1Department of Health Sciences, Major in Rehabilitation Science, Physical Therapy Program, Nagoya, Japan
2Department of Orthopaedic Surgery, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
Corresponding author: Satoshi Kato Department of Orthopaedic Surgery, Kanazawa University Graduate School of Medical Sciences, 13-1 Takara-machi, Kanazawa 920-0934, Japan. Tel: +81-76-265-2374 Fax: +81-76-234-4261 E-mail: skato323@gmail.com
• Received: September 25, 2025 • Revised: December 24, 2025 • Accepted: February 2, 2026
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
To investigate the effects of social restrictions imposed during the coronavirus disease 2019 (COVID-19) pandemic on postoperative functional recovery in patients who underwent surgery for degenerative musculoskeletal disorders.
Methods
This longitudinal prospective cohort study included 291 patients categorized into pre-pandemic (surgery in 2018), early pandemic (2019), and late-pandemic (2020) groups based on their 1-year recovery period. The primary outcome was improvement in locomotive syndrome (LS) status 1 year after surgery. We analyzed the association between social limitations and LS improvement using multivariate logistic and segmented regression analyses.
Results
The late-pandemic group exhibited the lowest LS improvement rate (50.6%) and the highest prevalence of postoperative social contact limitations (61.0%). Multivariate analysis identified the absence of postoperative social contact limitation as a highly potent independent predictor of LS improvement (odds ratio, 10.01; 95% confidence interval, 5.40–19.34; p<0.01). Segmented regression analysis revealed a time lag: social contact limitations peaked in March 2020, whereas the decline in LS improvement rates began in October 2020.
Conclusion
Prolonged social restrictions negatively impacted functional recovery, particularly during the late phase of the pandemic. Social participation, specifically direct social contact, could be a critical and independent component of postoperative rehabilitation. These findings underscore the need to integrate psychosocial assessments into standard postoperative care to optimize patient outcomes.
Locomotor system disorders are among the leading causes of long-term care; thus, their prevention and treatment are regarded as critical components of public health strategies. To this end, the Japanese Orthopaedic Association (JOA) proposed the concept of “locomotive syndrome” (LS), a condition of reduced mobility due to musculoskeletal system dysfunction, including the bones, joints, muscles, and nerves [1]. LS assessment is widely performed, as it can predict future mobility decline and the risk of requiring care [2]. Surgery is often recommended as an effective intervention for patients with severe LS, with our previous work and other studies demonstrating significant postoperative improvements in LS status [3-5].
Beyond physical factors, psychosocial elements such as social isolation and social frailty have been increasingly recognized as significant health risk factors in older adults [6]. Social isolation is defined as an objective lack of contact with others, whereas social frailty refers to a syndrome characterized by loss of social roles and reduced participation in community activities [7]. These social conditions are linked not only to poor mental health but also to a decline in physical function [8] and an increased need for care [9]. Their connection to musculoskeletal health is particularly strong, with social frailty being highly prevalent in patients with osteoporosis [10] and LS occurring in approximately 90% of individuals with frailty [11]. These findings suggest a potentially vicious cycle: social isolation may promote physical inactivity and accelerate LS, whereas pain and immobility due to LS may result in social withdrawal, exacerbating social frailty. Despite this strong theoretical link, the direct effect of social isolation on postoperative functional recovery in orthopaedic patients remains largely unknown.
The coronavirus disease 2019 (COVID-19) pandemic, which began in late 2019, represents an unprecedented global health crisis. In Japan, the COVID-19 pandemic was associated with decreased muscle strength among older adults [12], and a substantial increase in the prevalence of LS (from 30% to 50%) was observed [13]. This unique and challenging period inadvertently created a natural experiment that provided a rare opportunity to investigate the direct effects of mandatory social restrictions on patient’s recovery.
This study aimed to investigate the effect of social restrictions during the COVID-19 pandemic on postoperative improvements in locomotive function among patients who underwent surgery for degenerative spinal or lower-extremity diseases. We hypothesized that a period of intense social restriction would be associated with poorer functional recovery, mediated by a reduction in physical activity resulting from limited opportunities for social participation.
METHODS
Study design
This longitudinal prospective cohort study was conducted at a single center. This study was part of an ongoing institutional registry established in 2015 to evaluate long-term postoperative functional recovery in patients with musculoskeletal disorders. For the specific purpose of this analysis, we included patients who underwent surgery between January 2018 and December 2020 and completed 1-year postoperative follow-up.
Ethics statement
This study was conducted in accordance with the principles of the Declaration of Helsinki, as revised in 2013, and was approved by the Institutional Review Board (IRB) of Kanazawa University Hospital Ethics Committee (approval number: 2015-109). Although the original IRB approval was obtained in 2015, the protocol has been continuously updated and amended to reflect evolving research questions and environmental changes since then. Written informed consent was obtained from all participants prior to surgery for the use of data in this longitudinal registry.
Participants
A total of 1,031 patients who underwent surgery for degenerative spinal or lower extremity disease at our institution between December 2015 and December 2021 were enrolled. All participants provided written informed consent prior to their inclusion in the study.
Eligible patients included those who completed assessments both preoperatively and 1 year postoperatively. The exclusion criteria were as follows: patients who (1) were lost to follow-up 1 year after surgery; (2) had missing assessment data; (3) had a history of COVID-19 infection preoperatively; and (4) underwent additional surgical procedures for other musculoskeletal disorders during the 1-year follow-up period. To investigate the impact of the COVID-19 pandemic on postoperative functional recovery, patients were categorized into three groups based on the timing of surgery and the corresponding social conditions in Japan during the 1-year postoperative recovery period. The pre-pandemic group included patients who underwent surgery in 2018, with their recovery period occurring in 2019, prior to the outbreak. The early pandemic group comprised patients who underwent surgery in 2019, and their recovery period in 2020 coincided with the first confirmed COVID-19 case, the declaration of the first state of emergency, and the implementation of the strictest social restrictions. Finally, the late-pandemic group consisted of patients who underwent surgery in 2020, with their recovery period in 2021 coinciding with the second state of emergency and prolonged restrictions. After applying the inclusion and exclusion criteria, 291 patients (pre-pandemic group, n=112; early pandemic group, n=102; late-pandemic group, n=77) were analyzed (Fig. 1).
The participants underwent surgery for cervical spine, lumbar spine, hip, knee, or foot and ankle disorders. Patients with cervical spine diseases underwent laminoplasty or decompression surgery for conditions such as cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament. Lumbar spine disorders such as lumbar spinal stenosis with or without segmental instability, were managed through posterior decompression or short-segment spinal fusion. Hip pathologies such as osteoarthritis and femoral head osteonecrosis were addressed using total hip arthroplasty. Knee diseases, including knee osteoarthritis, were treated with total knee arthroplasty, unilateral knee arthroplasty, or corrective osteotomy. Foot and ankle diseases, including ankle or foot joint osteoarthritis and forefoot deformities, were treated with arthrodesis or corrective osteotomy of the ankle and forefoot.
A standardized rehabilitation protocol was implemented in all cases at our institution (Supplementary Material S1). Rigorous COVID-19 infection control measures were implemented. To ensure safety, the distance between rehabilitation beds was increased. Adequate ventilation was maintained to avoid closed spaces. However, the content and frequency of the rehabilitation program remained consistent with the standard protocol. The physiotherapists strictly followed infection prevention protocols. No further supervised physical therapy was administered after the hospital discharge.
Procedure
The LS risk tests proposed by the JOA were performed before and 1 year after surgery. The skeletal mass index (SMI) was measured using bioimpedance analysis (InBody 570, InBody Corp.) to diagnose sarcopenia before surgery. Sarcopenia is diagnosed based on grip strength, gait speed, and SMI according to the definition proposed by the Asian Working Group for Sarcopenia [14]. However, Sakai et al. [15] pointed out that the underlying diseases may affect gait speed in adults with locomotor disorders; thus, muscle mass should be primarily used to assess sarcopenia. Therefore, in the present study, sarcopenia was defined as low SMI, with cutoff values of <7.0 kg/m2 for men and <5.7 kg/m2 for women [14].
The main outcome of this study was the improvement in LS, status, which was assessed using the stand-up test, two-step test, and the 25-question Geriatric Locomotive Function Scale (GLFS-25) (Supplementary Material S2) according to the JOA guideline [16]. The evaluation and scoring methods for each test have been described in previous studies [16-18]. The GLFS-25 is a self-administered questionnaire consisting of 25 items that assess pain, activities of daily living, social function, and mental health [19]. The risk classification for LS based on individual tests and overall assessment was divided into stages 0, 1, 2, and 3. Stage 1 LS indicated an initial reduction in mobility and was characterized by a GLFS-25 score≥7, difficulty in standing on one leg from a seat height of 40 cm, or a two-step test score<1.3 (calculated as the total length of two steps divided by height). Advanced stage 2 LS was identified as a GLFS-25 score≥16, difficulty in standing on both legs from a seat height of 20 cm, or a two-step test score<1.1. Stage 3 LS, the most severe form, was defined as a GLFS-25 score≥24, difficulty in standing on both legs from a seat height of 30 cm, or a two-step test score<0.9. The worst stage achieved across the three tests was used to classify the patients’ overall LS stage for further analysis [16]. LS improvement was defined as a downgrade in the overall LS stage after surgery compared with the preoperative stage.
Specific items from the GLFS-25 [19] were used to investigate the impact of social restrictions during the COVID-19 pandemic. Social interaction limitation was assessed using Question 22 (“Have you been restricted from meeting your friends?”); participants who responded “slightly restricted” or higher were considered to have experienced restrictions in social interactions. Additionally, broader social participation limitation was evaluated using Question 23 (“Have you been restricted from joining social activities [meeting friends, playing sports, engaging in activities and hobbies, etc.])?”; participants who answered “slightly restricted” or higher were considered to have experienced restrictions in social activity participation. The prevalence of each condition was analyzed.
Statistical analysis
The normality of the distribution of continuous variables was visually inspected using Q-Q plots and assessed using the Shapiro–Wilk test. Based on the results, continuous variables are presented as mean±standard deviation for normally distributed data or as median (minimum–maximum) for non-normally distributed data. Categorical variables are expressed as numbers (%). Group comparisons were conducted using one-way ANOVA or the Kruskal–Wallis test, followed by Tukey’s honestly significant difference test or Steel-Dwass post-hoc test, respectively. Preoperative and postoperative changes were analyzed using the paired t-test or Wilcoxon signed-rank test. Proportions were compared using the chi-squared or Fisher’s exact tests. A multivariate logistic regression model was constructed to identify the factors associated with LS improvement at 1 year postoperatively. Additionally, a segmented logistic regression analysis was conducted to evaluate the effect of surgical timing on the LS improvement rate and social contact limitation and to detect and estimate a potential change-point (breakpoint) in the trend of improvement over time. A continuous time variable representing the consecutive months of surgery from time variable=1 (January 2018) to time variable=36 (December 2020) was created and used as the primary independent variable in the model. Although the analysis was anchored to the surgery date, the graphical representation displays the trajectory starting from January 2019 (1 year postoperatively) to reflect the actual timing of the outcome assessment. Statistical analyses were performed using JMP software version 12 (SAS) and R software version 4.5.1 (The R Foundation for Statistical Computing), with statistical significance set at a p-value of <0.05.
RESULTS
Baseline characteristics of the participants
Table 1 presents the baseline demographic and clinical characteristics of participants. Comparisons among the three groups revealed no significant differences in age, sex, SMI, surgical site, or comorbidities. In contrast, the body mass index (BMI) differed significantly among the groups (p<0.05). Post-hoc comparisons indicated that the early pandemic group had a significantly higher BMI than the pre- and late-pandemic groups. Additionally, the prevalence of sarcopenia was significantly higher in the late-pandemic group than in the pre-pandemic and early pandemic groups (p<0.05, chi-square test). Adjusted residual analysis indicated a significantly higher frequency of sarcopenia in the late pandemic group (adjusted residual=2.03).
LS improvement after surgery
Table 2 presents the LS stages, improvement rates in the three LS risk tests (stand-up test, two-step test, and GLFS-25), and prevalence of social contact and activity limitations among the surgical timing groups (pre-pandemic, early-pandemic, late-pandemic groups) and in the entire cohort. Regarding the LS stage, no significant intergroup differences were observed preoperatively (p=0.35) or postoperatively (p=0.86). Similarly, the overall LS improvement rate did not differ significantly among the groups (p=0.36). However, a numerical trend was observed, where the improvement rate was lower in the late-pandemic group (50.6%) than in the pre-pandemic (58.9%) and early pandemic groups (60.8%). This variation suggests that surgical timing may have influenced recovery; thus, further analyses, including multivariate and segmented regression modeling, were conducted to explore this relationship.
The prevalence of social contact and activity limitations was also analyzed to investigate the impact of social restrictions related to the COVID-19 pandemic. For social contact limitation, no significant differences were observed among the groups preoperatively (p=0.22). In contrast, a significant difference was observed postoperatively (p<0.01). The late-pandemic group exhibited the highest proportion of patients reporting social limitations (61.0%; adjusted residual=4.19), whereas the pre-pandemic group had the lowest (29.5%). Regarding social activity limitations, there were no significant differences among the groups preoperatively (p=0.86). Postoperatively, although the late-pandemic group showed a slightly higher proportion of limitations compared with the other groups (57.5% vs. 52.7% and 51.9%), the difference was not statistically significant (p=0.06). Comparing the pre- and postoperative frequencies within each group, the late-pandemic group showed no significant improvement in either social contact or activity limitation after surgery. Conversely, both the pre-and early pandemic groups exhibited significant reductions in the prevalence of these limitations postoperatively. These findings suggest that social restrictions related to the COVID-19 pandemic may have affected the recovery of social participation differently among the surgical timing groups.
Multivariate analysis of factors associated with LS improvement
Multivariate logistic regression analysis was conducted to identify factors associated with the improvement of one or more LS stages (Table 3). The independent variables included in the model were age, sex, BMI, surgical site (cervical spine, lumbar spine, hip, knee, foot, and ankle), surgical timing groups (pre-pandemic, early pandemic, and late-pandemic groups), presence of sarcopenia, preoperative LS stage, and presence of social contact and activity limitations before and after surgery. The overall model was statistically significant (p<0.01, pseudo-R2=0.27). The likelihood of LS stage improvement was independently associated with age (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.88–0.95; p<0.01), preoperative LS stage 2 (OR, 5.13; 95% CI, 1.48–20.34; p<0.01), preoperative LS stage 3 (OR, 24.24; 95% CI, 7.15–96.34; p<0.01), and the absence of postoperative social contact limitation (OR, 10.01; 95% CI, 5.40–19.34; p<0.01).
Segmented regression analysis: breakpoints in LS improvement and social contact limitation
Segmented regression analysis was conducted to further examine the temporal trends in outcomes that were potentially influenced by social conditions during the COVID-19 pandemic. Regarding social contact limitations, a significant change in the slope of the relationship between the month of surgery and the prevalence of limitations was observed. A breakpoint was identified at time variable=27 (corresponding to March 2020), with an estimated standard error of 4.91. Before the breakpoint, the prevalence exhibited a significant upward trend over time (slope=0.086, p<0.01). After the breakpoint, the slope decreased (change in slope=-0.157), suggesting a reversal of the increasing trend in social restrictions following the onset of the pandemic. The segmented regression model yielded an Akaike information criterion (AIC) value of 374.7.
Segmented regression analysis also identified a breakpoint in the LS improvement rate at time variable=34 (corresponding to October 2020), with an estimated standard error of 4.69.
Before the breakpoint, the improvement rate remained relatively stable with no significant trend (slope=-0.015, p=0.24). However, after the breakpoint, a marked decline in slope was observed (change in slope=-0.441), indicating a sharp drop in the probability of improvement. The segmented regression model yielded an AIC of 401.0.
The segmented regression results for the monthly transition in the improvement rate of the LS stage and the prevalence of social activity limitation are shown in Fig. 2.
DISCUSSION
The present study aimed to evaluate whether social restrictions during the COVID-19 pandemic affected postoperative improvements in locomotive function in patients who underwent surgery for degenerative spinal or lower-extremity diseases. To our knowledge, this is the first longitudinal study to investigate how pandemic-related societal changes affect postoperative locomotive recovery, as assessed using direct physical performance measures rather than solely questionnaires, in a large cohort of patients who underwent musculoskeletal surgery.
Notably, our multivariable logistic regression analysis revealed that the absence of postoperative social contact limitation was a highly potent independent predictor of LS stage improvement (OR, 10.01). Although patients with severe preoperative disability (LS stage 3) showed the highest odds of improvement (OR, 24.24), likely due to greater room for recovery, the impact of preserving social contact was remarkably strong, surpassing that of age (OR, 0.92) or moderate preoperative limitations (LS stage 2: OR, 5.13). This finding suggests that the health impact of the COVID-19 pandemic manifested not only as direct harm from viral infection but also as severe indirect consequences on functional health through social isolation. These consequences are likely the result of society-wide lifestyle changes, such as reduced opportunities for face-to-face interaction and community participation, which are linked to heightened emotional distress and physical frailty in older populations [20].
A large-scale survey in the UK reported a nearly 10% decline in physical activity during lockdowns, with older adults being disproportionately affected [21]. Similarly, a previous study in Japan demonstrated that a reduction in social outings was independently associated with a decline in physical function among older adults during the pandemic [22]. Collectively, these reports support our finding that restricted social participation, specifically the lack of direct social contact, significantly hinders postoperative LS recovery.
Our group comparison revealed that the late-pandemic group (surgeries performed in 2020; recovery period in 2021) faced the greatest challenges. Although the difference was not statistically significant, this group showed the lowest trend in LS improvement rate (50.6%) compared with the pre-pandemic (58.9%) and early pandemic groups (60.8%). Furthermore, the late-pandemic group exhibited a significantly higher prevalence of postoperative social contact limitation and uniquely failed to show significant improvement in this domain from pre-to post-surgery. This cohort likely faced a “double burden.” First, they underwent surgery with a significantly higher prevalence of sarcopenia, consistent with previous reports indicating an increase in sarcopenia during the COVID-19 pandemic [23]. As sarcopenia is an established negative prognostic factor for postoperative recovery [24], this baseline disadvantage likely compromised the outcomes. Second, their critical 1-year recovery period coincided with 2021, which was characterized by prolonged states of emergency and “pandemic fatigue” in Japan. Unlike the early phase of the pandemic, where acute anxiety might have prompted temporary behavioral changes, the prolonged restrictions in 2021 may have entrenched social isolation and sedentary habits, severely hampering rehabilitation potential.
Our segmented regression analysis provides a nuanced view of these temporal dynamics. Crucially, the prevalence of social contact limitations peaked for surgeries performed in March 2020. This timing coincided perfectly with the onset of the COVID-19 pandemic and the first state of emergency in Japan, validating the direct impact of societal measures on patient behavior. Interestingly, the breakpoint for the decline in the LS improvement rate was identified in October 2020, approximately seven months after the peak of social restrictions. This time lag suggests that the negative impact of social isolation on physical recovery is cumulative rather than immediate. The loss of social contact in early 2020 likely led to gradual deconditioning or lack of motivation, which manifested as a marked drop in functional recovery rates by late 2020. This finding strongly implies that maintaining social connections is an essential component of long-term physical rehabilitation.
This study had several strengths, including its large cohort, longitudinal design spanning the pre- to intra-pandemic periods, and the use of objective performance-based measures. Nevertheless, this study had some limitations. First, this study included a heterogeneous cohort and various surgical procedures; however, the distribution of surgical sites was comparable among the groups. Second, we could not account for unmeasured confounders such as specific home exercise habits and individual social support networks. Third, regarding the lower improvement rate in the late-pandemic group, a potential ceiling effect cannot be ruled out. Although the difference was not statistically significant, this group had a numerically lower proportion of patients with severe preoperative disability (LS stage 3) than the other groups. While our multivariate analysis controlled for preoperative LS stage, the relatively better baseline status in this group might have resulted in a smaller room for improvement, potentially contributing to the lower improvement rate observed. Finally, our data do not extend to the post-pandemic era, limiting comparisons to a period during which the restrictions were fully lifted. Future research should focus on developing and evaluating interventions aimed at promoting social participation to optimize functional outcomes in this vulnerable population.
In conclusion, this study revealed that postoperative social contact limitations are independent predictors of poor functional recovery in patients who undergo surgery for degenerative spinal and lower-extremity diseases. Our findings strongly suggest that social participation is not merely a desirable outcome of recovery but also an active ingredient in the rehabilitation process. Even in the post-pandemic world, supporting patients’ social ecosystems may be as crucial as prescribing the correct exercise.
CONFLICTS OF INTEREST
No potential conflict of interest relevant to this article was reported.
FUNDING INFORMATION
This work was supported in part by a research grant from JSPS KAKENHI (grant number JP 21K17509). The funding did not have any role in the study design; in the collection, analysis, and interpretation of data; or in manuscript writing.
AUTHOR CONTRIBUTION
Conceptualization: Kurokawa Y, Kato S. Investigation: Kurokawa Y, Shimizu T. Methodology: Kurokawa Y, Kato S. Data curation: Kurokawa Y. Formal analysis: Kurokawa Y. Funding acquisition: Kurokawa Y. Project administration: Kato S. Visualization: Kurokawa Y. Validation: Kurokawa Y. Resources: Kato S, Kabata T, Matsubara H, Yokogawa N, Shimizu T, Demura S. Supervision: Kato S, Demura S. Writing – original draft: Kurokawa Y. Writing – review and editing: Kato S. Approval of final manuscript: all authors.
ACKNOWLEDGMENTS
The authors thank all patients, doctors, and physical therapists who participated in the study.
DATA AVAILABILITY STATEMENT
The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.
Flowchart illustrating the patient selection process of the study. COVID-19, coronavirus disease 2019.
Fig. 2.
Temporal trends in postoperative LS recovery and social contact limitation identified by segmented regression analysis. The graph illustrates the monthly transition of the predicted probability based on the date of surgery from January 2018 to December 2020. The vertical dashed lines indicate the estimated breakpoints (change points) for each outcome. Although the actual outcomes were assessed 1 year postoperatively (i.e., observation period: January 2019–December 2021), the x-axis represents the surgical timing to highlight the impact of the pandemic onset. The red line indicates the prevalence of social contact limitations, which peaked in March 2020 (coinciding with the COVID-19 outbreak) and subsequently decreased. The blue line denotes the improvement rate in the LS stage, with a marked decline observed after the breakpoint in October 2020. LS, locomotive syndrome; COVID-19, coronavirus disease 2019.
Table 1.
Baseline characteristics of patients in this study (n=291)
Characteristic
Total (n=291)
Pre-pandemic group (n=112)
Early-pandemic group (n=102)
Late-pandemic group (n=77)
p-value
Age (yr)
66.8±8.8
66.6±8.5
67.1±8.8
66.9±9.4
0.90
Sex (male/female)
78/213
31/81
23/79
24/53
0.42
BMI (kg/m2)
24.4±4.0
23.8±3.9
25.4±3.9
23.9±4.1
0.01
SMI (kg/m2)
6.5±1.0
6.4±0.9
6.5±1.1
6.4±1.0
0.58
Surgical site
0.12
Cervical spine
17 (5.8)
5 (4.5)
7 (6.9)
5 (6.5)
Lumbar spine
92 (31.6)
31 (27.7)
28 (27.5)
33 (42.9)
Hip
128 (44.0)
52 (46.4)
44 (43.1)
32 (41.6)
Knee
20 (6.9)
10 (8.9)
9 (8.8)
1 (1.3)
Foot and ankle
34 (11.7)
14 (12.5)
14 (13.7)
6 (7.8)
Comorbidity
Diabetes mellitus
38 (13.1)
15 (13.4)
13 (12.7)
10 (13.0)
0.99
Chronic cardiac disease
17 (5.8)
6 (5.4)
6 (5.9)
5 (6.5)
0.94
Sarcopenia
94 (32.3)
37 (33.0)
25 (24.5)
32 (41.6)
0.05
Values are presented as mean±standard deviation, number only, or number (%).
p-values were based on chi-square tests for categorical variables and ANOVA or the Kruskal–Wallis test for continuous variables. When significant, a post-hoc comparison was conducted; the details are described in the text.
BMI, body mass index; SMI, skeletal muscle index.
Table 2.
Comparison of LS severity, functional test-based improvements, and social activity limitations among the surgical timing groups and the entire cohort (n=291)
Total (n=291)
Pre-pandemic group (n=112)
Early-pandemic group (n=102)
Late-pandemic group (n=77)
p-value
Preoperative LS status
0.35
Stage 0
0 (0)
0 (0)
0 (0)
0 (0)
Stage 1
19 (6.5)
6 (5.4)
4 (3.9)
9 (11.7)
Stage 2
61 (21.0)
23 (20.5)
22 (21.6)
16 (20.8)
Stage 3
211 (72.5)
83 (74.1)
76 (74.5)
52 (67.5)
Postoperative LS status
0.86
Stage 0
25 (8.7)
11 (9.8)
8 (7.8)
6 (7.8)
Stage 1
99 (34.1)
34 (30.4)
40 (39.2)
26 (33.8)
Stage 2
79 (27.2)
32 (28.6)
24 (23.6)
24 (31.2)
Stage 3
87 (30.0)
35 (31.2)
30 (29.4)
21 (27.2)
Postoperative LS improvement
167 (57.4)
66 (58.9)
62 (60.8)
39 (50.6)
0.36
Social contact limitation
Before surgery
160 (55.0)
68 (60.7)
55 (53.9)
37 (48.9)
0.22
At 1 year after surgery
119 (40.9)
33 (29.5)
39 (38.2)
47 (61.0)
<0.01
Social activity limitation
Before surgery
227 (78.0)
89 (79.5)
78 (76.5)
60 (77.9)
0.86
At 1 year after surgery
164 (56.4)
59 (52.7)
53 (51.9)
52 (57.5)
0.06
Values are presented as number (%).
p-values were based on chi-square tests for categorical variables and ANOVA or Kruskal–Wallis tests for continuous variables. When significant, post-hoc comparisons were conducted; details are described in the text.
LS, locomotive syndrome.
Table 3.
Multivariate analysis of factors associated with LS improvement after surgery
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Impact of Social Restrictions During the Coronavirus Disease 2019 Pandemic on Functional Recovery After Musculoskeletal Surgery
Fig. 1. Flowchart illustrating the patient selection process of the study. COVID-19, coronavirus disease 2019.
Fig. 2. Temporal trends in postoperative LS recovery and social contact limitation identified by segmented regression analysis. The graph illustrates the monthly transition of the predicted probability based on the date of surgery from January 2018 to December 2020. The vertical dashed lines indicate the estimated breakpoints (change points) for each outcome. Although the actual outcomes were assessed 1 year postoperatively (i.e., observation period: January 2019–December 2021), the x-axis represents the surgical timing to highlight the impact of the pandemic onset. The red line indicates the prevalence of social contact limitations, which peaked in March 2020 (coinciding with the COVID-19 outbreak) and subsequently decreased. The blue line denotes the improvement rate in the LS stage, with a marked decline observed after the breakpoint in October 2020. LS, locomotive syndrome; COVID-19, coronavirus disease 2019.
Graphical abstract
Fig. 1.
Fig. 2.
Graphical abstract
Impact of Social Restrictions During the Coronavirus Disease 2019 Pandemic on Functional Recovery After Musculoskeletal Surgery
Characteristic
Total (n=291)
Pre-pandemic group (n=112)
Early-pandemic group (n=102)
Late-pandemic group (n=77)
p-value
Age (yr)
66.8±8.8
66.6±8.5
67.1±8.8
66.9±9.4
0.90
Sex (male/female)
78/213
31/81
23/79
24/53
0.42
BMI (kg/m2)
24.4±4.0
23.8±3.9
25.4±3.9
23.9±4.1
0.01
SMI (kg/m2)
6.5±1.0
6.4±0.9
6.5±1.1
6.4±1.0
0.58
Surgical site
0.12
Cervical spine
17 (5.8)
5 (4.5)
7 (6.9)
5 (6.5)
Lumbar spine
92 (31.6)
31 (27.7)
28 (27.5)
33 (42.9)
Hip
128 (44.0)
52 (46.4)
44 (43.1)
32 (41.6)
Knee
20 (6.9)
10 (8.9)
9 (8.8)
1 (1.3)
Foot and ankle
34 (11.7)
14 (12.5)
14 (13.7)
6 (7.8)
Comorbidity
Diabetes mellitus
38 (13.1)
15 (13.4)
13 (12.7)
10 (13.0)
0.99
Chronic cardiac disease
17 (5.8)
6 (5.4)
6 (5.9)
5 (6.5)
0.94
Sarcopenia
94 (32.3)
37 (33.0)
25 (24.5)
32 (41.6)
0.05
Total (n=291)
Pre-pandemic group (n=112)
Early-pandemic group (n=102)
Late-pandemic group (n=77)
p-value
Preoperative LS status
0.35
Stage 0
0 (0)
0 (0)
0 (0)
0 (0)
Stage 1
19 (6.5)
6 (5.4)
4 (3.9)
9 (11.7)
Stage 2
61 (21.0)
23 (20.5)
22 (21.6)
16 (20.8)
Stage 3
211 (72.5)
83 (74.1)
76 (74.5)
52 (67.5)
Postoperative LS status
0.86
Stage 0
25 (8.7)
11 (9.8)
8 (7.8)
6 (7.8)
Stage 1
99 (34.1)
34 (30.4)
40 (39.2)
26 (33.8)
Stage 2
79 (27.2)
32 (28.6)
24 (23.6)
24 (31.2)
Stage 3
87 (30.0)
35 (31.2)
30 (29.4)
21 (27.2)
Postoperative LS improvement
167 (57.4)
66 (58.9)
62 (60.8)
39 (50.6)
0.36
Social contact limitation
Before surgery
160 (55.0)
68 (60.7)
55 (53.9)
37 (48.9)
0.22
At 1 year after surgery
119 (40.9)
33 (29.5)
39 (38.2)
47 (61.0)
<0.01
Social activity limitation
Before surgery
227 (78.0)
89 (79.5)
78 (76.5)
60 (77.9)
0.86
At 1 year after surgery
164 (56.4)
59 (52.7)
53 (51.9)
52 (57.5)
0.06
Reference
aOR
p-value
95% CI
Age (yr)
+1 year
0.92
<0.01
0.88–0.95
Preoperative stage
Stage 2 LS
Preoperative stage 0, 1, or 3 LS
5.13
<0.01
1.48–20.3 4
Stage 3 LS
Preoperative stage 0, 1, or 2 LS
24.24
<0.01
7.15–96.34
Pre-pandemic phase
Early-pandemic or late-pandemic phase
1.57
0.14
0.86–2.90
Postoperative social contact limitation
No limitation
10.01
<0.01
5.40–19.34
Table 1. Baseline characteristics of patients in this study (n=291)
Values are presented as mean±standard deviation, number only, or number (%).
p-values were based on chi-square tests for categorical variables and ANOVA or the Kruskal–Wallis test for continuous variables. When significant, a post-hoc comparison was conducted; the details are described in the text.
BMI, body mass index; SMI, skeletal muscle index.
Table 2. Comparison of LS severity, functional test-based improvements, and social activity limitations among the surgical timing groups and the entire cohort (n=291)
Values are presented as number (%).
p-values were based on chi-square tests for categorical variables and ANOVA or Kruskal–Wallis tests for continuous variables. When significant, post-hoc comparisons were conducted; details are described in the text.
LS, locomotive syndrome.
Table 3. Multivariate analysis of factors associated with LS improvement after surgery
, Satoshi Kato, MD, PhD2
