Laminectomy with internal fixation and osseofusion is a common surgery for treating degenerative spinal diseases. It removes excessive bone spurs and removes the lamina for decompression to relieve nerve compression, and then utilizes a spinal fixation system to stabilize the structure to relieve lower limb pain, paralysis, and other symptoms. However, the spinal cord that lacks lamina coverage after surgery is often compressed by scar tissue formation and hematoma, leading to postoperative back and lower limb pain. Therefore, this trial is divided into two groups, comparing the use of the cross connector of the ORION spinal system - the spinal lamina cover and the general spinal fixation system (without lamina cover). For participants undergoing laminectomy with internal fixation and osseofusion, after utilizing the spinal lamina cover of the ORION spinal system, whether the nerve compression caused by postoperative scar tissue formation and hematoma can be effectively reduced, and the pain in the back and lower limbs can be improved.

Inclusion Criteria:

• Gender and age: females and males are at least 20 years old
• Who with degenerative lumbar spondylolisthesis in one or two consecutive segments from lumbar vertebra L1 to sacral vertebra S1, and have objective evidence of back pain and numbness radiating to the lower limbs.
• Clinical symptoms of degenerative lumbar spondylolisthesis, accompanied by objective symptoms of neurological deficit; spinal stenosis, neurogenic claudication or bilateral radiating pain.
• Have received at least 3 months of non-surgical treatment without effectiveness.
• Radiographic examination was consistent with clinical symptoms of degenerative spondylolisthesis or spinal stenosis.
• After diagnosis who needs laminectomy with internal fixation and osseofusion
• Able and willing to sign the consent form and answer the questionnaire.

Exclusion Criteria:

• Already had lumbar surgery at the same lumbar vertebra
• Physically health not well
• Probably pregnant
• Who suffering from malignant tumors or infections
• below 20 years old
• Unable and unwilling to answer the questionnaire and return to the hospital for treatment
• Unable to undergo MRI examination due to any reason, such as having a cardiac rhythm regulator, ferromagnetic implants, or claustrophobia.