Incidence of back pain from initial presentation to 3 years of follow-up in subjects with untreated adolescent idiopathic scoliosis

BACKGROUND

Although back pain may be present in subjects with adolescent idiopathic scoliosis (AIS), its natural history is unknown. Therefore, this study evaluated the incidence of back pain in scoliotic adolescents longitudinally.

METHODS

This retrospective analysis examined prospectively collected pain subscale data of the Scoliosis Research Society questionnaire between the initial presentation and up to 3 years of follow-up. Consecutive subjects with AIS aged 10-18 at baseline managed by observation within the study period were included. Study subjects with at least one time point of follow-up data were considered. Alternatively, a group with physiotherapy-treated was also included for comparison.

RESULTS

We enrolled 428 subjects under observation. The incidence of back pain among study subjects was 14.7%, 18.8%, and 19.0% for the first year, second year, and third year of follow-up, respectively. Most experienced mild pain (1 out of 5 points) throughout the study. Neither incidence nor intensity of pain significantly differed between subjects under observation and received physiotherapy. Additionally, study subjects with a new onset of back pain had poorer function, self-image, and mental health scores than those without pain.

CONCLUSION

We investigated the incidence of back pain longitudinally in subjects suffering from AIS. Further validation of the current results is warranted.

Impact of mental health components on the development of back pain in young adults with adolescent idiopathic scoliosis

BACKGROUND

Back pain occurs commonly in adults and is multifactorial in nature. This study aimed to assess the prevalence and intensity of back pain during young adulthood in subjects with adolescent idiopathic scoliosis (AIS), as well as factors that may be associated with its prognosis.

METHODS

Subjects with AIS aged 20-39 treated conservatively were included in this study. Patient-reported outcome measures in adulthood involved episodes of back pain, and scales of self-image, depression, anxiety, and stress. Additionally, pain, self-image, and mental health scores were retrieved at the first clinic consultation. Occurrence of back pain was defined as a numeric pain rating scale ≥ 6.

RESULTS

101 participants were enrolled. The prevalence of back pain in the lifetime, past 12 months, past 6 months, past 1 month, past 7 days, and past 24 h were 37%, 35%, 31%, 27%, 23%, and 20%, respectively. Male, self-image, and depression were significant associated factors for the development of back pain at all time points. Furthermore, the analyses of the initial presentation of participants have shown that participants with back pain in adulthood were characterised by poor self-image and mental health during their adolescence.

CONCLUSION

The present study addressed the natural history of back pain in young adults with conservatively treated AIS. Psychological makeup has been shown to constitute the development of back pain and is strongly hinted as an early sign of having back pain in adulthood among subjects with AIS.

A new osteogenic protein isolated from Dioscorea opposita Thunb accelerates bone defect healing through the mTOR signaling axis

Delayed bone defect repairs lead to severe health and socioeconomic impacts on patients. Hence, there are increasing demands for medical interventions to promote bone defect healing. Recombinant proteins such as BMP-2 have been recognized as one of the powerful osteogenic substances that promote mesenchymal stem cells (MSCs) to osteoblast differentiation and are widely applied clinically for bone defect repairs. However, recent reports show that BMP-2 treatment has been associated with clinical adverse side effects such as ectopic bone formation, osteolysis and stimulation of inflammation. Here, we have identified one new osteogenic protein, named 'HKUOT-S2' protein, from Dioscorea opposita Thunb. Using the bone defect model, we have shown that the HKUOT-S2 protein can accelerate bone defect repair by activating the mTOR signaling axis of MSCs-derived osteoblasts and increasing osteoblastic biomineralization. The HKUOT-S2 protein can also modulate the transcriptomic changes of macrophages, stem cells, and osteoblasts, thereby enhancing the crosstalk between the polarized macrophages and MSCs-osteoblast differentiation to facilitate osteogenesis. Furthermore, this protein had no toxic effects in vivo. We have also identified HKUOT-S2 peptide sequence TKSSLPGQTK as a functional osteogenic unit that can promote osteoblast differentiation in vitro. The HKUOT-S2 protein with robust osteogenic activity could be a potential alternative osteoanabolic agent for promoting osteogenesis and bone defect repairs. We believe that the HKUOT-S2 protein may potentially be applied clinically as a new class of osteogenic agent for bone defect healing.

Application of silver nanoparticles for improving motor recovery after spinal cord injury via reduction of pro-inflammatory M1 macrophages

Silver nanoparticles (AgNPs) possess anti-inflammatory activities and have been widely deployed for promoting tissue repair. Here we explored the efficacy of AgNPs on functional recovery after spinal cord injury (SCI). Our data indicated that, in a SCI rat model, local AgNPs delivery could significantly recover locomotor function and exert neuroprotection through reducing of pro-inflammatory M1 survival. Furthermore, in comparison with Raw 264.7-derived M0 and M2, a higher level of AgNPs uptake and more pronounced cytotoxicity were detected in M1. RNA-seq analysis revealed the apoptotic genes in M1 were upregulated by AgNPs, whereas in M0 and M2, pro-apoptotic genes were downregulated and PI3k-Akt pathway signaling pathway was upregulated. Moreover, AgNPs treatment preferentially reduced cell viability of human monocyte-derived M1 comparing to M2, supporting its effect on M1 in human. Overall, our findings reveal AgNPs could suppress M1 activity and imply its therapeutic potential in promoting post-SCI motor recovery.

Fracture incidence and fracture-related mortality decreased with decreases in population mobility during the early days of the COVID-19 pandemic: an epidemiological study

INTRODUCTION

We investigated the impact of coronavirus disease 2019 (COVID-19) social distancing measures on fracture incidence and fracture-related mortality, as well as associations with population mobility.

METHODS

In total, 47 186 fractures were analysed across 43 public hospitals from 22 November 2016 to 26 March 2020. Considering the smartphone penetration of 91.5% in the study population, population mobility was quantified using Apple Inc's Mobility Trends Report, an index of internet location services usage volume. Fracture incidences were compared between the first 62 days of social distancing measures and corresponding preceding epochs. Primary outcomes were associations between fracture incidence and population mobility, quantified by incidence rate ratios (IRRs). Secondary outcomes included fracture-related mortality rate (death within 30 days of fracture) and associations between emergency orthopaedic healthcare demand and population mobility.

RESULTS

Overall, 1748 fewer fractures than projected were observed during the first 62 days of COVID-19 social distancing (fracture incidence: 321.9 vs 459.1 per 100 000 person-years, P<0.001); the relative risk was 0.690, compared with mean incidences during the same period in the previous 3 years. Population mobility exhibited significant associations with fracture incidence (IRR=1.0055, P<0.001), fracture-related emergency department attendances (IRR=1.0076, P<0.001), hospital admissions (IRR=1.0054, P<0.001), and subsequent surgery (IRR=1.0041, P<0.001). Fracture-related mortality decreased from 4.70 (in prior years) to 3.22 deaths per 100 000 person-years during the COVID-19 social distancing period (P<0.001).

CONCLUSION

Fracture incidence and fracture-related mortality decreased during the early days of the COVID-19 pandemic; they demonstrated significant temporal associations with daily population mobility, presumably as a collateral effect of social distancing measures.

Functional recovery priorities and community rehabilitation service preferences of spinal cord injury individuals and caregivers of Chinese ethnicity and cultural background

Introduction

Spinal cord injury (SCI) causes significant and permanent disability affecting motor, sensory and autonomic functions. We conducted a survey on the priorities of functional recovery and preferences for community rehabilitation services in a cohort of Chinese individuals with SCI as well as the primary caregivers. The study also investigated their views on advanced technology and research.

Methods

An online platform with a self-administered questionnaire was used to collect the opinions of clients that received services from an SCI follow-up clinic, a self-help association, or a non-government organization from 1 September−31 December 2021.

Results

Eighty-seven subjects (74 individuals with SCI−48 tetraplegic, 26 paraplegic, and 13 caregivers) responded to the survey. Recovery of arm/hand function was given the highest priority among tetraplegics, followed by upper trunk/body strength and balance, and bladder/bowel function. Sexual function had a significant lower ranking than all priority areas except normal sensation (p < 0.05). Paraplegics viewed bladder/bowel function as the most important area of functional recovery, followed by walking movement, upper trunk/body strength and balance, elimination of chronic pain, and regaining normal sensation. There was no statistically significant difference among the top priority areas (p > 0.05). In contrast to previous studies done in Western populations, the study revealed that sexual function was ranked as the lowest by all 3 groups of respondents (tetraplegics, paraplegics, and caregivers). The majority of participants thought community rehabilitation services were inadequate. Most of the respondents were interested to try advanced technology which would facilitate their daily life and rehabilitation. About half of the individuals with SCI thought advance in technology and research could bring significant improvement in their quality of life in the coming 10 years.

Conclusion

This survey is the first study specifically looking into the recovery and rehabilitation priorities of a Chinese population of individuals with SCI. This is also the first study to investigate the priorities of the primary caregivers of SCI individuals. The findings are useful as a reference for planning of future research and provision of rehabilitation services for the SCI community locally and in other parts of China.

Patient-reported outcomes in a Chinese cohort of osteogenesis imperfecta unveil psycho-physical stratifications associated with clinical manifestations

Background

Osteogenesis imperfecta (OI) is a rare congenital disorder of the skeletal system, inflicting debilitating physical and psychological distress on patients and caregivers. Over the decades, much effort has been channeled towards understanding molecular mechanisms and developing new treatments. It has recently become more apparent that patient-reported outcome measurements (PROM) during treatment, healing and rehabilitation are helpful in facilitating smoother communication, refining intervention strategies and achieving higher quality of life. To date, systematic analyses of PROM in OI patients remain scarce.

Results

Here, utilizing a PROM Information System, we report a cross-sectional and longitudinal study in a southern Chinese cohort of 90 OI patients, covering both the child and adult age-groups. In the child group where both self and parental surveys were obtained, we identified two clusters of comparable sizes showing different outlooks in physical mobility and emotional experiences. One cluster (Cluster 1) is more negative about themselves than the other (Cluster 2). A concordance of 84.7% between self and parental assessments was recorded, suggesting the stability and validity of PROM-based stratification. Clinical subtyping, deformity, leg length discrepancy, and limited joint mobility were significantly associated with this stratification, with Cluster 1 showing higher percentages of severe phenotypes than Cluster 2. Since OI is a genetic disorder, we performed genetic testing on 72 of the 90 patients, but found no obvious association between genotypes and the PROM stratification. Analyses of longitudinal data suggested that patients tended to stay in the same psychological state, in both clusters. Adult patients also showed a continuous spectrum of self-evaluation that matches their clinical manifestations.

Conclusion

By systematically analyzing patient-reported outcomes, our study demonstrated the link between the sociopsychological wellbeing of OI patients, and their clinical manifestations, which may serve as the basis for evaluating clinical interventions and help achieve better patient-centric medical practices. The lack of genotype-PROM association may be due to the diverse mutational spectrum in OI, which warrants further investigation when a larger sample size is available.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02394-7.

A Randomized Controlled Trial to Evaluate the Clinical Effectiveness of 3D-Printed Orthosis in the Management of Adolescent Idiopathic Scoliosis

STUDY DESIGN

Prospective randomized controlled trial.

OBJECTIVE

To compare clinical effectiveness and quality of life (QoL) of the 3D-printed orthosis (3O) and conventional orthosis (CO) for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Using 3D printing technology to design and fabricate orthoses to manage AIS aiming to improve in-orthosis correction and patients' compliance that are considered essential factors of effective treatment. Clinical evaluation was conducted to study the effectiveness of this innovative method.

METHODS

Thirty females with AIS who met the criteria (age 10-14, Cobb 20-40°, Risser sign 0-2, ≤12 months after menarche) were recruited. Subjects were randomly allocated to the 3O group (n = 15, age 12.4, Cobb 31.8°) and CO group (n = 15, age 12.0, Cobb 29.3°). All patients were prescribed for full-time wearing (23 hours/d) and follow-up every 4 to 6 months until bone maturity. Compliance was monitored by thermosensors, while QoL was assessed using three validated questionnaires.

RESULTS

Comparable immediate in-orthosis correction was observed between 3O (-11.6°, P < 0.001) and CO groups (-12.9°, P < 0.001). In the QoL study via SRS-22r, the 3O group got worse results after 3 months in aspects of function, self-image, and mental health (-0.5, -0.6, -0.7, P < 0.05) while the CO group had worse results in aspects of self-image and mental health (-0.3, -0.3, P < 0.05). No significant difference was found in QoL assessments between groups. After 2 years of follow-up, 22 patients were analyzed with 4 dropouts in each group. Comparable angle reduction was observed in both groups (3O: -2.2°, P = 0.364; CO: -3.5°, P = 0.193). There was one subject (9.1%) in the 3O group while two subjects (18.2%) in the CO group had curve progression >5°. Daily wearing hours were 1.9 hours longer in the 3O group than the CO group (17.1 vs. 15.2 hours, P = 0.934).

CONCLUSION

The 3O group could provide comparable clinical effects as compared with the CO group while patients with 3O showed similar compliance and QoL compared to those with CO.Level of Evidence: 1.

A biomechanical study on the effect of lengthening magnitude on spine off-loading in magnetically controlled growing rod surgery: Implications on lengthening frequency

Purpose: To assess whether the magnitude of lengthening in magnetically controlled growing rod (MCGR) surgeries has an immediate or delayed effect on spinal off-loading. Methods: 9 whole porcine spines were instrumented using two standard MCGRs from T9 to L5. Static compression testing using a mechanical testing system (MTS) was performed at three MCGR lengthening stages (0 mm, 2 mm, and 6 mm) in each spine. At each stage, five cycles of compression at 175N with 25 min of relaxation was carried out. Off-loading was derived by comparing the load sustained by the spine with force applied by the MTS to the spine. Micro-CT imaging was subsequently performed. Results: The mean load sustained by the vertebral body before lengthening was 39.69N, and immediately after lengthening was 25.12N and 19.91N at 2 mm and 6 mm lengthening, respectively; decreasing to 10.07N, 8.31N, and 8.17N after 25 minutes of relaxation, at 0 mm, 2 mm, and 6 mm lengthening stages, respectively. There was no significant difference in off-loading between 2 mm and 6 mm lengthening stages, either instantaneously (p = 0.395) or after viscoelastic relaxation (p = 0.958). CT images showed fractures/separations at the level of pedicle screws in six spines and in the vertebral body's growth zone in five spines after 6 mm MCGR lengthening. Conclusion: This study demonstrated MCGRs cause significant off-loading of the spine leading to stress shielding. 6 mm of lengthening caused tissue damage and microfractures in some spines. There was no significant difference in spine off-loading between 2 mm and 6 mm MCGR lengthening, either immediately after lengthening or after viscoelastic relaxation.

The first magnetically controlled growing rod (MCGR) in the world - lessons learned and how the identified complications helped to develop the implant in the past decade: case report

Background

The first magnetically controlled growing rod (MCGR) was implanted in 2009. Since then multiple complications have been identified that have helped drive the development of the MCGR and its surgery. The aim of this report is to illustrate how identified complications in the first MCGR helped with developments in the past decade and to report a unique failure mechanism with stud fracture close to the barrel opening.

Case presentation

A 5-year old girl with a scoliosis of 58.5 degrees at T1–9 and 72.8 degrees at T9-L4 had a single MCGR inserted and anchored at T3–4 and L3–4. At postoperative 13 months the MCGR was noted to have lost of distraction between lengthening episodes due to unrestricted turning of the internal magnet. To prevent further loss of distraction, an external magnet was placed outside the skin to prevent the magnet from turning back. The overall balance was suboptimal and after the rod was fully distracted, proximal junctional kyphosis occurred. Subsequently, the MCGR was modified with an internal keeper plate to prevent loss of distraction and a dual set of these rods were implanted when the patient was 9 years old. Extension proximally to C7-T1 was done to manage the proximal junctional kyphosis. Her spinal balance improved and distractions continued. She subsequently developed add-on below and the piston rod was not aligned with the actuator. The lumbar spine was also observed to have autofusion. She subsequently had final fusion surgery performed at the age of 15 from C7-L4 leaving a residual tilt below to avoid fusion to the pelvis. The final extracted rod on the left side indicated the “crooked rod sign” on X-ray and rod dissections revealed a new failure mechanism of stud fracture close to the barrel opening. Body fluids and tissue may infiltrate the rod despite no obvious deformation or fractures resulting in hastened wearing of the threads.

Conclusions

There are various complications associated with MCGRs that are related to rod design and surgical inexperience. Repeated rod stalling is not recommended with potential stud fracture and “crooked rod sign”. Rotor stalling and thread wearing which indicates rod failure still require solutions.

The Natural History of Ossification of Yellow Ligament of the Thoracic Spine on MRI: A Population-Based Cohort Study

PURPOSE

To assess the natural history of ossification of yellow ligament (OYL) in the thoracic spine and determine risk factors for progression based on a longitudinal population-based cohort.

METHODS

A prospective, longitudinal cohort study was performed on a population-based cohort of Southern Chinese volunteers. T2-weighted magnetic resonance imaging (MRI) was used at baseline to identify any OYL and was verified with computed tomography. Follow-up MRI was performed 5 years later. Parameters under study included the size of OYL, levels of involvement, morphology (round, triangular, beak), whether it crossed the midline and any disc degeneration.

RESULTS

A total of 114 (6.1%) individuals were identified to have OYL at baseline out of the 1864 individuals. Size progression occurred predominantly at the lower thoracic region. Majority of the new OYL were also in the lower thoracic spine and was associated with higher body mass index (BMI). Smokers were associated with OYL size progression while patients with higher BMI tended to develop new OYL at follow-up. Progression commonly occurred at the lower thoracic levels and regression occurred mostly at the upper thoracic levels.

CONCLUSIONS

This is the first population-based series addressing the natural history of OYL. Better understanding of the natural history of OYL may provide incentive to introduce preventive measures such as weight reduction and close monitoring for myelopathy development in those at-risk groups for progression. This is especially important for patients with lower thoracic OYL and who are smokers with higher BMI.

LEVEL OF EVIDENCE

1 (prognostic study).

Directed Differentiation of Notochord-like and Nucleus Pulposus-like Cells Using Human Pluripotent Stem Cells

Intervertebral disc degeneration might be amenable to stem cell therapy, but the required cells are scarce. Here, we report the development of a protocol for directed in vitro differentiation of human pluripotent stem cells (hPSCs) into notochord-like and nucleus pulposus (NP)-like cells of the disc. The first step combines enhancement of ACTIVIN/NODAL and WNT and inhibition of BMP pathways. By day 5 of differentiation, hPSC-derived cells express notochordal cell characteristic genes. After activating the TGF-β pathway for an additional 15 days, qPCR, immunostaining, and transcriptome data show that a wide array of NP markers are expressed. Transcriptomically, the in vitro-derived cells become more like in vivo adolescent human NP cells, driven by a set of influential genes enriched with motifs bound by BRACHYURY and FOXA2, consistent with an NP cell-like identity. Transplantation of these NP-like cells attenuates fibrotic changes in a rat disc injury model of disc degeneration.

Predictors of neurologic outcome after surgery for cervical ossification of the posterior longitudinal ligament differ based on myelopathy severity: a multicenter study

OBJECTIVE

The purpose of this retrospective multicenter study was to compare prognostic factors for neurological recovery in patients undergoing surgery for cervical ossification of the posterior longitudinal ligament (OPLL) based on their presenting mild, moderate, or severe myelopathy.

METHODS

The study included 372 consecutive patients with OPLL who underwent surgery for cervical myelopathy between 2006 and 2016 in East Asian countries with a high OPLL prevalence. Baseline and postoperative clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) myelopathy score and recovery ratio. Radiographic assessment included occupying ratio, cervical range of motion, and sagittal alignment parameters. Patient myelopathy was classified as mild, moderate, or severe based on the preoperative JOA score. Linear and multivariate regression analyses were performed to identify patient and surgical factors associated with neurological recovery stratified by baseline myelopathy severity.

RESULTS

The mean follow-up period was 45.4 months (range 25-140 months). The mean preoperative and postoperative JOA scores and recovery ratios for the total cohort were 11.7 ± 3.0, 14.5 ± 2.7, and 55.2% ± 39.3%, respectively. In patients with mild myelopathy, only age and diabetes correlated with recovery. In patients with moderate to severe myelopathy, older age and preoperative increased signal intensity on T2-weighted imaging were significantly correlated with a lower likelihood of recovery, while female sex and anterior decompression with fusion (ADF) were associated with better recovery.

CONCLUSIONS

Various patient and surgical factors are correlated with likelihood of neurological recovery after surgical treatment for cervical OPLL, depending on the severity of presenting myelopathy. Older age, male sex, intramedullary high signal intensity, and posterior decompression are associated with less myelopathy improvement in patients with worse baseline function. Therefore, myelopathy-specific preoperative counseling regarding prognosis for postoperative long-term neurological improvement should include consideration of these individual and surgical factors.

Multidisciplinary programme for rehabilitation of chronic low back pain - factors predicting successful return to work

Background

There are no clear indicators for predicting return to work for patients with chronic low back pain (LBP). We aim to report the outcomes of a 14-week multidisciplinary programme targeting patients with chronic LBP who failed conventional physiotherapy to provide functional rehabilitation. Also, this study will identify factors predicting successful return to work (RTW).

Methods

A collected cohort of patients with chronic LBP was consecutively enrolled into the programme from 1996 to 2014. All recruited patients failed to RTW despite at least 3 months of conservative treatment. Patient underwent weekly multidisciplinary sessions with physiotherapists, occupational therapists and clinical psychologists. Patient perceived function was considered the primary outcome of the programme. Patients were assessed for their sitting, standing and walking tolerance. Oswestry Disability Index (ODI) and Spinal Function Sort Score (SFSS) were used to assess patient perceived disability.

Results

One hundred and fifty-eight patients were recruited. After the programme, statistically significant improvement was found in ODI (47.5 to 45.0, p = 0.01) and SFSS (98.0 to 109.5, p <  0.001). There was statistically significant improvement (p <  0.01) in sitting, standing, walking tolerance and straight leg raise tests. 47.4% of the patients were able to meet their work demand. Multivariate logistic regression model (R² = 59.5%, χ² (9) = 85.640, p <  0.001) demonstrated that lower initial job demand level and higher patient-perceived back function correlated with greater likelihood of returning to work.

Conclusion

The results of this study may support the use of this multidisciplinary programme to improve patient function and return to work.

Are Higher Global Alignment and Proportion Scores Associated With Increased Risks of Mechanical Complications After Adult Spinal Deformity Surgery? An External Validation

BACKGROUND

The Global Alignment and Proportion (GAP) score, based on pelvic incidence-based proportional parameters, was recently developed to predict mechanical complications after surgery for spinal deformities in adults. However, this score has not been validated in an independent external dataset.

QUESTIONS/PURPOSES

After adult spinal deformity surgery, is a higher GAP score associated with (1) an increased risk of mechanical complications, defined as rod fractures, implant-related complications, proximal or distal junctional kyphosis or failure; (2) a higher likelihood of undergoing revision surgery to treat a mechanical complication; and (3) is a lower (more proportioned) GAP score category associated with better validated outcomes scores using the Oswestry Disability Index (ODI), Scoliosis Research Society-22 (SRS-22) and the Short Form-36 questionnaires?

METHODS

A total of 272 patients who had undergone corrective surgeries for complex spinal deformities were enrolled in the Scoli-RISK-1 prospective trial. Patients were included in this secondary analysis if they fulfilled the original inclusion criteria by Yilgor et al. From the original 272 patients, 14% (39) did not satisfy the radiographic inclusion criteria, the GAP score could not be calculated in 14% (37), and 24% (64) did not have radiographic assessment at postoperative 2 years, leaving 59% (159) for analysis in this review of data from the original trial. A total of 159 patients were included in this study,with a mean age of 58 ± 14 years at the time of surgery. Most patients were female (72%, 115 of 159), the mean number of levels involved in surgery was 12 ± 4, and three-column osteotomy was performed in 76% (120 of 159) of patients. The GAP score was calculated using parameters from early postoperative radiographs (between 3 and 12 weeks) including pelvic incidence, sacral slope, lumbar lordosis, lower arc lordosis and global tilt, which were independently obtained from a computer software based on centralized patient radiographs. The GAP score was categorized as proportional (scores of 0 to 2), moderately disproportional (scores of 3 to 6), or severely disproportional (scores higher than 7 to 13). Receiver operating characteristic area under curve (AUC) was used to assess associations between GAP score and risk of mechanical complications and risk of revision surgery. An AUC of 0.5 to 0.7 was classified as "no or low associative power", 0.7 to 0.9 as "moderate" and greater than 0.9 as "high". We analyzed differences in validated outcome scores between the GAP categories using Wilcoxon rank sum test.

RESULTS

At a minimum of 2 years' follow-up, a higher GAP score was not associated with increased risks of mechanical complications (AUC = 0.60 [95% CI 0.50 to 0.70]). A higher GAP score was not associated with a higher likelihood of undergoing a revision surgery to treat a mechanical complication (AUC = 0.66 [95% 0.53 to 0.78]). However, a moderately disproportioned GAP score category was associated with better SF-36 physical component summary score (36 ± 10 versus 40 ± 11; p = 0.047), better SF-36 mental component summary score (46 ± 13 versus 51 ± 12; p = 0.01), better SRS-22 total score (3.4 ± 0.8 versus 3.7 ± 0.7, p = 0.02) and better ODI score (35 ± 21 versus 25 ± 20; p = 0.003) than severely disproportioned GAP score category.

CONCLUSION

Based on the findings of this external validation study, we found that alignment targets based on the GAP score alone were not associated with increased risks of mechanical complications and mechanical revisions in patients with complex adult spinal disorders. Parameters not included in the original GAP score needed to be considered to reduce the likelihood of mechanical complications.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Clinical implications of lumbar developmental spinal stenosis on back pain, radicular leg pain, and disability

AIMS

To study the associations of lumbar developmental spinal stenosis (DSS) with low back pain (LBP), radicular leg pain, and disability.

METHODS

This was a cross-sectional study of 2,206 subjects along with L1-S1 axial and sagittal MRI. Clinical and radiological information regarding their demographics, workload, smoking habits, anteroposterior (AP) vertebral canal diameter, spondylolisthesis, and MRI changes were evaluated. Mann-Whitney U tests and chi-squared tests were conducted to search for differences between subjects with and without DSS. Associations of LBP and radicular pain reported within one month (30 days) and one year (365 days) of the MRI, with clinical and radiological information, were also investigated by utilizing univariate and multivariate logistic regressions.

RESULTS

Subjects with DSS had higher prevalence of radicular leg pain, more pain-related disability, and lower quality of life (all p < 0.05). Subjects with DSS had 1.5 (95% confidence interval (CI) 1.0 to 2.1; p = 0.027) and 1.8 (95% CI 1.3 to 2.6; p = 0.001) times higher odds of having radicular leg pain in the past month and the past year, respectively. However, DSS was not associated with LBP. Although, subjects with a spondylolisthesis had 1.7 (95% CI 1.1 to 2.5; p = 0.011) and 2.0 (95% CI 1.2 to 3.2; p = 0.008) times greater odds to experience LBP in the past month and the past year, respectively.

CONCLUSION

This large-scale study identified DSS as a risk factor of acute and chronic radicular leg pain. DSS was seen in 6.9% of the study cohort and these patients had narrower spinal canals. Subjects with DSS had earlier onset of symptoms, more severe radicular leg pain, which lasted for longer and were more likely to have worse disability and poorer quality of life. In these patients there is an increased likelihood of nerve root compression due to a pre-existing narrowed canal, which is important when planning surgery as patients are likely to require multi-level decompression surgery. Cite this article: Bone Joint J 2021;103-B(1):131-140.

Brace Effectiveness Is Related to 3-Dimensional Plane Parameters in Patients with Adolescent Idiopathic Scoliosis

BACKGROUND

Although scoliosis is a 3-dimensional (3D) deformity, little research has been performed on the use of 3D imaging in brace curve correction. The purpose of the present study was to determine the effect of axial-plane parameters on the outcomes of bracing with a thoracolumbosacral orthosis for adolescent idiopathic scoliosis.

METHODS

This prospective longitudinal cohort study included patients with adolescent idiopathic scoliosis who fulfilled the criteria for bracing according to the Scoliosis Research Society, and was conducted from the time the patient began wearing the brace through a minimum follow-up of 2 years or until a surgical procedure was performed. Radiographs made with use of an EOS Imaging System were used to reconstruct 3D images of the spine at the pre-brace, immediate in-brace, 1-year in-brace, and latest follow-up out-of-brace stages. Univariate and multiple linear regressions were performed to determine the association between axial rotation correction and curve progression at the time of the latest follow-up. Logistic regressions were performed to model the probability of risk of progression.

RESULTS

Fifty-three patients were enrolled, and 46 patients were included in the analysis. At the time of the latest follow-up, 30 patients did not experience curve progression and 16 patients had curve progression. There was no difference in baseline demographic characteristics between groups. For the transverse-plane parameters, there was a significant difference between non-progression and progression groups in pre-brace apical vertebral rotation (4.5° ± 11.2° compared with -2.4° ± 9.8°, respectively; p = 0.044) and in 1-year in-brace apical vertebral rotation correction velocity (2.0° ± 5.0°/year compared with -1.7° ± 4.4°/year, respectively; p = 0.016). Logistic regression analysis showed that pre-brace apical vertebral rotation (odds ratio, 1.063; 95% confidence interval, 1.000 to 1.131; p = 0.049) and 1-year in-brace apical vertebral rotation correction velocity (odds ratio, 1.19; 95% confidence interval, 1.021 to 1.38; p = 0.026) were associated with an increased risk of curve progression. There was no difference in Scoliosis Research Society 22-Item scores between patients who experienced curve progression and those who did not.

CONCLUSIONS

In this prospective study, we demonstrated that axial-plane parameters and the correction of these parameters during bracing are related to the successful use of the brace.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Prospects of cell replacement therapy for the treatment of degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) presents insidiously during middle-age with deterioration in neurological function. It accounts for the most common cause of non-traumatic spinal cord injury in developed countries and disease prevalence is expected to rise with the aging population. Whilst surgery can prevent further deterioration, biological therapies may be required to restore neurological function in advanced disease. Cell replacement therapy has been inordinately focused on treatment of traumatic spinal cord injury yet holds immense promise in DCM. We build upon this thesis by reviewing the pathophysiology of DCM as revealed by cadaveric and molecular studies. Loss of oligodendrocytes and neurons occurs via apoptosis. The tissue microenvironment in DCM prior to end-stage disease is distinct from that following acute trauma, and in many ways more favourable to receiving exogenous cells. We highlight clinical considerations for cell replacement in DCM such as selection of cell type, timing and method of delivery, as well as biological treatment adjuncts. Critically, disease models often fail to mimic features of human pathology. We discuss directions for translational research towards clinical application.

Impact of COVID-19 on Orthopaedic and Trauma Service: An Epidemiological Study

BACKGROUND

Coronavirus disease 2019 (COVID-19) has caused substantial disruptions to orthopaedic and trauma services. The purpose of the present study was to quantify its impact on surgical volume, hospitalizations, clinic appointments, and accident and emergency attendances to guide staffing and resource deployment for the sustenance of emergency services.

METHODS

Data were retrieved from all 43 Hong Kong public hospitals and 122 outpatient clinics from a population of 7.5 million residents. The "COVID-19 cohort" of patients who received treatment from January 25 to March 27, 2020, was compared with the "control cohort" of patients who received treatment during the same time of year over the past 4 years. Primary outcomes consisted of changes in patient diagnoses, number of operations performed, and hospitalizations during the COVID-19 pandemic. Secondary outcomes included differences in patient age and comorbidity, the nature of operations performed, types of anesthesia for orthopaedic procedures, difference in anesthetic times, wait times, and personal protective equipment (PPE) reserves.

RESULTS

A total of 928,278 patient-episodes (32,613 operations, 97,648 hospital admissions, 302,717 accident and emergency attendances, and 495,300 outpatient clinic attendances) were analyzed. Orthopaedic operations were reduced by 44.2%, from a mean (and standard deviation) of 795 ± 115.1 to 443.6 ± 25.8 per week (p < 0.001), with the ratio of emergency to elective operations increasing from 1.27:1 to 3.78:1. Operations for the treatment of upper and lower-limb fractures decreased by 23% (from 98.5 ± 14 to 75.9 ± 15.2 per week; p < 0.001) and 20% (from 210.6 ± 29.5 to 168.4 ± 16.9 per week; p < 0.001), respectively, whereas elective joint replacement and ligamentous reconstruction procedures decreased by 74% to 84% (p < 0.001). Operations for orthopaedic infections such as necrotizing fasciitis and septic arthritis remained similar (p > 0.05). The number of hospitalizations decreased by 41.2% (from 2,365 ± 243 to 1,391 ± 53 per week; p < 0.001), whereas clinical outpatient visits decreased by 29.4% (from 11,693 ± 2,240 to 8,261 ± 1,104 per week; p < 0.001). Patients did not endure longer wait times for emergency operations and accident and emergency consultations (p > 0.05). PPE consumption did not exceed procurement, with net increases in PPE reserves.

CONCLUSIONS

Demand for orthopaedic care remains, despite weekly reductions of 351 orthopaedic operations, 974 hospital admissions, and 3,432 clinic attendances. Orthopaedic surgeons and health-care professionals should factor this into consideration during staffing and resource deployment.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Postoperative Rigid Cervical Collar Leads to Less Axial Neck Pain in the Early Stage After Open-Door Laminoplasty-A Single-Blinded Randomized Controlled Trial

BACKGROUND

Cervical collars are used after laminoplasty to protect the hinge opening, reduce risks of hinge fractures, and avoid spring-back phenomena. However, their use may lead to reduced range of motion and worse neck pain.

OBJECTIVE

To investigate the clinical, radiological, and functional outcomes of patients undergoing single-door laminoplasty with or without collar immobilization.

METHODS

This was a prospective, parallel, single-blinded randomized controlled trial. Patients underwent standardized single-door laminoplasty with mini-plates for cervical myelopathy and were randomly allocated into 2 groups based on the use of collar postoperatively. Clinical assessments included cervical range of motion, axial neck pain (VAS [visual analogue scale]), and objective scores (short-form 36-item, neck disability index, and modified Japanese Orthopaedic Association). All assessments were performed preoperatively and at postoperative 1, 2, 3, and 6 wk, and 3, 6, and 12 mo. Comparative analysis was performed via analysis of variance adjusted by baseline scores, sex, and age as covariates.

RESULTS

A total of 35 patients were recruited and randomized to collar use (n = 16) and without (n = 19). There were no dropouts or complications. There were no differences between groups at baseline. Subjects had comparable objective scores and range of motion at postoperative time-points. Patients without collar use had higher VAS at postoperative 1 wk (5.4 vs 3.5; P = .038) and 2 wk (3.5 vs 1.5; P = .028) but subsequently follow-up revealed no differences between the 2 groups.

CONCLUSION

The use of a rigid collar after laminoplasty leads to less axial neck pain in the first 2 wk after surgery. However, there is no additional benefit with regards to range of motion, quality of life, and complication risk.

Minimum 2-Year Experience with Magnetically Controlled Growing Rods for the Treatment of Early-Onset Scoliosis: A Systematic Review

Magnetically controlled growing rods have been used to treat early-onset scoliosis for the last 9 years; however, few studies have been published, with only short-term follow-up. The aim of the present study is to systematically review the outcomes of magnetically controlled growing rods in the treatment of early-onset scoliosis with a minimum of 2-year follow-up. Studies were included if patients with early-onset scoliosis (scoliosis diagnosed before 10 years of age) underwent implantation of magnetically controlled growing rods with a minimum of 2-year follow-up. The literature review and data extraction followed the established preferred reporting items for systematic review and meta-analysis guidelines. Data of distraction frequency, number of distractions, distracted length, Cobb angle, kyphosis, T1-T12 length, and T1-S1 length preoperatively, postoperatively, and at final follow-up were collected. Data regarding complications and unplanned reoperations were also extracted. The mean values of these parameters were calculated, or pooled meta-analysis was performed if available. Ten articles were included in this systematic review, with a total of 116 patients and a follow-up period between 23 and 61 months. The mean preoperative Cobb angle and kyphosis angle were 60.1° and 38.0°, respectively, and improved to 35.4° and 26.1° postoperatively. At final follow-up, the Cobb and kyphosis angles were maintained at 36.9° and 36.0°, respectively. The average preoperative T1-T12 and T1-S1 lengths were 180.6 mm and 293.6 mm, respectively, and increased to 198.3 mm and 320.3 mm postoperatively. T1-T12 and T1-S1 lengths were 212.3 mm and 339.3 mm at final follow-up, respectively. The overall rate of patients with complications was 48% (95% confidence interval [CI], 0.38-0.58) and unplanned reoperation 44% (95% CI, 0.33-0.55) after sensitivity analysis. The current evidence from different countries with a minimum of a 2-year follow-up suggests that magnetically controlled growing rods are an effective technique to treat pediatric scoliosis and promote spine growth. However, nearly half of patients still developed complications or required unplanned reoperations.

Prediction of survival in patients with symptomatic spinal metastases: Comparison between the Tokuhashi score and expert oncologists

BACKGROUND

Existing scoring systems have suboptimal accuracy in prognosticating patients with spinal metastases. Currently, there is no superior method in predicting survival. This study aims to compare the accuracy of survival prediction by expert oncologists versus the revised Tokuhashi scores with actual survivals in a cohort of symptomatic spinal metastases patients.

METHODS

All patients who underwent surgical treatment for metastatic spinal tumours in a tertiary hospital between January 2011 to December 2015 were reviewed. Each patient's data was reconstructed into an anonymised clinical scenario and presented independently to five blinded attending oncologists with at least three years' post fellowship experience. They were surveyed for survival prediction twice at no less than four weeks' interval apart; the test-retest reliability was examined. The agreement of their prognostication and modified Tokuhashi scores were compared with actual survivals.

RESULTS

Fifty-five patients were included during the study period. The mean age at presentation was 61.1 years (range, 41 to 79), and mean actual survival was 21.6 months (range, 1 to 68). Cohen's kappa agreement with actual survival was higher by oncologists' estimation (0.52) than by revised Tokuhashi score prediction (0.31) (p = 0.018). Intra-class correlation showed high inter-reliability (0.71) between the five oncologists and a high test-retest reliability (0.69) between both rounds of the survey.

CONCLUSION

This study showed that expert oncologists provided more accurate survival prediction than revised Tokuhashi scores in patients with spinal metastases. Future studies are required to identify factors in their assessment that led to improved accuracy.

Traditional growing rod versus magnetically controlled growing rod for treatment of early onset scoliosis: Cost analysis from implantation till skeletal maturity

PURPOSE

To compare the yearly cost involved per patient in the use of magnetically controlled growing rod (MCGR) and traditional growing rods (TGRs) in the treatment of early onset scoliosis (EOS) and to assess the overall cost burden of MCGR with reference to patient and health-care infrastructure.

METHODS

For a hypothetical case of a 5-year-old girl with a diagnosis of EOS, a decision-tree model using TreeAge Software was developed to simulate annual health state transitions and compare the 8-year accumulative direct, indirect, and total cost among the four groups: (1) dual MCGRs with exchange every 2 years, (2) dual MCGRs with exchange every 3 years, (3) TGR with surgical distraction every year, and (4) TGR with surgical distraction every 6 months. Base-case values and ranges of clinical parameters reflecting complication rate after each type of surgical distraction were determined from a review of literature and expert opinion. Government gazette and expert opinion provided cost estimation of growing rods, surgeries, surgical complications, and routine follow-up. Microsimulation of 1000 individuals was conducted to test the variation in total direct costs (in 2016 Hong Kong dollars (HKD)) between individuals, and estimated the standard deviations of total direct costs for each group.

RESULTS

Over the projected treatment period, indirect costs incurred by patients and family were higher for the MCGR as compared to the TGR. However, the total costs incurred by MCGR groups (group 1: HKD164k; group 2: HKD138k) were lower than those incurred by TGR groups (group 3: HKD191k; group 4: HKD290k). Although the accumulative costs of three groups (TGR with distraction every year and MCGR replacing every 2 and 3 years) were approaching each other in the first 2 years after initial implantation, at year 3 the accumulative cost of MCGR exchange every 2 years was HKD36k more than the yearly TGR surgery due to the cost of implant exchange. The cost incurred by both the MCGR groups was less than that incurred by the TGR groups from year 4 to skeletal maturity.

CONCLUSIONS

The use of dual MCGRs, regardless of its 2- or 3-year exchange, was only cost saving and less expensive than the dual TGRs for EOS treatment from the fourth year of continuous treatment. Despite higher patient-related costs during MCGR treatment, it is important to consider the reduced risks and mental burden suffered by these children during repeat surgeries. With improved knowledge of the costs associated with long-term MCGR use, better constructed cost-effectiveness studies can be performed in the future.

Effectiveness of Schroth exercises during bracing in adolescent idiopathic scoliosis: results from a preliminary study-SOSORT Award 2017 Winner

BACKGROUND

Bracing has been shown to decrease significantly the progression of high-risk curves to the threshold for surgery in patients with adolescent idiopathic scoliosis (AIS), but the treatment failure rate remains high. There is evidence to suggest that Schroth scoliosis-specific exercises can slow progression in mild scoliosis. The aim of this study was to evaluate the efficacy of Schroth exercises in AIS patients with high-risk curves during bracing.

METHODS

A prospective, historical cohort-matched study was carried out. Patients diagnosed with AIS who fulfilled the Scoliosis Research Society (SRS) criteria for bracing were recruited to receive Schroth exercises during bracing. An outpatient-based Schroth program was given. Data for these patients were compared with a 1:1 matched historical control group who were treated with bracing alone. The assessor and statistician were blinded. Radiographic progression, truncal shift, and SRS-22r scores were compared between cases and controls.

RESULTS

Twenty-four patients (5 males and 19 females, mean age 12.3 ± 1.4 years) were included in the exercise group, and 24 patients (mean age 11.8 ± 1.1 years) were matched in the control group. The mean follow-up period for the exercise group was 18.1 ± 6.2 months. In the exercise group, spinal deformity improved in 17% of patients (Cobb angle improvement of ≥ 6°), worsened in 21% (Cobb angle increases of ≥ 6°), and remained stable in 62%. In the control group, 4% improved, 50% worsened, and 46% remained stable. In the subgroup analysis, 31% of patients who were compliant (13 cases) improved, 69% remained static, and none had worsened, while in the non-compliant group (11 cases), none had improved, 46% worsened, and 46% remained stable. Analysis of the secondary outcomes showed improvement of the truncal shift, angle of trunk rotation, the SRS function domain, and total scores in favor of the exercise group.

CONCLUSION

This is the first study to investigate the effects of Schroth exercises on AIS patients during bracing. Our findings from this preliminary study showed that Schroth exercise during bracing was superior to bracing alone in improving Cobb angles, trunk rotation, and QOL scores. Furthermore, those who were compliant with the exercise program had a higher rate of Cobb angle improvement. The results of this study form the basis for a randomized controlled trial to evaluate the effect of Schroth exercises during bracing in AIS.

TRIAL REGISTRATION

HKUCTR-2226. Registered 22 June 2017 (retrospectively registered).

Predictive factors for neurological deterioration after surgical decompression for thoracic ossified yellow ligament

PURPOSE

To investigate the rate and predictive factors of post-operative neurological deterioration in ossified yellow ligament (OYL) surgery.

METHODS

A retrospective review was conducted for all patients with thoracic OYL causing myelopathy requiring surgical decompression from January 1998 to December 2012. Clinical parameters under study included clinical presentation, distribution of OYL, pre-operative walking score, pre- and post-operative neurological status, status of intra-operative neurophysiological monitoring, and modified Japanese Orthopaedic Association (mJOA) score. Any complications were also recorded. All outcomes were measured at post-operative 1 week and at 2 years.

RESULTS

A total of 26 patients were included in this study. Most patients (92.3%) had Frankel grade D pre-operatively. The rate of neurological deterioration was 15.4% and was correlated with the presence of dural tear, extra-dural hematoma and spinal cord injury. Pre-operative walking score was prognostic of patients' walking ability in the post-operative period. Intra-operative monitoring of Somatosensory Evoked Potentials (SSEP) was found to be useful for monitoring spinal cord injury in OYL surgery, with a positive predictive value of 100% and a negative predictive value of 92.3%. The false negative rate of a SSEP signal drop was only 7.7% CONCLUSIONS: This is the first study exploring risk factors for post-operative neurological deterioration after surgery for thoracic OYL. The rate of neurological deficit is not small and prognostic factors for poor outcome include poor pre-operative walking score, presence of intra-operative dural tear, extra-dural hematoma and spinal cord injury, and intra-operative drop of SSEP signal.

Radiographic indices for lumbar developmental spinal stenosis

Background

Patients with developmental spinal stenosis (DSS) are susceptible to developing symptomatic stenosis due to pre-existing narrowed spinal canals. DSS has been previously defined by MRI via the axial anteroposterior (AP) bony spinal canal diameter. However, MRI is hardly a cost-efficient tool for screening patients. X-rays are superior due to its availability and cost, but currently, there is no definition of DSS based on plain radiographs. Thus, the aim of this study is to develop radiographic indices for diagnosing DSS.

Methods

This was a prospective cohort of 148 subjects consisting of patients undergoing surgery for lumbar spinal stenosis (patient group) and asymptomatic subjects recruited openly from the general population (control group). Ethics approval was obtained from the local institutional review board. All subjects underwent MRI for diagnosing DSS and radiographs for measuring parameters used for creating the indices. All measurements were performed by two independent investigators, blinded to patient details. Intra- and interobserver reliability analyses were conducted, and only parameters with near perfect intraclass correlation underwent receiver operating characteristic (ROC) analysis to determine the cutoff values for diagnosing DSS using radiographs.

Results

Imaging parameters from a total of 66 subjects from the patient group and 82 asymptomatic subjects in the control group were used for analysis. ROC analysis suggested sagittal vertebral body width to pedicle width ratio (SBW:PW) as having the strongest sensitivity and specificity for diagnosing DSS. Cutoff indices for SBW:PW were level-specific: L1 (2.0), L2 (2.0), L3 (2.2), L4 (2.2), L5 (2.5), and S1 (2.8).

Conclusions

This is the first study to define DSS on plain radiographs based on comparisons between a clinically relevant patient group and a control group. Individuals with DSS can be identified by a simple radiograph using a screening tool allowing for better cost-saving means for clinical diagnosis or research purposes.

The use of the distal radius and ulna classification for the prediction of growth: peak growth spurt and growth cessation

AIMS

We report the use of the distal radius and ulna (DRU) classification for the prediction of peak growth (PG) and growth cessation (GC) in 777 patients with idiopathic scoliosis. We compare this classification with other commonly used parameters of maturity.

PATIENTS AND METHODS

The following data were extracted from the patients' records and radiographs: chronological age, body height (BH), arm span (AS), date of menarche, Risser sign, DRU grade and status of the phalangeal and metacarpal physes. The mean rates of growth were recorded according to each parameter of maturity. PG was defined as the summit of the curve and GC as the plateau in deceleration of growth. The rates of growth at PG and GC were used for analysis using receiver operating characteristic (ROC) curves to determine the strength and cutoff values of the parameters of growth.

RESULTS

The most specific grades for PG using the DRU classification were radial grade 6 and ulnar grade 5, and for GC were radial grade 9 and ulnar grade 7. The DRU classification spanned both PG and GC, enabling better prediction of these clinically relevant stages than other methods. The rate of PG (≥ 0.7 cm/month) and GC (≤ 0.15 cm/month) was the same for girls and boys, in BH and AS measurements.

CONCLUSION

This is the first study to note that the DRU classification can predict both PG and GC, providing evidence that it may aid the management of patients with idiopathic scoliosis. Cite this article: Bone Joint J 2016;98-B:1689-96.

A rare postoperative complication of anterior lower thoracic instrumentation: diaphragmatic laceration with hemothorax

PURPOSE

To highlight the importance of preventing visceral injury due to prominent anterior implants at the spinal column.

METHODS

A 52-year-old man with cord compression was treated with a T9/10 discectomy and instrumented fusion via a right thoracotomy and trans-pleural approach. Postoperatively, he had improved lower limb numbness. However, after a bout of coughing, there was sudden increase in chest drain output, hemodynamic instability and massive fluid collection in the right chest cavity.

RESULTS

Emergency re-exploration of the thoracotomy was performed and a 6 cm laceration of the right postero-medial diaphragm was identified as the bleeding source and was found to be in close proximity with the locking nut of the anterior implants. The laceration was repaired and a soft synthetic patch was used to cover the implants. Postoperatively, the hemothorax resolved and the patient recovered from the neurological deficit.

CONCLUSIONS

Prevention of diaphragmatic injury can be performed using lower profile and less sharp-edged implants. Implant coverage with a soft synthetic material is necessary if unable to perform direct repair of the parietal pleura over the implants.

Frequent small distractions with a magnetically controlled growing rod for early-onset scoliosis and avoidance of the law of diminishing returns

PURPOSE

To assess the effect of frequent small distractions with a magnetically controlled growing rod (MCGR) on spinal length gain and achieved distraction length in children with early-onset scoliosis (EOS), and to determine whether the law of diminishing returns applies to this group of patients with MCGR.

METHODS

A consecutive series of 3 males and 4 females with EOS who underwent MCGR implantation at a mean age of 10.2 years and were followed up for a mean of 3.8 years were reviewed. Distraction was aimed at 2 mm monthly. The coronal Cobb angle, T1-S1 length gain, and achieved distraction length were measured at 6-monthly intervals.

RESULTS

The mean total number of distractions was 31. Four of the patients had problems that may have affected distractions. The mean coronal Cobb angle improved post-operatively and was maintained throughout the follow-up period. The mean T1-S1 length gain and achieved distraction length varied over the follow-up period and did not diminish with repeated lengthening.

CONCLUSIONS

Frequent small distractions with the MCGR for EOS enable T1-S1 and achieved distraction length gain without significant reduction in gain after repeated lengthening.

Classification of Schmorl's nodes of the lumbar spine and association with disc degeneration: a large-scale population-based MRI study

OBJECTIVE

Schmorl's nodes (SN) are highly associated with lumbar disc degeneration (DD). However, SN present with different morphologies/topographies that may be associated with varying degrees of DD. This study proposed a classification of SN to determine their morphological/topographical prevalence and association with the severity of DD.

METHODS

Sagittal T2-weighted MRIs were assessed to identify SN and additional imaging findings from L1-S1 in 2,449 individuals. SN characteristics were classified by six criteria: disc level; endplate involvement; shape; size; location of endplate zone; and the presence of marrow changes. Hierarchical clustering was performed to identify distinct SN characteristics with endplate patterns.

RESULTS

Good to excellent observer classification reliability was noted. SN most commonly presented at the L1 and L2 disc levels, and entailed one-third of the endplate, predominantly the middle zone. Round shape (39.2%) was the most common SN shape. Four specific SN and endplate linkage patterns were identified. 8.3% of identified SN (n = 960) were "Atypical SN". Multivariable regression showed that "Typical SN" and "Atypical SN", depending on levels, were associated with an adjusted 2- to 4-fold and a 5- to 13-fold higher risk of increased severity of DD, respectively (p < 0.05).

CONCLUSIONS

This is the first large-scale magnetic resonance imaging (MRI) study to propose a novel SN classification. Specific SN-types were identified, which were associated with more severe DD. This study further broadens our understanding of the role of SN and degrees of DD, further expanding on the SN phenotyping that can be internationally adopted for utility assessment.

Matrix metalloproteinase 12 is an indicator of intervertebral disc degeneration co-expressed with fibrotic markers

OBJECTIVE

Recent evidence suggests a role of fibrogenesis in intervertebral disc (IVD) degeneration. We aim to explore if fibrotic genes may serve as IVD degeneration indicators, and if their expression is associated with myofibroblast activity.

DESIGN

Transcriptional expression of fibrosis markers (COL1A1, COL3A1, FN1, HSP47, MMP12, RASAL1) were analyzed in degenerated (D) and non-degenerated (ND) human nucleus pulposus (NP) and annulus fibrosus (AF) cells, along with traditional (SOX9, ACAN) and newly established degeneration markers (CDH2, KRT19, KRT18, FBLN1, MGP, and COMP). Protein expression was investigated by immunohistochemistry in human IVDs, and in rodent IVDs undergoing natural ageing or puncture-induced degeneration. Co-expression with myofibroblast markers was examined by double staining on human and rat specimens. Disc degeneration severity and extent of fibrosis were determined by histological scoring and picrosirius red staining respectively.

RESULTS

Human D-NP showed more intensive staining for picrosirius red than ND-NP. Among the genes examined, D-NP showed significantly higher MMP12 expression along with lower KRT19 expression. Protein expression analysis revealed increased MMP12(+) cells in human D-IVD. Histological scoring indicated mild degeneration in the punctured rat discs and discs of ageing mouse. Higher MMP12 positivity was found in peripheral NP and AF of the degenerative rat discs and in NP of the aged mice. In addition, human D-NP and D-AF showed increased α-SMA(+) cells, indicating enhanced myofibroblast activity. MMP12 was found co-expressed with α-SMA, FSP1 and FAP-α in human and rat degenerative IVDs.

CONCLUSIONS

Our study suggests that in addition to a reduced KRT19 expression, an increased expression of MMP12, a profibrotic mediator, is characteristic of disc degenerative changes. Co-expression study indicates an association of the increased MMP12 positivity with myofibroblast activity in degenerated IVDs. Overall, our findings implicate an impact of MMP12 in disc cell homeostasis. The precise role of MMP12 in IVD degeneration warrants further investigation.

Psychometric validation of the EuroQoL 5-Dimension 5-Level (EQ-5D-5L) in Chinese patients with adolescent idiopathic scoliosis

Background

Scoliosis is a common spinal deformity that occurs often during adolescence. Previous studies suggested that adolescent idiopathic scoliosis (AIS) patients can have various aspects of their lives being affected, due to disease presentation and/or treatment received. It is important to define a reliable instrument based on which the affected patients’ health-related quality of life can be assessed. This study aims to assess the validity, reliability and sensitivity of the EuroQoL 5-dimension 5-level (EQ-5D-5L) in Chinese patients with AIS.

Methods

Adolescent idiopathic scoliosis patients of Chinese descent were prospectively recruited to complete both the traditional Chinese versions of the EQ-5D-5L and the refined Scoliosis Research Society-22 (SRS-22r) questionnaires. Patients’ demographic profiles and corresponding clinical parameters including treatment modalities, spinal curve pattern and magnitude, and duration of bracing were recorded. Telephone interviews were then conducted at least two weeks later for the assessment of test-retest reliability. Statistical analysis was performed: construct validity of the EQ-5D-5L domains were assessed using Spearman’s correlation test against the SRS-22r; whereas intra-class correlation coefficient (ICC) was used to assess the test-retest reliability, and agreement over the test-retest period was expressed in percentages. Also, the sensitivity of the EQ-5D-5L in differentiating various clinical known groups was determined by effect size, independent t-test and analysis of variance.

Results

A total of 227 AIS patients were recruited. Scores of domains of the EQ-5D-5L correlated significantly (r: 0.57-0.74) with the scores of the SRS-22r domains that were intended to measure similar constructs, supporting construct validity. The EQ-5D-5L domain responses and utility scores showed good test-retest reliability (ICC: 0.777; agreement: 76.4 -98.1 %). Internal consistency was good (Cronbach’s α: 0.78) for the EQ-5D-5L utility score. The EQ-5D-5L utility score was sensitive in detecting differences between subjects who had different treatment modalities and bracing duration, but not for curve pattern and its magnitude.

Conclusions

The EQ-5D-5L is found to be a valid, reliable and sensitive measure to assess the health-related quality of life in Chinese AIS patients. This potentiates the possibility of utilizing the EQ-5D-5L to estimate AIS patients’ health-related quality of life, based on which the outcome of various treatment options can eventually be evaluated.

Electronic supplementary material

The online version of this article (doi:10.1186/s13013-016-0083-x) contains supplementary material, which is available to authorized users.

Fibrotic-like changes in degenerate human intervertebral discs revealed by quantitative proteomic analysis

OBJECTIVE

Intervertebral disc degeneration (IDD) can lead to symptomatic conditions including sciatica and back pain. The purpose of this study is to understand the extracellular matrix (ECM) changes in disc biology through comparative proteomic analysis of degenerated and non-degenerated human intervertebral disc (IVD) tissues of different ages.

DESIGN

Seven non-degenerated (11-46 years of age) and seven degenerated (16-53 years of age) annulus fibrosus (AF) and nucleus pulposus (NP) samples were used. Proteins were extracted using guanidine hydrochloride, separated from large proteoglycans (PGs) by caesium chloride (CsCl) density gradient ultracentrifugation, and identified using liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS). For quantitative comparison, proteins were labeled with iTRAQ reagents. Collagen fibrils in the NP were assessed using scanning electron microscopy (SEM).

RESULTS

In the AF, quantitative analysis revealed increased levels of HTRA1, COMP and CILP in degeneration when compared with samples from older individuals. Fibronectin showed increment with age and degeneration. In the NP, more CILP and CILP2 were present in degenerated samples of younger individuals. Reduced protein solubility was observed in degenerated and older non-degenerated samples correlated with an accumulation of type I collagen in the insoluble fibers. Characterization of collagen fibrils in the NP revealed smaller mean fibril diameters and decreased porosity in the degenerated samples.

CONCLUSIONS

Our study identified distinct matrix changes associated with aging and degeneration in the intervertebral discs (IVDs). The nature of the ECM changes, together with observed decreased in solubility and changes in fibril diameter is consistent with a fibrotic-like environment.

Clinical utility of ultrasound to prospectively monitor distraction of magnetically controlled growing rods

BACKGROUND CONTEXT

Growing rods are commonly used for surgical treatment of skeletally immature patients with scoliosis, but require repeated surgeries for distractions and are fraught with complications. As an alternative, the use of magnetically controlled growing rods (MCGR) allows for more frequent non-invasive distractions to mimic normal growth. However, more plain radiographs are needed to monitor increased distraction frequency, thereby increasing ionizing radiation exposure to the developing child. The use of ultrasound, which emits no radiation, has been found in a cross-sectional study to be reliable in measuring MCGR distractions.

PURPOSE

The study aims to address the prospective clinical utility of ultrasound compared with plain radiographs for assessing MCGR distractions.

STUDY DESIGN

This is a prospective study.

PATIENT SAMPLE

The study includes patients with early-onset scoliosis undergoing distractions after MCGR implant.

OUTCOME MEASURES

The distraction length on plain radiographs and ultrasound was measured.

METHODS

This is a prospective study of patients treated with MCGR. Patients with both single- and dual-rod systems were included. Outpatient distractions were performed at monthly intervals, targeting 2 mm of distraction on each occasion. Assessment of distraction length was monitored by ultrasound at each visit; plain radiographs were taken every 6 months and were compared with ultrasound measurements.

RESULTS

Nine patients (5 female, 4 male), with a mean of 29 distractions (standard deviation [SD] ±14.3), were recruited. The mean distracted length per 6 months was 5.7 mm (SD ±3.6 mm) on plain radiographs and 5.2 mm (SD ±3.9 mm) on ultrasound for the concave rod, and 6.1 mm (SD ±3.6 mm) on plain radiographs and 5.9 mm (SD ±3.8 mm) on ultrasound for the convex rod. Excellent inter- and intra-rater reliabilities were observed for radiographic and ultrasound measurements. An excellent correlation was noted between the two imaging modalities (r=0.93; p<.0001).

CONCLUSIONS

This is the first prospective study to validate that ultrasound assessment of MCGR distraction lengths was highly comparable with that of plain radiographs. The present study has verified that ultrasound can be used to document length changes by distraction over time and that it had high clinical utility. Ultrasound can be a reliable alternative to plain radiographs, thereby avoiding radiation exposure and its potential detrimental sequelae in the developing child.

An alternative to a randomised control design for assessing the efficacy and effectiveness of bracing in adolescent idiopathic scoliosis

Randomised controlled trials (RCTs) that assessed the efficacy of bracing for adolescent idiopathic scoliosis have suffered from small sample sizes, low compliance and lack of willingness to participate. The aim of this study was to assess the feasibility of a comprehensive cohort study for evaluating both the efficacy and the effectiveness of bracing in patients with adolescent idiopathic scoliosis. Patients with curves at greater risk of progression were invited to join a randomised controlled trial. Those who declined were given the option to remain in the study and to choose whether they wished to be braced or observed. Of 87 eligible patients (5 boys and 63 girls) identified over one year, 68 (78%) with mean age of 12.5 years (10 to 15) consented to participate, with a mean follow-up of 168 weeks (0 to 290). Of these, 19 (28%) accepted randomisation. Of those who declined randomisation, 18 (37%) chose a brace. Patients who were more satisfied with their image were more likely to choose bracing (Odds Ratio 4.1; 95% confidence interval 1.1 to 15.0; p = 0.035). This comprehensive cohort study design facilitates the assessment of both efficacy and effectiveness of bracing in patients with adolescent idiopathic scoliosis, which is not feasible in a conventional randomised controlled trial.

Enrichment of committed human nucleus pulposus cells expressing chondroitin sulfate proteoglycans under alginate encapsulation

OBJECTIVE

Intervertebral disc (IVD) degeneration is associated with a malfunction of the nucleus pulposus (NP). Alginate culturing provides a favorable microenvironment for the phenotypic maintenance of chondrocyte-like NP cells. However, NP cells are recently evidenced to present heterogeneous populations, including progenitors, fibroblastic cells and primitive NP cells. The aim of this study is to profile the phenotypic changes of distinct human NP cells populations and describe the dynamic expression of chondroitin sulfate glycosaminoglycans (CS-GAGs) in extended alginate encapsulation.

METHOD

Non-degenerated (ND-NPC) and degenerated (D-NPC) NP cells were expanded in monolayers, and subject to 28-day culture in alginate after serial passaging. CS-GAG compositional expression in monolayer-/alginate-cultured NP cells was evaluated by carbohydrate electrophoresis. Cellular phenotypic changes were assessed by immunologic detection and gene expression analysis.

RESULTS

Relative to D-NPC, ND-NPC displayed remarkably higher expression levels of chondroitin-4-sulfate GAGs over the 28-day culture. Compared with monolayer culture, ND-NPC showed increased NP marker expression of KRT18, KRT19, and CDH2, as well as chondrocyte markers SOX9 and MIA in alginate culture. In contrast, expression of fibroblastic marker COL1A1, COL3A1, and FN1 were reduced. Interestingly, ND-NPC showed a loss of Tie2+ but gain in KRT19+/CD24+ population during alginate culture. In contrast, D-NPC showed more consistent expression levels of NP surface markers during culture.

CONCLUSION

We demonstrate for the first time that extended alginate culture selectively enriches the committed NP cells and favors chondroitin-4-sulfate proteoglycan production. These findings suggest its validity as a model to investigate IVD cell function.

Insertional torque and pullout strength of pedicle screws with or without repositioning: a porcine study

PURPOSE. To evaluate the insertion torque and pullout strength of pedicle screws with or without repositioning. METHODS. 20 fresh porcine lumbar vertebrae of similar size were used. The entry point was at the site just lateral and distal to the superior facet joint of the vertebra, and to a depth of 35 mm. A 6.2-mm-diameter, 35-mm-long pedicle screw was inserted parallel to the superior end plate on one side as control. On the other side, an identical screw was first inserted 10º caudal to the superior end plate, and then repositioned parallel to the superior end plate. The insertional torque and pullout strength were measured. RESULTS. Three of the specimens were excluded owing to pedicle fractures during the pullout test. Repositioned pedicle screws were significantly weaker than controls in terms of the maximum insertional torque (3.20 ± 0.28 vs. 2.04 ± 0.28 Nm, 36% difference, p<0.01) and pullout strength (1664 ± 378 vs.1391 ± 295 N, p<0.01). CONCLUSION. Repositioning pedicle screws should be avoided, especially when the pedicle wall is breached. If repositioning is deemed necessary, augmentation with polymethyl methacrylate or a screw with a larger diameter should be considered.

The effect of excision of the posterior arch of C1 on C1/C2 fusion using transarticular screws

Transarticular screw fixation with autograft is an established procedure for the surgical treatment of atlantoaxial instability. Removal of the posterior arch of C1 may affect the rate of fusion. This study assessed the rate of atlantoaxial fusion using transarticular screws with or without removal of the posterior arch of C1. We reviewed 30 consecutive patients who underwent atlantoaxial fusion with a minimum follow-up of two years. In 25 patients (group A) the posterior arch of C1 was not excised (group A) and in five it was (group B). Fusion was assessed on static and dynamic radiographs. In selected patients CT imaging was also used to assess fusion and the position of the screws. There were 15 men and 15 women with a mean age of 51.2 years (23 to 77) and a mean follow-up of 7.7 years (2 to 11.6). Stable union with a solid fusion or a stable fibrous union was achieved in 29 patients (97%). In Group A, 20 patients (80%) achieved a solid fusion, four (16%) a stable fibrous union and one (4%) a nonunion. In Group B, stable union was achieved in all patients, three having a solid fusion and two a stable fibrous union. There was no statistically significant difference between the status of fusion in the two groups. Complications were noted in 12 patients (40%); these were mainly related to the screws, and included malpositioning and breakage. The presence of an intact or removed posterior arch of C1 did not affect the rate of fusion in patients with atlantoaxial instability undergoing C1/C2 fusion using transarticular screws and autograft.

Photochemically crosslinked collagen annulus plug: a potential solution solving the leakage problem of cell-based therapies for disc degeneration

Intra-disc injection of mesenchymal stem cells (MSCs) to treat disc degeneration may lead to unfavorable complications, particularly osteophyte formation. Development of an effective method to block the injection portal, prevent the leakage of injected cells and materials and, hence, prevent osteophyte formation is of the utmost importance before MSC-based therapies can be applied in a clinical setting. Here we seek to alleviate the cell leakage problem and the associated complication osteophyte formation by developing an injectable annulus plug to block the injection portal during intra-disc delivery. Specifically, we fabricated a needle-shaped collagen plug by photochemical crosslinking and successfully delivered it intra-discally, in association with MSCs in collagen microsphere carriers, using a custom-made delivery device. The mechanical performance of the plug and its effectiveness in reducing cell leakage were evaluated ex vivo under compression and in torsion push-out tests. The results demonstrate that the plug survived physiologically relevant loadings and significantly reduced leakage and enhanced retention of the injected materials. Finally, a pilot in vivo study in rabbits was conducted to evaluate the performance of the plug. Microcomputed tomography imaging and histology revealed that the plug significantly reduced osteophyte formation. This work suggests the potential of the annulus plug as an adjunct or annulus closure device for intra-disc delivery of cells and materials.

Effects of nucleus pulposus cell-derived acellular matrix on the differentiation of mesenchymal stem cells

Recent attempts to treat disc degeneration with mesenchymal stem cells (MSCs) showed encouraging results. Differentiating MSCs towards nucleus pulposus cell (NPC)-like lineages represents a speculative mechanism. Niche factors including hypoxia, growth factors and cell-cell interactions have been suggested but the matrix niche factor has not been studied. Our collagen microencapsulation provides a 3D model to study matrix niche as it enables the encapsulated cells to remodel the template matrix. We previously demonstrated the chondro-inductive role of of chondrocytes-derived matrix in MSCs and showed that NPCs maintained their phenotype and remodeled the template matrix of collagen microspheres into a glycosaminoglycan (GAG)-rich one. Here we aim to study the effects of NPC-derived matrix on MSC differentiation towards NPC-like lineages by firstly producing an NPC-derived matrix in collagen microspheres, secondly optimizing a decellularization protocol to discard NPCs yet retaining the matrix, thirdly repopulating the acellular NPC-derived matrix with MSCs and fourthly evaluating their phenotype. Finally, we injected these microspheres in a pilot rabbit disc degeneration model. Results showed that NPCs survived, maintained their phenotypic markers and produced GAGs. A decellularization protocol with maximal removal of the NPCs, minimal loss in major matrix components and partial retention of NPC-specific markers was identified. The resulting acellular matrix supported MSC survival and matrix production, and up-regulated the gene expression of NPC markers including type II collagen and glypican 3. Finally, injection of MSC in these microspheres in rabbit degenerative disc better maintained hydration level with more pronounced staining of GAGs and type II collagen than controls.

A new mechanism of injury in ankylosing spondylitis: non-traumatic hyperextension causing atlantoaxial subluxation

Ankylosing spondylitis (AS) is a progressive multisystem chronic inflammatory disorder. The hallmark of this pathological process is a progressive fusion of the zygapophyseal joints and disc spaces of the axial skeleton, leading to a rigid kyphotic deformity and positive sagittal balance. The ankylosed spine is unable to accommodate normal mechanical forces, rendering it brittle and susceptible to injury. Traumatic hyperextension injury of the cervical spine leading to atlantoaxial subluxation (AAS) in AS patients can often be fatal. We report a non-traumatic mechanism of injury in AS progressing to AAS attributable to persistent hyperextension, which resulted in fatal migration of C2 through the foramen magnum.

The role of cryopreservation in the biomechanical properties of the intervertebral disc

Implantation of intervertebral disc (IVD) allograft or tissue engineered disc constructs in the spine has emerged as an alternative to artificial disc replacement for the treatment of severe degenerative disc disease (DDD). Establishment of a bank of cryopreserved IVD allografts enables size matching and facilitates logistics for effective clinical management. However, the biomechanical properties of cryopreserved IVDs have not been previously reported. This study aimed to assess if cryopreservation with different concentrations of cryopreservant agents (CPA) would affect the dynamic viscoelastic properties of the IVD. Whole porcine lumbar IVDs (n = 40) were harvested and processed using various concentrations of CPA, 0 % CPA, 10 % CPA and 20 % CPA. The discs were cryopreserved using a stepwise freezing protocol and stored in liquid nitrogen. After four weeks of storage, the cryopreserved IVDs were quickly thawed at 37 °C for dynamic viscoelastic testing. The apparent modulus, elastic modulus (G'), viscous modulus (G") and loss modulus (G"/G') were calculated and compared to a fresh control group. Cryopreserved IVD without cryopreservants was significantly stiffer than the control. In the dynamic viscoelastic testing, cryopreservation with the use of CPA was able to preserve both G' and G" of an IVD. No significant differences were found between fresh IVD and IVD cryopreserved with 10 % CPA or 20 % CPA. This study demonstrated that CPAs at an optimal concentration could preserve the mechanical properties of the IVD allograft and can provide further credence for the application of long-term storage of IVD allografts for disc transplantation or tissue engineered construct applications.

Fabrication of micropillar substrates using replicas of alpha-particle irradiated and chemically etched PADC films

We proposed a simple method to fabricate micropillar substrates. Polyallyldiglycol carbonate (PADC) films were irradiated by alpha particles and then chemically etched to form a cast with micron-scale spherical pores. A polydimethylsiloxane (PDMS) replica of this PADC film gave a micropillar substrate with micron-scale spherical pillars. HeLa cells cultured on such a micropillar substrate had significantly larger percentage of cells entering S-phase, attached cell numbers and cell spreading areas.

A multidisciplinary rehabilitation programme for patients with chronic low back pain: a prospective study

PURPOSE

To examine the effectiveness of a multidisciplinary rehabilitation programme for patients with chronic low back pain in Hong Kong, and to identify factors associated with work resumption.

METHODS

57 men and 8 women aged 20 to 56 (mean, 39) years who had a more than 3-month history of low back pain and were unresponsive to more than 6 months of conventional treatment participated in a 14-week multidisciplinary rehabilitation programme involving physical conditioning, work conditioning, and work readiness. Training protocols entailed flexibility and endurance training, hydrotherapy, weight lifting, and work stimulation. Patients were assessed at baseline (week 1), week 7, week 14, and month 6 with regard to the intensity of low back pain, self-perceived disability, range of lumbar motion, isoinertial performance of the trunk muscles, and depression level. Patient demographics that influenced work resumption were identified using a prediction model. Patients who did and did not return to work were compared.

RESULTS

Of the 54 patients who completed all follow-up assessments, 28 returned to work and 26 did not. The latter was significantly older (37 vs. 42 years, p=0.038) and absent from work longer (11 vs. 22 months, p=0.029) than the former. The rehabilitation programme helped patients regain physical function and the ability to work. Patients who returned to work showed greater improvement in self-perceived disability and physical function.

CONCLUSION

This rehabilitation programme facilitated regain of physical functioning and the ability to return to work. The pre-programme employment status, duration of absence from work, and patient age were the most important predictors for work resumption.

Biochemical characterization of the cell-biomaterial interface by quantitative proteomics

Surface topography and texture of cell culture substrata can affect the differentiation and growth of adherent cells. The biochemical basis of the transduction of the physical and mechanical signals to cellular responses is not well understood. The lack of a systematic characterization of cell-biomaterial interaction is the major bottleneck. This study demonstrated the use of a novel subcellular fractionation method combined with quantitative MS-based proteomics to enable the robust and high-throughput analysis of proteins at the adherence interface of Madin-Darby canine kidney cells. This method revealed the enrichment of extracellular matrix proteins and membrane and stress fibers proteins at the adherence surface, whereas it shows depletion of extracellular matrix belonging to the cytoplasmic, nucleus, and lateral and apical membranes. The asymmetric distribution of proteins between apical and adherence sides was also profiled. Apart from classical proteins with clear involvement in cell-material interactions, proteins previously not known to be involved in cell attachment were also discovered.

A meta-analysis of the clinical effectiveness of school scoliosis screening

STUDY DESIGN

A meta-analysis that systematically reviewed the evaluation studies of a scoliosis screening program reported in the literature.

OBJECTIVE

To evaluate the best current evidence on the clinical effectiveness of school screening for adolescent idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

The use of school scoliosis screening is controversial, and its clinical effectiveness has been diversely reported.

METHODS

Data sources included 3 databases, namely, PubMed, Google scholar, CINAHL database, and the references from identified reviews and studies. Studies were included if: (1) they adopted a retrospective cohort design; (2) were screened using either the forward bending test (FBT), angle of trunk rotation, or Moiré topography; (3) reported results of screening tests and radiographic assessments; (4) screened adolescents only; (5) reported the incidence of curves with a minimum Cobb angle of 10 degrees or greater; and (6) reported the number of referrals for radiography. Reviews, comments, case studies, and editorials were excluded.

RESULTS

Thirty-six studies, including 34 from the 775 initially identified studies and 2 from the references, met the selection criteria. The pooled referral rate for radiography was 5.0%, and the pooled positive predictive values for detecting curves > or =10 degrees , curves > or =20 degrees , and treatment were 28.0%, 5.6%, and 2.6%, respectively. There was substantial heterogeneity across studies. Meta-regression showed that programs using the FBT alone reported a higher referral rate (odds ratio [OR] = 2.91) and lower positive predictive values for curves > or =10 degrees (OR = 0.49) and curves > or =20 degrees (OR = 0.34) than programs using other tests. Only one small study followed students until skeletal maturity and reported the sensitivity of screening; however, the specificity was not reported. No severe publication bias was noted.

CONCLUSION

The use of the FBT alone in school scoliosis screening is insufficient. We need large, retrospective cohort studies with sufficient follow-up to properly assess the clinical effectiveness of school scoliosis screening.