Study design:

A retrospective study.

Objective:

The aim of this study was to review clinical and imaging features in patients with lumbar spinal canal stenosis (LSS) with and without postoperative early progression of intervertebral disc degeneration (IDD) and to identify predictive factors.

Summary of background data:

Progression of IDD after lumbar decompression surgery can induce low back pain and leg pain, and may require revision surgery. However, risk factors for postoperative radiological changes indicating IDD linked to development of symptoms have not been described.

Methods:

We included 564 patients with LSS without degenerative lumbar scoliosis who underwent lumbar decompression surgery without fusion. Clinical features and imaging findings were compared in cases with (group P) and without (group N) progression of IDD (intervertebral disc wedge or narrowing) at 1 year after surgery.

Results:

Of the 564 patients, 49 (8.7%) were in group P. On preoperative MRI, all patients in group P had findings of vertebral bone marrow edema (diffuse high intensity on T2-weighted images and low-intensity on T1-weighted images), compared to only 5.4% in group N. The rate of revision surgery was significantly higher in group P in 5-years follow-up (12.2% vs. 1.4%, p < 0.01). In group P, 44.9% of patients developed postoperative symptoms associated with postoperative radiological changes, and the frequency was higher in narrowing-type than in wedge-type cases. Vertebral bone marrow edema area and IDD grade were not predictors for postoperative early IDD progression.

Conclusion:

Careful consideration is required to determine whether lumbar decompression surgery should be performed if vertebral bone marrow edema is detected on MRI, since this is a predictor for a negative clinical outcome. If surgery is symptomatically urgent, careful clinical and radiological follow-up are required.Level of Evidence: 4.