TY - JOUR
T1 - Preoperative motor strength and time to surgery are the most important predictors of improvement in foot drop due to degenerative lumbar disease
AU - MacKi, Mohamed
AU - Syeda, Sbaa
AU - Kerezoudis, Panagiotis
AU - Gokaslan, Ziya L.
AU - Bydon, Ali
AU - Bydon, Mohamad
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/2/15
Y1 - 2016/2/15
N2 - Objective Palsy of dorsiflexion, or foot drop, may be due to degenerative lumbar disease and amenable to posterior spinal decompression. The objective of this study is to measure prognostic factors of and time to foot drop improvement after posterior lumbar decompression. Methods We retrospectively reviewed 71 patients undergoing first-time, posterior lumbar decompression for foot drop due to degenerative spinal disease. Patient sex, age, comorbidities (Charlson Comorbidity Index), preoperative anterior tibialis strength (manual muscle testing, MMT), and duration of foot drop were ascertained from clinical notes. Prognostic factors affecting foot drop improvement were calculated with a discrete time proportional hazards model, in which follow-up times and outcome measures were binned into six time intervals: 1 week, 6 weeks, 3 months, 6 months, 1 year, and ≥ 1 year. Results Of the 71 patients, the mean age was 54.6 ± 16.0 years, and 66.2% (n = 47) were males. The mean Charlson Comorbidity Index was 2.42. During a mean follow-up of 30.4 months, dorsiflexion function improved postoperatively in 73.2% (n = 52) of patients. The median time to surgery from onset of foot drop was within 6 weeks, and the median preoperative MMT strength of patients with foot drop improvement was 3. Following a discrete-time proportional hazards model, duration of anterior tibialis palsy (HR = 0.67, P = 0.004) and preoperative muscle strength (HR = 1.10, P = 0.010) were significant predictors of foot drop improvement. Following an adjusted Kaplan-Meier analysis, the median time to foot drop improvement was within 6 weeks of surgical intervention. Conclusions Preoperative muscle strength and palsy duration were statistically significant predictors of foot drop improvement. Furthermore, the median time to improvement was 6 weeks.
AB - Objective Palsy of dorsiflexion, or foot drop, may be due to degenerative lumbar disease and amenable to posterior spinal decompression. The objective of this study is to measure prognostic factors of and time to foot drop improvement after posterior lumbar decompression. Methods We retrospectively reviewed 71 patients undergoing first-time, posterior lumbar decompression for foot drop due to degenerative spinal disease. Patient sex, age, comorbidities (Charlson Comorbidity Index), preoperative anterior tibialis strength (manual muscle testing, MMT), and duration of foot drop were ascertained from clinical notes. Prognostic factors affecting foot drop improvement were calculated with a discrete time proportional hazards model, in which follow-up times and outcome measures were binned into six time intervals: 1 week, 6 weeks, 3 months, 6 months, 1 year, and ≥ 1 year. Results Of the 71 patients, the mean age was 54.6 ± 16.0 years, and 66.2% (n = 47) were males. The mean Charlson Comorbidity Index was 2.42. During a mean follow-up of 30.4 months, dorsiflexion function improved postoperatively in 73.2% (n = 52) of patients. The median time to surgery from onset of foot drop was within 6 weeks, and the median preoperative MMT strength of patients with foot drop improvement was 3. Following a discrete-time proportional hazards model, duration of anterior tibialis palsy (HR = 0.67, P = 0.004) and preoperative muscle strength (HR = 1.10, P = 0.010) were significant predictors of foot drop improvement. Following an adjusted Kaplan-Meier analysis, the median time to foot drop improvement was within 6 weeks of surgical intervention. Conclusions Preoperative muscle strength and palsy duration were statistically significant predictors of foot drop improvement. Furthermore, the median time to improvement was 6 weeks.
KW - Degenerative lumbar disease
KW - Foot drop
KW - Motor strength improvement
KW - Spine surgery
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U2 - 10.1016/j.jns.2015.12.035
DO - 10.1016/j.jns.2015.12.035
M3 - Article
C2 - 26810531
AN - SCOPUS:84958962012
SN - 0022-510X
VL - 361
SP - 133
EP - 136
JO - Journal of the neurological sciences
JF - Journal of the neurological sciences
ER -