Biomechanical Effect of 3D-Printed Foot Orthoses in Patients with Knee Osteoarthritis

Kuang-Wei Lin,Yi-Tien Su,Chen-Shen Chen,Li-Wei Chou,Shun-Hwa Wei

doi:10.3390/app11094200

Kuang-Wei Lin, Yi-Tien Su + Show 3 more

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https://doi.org/10.3390/app11094200

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Journal: Applied sciences	Publication Date: May 5, 2021
Citations: 6	License type: CC BY 4.0

Affiliation: National Yang Ming Chiao Tung University

Abstract

Lateral wedges are a common conservative treatment for medial knee osteoarthritis (OA). However, use of lateral wedges might increase the ankle eversion moment. To minimize the risk of ankle symptoms, lateral wedges with custom arch support are suggested. However, the manufacturing process of a custom foot orthosis (FO) is complicated, labor-intensive, and time-consuming. The technology of 3D printing is an ideal method for mass customization. Therefore, the purpose of this study was to develop custom FOs using 3D-printing techniques and to evaluate the effects of 3D-printed FOs in patients with knee OA. Fifteen patients with medial knee OA were enrolled into this study. Kinematic and kinetic data were collected during walking by using an optical motion capture system. A paired-sample t-test was conducted to compare biomechanical variables under two conditions: walking in standard shoes (Shoe) and walking in shoes embedded with 3D-printed FOs (Shoe + FO). The results show that the first and second peak knee adduction moments were significantly reduced by 4.08% and 9.09% under the Shoe + FO condition. The FOs alter the biomechanical environment in a way that reduces the variables used to infer abnormal loads at the knee and ankle that could result in painful symptoms.

Highlights

Knee osteoarthritis (OA) is one of the most common musculoskeletal diseases in elderly people
The present study focused on the biomechanical effects of 3D-printed foot orthosis (FO) and analyzed data for the participants who wore and did not wear the 3D-printed FOs
The result indicated that a sample size of fourteen would be enough to detect a 5% difference in peak knee adduction moment (KAM), with a statistical power of 80% and a 5% level of significance

Summary

Introduction

Knee osteoarthritis (OA) is one of the most common musculoskeletal diseases in elderly people. The global age-standardized prevalence of symptomatic knee OA is 3.8% [1] It affects 8.1% of adults in China and is more common in women (10.3%) than in men (5.7%) [2]. The primary goal of many treatment approaches is to reduce the medial knee compartment contact force. In a linear regression model, the combination of the peak KAM and KFM provides a more accurate estimate of the peak medial knee compartment contact force than the peak KAM alone [6]. Both the KAM and KFM should be employed when investigating the knee joint loading indirectly. To reduce the KAM, nonsurgical treatment options include the use of a cane [7], the use of knee braces [8], gait modification [9], and the use of lateral wedges [10]

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