Sensor offers diagnostic data on recent orthopaedic surgery

According to a statement, the sensor can provide the kind of diagnostic data more usually derived from X-rays or invasive procedures.

A study presented at the Orthopaedic Research Society 2012 Annual Meeting in San Francisco revealed that the technology could make post-surgical diagnosis and follow-up more precise, efficient and cost effective.

‘The sensor provides opportunities to make specific and detailed diagnostics for a particular patient and to tailor care based on very objective and quantitative measures,’ said Dr Eric H Ledet, assistant professor at the Rensselaer Polytechnic Institute.

‘This highly unique sensor is very small [4mm in diameter and 500 microns in thickness], wireless and batteryless and requires no telemetry within the body. Its simplicity makes it less prone to failure and very inexpensive to produce,’ said Ledet.

The orthopaedic implant acts as a carrier for the sensor. The wireless sensor can monitor load, strain, motion, temperature and pressure in vivo. It can be placed into a spinal or fracture fixation implant — for example, to determine the patient’s progress.

‘For the patient that is progressing well, the information from the sensor enables the physician to determine that the patient can return to work without risk of injury,’ said Ledet. ‘The number of lost days at work is reduced.’

It can also alert the physician to potential problems, indicating that additional interventions may be needed.

‘By maintaining a simple platform, we’re able to customise the sensor and make it very, very small so it can be incorporated into a lot of different implants,’ said Rebecca A Wachs of the Rensselaer Polytechnic Institute. ‘By changing one small parameter, we can change the sensitivity of the sensor itself.’

The researchers are currently producing the sensor manually but anticipate that it will eventually be mass produced, driving down costs.