Applications of Infrared Thermography in Orthopaedics

Pathological conditions with ongoing inflammatory processes result in specific heat signatures at the affected body parts.

These patterns have shown to be persistent, reproducible, and infrared thermography (IRT) has been utilized to detect these changes and screening inflammatory conditions like rheumatoid arthritis, soft tissue injuries, surgical site infections, and monitoring surgical wound healing after various abdominal, plastic and thoracic surgeries.

The modern devices are advanced and their non contact, convenient and precise readings can aid in multiple medical sub fields. Orthopaedics as a broad entity has witnessed utilisation of this technology for different indications.

P. Kumar, A. Gaurav, R.K. Rajnish et al. presented a scoping review to assess these established indications and further scope of its utility.

A Medline search was done with specific keywords for studies of any design in English language discussing the usage of thermography in Orthopaedics. Animal studies, conference abstracts, systematic reviews, e-posters, case reports, book chapters, and studies describing the use of thermography in non-Orthopaedic patients were excluded.

Results:

• Total number of hits was 1380, out of which after removing duplicates and studies which were unrelated to IRT in orthopaedics, 108 studies were assessed.

• Full texts of 71 out of 108 studies were read, and finally, 43 studies were included.

These studies described the utility of IRT in orthopaedic sub-fields like

 Pain and arthritis (5),

 Charcot foot and neuropathic ulcers (6),

 Infections in diabetic foot and joint arthroplasty (3);

 Reflex sympathetic dystrophy (2),

 Carpal tunnel syndrome (5),

 Sports medicine (6),

 Paediatric orthopaedics (7),

 Spine (5), and

 Miscellaneous including ergonomics, elbow pain & compartment syndrome (4)

The authors concluded that - in practice, infrared thermography can be utilized in isolation as well as in combination with other parameters, e.g, ESR and C reactive protein in periprosthetic infections, to screen or diagnose a prospective case early, so as to initiate adequate treatment, be it debridement or targeted antibiotic therapy.

In other scenarios like assessment of bone union and related complications like non unions, thermography can pick up the periodic trends in heat signatures, which can indicate whether or not a certain case requires early response (surgical or medical) to improve the union chances.

As the technology will further improve and the cost benefit aspect improves, we will definitely see an uprise in utilisation of this novel device in the various sub-fields of orthopaedics on a wider scale.

Further reading:

Applications of thermal imaging with infrared thermography in Orthopaedics Prasoon Kumar, Ankit Gaurav, Rajesh Kumar Rajnish, Siddhartha Sharma, Vishal Kumar, Sameer Aggarwal, Sandeep Patel

Journal of Clinical Orthopaedics and Trauma

https://doi.org/10.1016/j.jcot.2021.101722