Intra- and Inter-Rater Reliability of Ultrasound in Plantar Fascia Thickness Measurement

SLR - June 2019 - Rebecca V. DeSimone

Reference: Nakhaee M, Mousavi ME, Mohseni-Bandpei MA, Shakourirad A, Safari MR, Kashani RV, Baneshi MR, Nakhaei M. Intra- and Inter-Rater Reliability of Ultrasound in Plantar Fascia Thickness Measurement. Iran J Radiol. 2018 July; 15(3).

Scientific Literature Review

Reviewed By: Rebecca V. DeSimone, DPM
Residency Program: Temple University Hospital, Philadelphia, PA

Podiatric Relevance: The plantar fascia is an important biomechanical structure in the foot. As foot and ankle surgeons, we see many patients complaining of heel pain with the ultimate diagnosis of plantar fasciitis. Using modalities, such as ultrasound, can help the foot and ankle surgeon evaluate the plantar fascia, can aid in both diagnosis and treatment and can save costs compared to use of MRI. This article compares intra- and inter-rater reliability of measuring plantar fascia thickness, which could have an effect on under- or overdiagnosing patients with plantar fasciitis.
 
Methods: Investigators used 12 healthy adults as subjects. The patients were prone with the shin elevated to 30 degrees and knees flexed. The foot was relaxed off the edge of the table and held in neutral position. Ultrasound measurements were carried out with a VF 5–12 MHZ linear array transducer. The transducer was used to measure the thickness of the plantar fascia in the longitudinal view at the calcaneus insertion and at two additional sites 5 mm and 10 mm from the insertion. The transducer was placed in the sagittal plane over the plantar aspect of the medial calcaneal tuberosity. Each heel was scanned and measured three times by both examiners.

Results: Intraclass correlation coefficients were used to analyze the significance between both intra- and inter-rater reproducibility of the measurements and found that there were no statistical differences in time or rater to measure plantar fascia thickness.

Conclusions: This study found that there was no difference in time used to perform the exam or performing provider (inter- and intra-rater) to measure plantar fascia thickness. This imaging study can be utilized in an office or clinic setting to further evaluate patients presenting with plantar fascia symptoms. As we continue to think about more time- and cost-effective measures to diagnose and treat patients, ultrasound may be a useful in-office tool. However, training in use of the device and interpretation of the image is necessary. Further studies are also needed to compare results obtained from MRI and ultrasound to confirm comparable efficacy in diagnosis.