Assessing the outcomes of spine surgery using global positioning systems.

STUDY

DESIGN

Pilot study.

OBJECTIVE

To examine whether surgical outcomes can be assessed objectively by advanced tracking technology, based on Global Positioning Systems (GPS).

SUMMARY OF BACKGROUND DATA: Outcome studies are the commonest way to assess the results of surgical procedures. The success of these efforts is impeded by a number of factors, including the lack of valid outcome measures, difficulty in assessing changes in patients' expectations (response shift) and confounding effects of secondary gains.

METHODS

The measurement of walking speed, distances, and number of walking events per day, claudication index (maximal walking distance), characteristics during motorized trips, and the amount of time spent outdoors were monitored in 2 patients undergoing spine surgery for several weeks using advanced tracking technologies.

RESULTS

In 1 patient, all parameters increased progressively from the time of surgery to the end of the recording period. These findings were consistent with her recovery from surgery. In a second patient, tracking showed the patient's difficulty in mobilizing, leading to the diagnosis of another orthopedic problem, and to total hip replacement surgery.

CONCLUSION

The technology presented in this pilot appears to be useful in understanding a patient's level and breathe of activity. These data will assist in better understanding the limitations imposed by specific musculoskeletal pathology and in monitoring perioperative function and complications and their related causes. Spatial data may indirectly reflect a patient's social and mental conditions. This interdisciplinary pilot may lead to the development of valid outcome measures for a range of medical conditions. Studies comparing questionnaires to this new outcome measure may shed light on issues like response shifts and secondary gain. Norms and clusters of spatial behaviors in different pathologies may enable better patient selection for medical, mental, and surgical interventions.