Purpose: Prospective study to assess ultrasonography (US) utility as an imaging tool for supraspinatus muscle atrophy diagnosis, establishing if there is any relationship between repairing supraspinatus tears and its eventual muscular recovery.
Methods: Observational study.
Selection criteria: adults with a full-thickness reparable supraspinatus tear confirmed arthroscopically. Clinical and imaging data pre- and postoperatively with 12 months of follow-up were recorded, including demographic data, Constant scale, Patte classification, repair type, and supraspinatus muscle belly US images in both shoulders, recording height, diameter, echogenicity (mean number of pixels between 0-black and 255-white), and central tendon pennate angle (PA).
Results: In total, 110 supraspinatus tears underwent arthroscopic repair (2015-2018). Mean age was 61 ± 8 years (46-77). We detected a correlation between atrophy and age in terms of echogenicity and PA (P = .01). Echogenicity improved from 54.5 to 51.0 (P = .365) and slightly deteriorated on the contralateral side from 51.6 to 52.9 (P = .351). Supraspinatus echogenicity compared to trapezius muscle reduced from 0.43 to 0.36 (P < .001). PA augmented from 5.8 to 8.6 (P < .001). Mean PA on the contralateral side was 8.6 preoperatively. Patte II cases showed the most significant improvement in terms of imaging evaluation of atrophy. Although Patte III cases almost did not improve in terms of atrophy, they improved clinically. We observed improvement after surgery in Constant score from 35 to 85 (P < .001). Minimal clinically important differences for Constant and visual analog scale were 44.45 ± 12.87 and 6.54 ± 1.41, respectively. Recurrence of symptoms was 13%, related to worse results of PA and echogenicity compared to nonrecurrences.
Conclusions: Supraspinatus atrophic muscle changes after repair can be reversed. It can be quantified using US imaging (histogram, histogram ratio and echogenicity reduction, pennate pattern, and PA augmentation). Patte II cases showed the best results after repair, demonstrated by US. The faster the repair, the better the results without being influenced by repair type. The bigger the tear and retraction, the more echogenicity and less PA, with worse clinical and US results.
Level of evidence: Level III, prospective therapeutic study.
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