Correlation of High-resolution Ultrasonography and Conventional Radiography in the Evaluation of Heel Pain at Kenyatta National Hospital Principal Investigator

Abstract

Background: The recent improvements in ultrasound technology coupled with wide availability, safety, portability, cost-effectiveness, non-ionizing with high spatial resolution renders it the initial choice of imaging for the evaluation of most musculoskeletal diseases. Ultrasound is a particularly useful tool to quickly and accurately localize and characterize pathologies of the sole. Heel pain is a common presenting complaint and affects a wide range of the adult population. Plantar fasciitis is the commonest cause in primary care settings. It presents with heel pain, discomfort, and disability limiting day-to-day weight-bearing activities. Although clinical history and examination give useful information, imaging allows further assessment of the plantar fascia and helps to determine the differentials. In our setup, the first imaging modality requested is a plain radiograph which is a limited modality when it comes to depicting soft tissue pathology. With the above-mentioned, ultrasound could be used as the diagnostic imaging modality for evaluating the heel as well as allow for follow up of patients with known plantar fascia disorders. Objective: To quantify, characterize and correlate the ultrasonographic and radiographic findings in the diagnosis of plantar fascia disorders in patients presenting with heel pain at Kenyatta National Hospital Sample size: Fifty nine (59) patients with heel pain were included in the study. Sampling Design: This was a prospective descriptive study. Study setting: Radiology Departments of the University of Nairobi and Kenyatta National Hospital Study duration: The study was carried out between May 2021 and November 2021 Study Methodology: Following ethical approval, 59 consecutive patients referred for either a heel ultrasound or radiograph to the Department of Radiology, University of Nairobi or Department of Radiology, Kenyatta National Hospital because of heel pain were included in the study. The ultrasound examination was conducted as per the ESSR guidelines 2010 using General Electric Logic 7 or Phillips HD 11 at UoN and Toshiba- Aplio 400 or Philip 70G at

KNH for the performance of a heel ultrasound. Lateral heel radiographs done were reviewed thereafter. Findings were captured in a data collection form. The data was analyzed using SPSS Version 22. Study results Normal findings were recorded in 8 patients (13.6%) with abnormal findings seen in 51 patients accounting for 86.4%. The abnormal findings were twice more common in females (40) than in men (19) with a mean age of 42.3(SD 12.4) years. Heel pain was the only presenting complaint in the examined patients, majority 48(81.3%) presenting within a duration of 1 month and 1 year with a mean duration of 6 months (IQR 3.0-12.0). The mean weight was 79.7kg (SD 10.6) with only 9 (15.3%) patients categorized as having healthy weight, while the rest of the patients ranged from overweight 21 (35.6%) to obese 29 (49.2%). The most prevalent pathology was plantar fasciitis in 45 (76.3%) followed by plantar fascia tears 6 (10.2%). There was a statistical significant association between plantar fasciitis with age and BMI as assessed by the independent sample t-test (p value = <0.001 and 0.010 respectively). Abnormal plantar fascia thickness (67%) and echogenicity (71.6%) were the most sonographic findings encountered. An associated common finding of calcaneal spur (60.2% and 69.3%) was seen in both ultrasound and X-ray respectively. The sensitivity, specificity, PPV, NPV and diagnostic accuracy of heel ultrasound compared to plain radiography was 97.5%, 60.2%, 69.5%, 97.2% and 78.6% for abnormal plantar fascia thickness, 87.6%, 100%, 100%, 75.5% and 85.9% for calcaneal spurs and 100%, 64.4%, 80.2%, 100% and 85.4% for cortical irregularities, respectively. Conclusion Heel sonography achieved acceptable diagnostic accuracy of 78.6% when compared to plain radiography in the diagnosis of plantar fascia disorders. It may be considered an initial imaging modality to confirm clinically suspected plantar fasciitis in point-of-care settings