Gait Changes as the Result of Deformity Reconstruction Surgery in Adult Female Lumbar Scoliotics

Orthopaedic Surgery, Washington University School of Medicine
Human Performance Laboratory, Barnes-Jewish Hospital, St. Louis, MO, USA

INTRODUCTION:
Gait comparisons between pre and postoperative deformity reconstruction in adult females with lumbar spinal deformity (scoliosis > 50º, kyphosis > 0º) and able-bodied adults have never been reported.

PURPOSE:
To compare the pre and postoperative gait of a group of adult lumbar deformity patients and to compare functional outcomes to a group of able-bodied adults.

METHODS:
17 female adults (7 primary, 10 revision with fixed sagittal imbalance [FSI], age range 27-64) underwent pre and 1 year postop deformity reconstruction gait analysis. 9 female able-bodied adults with no spinal deformity or pathology (age range 32-58) served as controls. 36 reflective surface markers were placed on a subject to create a 12-link segment model. A 6 camera video system recorded each subject as she walked along a 9 m walkway. Markers were tracked to produce 3D coordinates over the gait cycle. Only gait speed and 2 motion variables will be reported here. The motion variables were calculated at right initial contact and described the sagittal orientation of the pelvis with respect to (wrt) the laboratory coordinate system (e.g., pelvic inclination) and the sagittal vertical alignment (SVA) (e.g., sagittal balance). Each subject also performed a pre and postop graded exercise test (GXT) on a treadmill, where she walked until reaching 70% of her maximum heart rate. Paired and unpaired t-tests were used to determine if significant differences existed among the conditions and group (p<0.05).

RESULTS:
The primary group significantly improved their pelvic inclination postop such that it was no longer different from the able-bodied group. The revision (FSI) group significantly improved their SVA postop such that it was no longer different from the able-bodied group. The revision group had a significant improvement in their GXT, yet it remained different from able-bodied, postop. The Primary group remained the same as the able body group for the GXT, postop. Gait speed remained significantly less than able-bodied controls (130 cm/s ± 14) for both the primary (106 cm/s ±24) and revision (88.75 cm/s ±27) groups.

DISCUSSION:
Objective gait data have not been previously reported for these groups. Sample results displayed significant improvements in gait following spinal fusion surgery for both primary and revision groups. The revision patients demonstrated significantly improved walking endurance at 1year postop. This study was funded in full by the SRS.