# Effect of an Innovative Biofeedback Insole on Patient Rehabilitation after Total Knee Arthroplasty
## 4 Discussion  
We investigated the use of a smart insole during the rehabilitation of patients who underwent total knee replacement. We found that the use of this device led to several advantages: it improved patients compliance and willingness to follow the rehabilitation protocol, it provided better assessment by the physiotherapist of patients' post-op progress, and it improved patients' overall satisfaction. Sometimes after discharge from rehabilitation centers, it is difficult to follow up with outpatients in their domestic activities to monitor their gait, load, and functional daily activities [24]. In addition, patients instructed not to weight load on the operated limb sometimes do not load it sufficiently when they are instructed to do so, leading to different complications (e.g., algodystrophy, venous blood return deficit, muscular atrophy, and bone loss) and a consequent delay in complete recovery [25]. [PERSON] [4] demonstrated that the use of some kind of bio-feedback device improves patients' ability to comply with rehabilitation protocol, therefore making their recovery more efficient and effective. Traditional ways of controlling patient weight bearing during rehabilitation are based on physiotherapists' subjective inputs, and therefore patients cannot be trained in an ideal way. The present study has some limitations as it was a single-arm investigation and the analyzed patient cohort was relatively small. However, our findings seem to support the routine use of the instrumented Blu Insole as a valid and easy-to-use device during rehabilitation after TKA surgery, with the aim of consolidating physiotherapy protocols;  
Figure 3: Patients able or unable to achieve the weight-bearing targets at various days post-op. All enrolled patients except one succeeded in loading the lower limb with >80% bodyweight at day 15. One other patient could not reach full weight bearing load at day 15 post-op due to a neurological deficit relapse with cruralgia secondary to degenerative lumbar discopathy. reducing recovery stay; and, above all, improving functional recovery, especially in young, active patients. The rise of patient accountability and deeper involvement during their rehabilitation made them more active and cooperative, with a further improvement in results and compliance. Our findings seem to support the extension of insole use to all lower limb surgeries that require progressive weight bearing. Without a doubt, it is of high importance to quantify and register this rehabilitation method, making it a provable, reproducible, and comparable parameter in orthopedic and traumatologic lower limb surgeries. It is also possible to use the insole after some months or years to quickly monitor limb maintenance without additional costs. Our findings are also in agreement with the systematic review of [PERSON] et al. [26], who reported strong improvement in rehabilitation with instrumented insole; with the study of [PERSON] et al. [27], that state that even if the main focus was on Parkinson disease, that in order to build a successful systems for patients' gait rehabilitation, the use of technological solutions is beneficial; and with the recent study of [PERSON] et al. [28], that states that wearable health monitoring devices allow for measuring physiological parameters without restricting individuals' daily activities, providing information that is reflective of an individual's health and well-being. We believe we must further extend the application of this device to analogous areas to evaluate focused protocols depending on the surgery (e.g., unicompartmental knee arthroplasty vs. TKA) and the possible use of a double insole to find better solutions, particularly after lower limb arthroplasties (e.g., combined total knee and hip replacements or bilateral TKA). Further randomized studies with larger patient groups will be needed to confirm our findings. Conceptualization, G.C. and B.I. ; methodology, M.M. ; software, M.M., G.B. and R.R. ; validation, M.M., G.B. and R.R. ; formal analysis, M.M.