A Randomized Controlled Trial for the Intervention Effect of Early Exercise Therapy on Axial Pain after Cervical Laminoplasty

INTRODUCTION: Cervical isometric muscle strengthening and cervical range of motion (ROM) training are recommended after laminoplasty (LP). However, their preventive effects on axial pain are unclear. We examined whether neck extension muscle strengthening and cervical ROM training from the early postoperative period effectively suppress postoperative axial pain. METHODS: Sixty-one patients undergoing a muscle-preserving LP attached to C2 and C7 for cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament were randomly allocated to the cervical exercise (33 patients) or nonexercize (28 patients) groups. Postoperative cervical collars were not worn in any cases. The cervical exercise group underwent neck extension isometric muscle strengthening and cervical ROM exercises for 3 months starting on postoperative day 2. Changes in axial pain (visual analog scale [VAS]) from baseline at 2 weeks and 3 months after surgery were evaluated as the primary outcome. Cervical muscle strength, cervical ROM, and Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) scores were evaluated as secondary outcomes. RESULTS: Axial pain was significantly exacerbated at 2 weeks after LP compared with before surgery, and then, a significant improvement was observed at 3 months after surgery. No significant interaction was observed between the intervention and nonintervention groups. There was no difference in secondary outcomes between groups. The change in the VAS of axial pain from before surgery to 3 months after surgery showed a greater decreased neck extension muscle strength resulting in severer axial pain. CONCLUSIONS: Cervical muscle strengthening and cervical ROM exercise from the early postoperative period did not relieve axial pain at 2 weeks and 3 months after a muscle-preserving LP attached to C2 and C7. No significant difference in neck extension muscle and cervical movement was observed between the intervention and nonintervention groups. Therefore, a muscle-preserving LP attached to C2 and C7 is a good strategy to prevent axial pain in the early postoperative period. Clinical Trials Registration Number: UMIN000040692