Objective
To examine 1) the validity of ultrasound imaging to measure osteophytes, and 2) the association between osteophytes and IAT.
Design
Case-control study
Setting
Academic medical center
Participants
20 persons with chronic unilateral IAT (Age: 58.7 ± 8.3 years, 50% female) and 20 age- and gender-matched controls (Age: 57.4 ± 9.8 years, 50% female) participated in this case-control study.
Intervention
Not applicable.
Main Outcome Measures
Symptoms severity was assessed using the Foot and Ankle Ability Measure (FAAM), Victorian Institute of Sport Assessment- Achilles questionnaire (VISA-A), and the Numerical Rating Scale (NRS). Length of osteophytes was measured bilaterally in both groups using ultrasound imaging and additionally on the symptomatic side of the IAT group using radiographs. The intraclass correlation coefficient was used to examine the agreement between ultrasound and radiograph measures. McNemar, Wilcoxon Signed Rank and Fisher’s exact tests were used to compare the frequency and length of osteophytes between sides and groups. Pearson correlation was used to examine the association between osteophyte length and symptom severity.
Results
There was good agreement (ICC ≥0.75) between ultrasound and radiograph osteophyte measures. There were no statistically significant differences (P>0.05) between sides or groups in the frequency of osteophytes. Osteophytes were larger on the symptomatic side of the IAT group compared to the asymptomatic side (P= 0.01) and controls (P=0.03). There were no associations between osteophyte length and symptom severity.
Conclusions
Ultrasound imaging is a valid measure of osteophyte length, which is associated with IAT. While a larger osteophyte indicates pathology, it does not indicate more severe IAT symptom severity.