Non-invasive biomechanical intervention leads to low rates of total knee replacement and reduced utilization of healthcare resources among older adults with chronic knee pain: a 5-year follow-up study

Abstract

BACKGROUND: Chronic knee pain, primarily associated with knee osteoarthritis (OA), is a leading cause of disability among older adults and place an immense burden on patients and healthcare systems, exceeding $80 billion in direct medical costs annually. Current non-surgical solutions to treat chronic knee pain provide limited relief of symptoms. The present study aims to assess the long-term effect of a biomechanical, non-invasive intervention on total knee replacement (TKR) incidence and the utilization of healthcare resources over five years. METHODS: This was a retrospective study among older adults with chronic knee pain, primarily due to OA, who received the biomechanical intervention between 2014 and 2017. An independent survey institute contacted patients between August and September 2022 to confirm their surgical status and utilization of other healthcare services, covering at least five years of follow-up. During the intervention, patients were provided with a FDA-cleared shoe-like device, which includes two convex pods attached to the sole. The pods are attached to the shoe in a customized manner based on the patient's gait and pain (i.e., calibrated). The device shifts the foot's center of pressure to reduce the knee joint load and alleviate pain. The device also creates controlled perturbation that challenges gait and posture stability and creates neuromuscular training. Patients were instructed to wear the device for up to 2-3 hours a day during their daily routine and invited to follow-up sessions for treatment modifications. RESULTS: Four hundred and fourteen patients responded to the survey. Their mean (SD) age was 66.5 (4.2) years, 65% were women and 82% of patients were diagnosed with knee OA. At five years since inception, the TKR incidence rate was 18.4% with 95% CI (14.6%, 22.1%). Most responders (79%) reported using other healthcare resources and services to treat their knee pain before the intervention. Of them, 64% ceased receiving intra-articular injections to the knee, 44% discontinued using pain medication and 46% stopped receiving physiotherapy. CONCLUSION: This biomechanical, non-invasive intervention is a beneficial and sustainable intervention that reduces healthcare resource utilization, including avoidance of TKR and chronic knee pain. With the constant increase in the prevalence of chronic knee pain, offering this intervention to patients can help address the increasing burden on the healthcare system and society. TRIAL REGISTRATION: NIH protocol no. NCT00767780