Analysis of factors affecting baseline SF-36 Mental Component Summary in Adult Spinal Deformity and its impact on surgical outcomes

Patient Acceptable Symptom State Thresholds for the Knee Society Score, Oxford Knee Score, and 36-Item Short Form Survey Ten Years Following Unicompartmental Knee Arthroplasty

BACKGROUND

The patient acceptable symptom state (PASS) refers to a cutoff value on any patient-reported outcome measures (PROMs) scale, beyond which patients consider themselves as having achieved an acceptable outcome. This study aimed to identify PASS thresholds for knee-specific and generic PROMs at 10 years post-unicompartmental knee arthroplasty (UKA).

METHODS

There were 269 patients who underwent UKA for medial osteoarthritis from 2004 to 2007 at a single institution and were surveyed preoperatively and 10 years postoperatively using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), 36-Item Short Form Survey (SF-36) Mental Component Score (MCS), and SF-36 Physical Component Score (PCS). Treatment outcomes and expectations were assessed using an anchor question, and PASS attainment was determined using the Youden index on a receiver operating characteristic (ROC) curve. Also, a similar study that identified 2-year long-term PROM PASS thresholds for UKA was referenced and compared.

RESULTS

Overall, 91.1% reported acceptable outcomes. The area under the curve for ROCs of KSKS, OKS, and PCS were 0.80, 0.75, and 0.71, respectively. The area under the curve for ROCs of KSFS and MCS were both 0.64. The PASS thresholds were 67.5 for KSFS, 70.5 for KSKS, 39.5 for OKS, 44.6 for PCS, and 43.8 for MCS. Patients who achieved a PASS were at least 3 times more likely to have satisfactory outcomes.

CONCLUSIONS

To our knowledge, this is the first study that identified 10-year long-term PROM PASS thresholds for UKA. Accounting for our finding that a decade-long follow-up yielded lower PASS thresholds, time-specific UKA PROM PASS thresholds should be considered.

LEVEL OF EVIDENCE

III.

The effects of back extensor strength in different body positions on health-related quality of life in patients with degenerative spinal deformity

BACKGROUND

Degenerative spinal deformity (DSD) is believed to originate from degeneration of the discs and facet joints and vertebral wedging. Currently, the nosogeny of DSD is not yet fully clarified and there has been no systematic study on the impact of their lower back muscle strength on quality of life.

OBJECTIVE

To determine the characteristics of back extensor strength (BES) in different body positions and examine their correlations with health-related quality of life (HQOL) in degenerative spinal deformity (DSD) patients.

METHODS

Participants comprised 60 DSD patients and 40 healthy volunteers. Maximal isometric BES was evaluated by dynamometers with the subject in three different positions (standing, prone, sitting). The visual analogue scale (VAS) score, Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RMQ), and 36-item Short Form Health Survey (SF-36) score were used to evaluate patient HQOL. Correlations between the BES in different body positions and HQOL were analysed.

RESULTS

The BES values in three body positions were significantly smaller in DSD patients than healthy subjects (P< 0.05). The standing BES was found to be negatively associated with ODI and RMQ (R= 0.313, p< 0.05 and R= 0.422, p< 0.01, respectively). A negative relationship between sitting BES and RMQ was also seen (R= 0.271, p< 0.05). In addition, the standing and prone BES were positively correlated with the physical functioning score of the SF-36 (R= 0.471, p< 0.01 and R= 0.289, p< 0.05, respectively), and the sitting BES was positively correlated with the role-physical score of the SF-36 (R= 0.436, p< 0.01).

CONCLUSION

The results indicate that the back extensor muscle is compromised in DSD patients and there are differences in predicting the severity of disability and physical HQOL scores with BES in different positions. Standing BES was the most reliable contributor to HQOL among three body positions.

Outcome of spine surgery in patients with depressed mental states: a Canadian spine outcome research network study

BACKGROUND CONTEXT

Depression is higher among spine patients than among the general population. Some small studies, but not others, have suggested that depression may be a predictor of worse outcome after surgery.

PURPOSE

Determination whether there is an association between depression and worse response to surgery among spine patients.

STUDY DESIGN/SETTING

The national, prospective, Canadian Spine Outcome Research Network (CSORN) surgical outcome registry.

PATIENT SAMPLE

All patients in the CSORN registry who received surgery for thoracic or lumbar degenerative deformity, stenosis, spondylolisthesis, disc disease, or disc herniation with a minimum of 12 months follow-up postoperation (n = 2310).

OUTCOME MEASURES

Oswestry Disability Index (ODI), SF12 Physical Component Score (PCS), European Quality of Life (EuroQoL), and pain scales.

METHODS

Change in preoperative to 12-month postoperative ODI, and secondary measures, were compared to assess if there was an association between preoperative depression, as measured by PHQ9, and smaller response to surgery. Multivariate regression analysis was used to search for preoperative factors which might interact with PHQ9 to predict ODI outcome.

RESULTS

Patients with PHQ9<5, associated with minimal to no depression, had the smallest ODI improvement (-16.8 [95%CI -18.1 to -15.3]) and patients with severe preoperative depression (PHQ9 ≥ 10) had the largest ODI improvement (-22.8 [95%CI -24.1 to -21.5]; p<.00001). Similar findings were found in the EQ5D and PCS. Pain improvement was not different between depression levels. Multivariate modeling found worse baseline PHQ9 and ODI, greater age, nicotine use, more operative levels, and worse American Society of Anesthesiology score was predictive of worse ODI outcomes.

CONCLUSIONS

Depressed patients have similar or better relative improvements in disability, quality of life, and pain, when compared to nondepressed patients, although their preoperative and postoperative levels of disability are higher. Surgeons should not be concerned that depression will reduce the patient-reported beneficial response to surgical intervention.

Improvements in Mental Well-Being and its Predictive Factors in Patients who Underwent Cervical versus Lumbar Decompression Surgery

Introduction

Mental well-being is essential for patient satisfaction. Therefore, a better understanding of the changes in the mental well-being of patients following spinal surgery can be useful to surgeons. We compared the 2-year postoperative change in the mental well-being of patients who underwent cervical and lumbar decompression surgery. Additionally, the predictive factors for improvement in mental well-being associated with both methods were evaluated.

Methods

The patients who underwent spinal decompression surgery and were followed >2 years postoperatively were enrolled (lumbar cohort: n=111, cervical cohort: n=121). The 36-item Short-Form Health Survey (SF-36) mental component summary (MCS) was set as the mental well-being parameter, and the minimal clinically important difference (MCID) was defined as 4.0. After adjusting the cervical and lumbar cohorts using propensity scores, the improvements in the MCS were compared between the groups using a mixed-effect model. To identify predictors for improvements, the correlation between the MCS changes and preoperative clinical scores was evaluated. Subsequently, multivariate linear regression was applied, which included variables with p<0.10 in the former analysis as explanatory variables, and the change of MCS as the objective variable.

Results

There were no significant differences in the MCS improvement between the adjusted cervical and lumbar cohorts; 47% and 49%, respectively, had MCS improvement score >MCIDs. However, predictors for the improvement were different between the two cohorts: SF-36 Social functioning in cervical surgery and lower back pain and SF-36 Role physical in lumbar surgery.

Conclusions

Although there was no significant difference in the improvement in the mental well-being between patients who underwent either cervical or lumbar decompression surgery, less than half of the patients in both groups achieved a meaningful improvement. Preoperative back pain and personal activity were independent predictors in the lumbar cohort, while social functioning was the only predictor in the cervical cohort.

Level of evidence: III

Evaluation of lumbar stiffness after long-level fusion for degenerative lumbar scoliosis via a Chinese version of the lumbar stiffness disability index

BACKGROUND CONTEXT

Long-level spinal fusion for degenerative lumbar scoliosis (DLS)seeks to eliminate spinal motion in an attempt to alleviate pain, improve deformity, and reduce disability. However, this surgery considerably impairs the performance of activities of daily living (ADL) due to the resulting stiffness. The lumbar stiffness disability index (LSDI) is a validated measure of the effect of lumbar stiffness on functional activity, but this index might not be fully applicable to the elderly Chinese population given several specific lifestyle characteristics.

PURPOSE

To evaluate lumbar stiffness in patients with DLS after long-level fusion by Chinese-LSDI (C-LSDI).

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

A total of 129 DLS patients who underwent long-level (≧4 levels) fusion surgery with at least one-year follow-up from June 2009 to September 2017 were retrospectively included.

OUTCOME MEASURES

The C-LSDI was designed by modifying LSDI and Korean-LSDI (K-LSDI) based on elderly Chinese lifestyles and the internal consistency and retest repeatability of the patient-reported outcome questionnaire in the measurement of the impact of lumbar stiffness on functional abilities was assessed.

METHODS

The radiographic parameters including Cobb angle, apical vertebral translation (AVT), coronal vertical axis (CVA), sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and PI-LL, and clinical symptoms including visual analogue scale (VAS) for back and low extremity pain; Oswestry disability index (ODI), Japanese Orthopedic Association-29 (JOA-29), Scoliosis Research Society⁃22 (SRS-22), 36⁃Item short form survey (SF-36), physical component scores (PCS) and mental component scores (MCS) were measured preoperatively and at the last follow-up.

RESULTS

Compared with LSDI and K-LSDI, the C-LSDI demonstrated higher internal consistency (Cronbach's alpha=0.902) and retest reliability (Internal consistency coefficients, ICC=0.904) in the elderly Chinese population. All patients showed increased lumbar stiffness and significant improvement in pain and deformity postoperatively. Regarding items, such as performing personal hygiene after toileting and getting out of a car, people reported more inconvenience with increasingly fixed levels.

CONCLUSIONS

This study demonstrated that the C-LSDI questionnaire was a reliable and valid instrument for assessing functional limitations due to lumbar stiffness among elderly Chinese patients with DLS after long-level fusion. Although the effects of stiffness did trend toward greater impacts among patients who underwent longer fusions, most patients were satisfied with trade-offs of function and pain relief in exchange for perceived increases in lumbar stiffness.

Depression Symptoms Are Associated with Poor Functional Status Among Operative Spinal Deformity Patients

STUDY DESIGN

Retrospective review of prospective multicenter database.

OBJECTIVE

The aim of this study was to investigate how preoperative mental status affects preoperative and postoperative disability and health scores in adult spinal deformity (ASD) patients.

SUMMARY OF BACKGROUND DATA

The relationship between health-related quality of life (HRQOL) and depression has previously been documented. However, the influence of depression on clinical outcomes among ASD patients is not well understood.

METHODS

ASD patients with minimum 2-year follow-up were stratified based on preoperative mental health measured by Short Form 36 (SF-36) mental component score (MCS). Patients with MCS in the 25th and 75th percentile of the cohort were designated as having low and high MCS, respectively. After matching by preoperative demographics and deformity, pre- and post-HRQOL were compared between the two groups. Further analysis was performed to identify individualized questions on the SF-36 that could potentially screen for patients with low MCS.

RESULTS

Five hundred thirteen patients were assessed (58.4 years' old, 79% women, mean MCS 45.5). Thresholds for low and high MCS cohorts were 35.0 and 57.3, respectively. After matching by preoperative alignment, low MCS patients had worse Oswestry Disability Index (ODI) (52.3 ± 17.0 vs. 35.7 ± 14.6, P < 0.001) and Scoliosis Research Society-22R scores for all domains (all P < 0.001) compared to high MCS patients. Similar results were maintained at 2-year postop, with low MCS patients having a worse ODI (35.2 ± 20.2 vs. 19.7 ± 18.6, P < 0.001) and MCS (42.4 ± 13.5 vs. 58.6 ± 7.1, P < 0.001). Despite similar preoperative Physical Component Score (PCS), low MCS patients were less likely to reach MCID for PCS (46.1% vs. 70.6%, P < 0.01) and had a lower satisfaction at 2-year follow-up (3.88 ± 1.07 vs. 4.39 ± 0.94, P < 0.001). Questions 5a, 9d, and 9f on the SF-36 were found to be independent predictors of low MCS.

CONCLUSION

ASD patients with low MCS are more likely to experience functional limitations before and after surgery and are less likely to be satisfied postoperatively, even when similar clinical goals are achieved. Incorporating psychological factors may assist in decision making.Level of Evidence: 3.

Prospective investigation of Oswestry Disability Index and short form 36 subscale scores related to sagittal and coronal parameters in patients with degenerative lumbar scoliosis

PURPOSE

This study investigated relationships of Oswestry Disability Index (ODI) and Short Form 36 (SF-36) total and subscale scores with global spinal parameters in patients with degenerative lumbar scoliosis (DLS).

METHODS

This was a prospective single-center study of 126 consecutive patients with DLS. Disability was evaluated using the ODI and SF-36 total and subscale scores. Sagittal and coronal parameters were measured. Pearson's correlation analysis was performed to determine relationships between disability and radiographic parameters.

RESULTS

The study population included 76 women and 15 men (mean age, 70.2 ± 8.4 years). Mean Cobb angle was 18.9° ± 8.0°. The ODI total score and SF-36 physical component score were only correlated with coronal parameters. ODI pain intensity, personal care, lifting, sitting, and sex life domains were only correlated with coronal parameters. The walking, standing, social life, and traveling domain scores were correlated with coronal and sagittal parameters. The SF-36 bodily pain and vitality domain scores were only correlated with coronal parameters. The SF-36 physical function domain score was correlated with both coronal and sagittal parameters. Among the clinical and radiographic parameters, the personal care score and the coronal vertical-axis had the strongest correlation (r = 0.425), although the r² value was only 0.18.

CONCLUSIONS

ODI total score and most of the subscale scores were significantly, but weakly correlated with coronal parameters. Sagittal parameters were only correlated with some of the ODI and SF-36 subscale scores. Analysis using ODI and SF-36 subscale scores may aid in understanding and treatment of disability in patients with DLS.

Assessment of isokinetic trunk muscle strength and its association with health-related quality of life in patients with degenerative spinal deformity

Background

A considerable portion of the elderly population are increasingly afflicted by degenerative spinal deformity (DSD), which seriously affects patient health-related quality of life (HRQoL). HRQoL index is used across many studies to show correlations between radio-graphical alignment, disability, and pain in patients with DSD. However, imaged structural deformity represents only one aspect for consideration, namely, the disability effect of DSD. We assessed the isokinetic strength of trunk muscle in patients with degenerative spinal deformity (DSD), and investigated its relationship with HRQoL.

Methods

In total, 38 patients with DSD (DSD group) and 32 healthy individuals (control group) were recruited. Both groups were homogeneous for age, weight, height and body mass index (BMI). Assessments were performed using the isokinetic dynamometer IsoMed-2000; trunk extensor, flexor strength and flexion/extension (F/E) ratios were explored concentrically at speeds of 30°, 60° and 120° per second. The grip strength of both hands was measured using a hand-held dynamometer. Visual analogue scale (VAS) scores, the Oswestry Disability Index (ODI), a Roland-Morris disability questionnaire (RDQ), and a 36-item Short Form Health Survey (SF-36) evaluated patient HRQoL. Correlations between trunk strength and HRQoL were analyzed.

Results

When compared with the control group, the DSD group showed lower trunk extensor strength at three velocity movements, and higher F/E ratios at 60° and 120°/s (p < 0.05). Both groups exhibited similar trunk flexor strength and grip strength (p > 0.05). In DSD group, trunk extensor strength at 60°/s was negatively associated with ODI and RDQ (p < 0.05). A negative relationship between trunk flexor strength at 120°/s and ODI was also recorded (p < 0.05). In addition, trunk extensor strength at 60°/s and trunk flexor strength at 120°/s were positively correlated with physical functioning and role-physical scores according to the SF-36 (p < 0.05).

Conclusions

We identified isolated trunk extensor myopathy in DSD, which causes an imbalance in trunk muscle strength. Isokinetic trunk extensor strength at 60°/s and trunk flexor strength at 120°/s can predict disability, and decrease physical HRQoL in DSD patients.

Assessment of the association between paraspinal muscle degeneration and quality of life in patients with degenerative lumbar scoliosis

The present study aimed to determine the characteristics of multifidus, erector spinae and psoas major degeneration in elderly patients with degenerative lumbar scoliosis (DLS) and the correlation between asymmetric changes and patient quality of life. A total of 49 patients with lumbar scoliosis (DLS group) and 38 healthy individuals (control group) were prospectively examined. The functional cross-sectional area, cross-sectional area difference index (CDI) and fat infiltration rate (FIR) of the multifidus, erector spinae and psoas major at the apical vertebral level were measured using MRI. The visual analogue scale (VAS) score, Oswestry Disability Index (ODI) and 36-item Short Form Health Survey (SF-36) score were used to evaluate patient quality of life. Correlations between the degree of asymmetric muscular degeneration and quality of life were analysed. The CDI of the multifidus, erector spinal and psoas major was higher in the DLS group compared with that in the control group. The CDI of the multifidus was found to be positively associated with the Cobb angle of lumbar scoliosis. Similar results were obtained for fat infiltration between the two groups. In addition, the CDI and FIR difference index of the multifidus was positively correlated with the VAS score and ODI but negatively correlated with the SF-36 score. The quality of life significantly decreased with increasing asymmetric atrophy and fat infiltration in the multifidus. Thus, strategies to enhance the function of the multifidus may have a positive impact on quality of life (Chinese Clinical Trial Registry, registration date, 2018.11.12; registration no. ChiCTR1800019459.).

Effect modifiers for patient-reported outcomes in operatively and nonoperatively treated patients with adult symptomatic lumbar scoliosis: a combined analysis of randomized and observational cohorts

OBJECTIVE

Adult symptomatic lumbar scoliosis (ASLS) is a common and disabling condition. The ASLS-1 was a multicenter, dual-arm study (with randomized and observational cohorts) examining operative and nonoperative care on health-related quality of life in ASLS. An aim of ASLS-1 was to determine patient and radiographic factors that modify the effect of operative treatment for ASLS.

METHODS

Patients 40-80 years old with ASLS were enrolled in randomized and observational cohorts at 9 North American centers. Primary outcomes were the differences in mean change from baseline to 2-year follow-up for the SRS-22 subscore (SRS-SS) and the Oswestry Disability Index (ODI). Analyses were performed using an as-treated approach with combined cohorts. Factors examined were prespecified or determined using regression tree analysis. For each potential effect modifier, subgroups were created using clinically relevant cutoffs or via regression trees. Estimates of within-group and between-group change were compared using generalized linear mixed models. An effect modifier was defined as a treatment effect difference greater than the minimal detectable measurement difference for both SRS-SS (0.4) and ODI (7).

RESULTS

Two hundred eighty-six patients were enrolled and 256 (90%) completed 2-year follow-up; 171 received operative treatment and 115 received nonoperative treatment. Surgery was superior to nonoperative care for all effect subgroups considered, with the exception of those with nearly normal pelvic incidence-lumbar lordosis (PI-LL) match (≤ 11°). Male patients and patients with more (> 11°) PI-LL mismatch at baseline had greater operative treatment effects on both the SRS-SS and ODI compared to nonoperative treatment. No other radiographic subgroups were associated with treatment effects. High BMI, lower socioeconomic status, and poor mental health were not related to worse outcomes.

CONCLUSIONS

Numerous factors previously related to poor outcomes with surgery, such as low mental health, lower socioeconomic status, and high BMI, were not related to outcomes in ASLS in this exploratory analysis. Those patients with higher PI-LL mismatch did improve more with surgery than those with normal alignment. On average, none of the factors considered were associated with a worse outcome with operative treatment versus nonoperative treatment. These findings may guide future prospective analyses of factors related to outcomes in ASLS care.

Effect of Perioperative Mental Status on Health-related Quality of Life in Patients With Adult Spinal Deformities

STUDY DESIGN

A retrospective study.

OBJECTIVE

We aimed to evaluate the impact of mental status on the clinical outcomes of patients with adult spinal deformity (ASD).

SUMMARY OF BACKGROUND DATA

Limited information is currently available on how preoperative mental status affects postoperative health-related quality of life (HRQOL) in patients with ASD.

METHODS

We enrolled 165 patients with ASD who underwent corrective surgery at a single university hospital between March 2010 and September 2015. We compared Scoliosis Research Society-22r (SRS-22r) and Oswestry Disability Index (ODI) scores using various x-ray parameters at these time points: preoperative period and postoperative 2 years. Additionally, to determine the associations between perioperative complications and mental health disorders, we examined these x-ray parameters: lumbar lordosis, thoracic kyphosis, sacral slope, pelvic incidence, pelvic tilt, sagittal vertical axis (SVA), and T1 pelvic angle (TPA).

RESULTS

We found correlations between the preoperative SRS-22r total score and preoperative ODI (r = -0.692, P < 0.01) and postoperative ODI (r = -0.443, P < 0.01). Preoperative SRS-22r mental domain correlated with preoperative ODI (r = -0.561, P ≤ 0.01) and postoperative ODI (r = -0.315, P ≤ 0.01). Perioperative (preoperative and postoperative) SRS-22r mental domain did not correlate with the postoperative x-ray parameters except for SVA and TPA. Postoperative mental health correlated with early infection (P < 0.05), hematoma (P < 0.05), deep vein thrombosis (P < 0.05), and delirium (P < 0.05). Regression analysis revealed that preoperative SRS-22r mental health score correlated with preoperative ODI (P < 0.001) and postoperative ODI (P < 0.001). The regression coefficient number between preoperative SRS-22r mental health score and perioperative (preoperative and postoperative) ODI improved from -17.3 to -10.2 from preoperative to postoperative periods.

CONCLUSION

Diminished preoperative mental health worsened postoperative HRQOL. Perioperative complications influence postoperative mental status and HRQOL; hence, screening preoperative mental health is important.

LEVEL OF EVIDENCE

3.

Development of Deployable Predictive Models for Minimal Clinically Important Difference Achievement Across the Commonly Used Health-related Quality of Life Instruments in Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective analysis of prospectively-collected, multicenter adult spinal deformity (ASD) databases.

OBJECTIVE

To predict the likelihood of reaching minimum clinically important differences in patient-reported outcomes after ASD surgery.

SUMMARY OF BACKGROUND DATA

ASD surgeries are costly procedures that do not always provide the desired benefit. In some series only 50% of patients achieve minimum clinically important differences in patient-reported outcomes (PROs). Predictive modeling may be useful in shared-decision making and surgical planning processes. The goal of this study was to model the probability of achieving minimum clinically important differences change in PROs at 1 and 2 years after surgery.

METHODS

Two prospective observational ASD cohorts were queried. Patients with Scoliosis Research Society-22, Oswestry Disability Index , and Short Form-36 data at preoperative baseline and at 1 and 2 years after surgery were included. Seventy-five variables were used in the training of the models including demographics, baseline PROs, and modifiable surgical parameters. Eight predictive algorithms were trained at four-time horizons: preoperative or postoperative baseline to 1 year and preoperative or postoperative baseline to 2 years. External validation was accomplished via an 80%/20% random split. Five-fold cross validation within the training sample was performed. Precision was measured as the mean average error (MAE) and R values.

RESULTS

Five hundred seventy patients were included in the analysis. Models with the lowest MAE were selected; R values ranged from 20% to 45% and MAE ranged from 8% to 15% depending upon the predicted outcome. Patients with worse preoperative baseline PROs achieved the greatest mean improvements. Surgeon and site were not important components of the models, explaining little variance in the predicted 1- and 2-year PROs.

CONCLUSION

We present an accurate and consistent way of predicting the probability for achieving clinically relevant improvement after ASD surgery in the largest-to-date prospective operative multicenter cohort with 2-year follow-up. This study has significant clinical implications for shared decision making, surgical planning, and postoperative counseling.

LEVEL OF EVIDENCE

4.