We would like to thank Dr. Chai et al. [1] for their detailed response and interest. We have carefully reviewed their response and appreciate the opportunity to discuss this issue further. Below, we offer our thoughts on the points raised in their response:
Although the literature on the use of ultrasonography (US) for diagnosing myofascial pain syndrome (MPS) is somewhat limited, there has been a notable increase in research on this topic in recent years. MPS is a prevalent condition, with estimates suggesting that among patients with chronic musculoskeletal pain, the prevalence of MPS can range from 85% to 95% [2]. Despite its commonality, MPS is frequently overlooked by clinicians. Moreover, physical examinations have been reported as unreliable in diagnosing MPS [3].
US imaging techniques, including grayscale, Doppler, and elastographic US, have shown promise in accurately localizing myofascial trigger points (MTrPs) with varying degrees of diagnostic accuracy, reporting sensitivity rates between 33% and 91% and specificity rates from 75% to 100% [4]. Typically, a myofascial trigger point appears on US imaging as a hypoechoic nodule with well-defined borders and a heterogeneous internal echotexture. Vibratory sonoelastography typically displays these nodules as hard, while Doppler imaging reveals altered blood flow patterns around MTrPs, with active MTrPs exhibiting high-resistance and retrograde diastolic flow [5]. Additionally, US guidance improves the detection of local twitch responses in deep muscles, which are frequently overlooked by visual inspection alone [6]. The local twitch response is a recognized diagnostic criterion for MPS. Observing this response aids in confirming the MPS diagnosis. To date, there have been no cases where US has been employed to diagnose MPS in the interossei muscles or other parts of the foot. However, given the existing literature, we believe such applications are feasible. We consider our correspondence to be of significant value as it may inspire further research in this area.
We believe that our exchange of views on these issues has the potential to encourage further research. Thank you again for your response and interest. If you would like to discuss the topic further or provide additional information, we would be happy to respond.
References1. Chai JW, Kim DH, Kim HJ, Seo J. Re: Casting light on the overlooked trigger point of the interosseous muscles in metatarsalgia: insights and treatment strategies. Ultrasonography 2024;43:297–298.
![]() ![]() ![]() ![]() 2. Mazza DF, Boutin RD, Chaudhari AJ. Assessment of myofascial trigger points via imaging: a systematic review. Am J Phys Med Rehabil 2021;100:1003–1014.
![]() ![]() ![]() 3. Sikdar S, Shah JP, Gebreab T, Yen RH, Gilliams E, Danoff J, et al. Novel applications of ultrasound technology to visualize and characterize myofascial trigger points and surrounding soft tissue. Arch Phys Med Rehabil 2009;90:1829–1838.
![]() ![]() ![]() 4. Elbarbary M, Sgro A, Goldberg M, Tenenbaum H, Azarpazhooh A. Diagnostic applications of ultrasonography in myofascial trigger points: a scoping review and critical appraisal of literature. J Diagn Med Sonogr 2022;38:559–573.
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