The Journal of the American Osteopathic Association, 2012/08, 112(8):535. doi: 10.7556/jaoa.2012.112.8.529, type of study: ,ct,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Full text    (https://www.degruyter.com/document/doi/10.7556/jaoa.2012.112.8.529/html)

Keywords:

3D models [4]
arthroplasty [20]
clinical trial [674]
knee [117]
OMT [3924]
osteopathic manipulative treatment [3945]
post-operative care [84]

Abstract:

Background: Total knee arthroplasty is one of the most successful operations performed in the United States. According to the Agency for Healthcare Research and Quality, more than 600,000 knee replacements are performed each year in the United States. Most patients begin exercising their knee the day after surgery. Typically, a physical therapist will provide patients with specific exercises to strengthen and restore knee movement to allow walking and other normal daily activities soon after surgery. The use of osteopathic medicine in the perioperative period is well documented in the literature. However, the use of osteopathic manipulative treatment (OMT) techniques (articulatory, facilitated positional release, fascial ligamentous release, functional, myofascial/integrated neuromuscular release, and soft tissue) and the effect in the post–total knee arthroplasty patient is not clear. Objective: To describe the benefit of OMT using 3-dimensional (3D) analysis. Our finite element model records 3D images of in vivo knee joint kinematics during OMT, determining impact of load and strain on soft tissue motion. Previous finite element knee models have described the mechanical forces generated by OMT and other forms of manual therapy, but no study has described the effect of OMT on the postarthroplasty knee using a 3D mathematical model. Methods: Explicit dynamic finite element analyses have been used to efficiently predict total knee replacement kinematics and contact mechanics during dynamic loading conditions. A 3D, finite element model was created by the acquisition of a computed tomography (CT) scan of a total knee arthroplasty. The image data were imported into Mimics version 8.1.1 for editing and 3D reconstruction. For this project, a CT scan with an XY resolution of 512×512 pixels was used, with a resulting pixel size of 0.391 mm and the helical scan was retro-reconstructed into 1-mm slices. The total number of slices in the scan was 217, and the scan was performed using 0° gantry tilt. A 3D voxel model of the bone under study was made. We found an appropriate threshold range that could best capture the relevant information contained in the knee joint. Using this threshold value, all pixels within this range were processed to a color mask. Once loaded into the software, the color mask acted as the input to the 3D reconstruction process, with all images properly registered and aligned for orientation. The computer-aided design (CAD) model was calibrated with other CAD-based software to analyze dynamic force. Using known data on the contact pressure distribution at the patient-physician contact region during osteopathic manipulation, the model was subjected to known load, stress, and strain values. Results: Osteopathic manipulation did not significantly affect the contact behavior of the arthroplasty components in all degrees of freedom. In addition, no compression of the fascia was observed, resulting in less stress on the polymer insert. Conclusion: The authors have explored the benefit of OMT utilizing the application of 3D rendering and CAD. The model demonstrated the relationship between the mechanical forces and fascial deformations produced in OMT, which may stimulate fascial mechanoreceptors. This approach can aid in the development of improved OMT techniques, which would be reconstructed from CT or magnetic resonance imaging.