MRI after successful lumbar discectomy

Area of Science:

• Radiology
• Neurosurgery
• Orthopedics

Background:

• Lumbar discectomy is a common surgical procedure.
• Postoperative Magnetic Resonance Imaging (MRI) is crucial for evaluating surgical outcomes.
• Establishing normal MRI findings after successful surgery is essential for accurate diagnosis.

Purpose of the Study:

• To define the typical range of MRI findings following successful lumbar discectomy.
• To differentiate expected postoperative changes from complications like recurrent disc herniation.

Main Methods:

• Prospective study of 34 patients with excellent clinical outcomes post-lumbar discectomy.
• Serial MRI examinations at 6 weeks and 6 months using T1-weighted (pre- and post-gadolinium) and T2-weighted sequences.
• Evaluation of contrast enhancement, surgical tract changes, dural sac mass effect, and nerve root enhancement.

Main Results:

• All patients exhibited contrast enhancement along the surgical tract at both 6 weeks and 6 months.
• Minimal dural sac mass effect from epidural scar was observed at 6 months.
• Recurrent disc herniation occurred in 20% of patients.
• Nerve root enhancement was seen in 20% at 6 weeks, resolving by 6 months, and sometimes associated with recurrence.

Conclusions:

• Postoperative MRI findings, including contrast enhancement and minimal epidural scarring, are common even in asymptomatic patients after successful lumbar discectomy.
• Interpreting postoperative MRI requires careful consideration as findings similar to failed back surgery syndrome can be present.
• These findings help establish a baseline for normal postoperative MRI, aiding in the detection of true complications.