Threshold-Anchored Mechanomyography Metrics for Patient Stratification in Spinal Decompression: Associations with...

Area of Science:

• Neurosurgery
• Biomedical Engineering

Background:

• Spinal decompression surgery has variable outcomes and high reoperation rates.
• Surgeons lack objective intraoperative tools to assess decompression adequacy.
• Mechanomyography (MMG) measures nerve excitability but optimal quantification for decompression is undefined.

Purpose of the Study:

• To explore associations between intraoperative MMG threshold changes and six-week pain outcomes.
• To compare threshold-anchored metrics (Threshold Reduction Ratio [TRR] and Threshold Excess [TE]) against percentage-based measures.

Main Methods:

• Prospective exploratory pilot study of 42 patients undergoing lumbar or cervical decompression.
• Recorded intraoperative MMG thresholds pre- and post-decompression.
• Compared three metrics: percentage change, TRR, and TE, with TRR and TE anchored to a 2.0 mA reference threshold.

Main Results:

• Threshold-anchored metrics (TRR, TE) showed substantially stronger correlations with pain improvement than percentage-based measures (TRR: r=0.656 vs. percentage: r=0.397).
• Threshold Excess demonstrated a dose-response relationship with pain improvement.
• Patients achieving MMG thresholds ≤2.0 mA had significantly higher odds of complete pain relief.

Conclusions:

• Threshold-anchored MMG metrics (TRR, TE) correlate better with early pain outcomes post-spinal decompression than percentage-based measures.
• These findings require external validation but may offer objective intraoperative feedback for surgical decision-making.
• Future research should explore patient-specific threshold targets for tailored decompression.