Introduction
Postoperative rehabilitation plays an important role to obtain a satisfactory result in fusion surgery for lumbar degenerative diseases. However, it remains to be clarified how physical activity progresses over time. The purposes of this study were to investigate the physical activity level and to identify the factors that influence it in the early postoperative period.
Methods
The subjects were 60 patients (26 males and 34 females; mean age 70.8 years) who underwent posterior instrumented interbody fusion for lumbar degenerative diseases from 2020 Apr. to 2022 Mar. The preoperative diagnoses were degenerative spondylolisthesis (35 cases), foraminal stenosis (17 cases), and isthmic spondylolisthesis (8 case).
Participants completed pre-operative patient-reported outcome measures (PROMs) including SF-36, the Roland-Morris Disability Questionnaire (RDQ), and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). Next day after admission, the surgery was performed, followed by postoperative rehabilitation supervised by a physical therapist without any braces. Mean length of hospital stay was 15 days (10 – 17days).
Intensity of activity, walking time, and step counts were recorded for the first 14 post-operative days, using wearable accelerometer (HJA-750C Active style Pro, Omron, Japan). Participants recorded daily pain scores, any needs of supervision and/or assistance on walking, and any conditions that hampered walking and ADLs. Statistical analysis was performed using general linear regression to examine postoperative changes in physical activity over time. It also examined the association between postoperative physical activity and factors that may limit activity. Statistical significance was defined as p-value of < 0.05.
Results
A progressive increase in light activity time, walking time, and number of steps was demonstrated during the first 14 days postoperatively (p<0.05). The walking time per day was average less than 1 hour during the same period. The patients spent sedentary time about 80% of their day. A reduced number of steps was associated strongly with postoperative pain and needs of supervision and/or assistance on walking. Dizziness and nausea were the most frequently symptoms to hamper their ADLs. Operative time and blood loss were not related to postoperative activity. The results of preoperative PROMs were also unrelated to the activity.
Discussion
The current study showed that light activity time, walking time, and number of steps progressively increased during the 14 days after instrumented posterior fusion surgery in lumbar degenerative diseases. However, it also demonstrated that the patients mainly spent the sedentary time at the same time-period. Strategies to reduce postoperative pain and manage postoperatively associated symptoms should be prepared to promote postoperative quick recovery process.