Prevalence of Coexistent Plantaris Tendon Pathology in Patients with Mid-Portion Achilles Pathology: A Retrospective MRI Study

Abstract

Co-existence of Plantaris tendinopathy (PT) in patients with mid-Achilles tendinopathy (Mid-AT) is of clinical significance. This study aims to describe the MRI-based pathological characteristics of co-existing PT and Mid-AT. One-hundred MRI studies of patients diagnosed with Mid-AT were retrospectively analysed by an experienced musculoskeletal radiologist. Presence or absence of a Plantaris tendon, co-existing PT with Mid-AT, insertional characteristics of Plantaris tendon, and maximum anteroposterior thickness of the tendon in Mid-AT (axial images) were evaluated. When PT co-existed with Mid-AT, the location of the tendon pathologies in relation to calcaneal insertion was assessed (sagittal images) and their association was analysed using the coefficient of variation (CV) and Pearson’s correlation coefficient. Plantaris was present in 84 cases (84%), and Mid-AT and PT co-existed in 10 cases (10%). A greater variability in the location of Plantaris pathology (CV = 42%) than Achilles tendinopathy (CV = 42%) was observed. The correlation coefficient also revealed a low and non-significant association between the location of two pathologies when they exist together (r = +0.06; p = 0.88). Clinical evaluation of Achilles tendon pain needs careful consideration into the possible co-existence of Plantaris pathology. The considerable difference observed in the location of PT and Mid-AT suggest possible isolated pathologies and differentials for Achilles tendon pain.

Achilles Scraping and Plantaris Tendon Removal Improves Pain and Tendon Structure in Patients with Mid-Portion Achilles Tendinopathy—A 24 Month Follow-Up Case Series

“…Recent research has demonstrated that plantaris tendon involvement can be found in patients with chronic midportion and insertional Achilles tendon tendinopathy, especially when there is medial Achilles tendon pain [ 19 , 34 , 35 , 36 ]. Cadaveric studies have demonstrated that there is an individual variability of the course of the plantaris tendon in relation to the Achilles tendon, with up to nine different courses demonstrated [ 17 ].…”

Snapping Plantaris Tendon: A Rare Case in a Competitive Dancer

“…Despite this dissonance, coexisting tendinopathies were found in 10% of the examined cases. 31 When conservative treatments for mid-substance Achilles tendinopathy with associated plantaris pathology fail, plantaris excision with or without Achilles tenosynovectomy has demonstrated good surgical outcomes for both recreational and high-level athletes. 32 - 34 …”

Sharp pain in a normal Achilles tendon of a professional female football player was related to a plantaris tendon in a rare position: a case report

“…Plantaris tendon-related pain is a relatively new diagnosis, mainly found in a subgroup of elite or recreationally active individuals [ 5 , 7 , 17 ]. There is typically pain on the medial side of a thickened Achilles midportion; sometimes described as sudden and sharp pain, but more often described as dull pain during loading.…”