Recovery Patterns of Lower Limb Motor Function Following Lumbar Spinal Stenosis Surgery: A Five-Year Retrospective...

Area of Science:

• Neurosurgery
• Orthopedics
• Rehabilitation Medicine

Background:

• Long-term motor recovery after lumbar spinal stenosis (LSS) surgery, particularly for mild paresis, remains incompletely understood.
• The foot-tapping test (FTT) provides an objective measure of subtle motor deficits, surpassing the limitations of conventional Manual Muscle Testing.

Purpose of the Study:

• To investigate 5-year motor recovery patterns following LSS surgery.
• To evaluate the utility of the foot-tapping test (FTT) in quantifying motor recovery.
• To identify prognostic factors influencing motor recovery after LSS surgery.

Main Methods:

• A retrospective cohort study analyzed patients undergoing primary LSS surgery for L5 nerve root involvement.
• The foot-tapping test (FTT) measured ankle dorsiflexions over 10 seconds to assess motor function.
• Linear mixed-effects models analyzed longitudinal FTT changes, adjusting for age, sex, and neurological intermittent claudication (NIC) type.

Main Results:

• FTT scores significantly improved over the 5-year follow-up period (P=0.004).
• Older age was identified as a negative predictor of motor recovery (P<0.001).
• While recovery rates were similar across NIC types initially, the Cauda Equina type showed significantly lower improvement at 3-5 years (P=0.043) and lacked significant improvement from baseline (P=0.289).

Conclusions:

• The FTT is a valuable tool for assessing long-term motor function after LSS surgery.
• Poorer long-term recovery in the Cauda Equina type suggests potentially severe, irreversible neural damage.
• Early surgical intervention may be crucial for improving long-term motor outcomes, especially in Cauda Equina type patients.