midfoot. Self-reported height and weight were recorded and body mass index (BMI) was calculated.
Results: Symptom duration (available in 11 patients) was 3 weeks in nine patients and 12 and 21 weeks in one patient each. Two patients reported antecedent trauma. Suspected diagnoses included fracture (fifth MT base [n = 12], cuboid [n = 2], os peroneum [n = 2], calcaneus [n = 1], NOS [n = 1]), peroneus tendonitis or tear (brevis [n = 3], not otherwise specified [NOS] [n = 6]), painful bump near the fifth MT base (n = 2), and proximal plantar fasciitis (n = 1). BMI ranged from 21.9 to 34.1 (mean, 28.6). In all, the LCPF appeared thick, frayed with increased intrasubstance signal intensity, and perifascial edema. A superimposed partial tear was seen in four patients. Four patient had insertional enthesophytes that demonstrated reactive bone marrow edema . Two patients had peroneus longus tenosynovitis, but no cases of tendinosis or tear were seen. In two patients, the os peroneum was normal. The maximum thickness of the LCPF ranged from 6.3 to 11.5 mm (mean, 7.5 mm).
Conclusion: Lateral cord plantar fasciitis presents with pain and variable swelling at the lateral midfoot. Pain at the lateral midfoot is commonly presumed to be due to fifth MT base stress fracture or tendinosis or tear of the peroneal tendon without consideration of lateral cord plantar fasciitis. The spectrum of MRI findings is identical to those more commonly seen at the calcaneal origin of the central cord but instead affects the insertion of the lateral cord onto the base of the fifth MT.