Gait abnormalities arising from latrogenic loss of lumbar lordosis secondary to Harrington instrumentation in lumbar fractures.

Six patients with lumbar fractures were studied at the Pathokinesiology laboratory at Rancho Los Amigos Hospital following posterior Harrington distraction instrumentation to identify changes in posture and gait associated with iatrogenic loss of lumbar lordosis. Three patients, all with painful rods, were treated with standard Harrington instrumentation and full length fusion. Three patients were treated with so-called "rodded long-fused short" procedures. It was thought that rod removal in the latter group would result in restoration of lumbar lordosis with concomitant improvement in posture and gait when compared to the full length fusion group. No significant difference between the two groups was found. Rod removal often resulted in kyphotic collapse at the previous fracture site despite solid posterior arthrodesis with net decrease in lumbar lordosis. Hip hyperextension, when available, was the favored compensatory mechanism for loss of lumbar lordosis. Otherwise, hip flexion and forward lean of the trunk was seen.