Previously fused, sagittally malaligned patients undergoing a pedicle subtraction osteotomy: early neurologic deficit recovery kinetics and their impact on patient-reported outcomes.

PURPOSE: To describe the incidence and recovery of motor weakness after pedicle subtraction osteotomy (PSO) for fixed sagittal imbalance and determine whether early postoperative weakness is associated with patient-reported outcomes (PROs) at latest available follow-up.

METHODS

We retrospectively reviewed consecutive adults undergoing revision posterior fusion with PSO (Schwab grade 3-4) for fixed sagittal imbalance from December 2015 to June 2022. Lower-extremity strength was graded 0-5, and weakness was defined as 3/5 or less in any distribution. PROs (SRS-22r, ODI, VAS back, and leg pain) were collected preoperatively through latest follow-up. Latest outcomes were compared by weakness status on postoperative day 5, 6 weeks, and 3 months.

RESULTS

Forty-nine patients (67% female; mean age 63 years) were included. Weakness was present in 4% preoperatively, increased to 27% on postoperative day 5, and declined to 12% at 6 weeks and 10% at 3 months; no patient had persistent weakness at latest follow-up. Weakness at 6 weeks was associated with worse latest SRS-22r Function, Self-Image, Mental Health, and Satisfaction (all p ≤ 0.033). At 3 months, weakness was associated with lower SRS Satisfaction (p = 0.004) and higher VAS leg pain (p = 0.009).

CONCLUSION

Motor weakness after revision PSO is common early and typically resolves. However, weakness persisting at 6 weeks or 3 months is associated with lower satisfaction and higher leg pain at latest available follow-up.