How wearable sensing can be used to monitor patient recovery following ACL reconstruction

Abstract

Anterior Cruciate Ligament (ACL) reconstructions are among the most common sports medicine procedures performed in the world. Over 100,000 patients in the United States annually elect to have ACL reconstruction (ACLR) in hopes of returning to pre-injury level of activity. In the first two years following an ACLR, patients are at their highest risk for re-injury to both the repaired and contralateral knee. The overall incidence rate of an ACLR patient having to go through a second repair in 24 months is six times greater than someone who has never had an ACL tear. Early detection of functional deficits is vital to optimize post-operative rehabilitation and to restore normal movement patterns in patients, especially in those who are young with continued risk exposure from competitive sports. The decision about when to return to unrestricted physical activity or competitive sports has come under much scrutiny due to the lack of evidence-based criteria that have sufficient predictive value. Current methods of detection require unconventional movements which cannot be done in the early stages of recovery in fear of damaging the newly repaired ligament. The need for a precise, objective, and whole-body approach to movement evaluation is essential for the health and safety of patients recovering from ACLR. The objective of our research is to leverage sensing technologies to monitor patients post ACLR and investigate how body sensors can be used to aid medical decision-making regarding rehabilitation progressions. In our study, patient data, extracted from wearable sensors during several functional assessments, was used for multi-level analysis to extract features indicative of mobility and muscle activation. In conclusion of our pilot, we have identified key features effective in determining patient health post-ACLR and implemented these into a machine learning model to estimate the efficacy of lower-body wearable sensors as a means of assessing patient recovery.