Decompression status of the spinal cord after cervical laminoplasty in various body positions and neck postures observed using percutaneous ultrasonography: Relationship with neurological recovery.

BACKGROUND

Percutaneous ultrasonography (PUS) is used to evaluate the status of the spinal cord after cervical laminoplasty (CLP). This technique helps assess real-time movements of the spinal cord and provides immediate information regarding the decompression status. Additionally, it can also be utilized to evaluate the status of the spinal cord in various body positions and neck postures. This study aimed to examine changes in the decompression status of the spinal cord after CLP for cervical spondylotic myelopathy (CSM) in different body positions and neck postures using PUS and to assess whether these decompression statuses are related to clinical outcomes at each time point.

METHODS

The study included 66 consecutive participants with CSM who underwent double-door CLP with suture anchors. PUS was performed postoperatively at 2 weeks, 3 months, 6 months, and 1 year in sitting [neck flexion (Flexion), neutral (Neutral), and extension (Extension)] and supine (Supine) positions. The decompression status was classified into grade I (noncontact), grade II (contact and apart), and grade III (contact). Clinical outcomes were evaluated using Japanese Orthopaedic Association (JOA) scores.

RESULTS

The decompression status improved until 3 months postoperatively in all body positions and neck postures and was stable onwards. It changed depending on body positions and neck postures and was worse in Flexion and better in Supine at all postoperative time points. Participants with grade I decompression status in Supine had a significantly better recovery rate of JOA scores after 3 months, 6 months, and 1 year postoperatively than those with grade II + III decompression status. However, this significant relationship was not observed in each sitting position.

CONCLUSIONS

The spinal cord after CLP is most decompressed in Supine. Sufficient and continuous restoration of the anterior subarachnoid space in supine position may indicate positive clinical outcomes after CLP.