Hybrid assistive limb (HAL) treatment for patients with severe thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL) in the postoperative acute/subacute phase: A clinical trial

Abstract

Context/Objective: The hybrid assistive limb (HAL) is a wearable exoskeleton robot that assists walking and lower limb movements via real-time actuator control. Our aim was to clarify the safety and feasibility of using the HAL robotic suit for rehabilitation in patients with severe thoracic myelopathy due to ossification of the posterior longitudinal ligament (T-OPLL).

Design: Uncontrolled case series; pre- and post-intervention measurement.

Setting: In-patient rehabilitation unit.

Intervention: HAL training was provided in 60-minuts session, 2–3 sessions per week, for a total of 10 sessions. HAL training was initiated on average 27.5 days post-surgery.

Patients: Eight patients (four males and four females; mean age, 60.9 ± 10.2 years) with severe myelopathy, who had undergone posterior decompression with instrumented fusion, were enrolled.

Outcome Measures: Gait speed, step length and cadence were measured along a 10-m walkway every session. The American Spinal Injury Association (ASIA) motor score (lower extremities) and Walking Index for Spinal Cord Injury (WISCI) II were also evaluated at baseline and after 10 sessions. The Japanese Orthopaedic Association (JOA) score was calculated over time after surgery.

Results: All participants completed the 10 training sessions, with no serious adverse effect noted. Gait speed, step length and cadence improved over time. Both the WISCI-II and ASIA motor (lower extremities) scores improved from baseline after 10 sessions. The JOA score improved over time post-surgery.

Conclusion: HAL training can be feasibly initiated in the early postoperative period, without severe adverse events in patients, with T-OPLL-related severe gait disturbance.

Keywords:

• Hybrid assistive limb
• Ossification of the posterior longitudinal ligament
• Postoperative acute phase
• Robot treatment
• Rehabilitation
• Exoskeleton robot

Acknowledgments

We thank Mayuko Sakamaki and Yumiko Ito of the Center for Innovative Medicine and Engineering (CIME) at the University of Tsukuba Hospital for their excellent technical assistance.

Disclaimer statements

Declaration of interest None.

Conflicts of interest A commercial party having a direct financial interest in the results of the research and supporting this article has conferred or will confer a financial benefit on one or more of the authors. One author is the CEO of Cyberdyne Inc, Ibaraki, Japan, which is the manufacturer of the robot suit HAL. Cyberdyne Inc was not directly involved in the study design; the collection, analysis, or interpretation of data; writing the report; or the decision to submit the paper for publication. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.

Informed consent Patients who agreed to participate in this study provided both oral and written informed consents.

Ethical approval The study was approved by the Institutional Review Board (IRB) of each institution involved in this study and was conducted according to the principles of the World Medical Association (WMA) Declaration of Helsinki—Ethical Principles for Medical Research Involving Human Subjects with the amendments made in Seoul, South Korea, in October 2008, with a note of clarification on paragraph 29 added by the WMA General Assembly in Washington (2002) and a note of clarification on paragraph 30 added by the WMA General Assembly in Tokyo (2004). This study was also conducted in accordance with the Japanese Medical Research Involving Human Subjects Act (WMO) and other guidelines, regulations, and acts. This study was registered with the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000014336).

Supplemental data for this article can be accessed on the publisher’s website https://doi.org/10.1080/10790268.2018.1525975.

ORCID

Shigeki Kubota http://orcid.org/0000-0003-4455-4585

Yukiyo Shimizu http://orcid.org/0000-0001-7491-4516

Hiroki Watanabe http://orcid.org/0000-0002-4436-5437

Additional information

Funding

This study was supported by the Industrial Disease Clinical Research Grants of the Ministry of Health Labour and Welfare, Japan (14060101-01).