A quick, cheap and non-invasive way to measure osteoarthritis

APPROACH found that a commercially-available motion-measuring technology could be used to gauge the extent of OA as an alternative or add-on to existing diagnostic options

There are a number of ways that osteoarthritis (OA) progression can be measured, but all come with drawbacks. While x-rays are the gold standard, they don’t tell us much about changes in cartilage, and a person might have symptoms a long time before anything obvious shows up on an x-ray.

Meanwhile, MRI is costly, and questionnaires are subjective.

The partners in APPROACH studied whether a commercially-available technology called GaitSmart® could offer added value in the evaluation of knee osteoarthritis as a non-invasive, inexpensive and highly-flexible alternative or add-on to help doctors make a diagnosis. They did this by first comparing how it measures up to the traditional tests, to try to find out whether it was any better at predicting the presence (and severity) of tissue damage.

The GaitSmart® system involves attaching six sensors to a person’s body and having them walk 15-20m at their own speed. Then sensors feed data to a laptop which analyses the results. The whole process takes about 10-15 minutes and is easy to transport and set up.

GaitSmart® was found to measure different features of OA as well as offer more information than what can be gathered through a survey. While information about a person’s demographic, combined with questionnaire responses, poorly predicts the presence of tissue damage on a conventional x-ray, adding GaitSmart® to the mix improved the prediction to moderate. It was also found that GaitSmart® can offer additional information on the severity of tissue damage as seen on conventional x-rays.

According to the study authors, few patients in Europe are offered an MRI scan due to cost and availability. Self-assessment from pain and limited functionality is more common in late stage, they say, when joint replacement is considered, by which time there no other options.  A GaitSmart® assessment earlier provides clinicians and patients with objective data to plan and assess treatment protocols.

While the system that was used in the APPROACH study was primarily designed for clinical trials, the second generation GaitSmart® II system, launched in 2020, consists of 7 sensors, corresponding straps, a charging dock and a tablet loaded with specific GaitSmart® analysis software.

According to the project authors, GaitSmart® could ultimately be used in a primary care setting, where a patient presenting with suspected knee osteoarthritis could have the test carried out by a healthcare assistant, with a report made available to the GP prior to consultation. The GP would review the patient and decide on a treatment plan, with the patient returning in three to four weeks for a repeat test to assess the efficiency of treatment.

The authors claim that it allows patients to be more invested in their progress as the changes in the report are easy to identify. GaitSmart® could also be used to flag abnormal changes or deterioration in gait in middle-age to elderly patients by being included as part of a routine check-up – again carried out by a healthcare assistant prior to a general GP consultation.

The diagnostic value of the GaitSmart® data for hip and knee OA and guiding rehabilitation following joint replacement and falls prevention has been proven, relevant to all of the above case uses. GaitSmart® can be used by doctors to aid referrals but also to guide patients that would otherwise be unable to access services and who would continue to deteriorate during the waiting period.

Furthermore, say the authors, access to physiotherapy is often difficult and in the current COVID-19-influenced situation, waiting times are at an all-time high.