Biomechanical analysis of locomotion after total sacrectomy in a single patient case.
To describe the biomechanics of locomotion after successful total sacrectomy and spinopelvic reconstruction.
Total sacrectomy is a complex surgery that has significant consequences for mobility after surgery due to loss of lower lumbar and sacral innervation to the lower extremities, and the anatomic dissociation of the spine from the pelvis. There is no existing literature quantifying locomotor biomechanics after total sacrectomy.
A 22-year-old female with a sacral osteosarcoma underwent an en bloc sacrectomy with L3 to pelvis instrumented fusion. Neuromuscular function was tested 1 year after surgery using monopolar needle electromyography. Three-dimensional motion capture and surface electromyography were used to quantify spatiotemporal characteristics of locomotion and lower extremity kinematics, kinetics, and muscle function during locomotion at 6 months and 1 year after surgery.
Electrodiagnostic testing suggested partial preservation and reinnervation of S1 nerve root function on the right, resulting in greater than expected activity in the hamstrings, gluteus maximus, and triceps surae postsurgically. Unexpectedly on the left, there was residual activity in the hamstrings, despite the loss of sacral innervation and the sciatic nerve. At 1 year after surgery, the patient was able to walk independently. Kinematic and kinetic impairments and compensations were most evident in the sagittal and coronal planes.
Excellent locomotor outcomes are possible after total sacrectomy.
Level of Evidence: N/A
The purpose of this study was to describe the biomechanics of locomotion after successful total sacrectomy and spinopelvic reconstruction. Locomotor biomechanics were assessed using 3-dimensional motion capture and electromyography. A functional, independent locomotor pattern was achieved after surgery, despite loss of sacral and lower lumbar innervation to the lower extremities.
*Division of Biokinesiology and Physical Therapy, and
†Keck School of Medicine of USC, University of Southern California, Los Angeles, CA;
‡Department of Physical Medicine and Rehabilitation, Kaiser Permanente Downey Medical Center, Downey, CA.
Address correspondence and reprint requests to Jo Armour Smith, PhD, PT, Division of Biokinesiology and Physical Therapy, University of Southern California, 1540 East Alcazar St, CHP-155, Los Angeles, CA 90089; E-mail: firstname.lastname@example.org
Acknowledgment date: February 27, 2014. First revision date: June 9, 2014. Second revision date: July 12, 2014. Acceptance date: July 16, 2014.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work.
Relevant financial activities outside the submitted work: consultancy, grants, employment, payment for lecture, royalties.