PMC8477042_01
Imaging findings of the cervical spine of the patient before surgery (A-C). Image findings of his cervical spine after surgery (D,E). Photograph and radiographs of the shoulders of the patient 7 months after surgery (F-H). (A) Cervical lateral radiograph revealing slight kyphosis of his cervical spine. (B) Sagittal reconstruction computed tomography (CT) image revealing disc space narrowing with a posterior spur at C5-C6 and C6-C7 and postdiscal ossification at C3-C4. (C) Midsagittal T2-weighted magnetic resonance (MR) image revealing that the spinal cord was severely compressed anteriorly at C3-C4 and C5-C6. (D) Cervical lateral radiograph 2 weeks after surgery revealing instrumented fusion at C3-C6. (E) Midsagittal T2-weighted MR image 4 weeks after surgery revealing adequate decompression of the spinal cord. (F) Anterior view showing muscle atrophy around his left shoulder. (G,H) Anterior-posterior radiographs of his right shoulder (B) and left shoulder (C) showing marked muscle atrophy in his left deltoid (red arrowhead) compared with that in his right deltoid (white arrowhead).
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F1
A plain lateral radiograph and a sagittal reconstruction image acquired using computed tomography (CT) before surgery showed slight kyphosis of the cervical spine (Figures 1A,B). Similarly, the images showed disc space narrowing with a posterior spur at C5-C6 and C6-C7, as well as postdiscal ossification at C3-C4 (Figures 1A,B). Midsagittal T2-weighted magnetic resonance imaging (MRI) showed severe anterior compression of the spinal cord at C3-C4 and C5-C6 (Figure 1C). The surgery comprised posterior decompression at C3-C7 and spinal fusion with lateral mass screws at C3-C6 (Figure 1D). Postoperative MRI showed sufficient decompression of the spinal cord (Figure 1E). On his first visit to our hospital, muscle atrophy of the left deltoid was evident (Figures 1F-H).
Images demonstrating C5 palsy after surgery and during the shoulder Hybrid Assistive Limb (HAL) training (A,B). Entire process of the shoulder HAL training of the patient (C). Photographs illustrating shoulder HAL abduction training in the scapular plane (D). (A) Schematic showing the time course of the development of and recovery from C5 palsy. (B) Photograph showing maximum abduction of the left shoulder. Before the second and 11th HAL training sessions, his left shoulder abduction angle was less than 90  while standing, and the deltoid muscle power was classified as manual muscle testing (MMT) grade 2. The arrow indicates the elevation of his left shoulder (shrugging), indicating compensatory movement due to contraction of the trapezius muscle. After the 23rd HAL training session, full abduction of his left shoulder was possible, and the deltoid muscle power improved to MMT grade 5. (C) The graph shows the chronological improvement in shoulder abduction and flexion angle and shoulder abduction power using handheld dynamometer (HHD) testing during shoulder HAL training sessions. After HAL training session 14, his deltoid muscle power improved to MMT grade 3 or higher. (D) The shoulder HAL consists of 1) an actuator for the shoulder joint on the lateral side, 2) arm attachments, 3) covered dressing with an arm-forearm splint, 4) surface electrode sensors on the deltoid, and 5) foundation.
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Between 7 and 26 months after surgery, the patient underwent left shoulder abduction training using a shoulder HAL for 23 sessions, with one session conducted principally once or twice a month, as an outpatient (Figures 2A,C). The shoulder HAL system comprises an actuator, an arm attachment, a surface electrode sensor, an arm-forearm splint, a manual controller, a battery, and a control device (Figure 2D and Supplementary Video). Before shoulder HAL training, his shoulder abduction angle was 30  in the standing position (Figure 2B and Supplementary Video) and 90  in the supine position. Subsequently, each training session lasted for 30-45 min and included 200-300 repetitions of shoulder abduction exercises using the shoulder HAL while the patient was in a seated position (Figure 2D and Supplementary Video).