Summary

In this study we present clinical evidence showing that thermal imaging may be a useful, simple, low-cost adjunct imaging tool for evaluation of rotator-cuff tears and may provide additional capability for identification of complete versus partial tears before surgery.

Abstract

Objective

This study evaluates the usefulness of smartphone-based thermal imaging for diagnosis of rotator-cuff tears (RCT) and whether this imaging modality can discriminate between partial and complete tears.

Methods

Forty-five patients (age 55±8 years old; male:female-27:18; complete:partial--24:21) with moderate-to-severe limitation in range of motion (ROM), and scheduled to undergo primary rotator-cuff arthroscopic repair, participated (ethics-approval #HFH-219-2020).
Thermal images were captured and skin temperature (ST) measured over the rotator cuff tear (RCT) and over the trapezius away from the tear from the superior and posterior aspects respectively using a FLIR-One-Pro thermal camera (FLIR Systems, Wilsonville, OR, USA) attached to a smartphone incorporating FLIRtools software. The primary outcomes were (1) the difference between the ST over the RCT and that of similar sites of the contralateral, unaffected shoulder (?ST-RCT), and (2) the difference between the ST over the uninjured trapezius on the side of the RCT and that of the unaffected side (?ST-trapezius). Tear status (complete/partial) was determined from the surgical records.

Results

When considering all patients together, the ST over the RCT, posterolateral to the acromioclavicular (AC) joint, was significantly warmer on the affected vs the unaffected side (mean±SD[n=45]: ?ST-RCT=0.34°C±0.14. p=0.008 by paired t-test). No difference in ST was detected over the area of the trapezius between affected and unaffected sides. However, patients with complete tear, had a greater (warmer) ?ST-RCT than those with partial tear (?ST-RCT, complete [n=24] -vs- partial [n=21]: 0.45°C±0.17, -vs- 0.22°C±0.22, p=0.008 -vs- p=0.162).

Conclusions

These studies provide evidence that thermal imaging may be a useful, simple, low-cost adjunct imaging tool for evaluation of rotator-cuff tears and may provide additional capability for identification of complete versus partial tears and the determination of the need for surgical intervention. Further studies involving advanced thermal properties are in progress.