Should dry spinal tuberculosis be managed differently than wet spinal tuberculosis?

Area of Science:

• Neurology
• Orthopedics
• Infectious Diseases

Background:

• Spinal tuberculosis (TB) presents as dry or wet forms, with dry TB characterized by caseation and minimal exudate, while wet TB involves abscess formation.
• Dry TB is often associated with poorer neurological recovery, potentially due to underlying vasculitis, ischemia, or myelitis, rather than solely mechanical compression.

Purpose of the Study:

• To quantify and compare neurological recovery and prognosis between dry and wet forms of spinal TB.
• To determine the statistical significance of differences in recovery patterns.

Main Methods:

• A retrospective cohort study analyzed data from 217 spinal TB patients over six years.
• Radiological (vertebral height loss, canal encroachment) and functional (ambulatory status, ASIA, LEMS scores) measures were used.
• Dry TB was defined by specific imaging criteria, including granulation tissue and absence of abscess or <30% canal encroachment.

Main Results:

• Dry TB patients had significantly poorer return to ambulation (75% vs. 31.5%) and longer time to achieve it (9.16 vs. 2.9 months) compared to wet TB (p=.01).
• Despite less canal encroachment (24.9% vs. 50.09%, p<.01) and preserved CSF flow in dry TB, neurological outcomes were worse.
• At final follow-up, a higher proportion of dry TB patients were ASIA A (25% vs. 0%), while wet TB had more ASIA E patients (72.7% vs. 56.25%, p=.04).

Conclusions:

• Spinal dry TB demonstrates inferior functional outcomes regarding ambulation time and final status.
• These poorer outcomes occur despite less severe spinal destruction and abscess formation in dry TB, suggesting non-compressive pathologies are critical.
• The findings underscore the importance of differentiating spinal TB types for accurate prognosis and treatment planning.