A New Approach to Quantify Functional Improvements Following X-Stop Spacer Procedure: A Case Report

The purpose of this case report was to study effects of X-Stop implant surgery on the continuous spinal movement kinematics using 3D motion analysis. A proposed 3D kinematic spinal model was used to assess lumbar continuous active range of motion (AROM) during a standardized lumbar extension/flexion preoperatively and at 2 months postoperatively of a patient who underwent the X-Stop procedure. To investigate levels of muscle activities, electromyography recordings were made from right and left rectus abdominis, erector spinae and biceps femoris muscles. Also, functional mobility and patient quality of life were evaluated using the 6-minute walk test and the Swiss spinal stenosis and PROMIS-29 questionnaire. At 2 months postoperative, lumbar AROM increased by 18.5 and 14° for flexion and extension respectively and less muscle activation level was observed, despite the increase in lumbar AROM. Unlike positional magnetic resonance imaging (MRI) that is a common approach to assess spinal posture in static positions, the proposed continuous-motion analysis approach is able to analyze the lumbar AROM dynamically during flexion and extension. In this case report, the results indicate that the lumbar AROM, functional mobility and quality of life have been improved following X-Stop surgical intervention. J Med Cases. 2015;6(5):205-210 doi: http://dx.doi.org/10.14740/jmc2104w