Immediate and late discal lesions on MRI in Magerl A thoracolumbar fracture: Analysis of 76 cases.

INTRODUCTION

Magerl type A thoracolumbar fracture is frequent, but consensus is lacking on management, which ranges from non-operative treatment to corpectomy. It is, however, essential to spare adjacent discs in young patients. Historically, Magerl defined type A fracture in terms of isolated bone involvement. Subsequently, several authors suggested that discal lesions are associated, but results were inconsistent. The present study assessed the presence of immediate post-trauma discal lesions and late degeneration.

HYPOTHESIS

Type A fracture does not entail discal lesion.

MATERIAL AND METHOD

Fifty-four patients with type A fracture and immediate post-trauma MRI (76 fractures, 138 discs) were retrospectively reviewed. Twenty-seven also had follow-up MRI at a mean 32 months. Two observers analyzed adjacent discs on Oner's classification, on the immediate post-trauma MRI, and on follow-up MRI to assess disc degeneration.

RESULTS

Immediate post-trauma analysis of the cranial discs of the fractured vertebrae found 81% normal (type 1), none type 2, 7% type 3, 4% type 4, 7% type 5 and 1% type 6. Caudal discs were 97% type 1. Analysis at follow-up found degeneration in only 15% of cranial and 9% of caudal discs.

DISCUSSION

A large majority of type A fractures lead to no immediate discal lesions, and only 15% of cranial discs subsequently degenerate. MRI analyzing disc signal and morphology is essential before removing material.

LEVEL OF EVIDENCE

IV, retrospective study.