Staging achilles tendinopathy using ultrasound imaging: the development and investigation of a new ultrasound imaging criteria based on the continuum model of tendon pathology

Abstract

AimTo develop a standardised ultrasound imaging (USI)-based criteria for the diagnosis of tendinopathy that aligns with the continuum model of tendon pathology. Secondary aims were to assess both the intra-rater and inter-rater reliability of the criteria.MethodsA criteria was developed following a face validity assessment and a total of 31 Achilles tendon ultrasound images were analysed. Intra-rater and inter-rater reliability were assessed for overall tendinopathy stage (normal, reactive/early dysrepair or late dysrepair/degenerative) as well as for individual parameters (thickness, echogenicity and vascularity). Quadratic weighted kappa (kw) was used to report on reliability.ResultsIntra-rater reliability was ‘substantial’ for overall tendinopathy staging (kw rater A; 0.77, 95% CI 0.59 to 0.94, rater B; 0.70, 95% CI 0.52 to 0.89) and ranged from ‘substantial’ to ‘almost perfect’ for thickness (kw rater A; 0.75, 95% CI 0.59 to 0.90, rater B; 0.84, 95% CI 0.71 to 0.98), echogenicity (kw rater A; 0.78, 95% CI 0.62 to 0.95, rater B; 0.73, 95% CI 0.58 to 0.89) and vascularity (kw rater A; 0.86, 95% CI 0.74 to 0.98, rater B; 0.89, 95% CI 0.79 to 0.99). Inter-rater reliability ranged from ‘substantial’ to ‘almost perfect’ for overall tendinopathy staging (kw round 1; 0.75, 95% CI 0.58 to 0.91, round 2; 0.81, 95% CI 0.63 to 0.99), thickness (kw round 1; 0.65, 95% CI 0.48 to 0.83, round 2; 0.77, 95% CI 0.60 to 0.93), echogenicity (kw round 1; 0.70, 95% CI 0.54 to 0.85, round 2; 0.76, 95% CI 0.58 to 0.94) and vascularity (kw round 1; 0.89, 95% CI 0.79 to 0.99, round 2; 0.86, 95% CI 0.74 to 0.98). Inter-rater reliability increased from ‘substantial’ in round 1 (kw 0.75, 95% CI 0.58 to 0.91) to ‘almost perfect’ in round 2 (0.81, 95% CI 0.63 to 0.99).ConclusionIntra-rater and inter-rater reliability were ‘substantial’ to ‘almost perfect’ when utilising an USI-based criteria to diagnose Achilles tendinopathy. This is the first study to use the continuum model of tendon pathology to develop an USI-based criteria to diagnose tendinopathy.

Lower Limb Tendinopathy Tissue Changes Assessed through Ultrasound: A Narrative Review

“…Matthews et al [ 39 ] have recently proposed a new method to investigate Achilles tendinopathy with ultrasound, using the continuum model of tendinopathy development [ 12 ]. The results showed a moderate to excellent intra- and inter-rater reliability of the overall outcome (0.52–0.99).…”

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound – Part I: Extraarticular Pathologies

“…These changes have been described on US as increases in tendon dimensions and heterogeneous or diffuse changes in echogenicity [105,106]. Furthermore, the shadowing generated by fibrillar disorganization and the lack of parallel-aligned fibers contribute to areas of hypoechogenicity within the tendon matrix [78].…”

“…A clinical diagnosis of tendinopathy is primarily derived from the patient history and clinical tests. The latter have been shown to be sensitive for detecting tendinopathy, but they are not specific for identifying pathological changes when compared with imaging [78]. MSUS is the foremost imaging modality for tendon pathologies since it more sensitive than clinical examination and MRI for detecting pathological structural changes within tendons, but it does not always correlate with pain and dysfunction [79,80].…”

To What Extent Do Musculoskeletal Ultrasound Biomarkers Relate to Pain, Flexibility, Strength, and Function in Individuals With Chronic Symptomatic Achilles Tendinopathy?

“…These peripheral adaptations may increase sensitivity to chemical pain mediators and trigger an over-activation of nociceptors (70,71). Hence, the inclusion of quantitative Doppler-related MUBs may become indispensable to best capture such adaptions in the future, while also reinforcing their relevance in composite ultrasonography-based scoring when coupled with geometric and composition measures (i.e., thickness and echogenicity) (20,72). Part of the answer may also relate to sensitization of the central nervous system (i.e., central adaptations), commonly associated with chronic musculoskeletal impairments (73,74), or psychological factors affecting pain (e.g., pain catastrophizing and kinesiophobia) (75)(76)(77), which can both evolve independently to peripheral tendon alterations characterized with MUBs.…”

“…Furthermore, MUBs allow differentiating between several pathologies (e.g., partial tear, bursitis, peritendinitis) when clinical evaluation is not conclusive (4). Therefore, MUBs are tools frequently used in both clinical and research settings when characterizing the Achilles tendon integrity (20)(21)(22)(23)(24). Interestingly, bodies of evidence are conflicting regarding associations between MUBs and pain, flexibility, strength, and function (25)(26)(27)(28)(29)(30)(31)(32).…”