Introduction
Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity in teenagers that lead to spine surgery. Because spinal deformity may cause asymmetry in walking, it is conceivable that improved post-surgical spine alignment may improve gait pattern in these teenagers. The objective of the current systematic review was to summarize changes in spatiotemporal, kinematic, and kinetic parameters of gait after spine surgery in teenagers with AIS.
Methods
Five electronic databases (EMBASE, CINAHL, Scopus, Cochrane, PubMed) were searched from inception to June 1, 2023. Two reviewers independently screened the abstracts and full-text articles, extracted data, and rated the risk of bias of the included studies using various risk of bias assessment tools depending on the study design. Meta-analyses were conducted, if applicable. The Oxford Center for Evidence-Based Medicine guideline was used to evaluate the level of evidence of post-operative changes in gait parameters.
Results
A total of 3,809 citations were identified. Nine pre-post studies and five non-randomized controlled trials (418 participants) out of 55 full-text articles were included. All included pre-post studies as rated by the National Institutes of Health (NIH) quality assessment tool showed fair risk of bias. Those non-randomized controlled trials as evaluated by the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) displayed low (n=1), moderate (n=2) and serious risk of bias (n=2). The follow-up timepoints in the included studies were at 3-month, 7.7-month, 12-month, 20.5-month, 24-month and 10-year after spinal fusion. Twenty-three meta-analyses showed that there were significant decreases in cadence and walking speed one-year post-surgery as compared to pre-operative condition. However, there was no significant change in the step length at the one-year follow up. Both the pelvic and hip ranges of motion increased significantly in the frontal plane but decreased in the sagittal plane during walking one year after surgery, while the corresponding transverse pelvic range of motion significantly decreased. No significant post-surgical change was found in the thorax or thorax-pelvic motion, except a significant decrease in the sagittal thorax-pelvic motion at one year after surgery. For the gait kinetic parameters, the activation duration of rectus femoris during a gait cycle was significantly increased at one year after surgery, whereas the respective activation duration of gastrocnemius decreased. Meta-analyses revealed no significant changes in the activation durations of quadratus lumborum, erector spinae, semitendinosus, and tibialis anterior during a gait cycle at the one-year follow-up. However, internal, external, and total mechanical works were significantly increased one year after surgery. Collectively, there was only limited evidence for all the reported post-surgical changes in gait parameters.
Conclusions
Spinal fusion causes diverse spatiotemporal, kinematic, and kinetic parameters of gait in patients with AIS one year post surgery. However, it remains unclear whether these changes are clinically meaningful. Future studies should investigate whether the observed post-surgical changes in gait parameters are related to the corresponding improvement in balance control or functions of these teenagers.