Posterior spinal fusion for scoliosis in duchenne muscular dystrophy diminishes the rate of respiratory decline

Respiratory comorbidities and treatments in Duchenne muscular dystrophy: impact on life expectancy and causes of death

BACKGROUND

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder with progressive decline of pulmonary function increasing the risk of early mortality. The aim of this study was to explore the respiratory-related comorbidities, and the effect of these comorbidities and treatments on life expectancy and causes of death.

METHODS

All male patients living in Sweden with DMD, born and deceased 1970-2019, were included. Data regarding causes of death were collected from the Cause of Death Registry and cross-checked with the medical records along with diagnostics and relevant clinical features.

RESULTS

Hundred and twenty nine patients were included with a median lifespan of 24.3 years. Acute respiratory failure accounted for 63.3% of respiratory-related causes of death. 70.1% suffered at least one pneumonia, with first episode at a median age of 17.8 years. Hypoventilation was found in 73.0% with onset at 18.1 years. 60.5% had their first pneumonia before established hypoventilation. Age at onset of hypoventilation showed a strong correlation with age at first pneumonia. First pneumonia and scoliosis non-treated with scoliosis surgery increased the risk of dying of respiratory-related causes. In 10% of the patients, first pneumonia resulted in acute tracheostomy or early death. Patients treated with assisted ventilation had higher life expectancy compared to untreated patients.

CONCLUSIONS

Our results highlight the importance of identifying subclinical hypoventilation in a timely manner and the importance of an active treatment regime upon clinical signs of pneumonia.

Sleep in pediatric neuromuscular disorders

Sleep disordered breathing (SDB) is prevalent among children with neuromuscular disorders (NMD). The combination of respiratory muscle weakness, altered drive, and chest wall distortion due to scoliosis make sleep a stressful state in this population. Symptomatology can range from absent to snoring, nocturnal awakenings, morning headaches, and excessive daytime sleepiness. Sequelae of untreated SDB includes cardiovascular effects, metabolic derangements, and neurocognitive concerns which can be compounded by those innate to the NMD. The clinician should have a low threshold for obtaining polysomnography and recognize the nuances of individual disorders due to disproportionately impacted muscle groups such as hypoventilation in ambulating patients from diaphragm weakness. Non-invasive or invasive ventilation are the mainstay of treatment. In this review we explore the diagnosis and treatment of SDB in children with various NMD.

Distal fusion in Duchenne scoliosis: the relevance of preoperative pelvic obliquity. A case series study

PURPOSE

The aim of this study was to determine clinical and radiographic outcomes for Duchenne Muscular Dystrophy (DMD) patients who underwent posterior spinal fusion from T2/3 to L5 (without pelvic fixation), at this single centre.

METHODS

From January 2012 to January 2020, 29 consecutive DMD scoliosis patients underwent posterior spinal fusion using pedicle screws from T2/3 to L5 in a single center with a minimum of 3 years follow-up (FU). Radiologic measurements and chart review were performed.

RESULTS

Twenty nine patients aged 14 ± 1.5 years were included. No patient was lost to FU. All patients had significant correction in Cobb angle, pelvic obliquity (PO) and lumbar lordosis (LL), without loss of correction at last FU. The mean values for preoperative, immediate postoperative and last FU were CA 62o, 15o and 17o, PO: 21o, 8o and 9o; and LL 10o, -41o and -41o respectively. Correction in CA was independent of any variable analysed including implant density, rod diameter, traction, or bone density. Regarding PO, it was inversely related to age and independent of all other variables. Factors associated with postoperative complications were age and respiratory function.

CONCLUSIONS

It appears from our results that pelvic fixation might not always be required in DMD scoliosis surgery, when using pedicle screws with lowest instrumented vertebra at L5. However, larger preoperative PO values can be related with residual PO. It seems that probably related to the underlying condition, early surgery may decrease incidence of complications.

LEVEL OF EVIDENCE

IV.

Surgical and long-term functional outcomes of patients with Duchenne muscular dystrophy following spinal deformity correction

BACKGROUND

Life expectancy in patients with Duchenne muscular dystrophy (DMD) has improved due to advances in medical care. DMD patients develop progressive spinal deformity after loss of ambulatory function and onset of wheelchair dependence for mobility. There is limited published data on the effect of spinal deformity correction on long-term functional outcomes, quality of life (QoL), and satisfaction in DMD patients.

AIM

To investigate the long-term functional outcomes following spinal deformity correction in DMD patients.

METHODS

This was a retrospective cohort study from 2000-2022. Data was collected from hospital records and radiographs. At follow-up, patients completed the muscular dystrophy spine questionnaire (MDSQ). Statistical analysis was performed by linear regression analysis and ANOVA to analyse clinical and radiographic factors significantly associated with MDSQ scores.

RESULTS

Forty-three patients were included with mean age 14.4 years at surgery. Spino-pelvic fusion was performed in 41.9% of patients. Mean surgical time was 352.1 min and mean blood loss was 36% of estimated total blood volume. Mean hospital stay was 14.1 d. Postoperative complications occurred in 25.6% of patients. Mean preoperative scoliosis was 58°, pelvic obliquity 16.4°, thoracic kyphosis 55.8°, lumbar lordosis 11.1°, coronal balance 3.8 cm, and sagittal balance + 6.1 cm. Mean surgical correction of scoliosis was 79.2% and of pelvic obliquity was 80.8%. Mean follow-up was 10.9 years (range: 2-22.5). Twenty-four patients had died at follow-up. Sixteen patients completed the MDSQ at mean age 25.4 years (range 15.2-37.3). Two patients were bed-ridden and 7 were on ventilatory support. Mean MDSQ total score was 38.1. All 16 patients were satisfied with the results of spinal surgery and would choose surgery again if offered. Most patients (87.5%) reported no severe back pain at follow-up. Factors significantly associated with functional outcomes (MDSQ total score) included greater duration of post-operative follow-up, age, scoliosis postoperatively, correction of scoliosis, increased lumbar lordosis postoperatively, and greater age at loss of independent ambulation.

CONCLUSION

Spinal deformity correction in DMD patients leads to positive long-term effects on QoL and high patient satisfaction. These results support spinal deformity correction to improve long-term QoL in DMD patients.

Degree of Postoperative Curve Correction Decreases Risks of Postoperative Pneumonia in Patients Undergoing Both Fusion and Growth-friendly Surgical Treatment of Neuromuscular Scoliosis

INTRODUCTION

Due to a combination of poor respiratory muscle control and mechanical lung compression secondary to spine and chest wall deformities, patients with neuromuscular (NM) early-onset scoliosis (EOS) are at a high risk for pulmonary complications including pneumonia. The purpose of this study is to examine the effect of surgical intervention on the prevalence and risk of postoperative pneumonia in patients with NM EOS.

METHODS

In this retrospective cohort study, pediatric (18 y old and below) patients with NM EOS undergoing index fusion or growth-friendly instrumentation from 2000 to 2018 were identified. Patients were then categorized into 2 groups: those with ≥50% curve correction and those with <50% curve correction of the coronal deformity at the first postoperative visit. The primary outcome of interest was postoperative pneumonia occurring between 3 weeks and 2 years postoperatively. Manual chart review was supplemented with phone call surveys to ensure all occurrences of preoperative/postoperative pneumonia (ie, in-institution and out-of-institution visits) were accounted for.

RESULTS

A total of 35 patients (31% female, age at surgery: 10.3±4.3 y) with NM EOS met inclusion criteria. Twenty-three (66%) patients experienced at least 1 case of preoperative pneumonia. Twenty-six (74%) patients had ≥50% and 9 (26%) patients had <50% immediate postoperative curve correction. In total, 12 (34%) patients experienced at least 1 case of postoperative pneumonia (7 in-institution, 5 out-of-institution). Seven (27%) patients with ≥50% curve correction versus 5 (56%) with <50% curve correction experienced postoperative pneumonia. Relative risk regression demonstrated that patients with <50% curve correction had increased risk of postoperative pneumonia by 2.1 times compared with patients with ≥50% curve correction (95% confidence interval: 0.9; 4.9, P =0.099).

CONCLUSION

The prevalence of preoperative and postoperative pneumonia is high in patients with NM EOS. This study presents preliminary evidence suggesting that percent curve correction is associated with the occurrence of postoperative pneumonia in patients with NM EOS undergoing surgical correction.

Routine lung volume recruitment in boys with Duchenne muscular dystrophy: a randomised clinical trial

BACKGROUND

Impaired cough results in airway secretion retention, atelectasis and pneumonia in individuals with Duchenne muscular dystrophy (DMD). Lung volume recruitment (LVR) stacks breaths to inflate the lungs to greater volumes than spontaneous effort. LVR is recommended in DMD clinical care guidelines but is not well studied. We aimed to determine whether twice-daily LVR, compared with standard of care alone, attenuates the decline in FVC at 2 years in boys with DMD.

METHODS

In this multicentre, assessor-blinded, randomised controlled trial, boys with DMD, aged 6-16 years with FVC >30% predicted, were randomised to receive conventional treatment or conventional treatment plus manual LVR twice daily for 2 years. The primary outcome was FVC % predicted at 2 years, adjusted for baseline FVC % predicted, age and ambulatory status. Secondary outcomes included change in chest wall distensibility (maximal insufflation capacity minus FVC) and peak cough flow.

RESULTS

Sixty-six boys (36 in LVR group, 30 in control) were evaluated (median age (IQR): 11.5 years (9.5-13.5), median baseline FVC (IQR): 85% predicted (73-96)). Adjusted mean difference in FVC between groups at 2 years was 1.9% predicted (95% CI -6.9% to 10.7%; p=0.68) in the direction of treatment benefit. We found no differences in secondary outcomes.

CONCLUSION

There was no difference in decline in FVC % predicted with use of twice-daily LVR for boys with DMD and relatively normal lung function. The burden associated with routine LVR may outweigh the benefit. Benefits of LVR to maintain lung health in boys with worse baseline lung function still need to be clarified.

TRIAL REGISTRATION NUMBER

NCT01999075.

Short-term effect and effect on rate of lung function decline after surgery for neuromuscular or syndromic scoliosis

INTRODUCTION

Understanding the impact of scoliosis surgery on lung function is important for counseling patients about risks and benefits of surgery. We prospectively compared the trends in lung function test (LFT) results before and after scoliosis surgery in children with neuromuscular diseases or dysmorphic syndromes. We hypothesized a stabilization.

METHODS

We prospectively included children with neuromuscular or syndromic scoliosis able to perform LFTs. We studied (forced) vital capacity ([F]VC), ratio of forced expiratory volume in 1 s (FEV₁ ) and FVC, and peak expiratory flow (PEF). Preoperative LFT results were compared with results 3-4 months after surgery. The mean monthly change in LFT results up to 2 years after surgery was compared with the preoperative natural history using linear mixed-effects models.

RESULTS

We included 43 patients. No significant change was observed in absolute values of (F)VC, FEV₁ /FVC, and PEF before and after surgery. In 23 neuromuscular patients median standardized VC, FVC, and PEF decreased significantly after surgery from 43% to 33%, 42% to 31%, and 51% to 40%, respectively. In 20 syndromic patients, median FVC decreased from 68% to 65%. The monthly rate of change in FVC did not change significantly in both groups with a mean difference of 0.18% (95% CI: -0.27, -0.61) and -0.44% (95% CI: -1.05, 0.16).

CONCLUSION

No stabilization of lung function 3-4 months after scoliosis surgery was observed in children with neuromuscular and syndromic scoliosis with restrictive lung function disease. The effect on the rate of lung function decline remains inconclusive.

Protocol-driven early tracheal extubation in patients with flaccid neuromuscular scoliosis and pre-existing lung disease

PURPOSE

To review the results of a postoperative respiratory pathway for patients with muscular dystrophy (MD) and spinal muscular atrophy (SMA) undergoing spinal surgery.

METHODS

With IRB approval, a retrospective review was done on all patients with SMA and MD undergoing spinal surgery on a neuromuscular protocol. Baseline demographics, perioperative results, and long-term outcomes were collected. Per the protocol, patients remained intubated after surgery and were transported to the intensive care unit (ICU) for extubation. We present the results of protocol implementation and compare patients with MD to those with SMA.

RESULTS

Twenty-four patients were treated using the protocol. Average age was 13.1 years. Severe restrictive lung disease was present in 75% of patients. Nocturnal BiPAP was required in 68% of patients. Average number of instrumented levels was 17. All patients were immediately extubated upon entering the ICU. There were three respiratory complications and only was patient was re-intubated. Average ICU stay was 1.8 days and average hospital length of stay was 6.7 days. No differences in postoperative inspiratory or expiratory positive airway pressures were observed between the MD and SMA groups.

CONCLUSION

Through a multidisciplinary neuromuscular protocol, excellent clinical outcomes were achieved in patients with neuromuscular scoliosis and restrictive lung disease, with complication rates and length of stay significantly lower than previously published data.

LEVEL OF EVIDENCE

IV.

Early NIV is associated with accelerated lung function decline in Duchenne muscular dystrophy treated with glucocorticosteroids

Background

Use of non-invasive ventilation (NIV) in adolescents with Duchenne muscular dystrophy (DMD) has increased with concomitant extended survival.

Aim

To describe lung function (LF) changes with NIV in adolescents with DMD and to assess differences between Steroid Users and Steroid Naïve subjects.

Method

A retrospective cohort of adolescents with DMD initiating NIV over 10 years was conducted. Serial LF before and after NIV initiation was collated. Use of systemic glucocorticosteroids, adherence to NIV and presence of cardiac disease were assessed.

Results

Twenty-nine men started NIV, median age 14.66 years (IQR 2.35, 10.47–17.96). Nine were Steroid Users and eight were Steroid Naïve. Indications for NIV were apnoea–hypopnoea index >5 and/or nocturnal hypoventilation. LF is better (forced vital capacity (FVC) z-score −3.26 vs −5.41, p < 0.02) and decline slower (FVC z-score −0.58 per annum (pa) vs −0.68 pa, p<0.001) in Steroid Users compared with Steroid Naïve subjects. Following NIV initiation, FVC z-score decline slowed for the whole (−0.72 pa (95% CI −0.79 to 0.64) to −0.46 pa (95% CI −0.54 to 0.38) p < 0.001) and Steroid Naïve groups (−0.74 (95% CI −0.85 to 0.63) to −0.44 pa (95% CI −0.56 to 0.32) p < 0.001) but accelerated in the Steroid User group (−0.56 (95% CI −0.70 to 0.42) to −0.75 pa (95% CI −0.89 to 0.61) p < 0.001). Adherence to NIV and cardiac disease did not impact decline.

Conclusion

Overall, LF decline is reduced on NIV. Steroid Naïve patients have lower LF and faster decline, which slows following NIV initiation. An accelerated LF decline was seen on NIV in Steroid Users which requires further prospective research.

The clinical course of Duchenne muscular dystrophy in the corticosteroid treatment era: a systematic literature review

Background

Duchenne muscular dystrophy (DMD) is a severe rare progressive inherited neuromuscular disorder, leading to loss of ambulation (LOA) and premature mortality. The standard of care for patients with DMD has been treatment with corticosteroids for the past decade; however a synthesis of contemporary data describing the clinical course of DMD is lacking. The objective was to summarize age at key clinical milestones (loss of ambulation, scoliosis, ventilation, cardiomyopathy, and mortality) in the corticosteroid-treatment-era.

Methods

A systematic review was conducted using MEDLINE and EMBASE. The percentage experiencing key clinical milestones, and the mean or median age at those milestones, was synthesized from studies from North American populations, published between 2007 and 2018.

Results

From 5637 abstracts, 29 studies were included. Estimates of the percentage experiencing key clinical milestones, and age at those milestones, showed heterogeneity. Up to 30% of patients lost ambulation by age 10 years, and up to 90% by 15 years of age. The mean age at scoliosis onset was approximately 14 years. Ventilatory support began from 15 to 18 years, and up to half of patients required ventilation by 20 years of age. Registry-based estimates suggest that 70% had evidence of cardiomyopathy by 15 years and almost all by 20 years of age. Finally, mortality rates up to 16% by age 20 years were reported; among those surviving to adulthood mortality was up to 60% by age 30 years.

Conclusions

Contemporary natural history studies from North America report that LOA on average occurs in the early teens, need for ventilation and cardiomyopathy in the late teens, and death in the third or fourth decade of life. Variability in rates may be due to differences in study design, treatment with corticosteroids or other disease-modifying agents, variations in clinical practices, and dystrophin mutations. Despite challenges in synthesizing estimates, these findings help characterize disease progression among contemporary North American DMD patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01862-w.

Risk factors associated with prolonged intensive care unit stay after posterior spinal fusion for Duchenne muscular dystrophy

BACKGROUND

The perioperative complication rate for spinal fusion in Duchenne muscular dystrophy (DMD) remains high and sometimes prolonged perioperative intensive care is needed. We investigated preoperative and intraoperative risk factors associated with prolonged intensive care unit (ICU) stay after posterior spinal fusion.

METHODS

We reviewed the records of 49 consecutive DMD patients who underwent posterior spinal fusion. Instrumentation was performed from T4 to L5 (46 cases) or to the ilium (3 cases). We recorded the preoperative Cobb angle and perioperative clinical data from patient records. Patients were divided into two groups (ICU stay 0 or 1 day, 2 days or longer). Chi-square and t tests were used for univariate analysis. Factors with p < 0.05 in the univariate analysis were entered into a multilevel logistic regression analysis.

RESULTS

The average age of patients at surgery was 14.2 years (range 11-20 years). Their preoperative Cobb angle was 79.2° (range 40°-154°). Average operative time was 325.3 min (range 225-507 min). The average estimated blood loss (EBL) was 1673.0 ml (range 500-3785 ml). Eight patients stayed in the ICU for 2 days or longer for postoperative monitoring and treatment. Univariate analysis found statistical difference between the two groups in preoperative Cobb angle, Thoracolumbar kyphosis, %VC, operation time, and EBL during surgery. After multiple logistic regression analysis, Cobb angle and EBL was identified as an independent factor. The patients with a larger Cobb angle and greater EBL had a higher rate of prolonged ICU stay in interquartile range-based comparison.

CONCLUSIONS

The present study suggests the preoperative Cobb angle and intraoperative EBL could be predictors for postoperative course in posterior spinal fusion for DMD patients.

Pulmonary function testing in patients with neuromuscular disease

Progressive neuromuscular disease leads to muscle weakness or failure that produces loss of pulmonary function and clinical respiratory morbidity. Tracking pulmonary function in a practical and effective way is very important because it can help identify a stage of disease when a morbidity, such as inadequate airway clearance or respiratory failure, may be present. There are four general categories of pulmonary function outcome measures such as volume, flow, pressure, and gas exchange. These outcome measures have variable precision and accuracy in predicting clinical change, and practicality in performing them relative to age and condition. It is widely recommended to follow multiple measurements longitudinally and create an accurate and timely clinical picture. This manuscript will review the most commonly used and most practical measures for use in clinical practice and how they can help to assess morbidity, disease state, and help optimize patient management.

Comparison of survival analysis between surgical and non-surgical treatments in Duchenne muscular dystrophy scoliosis

BACKGROUND CONTEXT

There are still controversies about the effects of spinal surgeries for Duchenne muscular dystrophy (DMD) scoliosis on functional outcome, respiratory function, and the survival rate.

PURPOSE

The purpose of this retrospective investigation was to compare the clinical course over time between the patients who were treated surgically and those who were treated nonsurgically. Through this comparison, we tried to determine how surgical treatment could affect the functional status, pulmonary function, and survival rate in patients with DMD scoliosis.

STUDY DESIGN/SETTING

Single-center retrospective cohort study.

PATIENT SAMPLE

We reviewed the clinical data of 199 male patients with DMD scoliosis who were followed up at our center for an average of 6.4 years between 2003 and 2017.

OUTCOME MEASURES

The basic radiologic parameters evaluated include the Cobb angle and pelvic obliquity on a whole spine X-ray. Further, the Swinyard scale for functional status, forced vital capacity (FVC) for respiratory function, and mortality were compared between the surgical group and nonsurgical group.

METHODS

The radiologic parameters and Swinyard scale stage were compared between the surgical group and nonsurgical group at baseline and 2, 5, and 10 years. For the FVC, serial changes every year were investigated in both groups. Mortality was surveyed between the surgical group and nonsurgical group.

RESULTS

Of the 199 patients, 99 patients underwent the instrumented spinal fusion surgery and 100 patients in the nonsurgical group opted for conservative management. Radiologic results of the two groups were not different at baseline, but during the follow-up periods, the surgical group demonstrated better Cobb angles and pelvic obliquities. The surgical group showed a better functional status than did the nonsurgical group (6.7±0.9 versus [vs.] 7.2±0.7, p<.001). These functional differences between the groups were continuously observed during the follow-up period. Similarly, the FVC at baseline was higher in the surgical group than in the nonsurgical group (1005.7±421.4 mL vs. 787.3±574.1 mL, p=.005). Although FVC in the nonsurgical group consistently decreased during the follow-up (4.8% decrease/year), FVC in the surgical group increased up to the 2-year follow-up period compared with the baseline value and decreased during the follow-up period (2.8% decrease/year). Mortality was higher in the nonsurgical group than in the surgical group (n=22/100, 22.0% vs. n=8/99, 8.1%; p<.001) during an average follow-up duration of 6.4 years. Mean survival was longer in the surgical group than in the nonsurgical group (12.2 years vs. 8.3 years, hazard ratio=2.43, p=.02).

CONCLUSIONS

Spinal surgery for DMD scoliosis improved the FVC for approximately 2 years postoperatively compared to non-surgical treatment. The surgical group had a better functional status and FVC at baseline than the non-surgical group. The positive effect of surgical treatment on the FVC is owing to scoliosis correction, which delayed the decrease of FVC and consequently extended the survival rate of the patients with DMD scoliosis.

Impact of scoliosis surgery on pulmonary function in patients with muscular dystrophies and spinal muscular atrophy

BACKGROUND

Scoliosis is a common complication of severe neuromuscular diseases. The aim of this study is to determine the impact of posterior spinal fusion on pulmonary function parameters in patients with severe neuromuscular disease at our medical center.

METHODS

Retrospective chart review of all patients with severe neuromuscular disease who had posterior spinal fusion between 2012 and 2017 at Texas Children's Hospital. Patients with growing rods, brain injury or malformation, and/or spina bifida were excluded. Pulmonary function measures before and after spinal surgery were determined.

RESULTS

A total of 20 eligible patients were identified, 7 with Duchenne muscular dystrophy, 6 with spinal muscular atrophy, 3 with merosin deficient muscular dystrophy, 2 with Charcot-Marie-Tooth, 1 with central core disease, and 1 with dystroglycanopathy. The mean change in vital capacity from pre- to postspine surgery was a loss of 0.63 L for the spinal muscular atrophy patients, a loss of 0.36 L for the Duchenne muscular dystrophy patients, and a gain of 0.23 L for the merosin deficient patients. The difference between spinal muscular atrophy and merosin deficient patients was statistically significant (P = .02) CONCLUSION: In this single-center retrospective study, we found that after spine surgery for scoliosis, all patients with spinal muscular atrophy and most patients with Duchenne muscular dystrophy lost vital capacity, while the patients with merosin deficient muscular dystrophy gained vital capacity. These differences were not associated with differences is respiratory strength, body mass index, or surgical outcomes.

Safety and Efficacy of Treatment for Scolios Is Secondary to Spinal Muscular Atrophy Fused to Lumbar 5 Level

Introduction

Patients with spinal muscular atrophy (SMA) usually have progressive scoliosis. Although fusion of the sacrum or pelvis has been recommended for correcting pelvic obliquity (PO), the procedure is invasive. This study determined as to whether performing instrumentation to the fifth lumbar vertebra (L5) is safe and effective for scoliosis in patients with SMA.

Methods

Twelve patients with SMA underwent posterior spinal fusion and stopping instrumentation at the L5 level. We evaluated age at surgery, the duration of surgery, blood loss, complications, preoperative and postoperative Cobb angles, and PO.

Results

The mean age at surgery was 11.4 years; the mean duration of surgery was 319 minutes, and the mean blood loss was 1170 mL. The Cobb angle improved from 97.3° to 39.1° at 1 month postoperatively (correction rate, 60.9%) and to 42.3° at the final follow-up. PO was corrected from 27.8° to 13.1° at 1 month postoperatively (correction rate, 51.7%) and to 19.8° at the final follow-up. No complications were reported. All patients showed improvement in low back pain, with reduced difficulty while sitting. However, >10% correction loss of PO was observed in 6 patients with high preoperative PO.

Conclusions

The correction rate of scoliosis in SMA patients with posterior spinal fusion and instrumentation to the L5 level was acceptable, and no complications occurred. Scoliosis associated with SMA was more rigid and severer than scoliosis associated with Duchenne muscular dystrophy. Correction rates of the Cobb angle and PO in SMA patients with instrumentation to L5 were similar to those in SMA patients with instrumentation to the sacrum or pelvis. Correction loss of PO was greater in patients with high preoperative PO than in those with low preoperative PO. Instrumentation and fusion to L5 for scoliosis in patients with SMA seems safe and effective, except in cases of high preoperative PO.

Perioperative Complications in Posterior Spinal Fusion Surgery for Neuromuscular Scoliosis

Introduction

Patients with neuromuscular disorders sometimes show progressive spinal scoliosis. The surgery for neuromuscular scoliosis (NMS) has high rates of complications. In this study, we elucidated the perioperative complications in patients with NMS.

Methods

We included 83 patients with NMS (58 boys and 25 girls; 61 with muscular dystrophy, 18 with spinal muscular atrophy, and 4 others) who had undergone posterior fusion surgery for scoliosis. We evaluated the perioperative complications (within 3 months), age at time of surgery, operative time, blood loss, preoperative %VC and FEV_1.0 (%) for pulmonary function, and preoperative ejection fraction (EF) for cardiac function.

Results

There were 5 (6%) major complications, including pneumonia and a cardiovascular complication requiring intensive care unit (ICU) care, and 15 (18%) minor complications including viral enteritis and a urinary tract infection. Overall, there were 20 (24%) complications. Three of the 5 major complications were pulmonary. The mean age at the time of surgery was 13.7 y, operative time was 304 min, and blood loss was 1530 ml. The mean preoperative %VC was 41%, FEV_1.0 was 91%, and EF was 60%. When we separated the patients into a group with major complications (n = 5) and a group without major complications (n = 78), the preoperative %VC in the group with major complications (23%) was significantly lower than that in the group without (42%) (p < 0.05). However, operative time, blood loss, preoperative FEV_1.0 (%) and EF between the two groups were not significantly different (p > 0.05).

Conclusions

Compared with the previous findings of the perioperative complication rate (45%-74%) for NMS, the complication rate was remarkably low in this case series. Because of advances in medical skills, including anesthesia and surgical instruments, surgery for NMS appears to be safe. However, patients with NMS with complications demonstrated severe restrictive ventilatory impairment preoperatively. Therefore, we should be vigilant for perioperative pulmonary complications especially in patients with NMS and preoperative severe restrictive ventilatory impairment.

Consensus on the diagnosis, treatment and follow-up of patients with Duchenne muscular dystrophy

INTRODUCTION

Duchenne muscular dystrophy (DMD) is the most common myopathy in children, with a worldwide prevalence of approximately 0.5 cases per 10,000 male births. It is characterised by a progressive muscular weakness manifesting in early childhood, with the subsequent appearance of musculoskeletal, respiratory, and cardiac complications, causing disability, dependence, and premature death. Currently, DMD is mainly managed with multidisciplinary symptomatic treatment, with favourable results in terms of the progression of the disease. It is therefore crucial to establish clear, up-to-date guidelines enabling early detection, appropriate treatment, and monitoring of possible complications.

DEVELOPMENT

We performed a literature search of the main biomedical databases for articles published in the last 10years in order to obtain an overview of the issues addressed by current guidelines and to identify relevant issues for which no consensus has yet been established. The degree of evidence and level of recommendation of the information obtained were classified and ordered according to the criteria of the American Academy of Neurology.

CONCLUSIONS

DMD management should be multidisciplinary and adapted to the patient's profile and the stage of clinical progression. In addition to corticotherapy, treatment targeting gastrointestinal, respiratory, cardiac, and orthopaedic problems, as well as physiotherapy, should be provided with a view to improving patients' quality of life. Genetic studies play a key role in the management of the disease, both in detecting cases and potential carriers and in characterising the mutation involved and developing new therapies.

Surgical Correction of Scoliosis in Patients With Duchenne Muscular Dystrophy: 30-Year Experience

BACKGROUND

The natural history of scoliosis in Duchenne muscular dystrophy (DMD) is progressive and debilitating if neglected. The purpose of this study was to evaluate outcomes related to spinal deformity surgery in patients with DMD over a 30-year period.

METHODS

This was a single center retrospective study of all operatively treated scoliosis in DMD patients over 30 years. Minimum follow-up was 2 years. Owing to changes in instrumentation over time, patients were divided into 2 groups: Luque or pedicle screws (PS) constructs. Radiographic, perioperative variables, pulmonary function test (preoperatively and postoperatively), and complication data were evaluated.

RESULTS

There were 60 subjects (Luque: 47, PS: 13). The Luque group was on average 13 years old, 53 kg, and had 7 years of follow-up. Coronal Cobb was 31±12 degrees preoperatively, 16±11 degrees at first postoperatively, and 21±15 degrees at final follow-up (P≤0.001). Pelvic obliquity was 7±6 degrees preoperatively, 5±5 degrees at first postoperatively (P=0.43), and 5±4 degrees at final follow-up (P=0.77). The majority of this group was fused to L5 (45%) or the sacrum (49%). The PS group was on average 14 years old, 65 kg, and had 4 years of follow-up. Coronal Cobb was 43±19 degrees preoperatively, 12±9 degrees at first postoperatively (P≤0.001), and 12±8 degrees at final follow-up. Pelvic obliquity was 6±5 degrees preoperatively, 3±3 degrees at first postoperatively (P=0.06), and 2±2 degrees at final follow-up (P=0.053). The majority were fused to the pelvis (92%). Both groups' pulmonary function declined with time. Both groups had high complication rates (Luque 68%; PS group 54%). The Luque group had more implant-related complications (26%); the PS group had a higher rate of early postoperative infections (23%).

CONCLUSIONS

Over a 30-year period of operative treatment of scoliosis in DMD, both PS constructs and Luque instrumentation improved coronal Cobb. The PS group had improved and maintained pelvic obliquity. Both groups had high complication rates.

LEVEL OF EVIDENCE

Level IV-therapeutic.

Perioperative Evaluation of Respiratory Muscle Strength after Scoliosis Correction in Patients with Duchenne Muscular Dystrophy

Study Design

Retrospective cohort study.

Purpose

To investigate the effect of spinal correction on respiratory muscle strength in patients with Duchenne muscular dystrophy (DMD).

Overview of Literature

Several studies have reported that scoliosis correction in patients with DMD does not improve pulmonary function. In these studies, pulmonary function was evaluated using the traditional spirometric values of percent vital capacity (%VC) and percent forced vital capacity (%FVC). However, traditional spirometry may not be suitable for patients with DMD because the results can be influenced by patient fatigue or level of understanding. Therefore, we evaluated respiratory function focusing on respiratory muscle strength using maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP), in addition to %VC and %FVC.

Methods

We retrospectively reviewed 16 patients with DMD who underwent spinal correction surgery between 2006 and 2011 at Kitasato University Hospital. All patients were males, and the mean age was 13.5 years. Respiratory muscle strength was evaluated using MIP, MEP, and SNIP. Measurements were obtained preoperatively and at 1 and 6 months postoperatively, and %VC and %FVC were obtained preoperatively and within 6 months postoperatively.

Results

The mean preoperative and postoperative %VC values were 54.0% and 51.7%, whereas the mean %FVC values were 53.9% and 53.2%, respectively. The mean MIP, MEP, and SNIP values obtained preoperatively and at 1 and 6 months postoperatively were as follows: MIP, 40.5, 42.7 and 47.2 cm H₂O; MEP, 26.0, 28.0, and 29.0 cm H₂O; and SNIP, 33.4, 33.0, and 33.0 cm H₂O; respectively. The mean MIP and MEP values significantly improved postoperatively. There were no significant differences in SNIP, %VC, or %FVC preand postoperatively.

Conclusions

By focusing on respiratory muscle strength, our results suggest that scoliosis correction in patients with DMD might have a favorable effect on respiratory function.

Factors influencing the evaluation and management of neuromuscular scoliosis: A review of the literature

Neuromuscular scoliosis (NMS) is the second most prevalent spinal deformity (after idiopathic scoliosis) and is usually first identified during early childhood. Cerebral palsy (CP) is the most common cause of NMS, followed by Duchenne muscular dystrophy (DMD). Progressive spinal deformity causes difficulty with daily care, walking and sitting, and can lead to back and rib pain, cardiac and pulmonary complications, altered seizure thresholds, and skin compromise. Early referral to specialist spinal services and early diagnosis of NMS is essential to ensure appropriate multidisciplinary patient management. The most important goals for patients are preservation of function, facilitation of daily care, and alleviation of pain. Non-operative management includes observation or bracing for less severe and flexible deformity in young patients as a temporising measure to provide postural support. Surgical correction and stabilisation of NMS is considered for patients with a deformity >40-50°, but may be performed for less severe deformity in patients with DMD. Post-operative intensive care, early mobilisation and nutritional supplementation aim to minimise the rate of post-surgical complications, which are relatively common in this patient group. However, surgical management of NMS is associated with good long-term outcomes and high satisfaction rates for patients, their relatives and carers.

Duchenne muscular dystrophy: the management of scoliosis

This study summaries the current management of scoliosis in patients with Duchenne Muscular Dystrophy. A literature review of Medline was performed and the collected articles critically appraised. This literature is discussed to give an overview of the current management of scoliosis within Duchenne Muscular Dystrophy. Importantly, improvements in respiratory care, the use of steroids and improving surgical techniques have allowed patients to maintain quality of life and improved life expectancy in this patient group.

The lifetime risk of pneumonia in patients with neuromuscular scoliosis at a mean age of 21 years: the role of spinal deformity surgery

BACKGROUND

Patients with neuromuscular disorders often have an increased risk of pneumonia and decreased lung function, which may further be compromised by scoliosis. Scoliosis surgery may improve pulmonary function in otherwise healthy patients, but no study has evaluated its effect on the risk of pneumonia in patients with neuromuscular scoliosis (NMS).

METHODS

The patient charts of 42 patients (mean age 14.6 years) who had undergone surgery for severe NMS (mean scoliosis 86°) were retrospectively reviewed from birth to a mean of 6.1 years (range 2.8-9.5) after scoliosis surgery. The main outcome was radiographically confirmed pneumonia as a primary cause for hospitalization. We excluded postoperative (3 months) pneumonia from the analyses.

RESULTS

The lifetime annual incidence of pneumonia was 8.0/100 before and 13.4/100 after scoliosis surgery (p > 0.10). The mean number of hospital days per year due to pneumonia were 0.59 (SD 2.3) before scoliosis surgery and 2.24 (SD 6.9) after surgery (p > 0.10). Multivariate analysis demonstrated that lifetime risk factors for pneumonia were epilepsy (RR 15.2, 95 % CI 1.3-176.8, p = 0.027), non-cerebral palsy (CP) etiology (RR = 10.2, 95 % CI 3.2-32.7, p < 0.001) and major scoliosis (main curve >70°; RR = 11.3, 95 % CI 1.8-70.7, p = 0.01).

CONCLUSIONS

Epilepsy, non-CP etiology and major scoliosis are significant risk factors for pneumonia in patients with NMS. Scoliosis surgery does not decrease the incidence of pneumonia in patients with severe NMS.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Surgery for scoliosis in Duchenne muscular dystrophy

BACKGROUND

Scoliosis in patients with Duchenne muscular dystrophy (DMD) is usually progressive and is treated with surgery. However, it is unclear whether the existing evidence is sufficiently scientifically rigorous to support a recommendation for spinal surgery for most patients with DMD and scoliosis. This is an updated review, and an updated search was undertaken in which no new studies were found for inclusion.

OBJECTIVES

To determine the effectiveness and safety of spinal surgery in patients with DMD with scoliosis. We intended to test whether spinal surgery is effective in increasing survival and improving respiratory function, quality of life, and overall functioning, and whether spinal surgery is associated with severe adverse effects.

SEARCH METHODS

On 16 June 2015 we searched the Cochrane Neuromuscular Disease Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL Plus. We also searched ProQuest Dissertation and Thesis database (January 1980 to June 2015), the National Institutes of Health Clinical Trials Database (6 January 2015), and the WHO International Clinical Trials Registry Platform (17 June 2015), and checked references. We imposed no language restrictions.

SELECTION CRITERIA

We planned to include controlled clinical trials using random or quasi-random allocation of treatment evaluating all forms of spinal surgery for scoliosis in patients with DMD in the review. The control interventions would have been no treatment, non-operative treatment, or a different form of spinal surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. Two review authors independently examined the search results and evaluated the study characteristics against inclusion criteria in order to decide which studies to include in the review.

MAIN RESULTS

Of the 49 relevant studies we found, none met the inclusion criteria for the review because they were not clinical trials, but prospective or retrospective reviews of case series.

AUTHORS' CONCLUSIONS

Since no randomized controlled clinical trials were available to evaluate the effectiveness of scoliosis surgery in patients with DMD, we can make no good evidence-based conclusion to guide clinical practice. Patients with scoliosis should be informed as to the uncertainty of benefits and potential risks of surgery for scoliosis. Randomized controlled trials are needed to investigate the effectiveness of scoliosis surgery, in terms of quality of life, functional status, respiratory function, and life expectancy.

Early limited instrumentation of scoliosis in Duchenne muscular dystrophy: is a single-rod construct sufficient?

BACKGROUND CONTEXT

Correction of scoliotic deformity in Duchenne muscular dystrophy (DMD) is performed to maintain adequate seating posture and facilitate comfort. Delaying surgery can predispose to greater morbidity as DMD exhibits progressive cardiorespiratory compromise. Early limited instrumentation may provide a solution to optimize patients with this condition.

PURPOSE

The aim was to assess outcomes for a cohort of DMD patients who had posterior single-rod instrumentation and bilateral spinal fusion of their neuromuscular scoliotic deformity.

STUDY DESIGN

This was a retrospective cohort study.

PATIENT SAMPLE

Forty-one consecutive patients were included.

OUTCOME MEASURES

Perioperative morbidity, seating outcomes, pulmonary function, deformity correction, and instrumentation integrity were assessed.

METHODS

Clinical and radiographic review was performed.

RESULTS

No perioperative mortality or neurologic deterioration was encountered. Total surgical time was 96 minutes, mean total blood loss was 2.3l, mean intensive care unit stay was 41 hours, and overall length of stay was 11 days. Mean Cobb angle improved from 24.3° to 15.6°, pelvic obliquity improved from 7° preoperatively to 5° postoperatively. Three patients had failure of fixation at a mean of 3.5 years. Forced vital capacity was 60% preoperatively and 56% at 1 year, forced expiratory volume/1 second was 67% and 62% at 1 year postoperatively. Seating and posture was satisfactory in all these patients.

CONCLUSIONS

The authors advocate early operative intervention using a limited instrumentation technique in patients with DMD to maintain seating balance and minimize perioperative morbidity.

Assessment and management of respiratory function in patients with Duchenne muscular dystrophy: current and emerging options

Duchenne muscular dystrophy (DMD) is an X-linked myopathy resulting in progressive weakness and wasting of all the striated muscles including the respiratory muscles. The consequences are loss of ambulation before teen ages, cardiac involvement and breathing difficulties, the main cause of death. A cure for DMD is not currently available. In the last decades the survival of patients with DMD has improved because the natural history of the disease can be changed thanks to a more comprehensive therapeutic approach. This comprises interventions targeted to the manifestations and complications of the disease, particularly in the respiratory care. These include: 1) pharmacological intervention, namely corticosteroids and idebenone that significantly reduce the decline of spirometric parameters; 2) rehabilitative intervention, namely lung volume recruitment techniques that help prevent atelectasis and slows the rate of decline of pulmonary function; 3) scoliosis treatment, namely steroid therapy that is used to reduce muscle inflammation/degeneration and prolong ambulation in order to delay the onset of scoliosis, being an additional contribution to the restrictive lung pattern; 4) cough assisted devices that improve airway clearance thus reducing the risk of pulmonary infections; and 5) non-invasive mechanical ventilation that is essential to treat nocturnal hypoventilation, sleep disordered breathing, and ultimately respiratory failure. Without any intervention death occurs within the first 2 decades, however, thanks to this multidisciplinary therapeutic approach life expectancy of a newborn with DMD nowadays can be significantly prolonged up to his fourth decade. This review is aimed at providing state-of-the-art methods and techniques for the assessment and management of respiratory function in DMD patients.

Duchenne muscular dystrophy

Duchenne muscular dystrophy, an X-linked disorder, has an incidence of one in 5000 boys and presents in early childhood with proximal muscle weakness. Untreated boys become wheelchair bound by the age of 12 years and die of cardiorespiratory complications in their late teens to early 20s. The use of corticosteroids, non-invasive respiratory support, and active surveillance and management of associated complications have improved ambulation, function, quality of life and life expectancy. The clinical features, investigations and management of Duchenne muscular dystrophy are reviewed, as well as the latest in some of the novel therapies.

Scoliosis and the impact in neuromuscular disease

Scoliosis can alter respiratory mechanics by changing the orientation of the muscles and joints of the respiratory system and in severe forms can put a patient at risk of severe respiratory morbidity or respiratory failure. However, perhaps the most important factor in determining the pulmonary morbidity in scoliosis is the balance between the "load" or altered respiratory mechanics and the "pump" or the respiratory muscle strength. Therefore, scoliosis in patients with neuromuscular disease will both lead to increased "load" and a weakened "pump", an exceptionally unfortunate combination. While progressive neuromuscular disease by its nature does not respond favorably to attempts to improve respiratory muscle strength, the natural approach of early proactive management of the "load" and in the case of scoliosis a variety of different strategies have been tried with variable short term and long term results. Figuring this out requires both an understanding of the underlying pathophysiology of a particular neuromuscular condition and the available options for and timing of surgical intervention.

Incidence and risk factors for post-operative complications after scoliosis surgery in patients with Duchenne muscular dystrophy : a comparison with other neuromuscular conditions

We report the incidence of and risk factors for complications after scoliosis surgery in patients with Duchenne muscular dystrophy (DMD) and compare them with those of other neuromuscular conditions. We identified 110 (64 males, 46 females) consecutive patients with a neuromuscular disorder who underwent correction of the scoliosis at a mean age of 14 years (7 to 19) and had a minimum two-year follow-up. We recorded demographic and peri-operative data, including complications and re-operations. There were 60 patients with cerebral palsy (54.5%) and 26 with DMD (23.6%). The overall complication rate was 22% (24 patients), the most common of which were deep wound infection (9, 8.1%), gastrointestinal complications (5, 4.5%) and hepatotoxicity (4, 3.6%). The complication rate was higher in patients with DMD (10/26, 38.5%) than in those with other neuromuscular conditions (14/84, 16.7% (p = 0.019). All hepatotoxicity occurred in patients with DMD (p = 0.003), who also had an increased rate of deep wound infection (19% vs 5%) (p = 0.033). In the DMD group, no peri-operative factors were significantly associated with the rate of overall complications or deep wound infection. Increased intra-operative blood loss was associated with hepatotoxicity (p = 0.036). In our series, correction of a neuromuscular scoliosis had an acceptable rate of complications: patients with DMD had an increased overall rate compared with those with other neuromuscular conditions. These included deep wound infection and hepatotoxicity. Hepatotoxicity was unique to DMD patients, and we recommend peri-operative vigilance after correction of a scoliosis in this group.

[Current care strategies for Duchenne muscular dystrophy]

BACKGROUND

The medical care of patients with Duchenne muscular dystrophy (DMD) is an interdisciplinary and multifaceted task. The vast majority of those affected show a nearly constant course which is reflected in a corresponding stage-oriented treatment concept. Although there is still no causal therapy available for DMD, the course and in particular the quality of life of patients can be decisively improved by established medical practices.

THERAPEUTIC STRATEGIES

The orthopedic problems of DMD patients include contractures of the upper and lower extremities as well as sitting instability due to progressive scoliosis with pelvic imbalance. The orthopedic treatment incorporates conservative measures, such as physiotherapy, provision of orthotic devices and wheelchairs as well as surgery to resolve contractures of the lower extremities and surgical stabilization of the spine. Furthermore, in these patients orthopedic surgeons and trauma surgeons are confronted with the treatment and prophylaxis of fractures induced by osteoporosis. An early onset of glucocorticoid therapy markedly delays the loss of motor abilities.

TREATMENT ASPECTS

An important aspect in the care of DMD patients is the timely prophylaxis and treatment of respiratory insufficiency with regular sessions of breathing therapy, learning breathing and coughing techniques and the sufficiently early start of non-invasive mechanically assisted ventilation. Of similar relevance are also the early recognition and cardioprotective treatment of cardiomyopathy.

CONCLUSION

The orthopedic surgeon accompanies the patient and family through all stages of the disease and must be appropriately informed on current management and treatment strategies even outside the limits of the personal field of specialization.

Functional outcomes in Duchenne muscular dystrophy scoliosis: comparison of the differences between surgical and nonsurgical treatment

BACKGROUND

While most studies of Duchenne muscular dystrophy scoliosis focus on technical and radiographic indices, functional status is a more important factor to consider in the management of Duchenne muscular dystrophy. The objectives of the current study were to compare the pulmonary function, radiographic outcome, and functional recovery, with use of validated questionnaires, in surgically and nonsurgically treated patients with Duchenne muscular dystrophy who have scoliosis.

METHODS

Sixty-six patients (forty treated surgically and twenty-six treated nonsurgically) with a minimum follow-up of two years were included in this study. Forced vital capacity, radiographic parameters (the Cobb angle, lordosis, and pelvic obliquity), and functional status, according to the modified Rancho scale and manual muscle test, were measured preoperatively and at the time of the final follow-up. The Muscular Dystrophy Spine Questionnaire (MDSQ) was completed at the final follow-up evaluation.

RESULTS

Pulmonary function, functional scores (manual muscle test and modified Rancho scale), and radiographic measurements, except for lordosis, were similar for both groups at the time of the initial consultation (p > 0.05). At the time of the final follow-up, all radiographic parameters were significantly improved in the surgical group compared with the nonsurgical group. The mean score (and standard deviation) on the manual muscle test was not significantly different between the surgical and nonsurgical groups (23.2 ± 8.3 versus 22.8 ± 6.3; p = 0.828). The mean score on the modified Rancho scale also showed similar results in the groups (3.9 ± 0.3 and 4.04 ± 0.3, respectively; p = 0.088). The surgical group had higher mean MDSQ scores than the nonsurgical group (35.1 ± 14.7 and 26.9 ± 9.9, respectively; p = 0.008). Both groups showed a decrease in forced vital capacity at the time of the final follow-up, but the deterioration of forced vital capacity was significantly slower (p = 0.035) in the surgical group (268 ± 361 mL) than in the nonsurgical group (536 ± 323 mL).

CONCLUSIONS

Surgery in patients who had Duchenne muscular dystrophy with scoliosis improved function and decreased the rate of deterioration of forced vital capacity compared with patients treated conservatively. However, the muscle power and forced vital capacity decreased in both groups.

Progression of spinal deformity in wheelchair-dependent patients with Duchenne muscular dystrophy who are not treated with steroids

We determined the frequency, rate and extent of development of scoliosis (coronal plane deformity) in wheelchair-dependent patients with Duchenne muscular dystrophy (DMD) who were not receiving steroid treatment. We also assessed kyphosis and lordosis (sagittal plane deformity). The extent of scoliosis was assessed on sitting anteroposterior (AP) spinal radiographs in 88 consecutive non-ambulatory patients with DMD. Radiographs were studied from the time the patients became wheelchair-dependent until the time of spinal fusion, or the latest assessment if surgery was not undertaken. Progression was estimated using a longitudinal mixed-model regression analysis to handle repeated measurements.

Scoliosis ≥ 10° occurred in 85 of 88 patients (97%), ≥ 20° in 78 of 88 (89%) and ≥ 30° in 66 of 88 patients (75%). The fitted longitudinal model revealed that time in a wheelchair was a highly significant predictor of the magnitude of the curve, independent of the age of the patient (p <  0.001). Scoliosis developed in virtually all DMD patients not receiving steroids once they became wheelchair-dependent, and the degree of deformity deteriorated over time.

In general, scoliosis increased at a constant rate, beginning at the time of wheelchair-dependency (p < 0.001). In some there was no scoliosis for as long as three years after dependency, but scoliosis then developed and increased at a constant rate. Some patients showed a rapid increase in the rate of progression of the curve after a few years – the clinical phenomenon of a rapidly collapsing curve over a few months.

A sagittal plane kyphotic deformity was seen in 37 of 60 patients (62%) with appropriate radiographs, with 23 (38%) showing lumbar lordosis (16 (27%) abnormal and seven (11%) normal).

This study provides a baseline to assess the effects of steroids and other forms of treatment on the natural history of scoliosis in patients with DMD, and an approach to assessing spinal deformity in the coronal and sagittal planes in wheelchair-dependent patients with other neuromuscular disorders.

Cite this article: Bone Joint J 2014;96-B:100–5.

Surgery for scoliosis in Duchenne muscular dystrophy

BACKGROUND

Scoliosis in people with Duchenne muscular dystrophy is usually progressive and treated with surgery. However, it is unclear whether the existing evidence is sufficiently scientifically rigorous to support a recommendation for spinal surgery for most people with Duchenne muscular dystrophy and scoliosis. This is an updated review and an updated search was undertaken in which no new studies were found.

OBJECTIVES

To determine the effectiveness and safety of spinal surgery in people with Duchenne muscular dystrophy with scoliosis. We intended to test whether spinal surgery is effective in increasing survival, improving respiratory function, improving quality of life and overall functioning; and whether spinal surgery is associated with severe adverse effects.

SEARCH METHODS

We searched the specialized registers of the Cochrane Neuromuscular Disease Group (31 July 2012), MEDLINE (January 1966 to July 2012), EMBASE (January 1947 to July 2012), CENTRAL (2012, Issue 7 in the Cochrane Library), CINAHL Plus(January 1937 to July 2012), Proquest Dissertation and Thesis Database (January 1980 to July 2012), and the National Institute of Health Clinical Trials Database (July 2012). No language restrictions were imposed.

SELECTION CRITERIA

We planned to include controlled clinical trials using random or quasi-random allocation of treatment evaluating all forms of spinal surgery for scoliosis in people with Duchenne muscular dystrophy in the review. The control interventions would have been no treatment, non-operative treatment, or a different form of spinal surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently examined the search results and evaluated the study characteristics against inclusion criteria to decide which ones would be included in the review.

MAIN RESULTS

On searching, 47 studies were relevant but none met the inclusion criteria for the review, because they were not clinical trials but prospective or retrospective reviews of case series.

AUTHORS' CONCLUSIONS

Since there were no randomized controlled clinical trials available to evaluate the effectiveness of scoliosis surgery in people with Duchenne muscular dystrophy, no evidence-based recommendation can be made for clinical practice. People with scoliosis should be informed about the uncertainty of benefits and potential risks of surgery for scoliosis. Randomized controlled trials are needed to investigate the effectiveness of scoliosis surgery, in terms of quality of life, functional status, respiratory function and life expectancy.

Quality of life after surgery for neuromuscular scoliosis

Surgery in patients with neuromuscular scoliosis is associated with a higher rate of complications. It is still controversially discussed whether the patients truly benefit from deformity correction. The purpose of this study is to investigate if the quality of life has been improved and if the patients and their caregivers are satisfied with the results of surgery. This is a retrospective clinical outcome study of 46 patients with neuromuscular scoliosis which were treated with primary stable posterior pedicle screw instrumentation and correction. To achieve fusion only autologous bone was used. Follow up was minimum 2 years and maximum 5 years with an average of 36 months. The patients and/or their caregivers received a questionnaire based on the PEDI (pediatric disability inventory) and the GMFS (gross motor function score). The patients (and their caregivers) were also asked if the quality of life has improved after surgery. Only 32 of 46 patients answered the questionnaire. The answers showed a high approval-rate regarding the patients satisfaction with the surgery and the improvement of quality of life. The questionnaire could be answered from 1 (I do not agree) to 4 (I completely agree). The average agreement to the following statements was: i) the quality of life has improved: 3.35; ii) I am satisfied with surgery: 3.95; iii) the operation has fulfilled my expectations: 3.76. The average age at surgery was 12.7 years. The mean pre-operative cobb-angle of the main curve was 83.1° with a correction post-operatively to a mean of 36.9° and 42.6° at final follow-up. That is an average correction of 56.9%. Although spinal fusion in neuromuscular scoliosis is associated with a higher rate of complications our results show that the patients and their caregivers are satisfied with the operation and the quality of life has improved after surgery.

The effect of posterior spinal fusion on respiratory function in Duchenne muscular dystrophy

PURPOSE

Posterior instrumented spinal fusion is indicated for progressive scoliosis that develops in Duchenne muscular dystrophy (DMD) patients. Whilst spinal fusion is known to improve quality of life, there is inconsistency amongst the literature regarding its specific effect on respiratory function. Our objective was to determine the effect of scoliosis correction by posterior spinal fusion on respiratory function in a large cohort of patients with DMD. Patients with DMD undergoing posterior spinal fusion were compared to patients with DMD not undergoing surgical intervention.

METHODS

An observational study of 65 patients with DMD associated scoliosis, born between 1961 and 2001: 28 of which underwent correction of scoliosis via posterior spinal fusion (Surgical Group) and 37 of which did not undergo surgical intervention (Non-Surgical Group). Pulmonary function was assessed using traditional spirometry. Comparisons were made between groups at set times, and by way of rates of change over time.

RESULTS

There was no correlation between the level of respiratory dysfunction and the severity of scoliosis (as measured by Cobb angle) for the whole cohort. The Surgical Group had significantly worse respiratory function at a comparable age pre-operatively compared to the Non-Surgical Group, as measured by per cent predicted forced vital capacity (p = 0.02) on spirometry. The rate of decline of forced vital capacity and per cent predicted forced vital capacity was not slowed following surgery compared to the non-operated cases. There was no significant difference in survival between the two groups.

CONCLUSIONS

Severity of scoliosis was not a key determinant of respiratory dysfunction. Posterior spinal fusion did not reduce the rate of respiratory function decline. These two points suggest that intrinsic respiratory muscle weakness is the main determinant of decline in respiratory function in DMD.

Influência da adequação postural em cadeira de rodas na função respiratória de pacientes com distrofia muscular de Duchenne

O objetivo deste estudo foi avaliar a influência da adequação postural em cadeira de rodas na função respiratória de pacientes com distrofia muscular de Duchenne (DMD). Participaram 12 pacientes com diagnóstico de DMD e que possuíam cadeira de rodas adaptada com idade variando de 10 a 22 anos. Cada indivíduo foi avaliado na própria cadeira de rodas e em uma cadeira de rodas padrão, ou seja, sem reclinação ou tilt. As cadeiras dos participantes possuíam adaptações no encosto e no assento, confeccionados de acordo com as especificidades de cada paciente. A avaliação consistiu em mensurar o volume minuto (VM), volume corrente (VC), capacidade vital forçada (CVF), pressões inspiratória (PImax) e expiratória (PEmax) máximas e pico de fluxo expiratório (PFE). Para análise dos dados, foi utilizado o teste t pareado, adotando-se o nível de significância de 0,05. As adaptações resultaram em melhores valores estatisticamente significativos de todos os parâmetros respiratórios: VM (8.963,3 e 10.762,5 mL/min; p=0,028), VC (319,1 e 433,6 mL; p=0,005), CVF (1.476,3 e 1.850 mL; p=0,005), PImax (-41,2 e -51,2 cmH2O; p=0,022), PEmax (29,6 e 36,7 cmH2O; p=0,004) e PFE (162,1 e 185 L/min; p=0,018). Nossos resultados sugerem que a adequação postural em cadeira de rodas influenciou positivamente a função respiratória de pacientes com DMD.

The natural history of cardiac and pulmonary function decline in patients with duchenne muscular dystrophy

STUDY DESIGN

Retrospective review of scoliosis progression, pulmonary and cardiac function in a series of patients with Duchenne Muscular Dystrophy (DMD).

OBJECTIVE

To determine whether operative treatment of scoliosis decreases the rate of pulmonary function loss in patients with DMD.

SUMMARY OF BACKGROUND DATA

It is generally accepted that surgical intervention should be undertaken in DMD scoliosis once curve sizes reach 35° to allow intervention before critical respiratory decline has occurred. There are conflicting reports, however, regarding the effect of scoliosis stabilization on the rate of pulmonary function decline when compared to nonoperative cohorts.

METHODS

We reviewed spinal radiographs, echocardiograms, and spirometry, hospital, and operative records of all patients seen at our tertiary referral center from July 1, 1992 to June 1, 2007. Data were recorded to Microsoft Excel (Microsoft, Redmond, WA) and analyzed with SAS (SAS Institute, Cary, NC) and R statistical processing software (www.r-project.org).

RESULTS

The percent predicted forced vital capacity (PPFVC) decreased 5% per year before operation. The mean PPFVC was 54% (SD = 21%) before operation with a mean postoperative PPFVC of 43% (SD = 14%). Surgical treatment was associated with a 12% decline in PPFVC independent of other treatment variables. PPFVC after operation declined at a rate of 1% per year and while this rate was lower, it was not significantly different than the rate of decline present before operation (P = 0.18). Cardiac function as measured by left ventricular fractional shortening declined at a rate of 1% per year with most individuals exhibiting a left ventricular fractional shortening rate of more than 30 before operation.

CONCLUSION

Operative treatment of scoliosis in DMD using the Luque Galveston method was associated with a reduction of forced vital capacity related to operation. The rate of pulmonary function decline after operation was not significantly reduced when compared with the rate of preoperative forced vital capacity decline.

Comparison between Operated Muscular Dystrophy and Spinal Muscular Atrophy Patients in terms of Radiological, Pulmonary and Functional Outcomes

STUDY DESIGN

Retrospective comparative study.

PURPOSE

To study and compare the surgical outcomes of muscular dystrophy (MD) and spinal muscle atrophy (SMA).

OVERVIEW OF LITERATURE

There are few reports that have evaluated and compared the surgical outcomes of MD and SMA patients.

METHODS

The patients (n = 35) were divided into two groups: a MD group with 24 patients and a SMA group with 11 patients. The average follow-up period was 21 months. All patients were operated for scoliosis correction using posterior instrumentation and fusion. In the immediate postoperative period, all efforts were made to reduce the pulmonary complications using non-invasive positive pressure ventilation and a coughing assist devices. The patients were evaluated by radiograph in terms of the Cobb's angle, pelvic obliquity, T1 translation, thoracic kyphosis and lumbar lordosis. The pulmonary function and self-image satisfaction were also assessed.

RESULTS

There was a lower correction rate in the MD group (41.5%) than in the SMA group (48.3%), even though the curves were smaller in the MD group. The correction in the pelvic obliquity was significantly better in the SMA group (p = 0.03). The predicted vital capacity showed a 4% reduction in the MD group 1 year after surgery, while the SMA group showed a 10% reduction. The peak cough flow and end tidal PCO(2) did not deteriorate and were well maintained. The average score for the improvement in self-image satisfaction postoperatively was 3.96 and 4.64 for the MD and SMA groups, respectively. The total complication rate was 45.7%; 14.3% of which were respiratory-related.

CONCLUSIONS

Surgical intervention for MD and SMA may be performed safely in patients with a very low forced vital capacity (< 30%) through aggressive preoperative and postoperative rehabilitation efforts.

Surgical correction of spinal deformity in patients with congenital muscular dystrophy

BACKGROUND

Congenital muscular dystrophy (CMD), among the myopathic disorders is one form of flaccid neuromuscular disorder (NMD). Patients with NMD frequently develop progressive spinal deformity. For NMD patients who have a severe spinal deformity, sitting is often difficult and is accompanied by pain and breakdown of the skin. Spinal deformity surgery in these patients has been highly effective in stabilizing the spine, maintaining upright, comfortable sitting balance, and improving patients' quality of life. However, many studies have reported significant rates of peri/postoperative complications in these patients. To our knowledge, there has been no study on the results of spinal deformity surgery in patients with CMD. The purpose of this study was to review the clinical and radiological results of spinal deformity surgery in this group of patients with CMD.

METHODS

Between 2004 and 2007, a total of 10 CMD patients underwent scoliosis surgery. There were three patients with Fukuyama CMD, three with Ullrich CMD, and 4 with nonsyndromic CMD (merosin-negative). They were nonambulatory. All the patients had standard posterior spinal fusion and pedicle-screw-alone fixation from T3 or T4 to L5 for spinal deformity. Our inclusion criteria required that each patient (1) had considerable difficulty with sitting balance and pain or breakdown of the skin due to scoliosis; (2) was able to ventilate his or her lung autonomously; (3) was not ventilator-dependent; and (4) did not have cardiac failure. Sufficient informed consent was important, and the decision to perform surgery was made by the patient/family with sufficient preoperative informed consent. Patients were trained with inspiratory muscle training (IMT) using an inspiratory muscle trainer (Threshold IMT) for 6 weeks prior to surgery Cardiac function was assessed preoperatively. Pulmonary function tests were performed preoperatively and postoperatively. Radiographic assessments were performed on sitting anteroposterior (AP) and lateral radiographs. These assessments were made periodically. The Cobb angles of the curves and spinal pelvic obliquity (SPO) on the coronal plane, thoracic kyphosis, and lumbar lordosis were measured. The preoperative AP radiograph and side-bending films were examined to determine flexibility. Patients' and parents' satisfaction were surveyed by a self-completed questionnaire at the last follow-up.

RESULTS

Percent forced vital capacity (%FVC) increased from a mean of 30% before IMT to a mean of 34% the day before surgery. The preoperative scoliosis was 75 degrees (range 61 degrees -95 degrees ). The scoliotic curvature on preoperative side-bending films was 19 degrees (range 11 degrees -28 degrees ). All patients were extubated on the day of surgery. No patients developed cardiac or respiratory complications. The scoliotic curvature was 18 degrees (range 10 degrees -25 degrees ) immediately after surgery, and 19 degrees (range 12 degrees -27 degrees ) at the last follow-up. The pelvic obliquity improved from a mean of 17 degrees (range 14 degrees -20 degrees ) preoperatively to a mean of 6 degrees (range 4 degrees -9 degrees ) postoperatively and to 7 degrees (range 4 degrees -10 degrees ) at the last follow-up. Balanced sitting posture was achieved and maintained. On the sagittal plane, good reconstruction of sagittal plane alignment was recreated and maintained. There were no major complications or deaths. All patients/parents completed the outcome satisfaction questionnaire. Eight patients/parents were very satisfied and two were satisfied.

CONCLUSIONS

Pedicle-screw-alone fixation and fusion to L5 was safe and effective in CMD patients with scoliosis of <95 degrees and pelvic obliquity of <20 degrees . Scoliosis curves were flexible (75% correction) on side-bending films preoperatively. Curve correction and maintenance of correction in the coronal and sagittal plane was excellent. The pelvic obliquity significantly improved. Balanced sitting posture was achieved and maintained in all patients. Our patients with CMD spinal deformity and a moderately and severely decreased FVC could be operated on safely and successfully with general anesthesia. All patients were extubated in the operating room. There were no major complications or deaths. We believe a FVC of <30% alone is not a predisposition to pulmonary complications. However, cardiomyopathy might be a determining risk of mortality, and we believe surgery for these patients should be avoided. Patients' and parents' satisfaction was high.

Surgical management of severe scoliosis with high risk pulmonary dysfunction in Duchenne muscular dystrophy: patient function, quality of life and satisfaction

In a previous study, the authors reported the clinical and radiological results of Duchenne muscular dystrophy (DMD) scoliosis surgery in 14 patients with a low FVC of <30%. The purpose of this study was to determine if surgery improved function and QOL in these patients. Furthermore, the authors assessed the patients' and parents' satisfaction. %FVC increased in all patients after preoperative inspiratory muscle training. Scoliosis surgery in this group of patients presented no increased risk of major complications. All-screw constructions and fusion offered the ability to correct spinal deformity in the coronal and pelvic obliquity initially, intermediate and long-term. All patients were encouraged to continue inspiratory muscle training after surgery. The mean rate of %FVC decline after surgery was 3.6% per year. Most patients and parents believed scoliosis surgery improved their function, sitting balance and quality of life even though patients were at high risk for major complications. Their satisfaction was also high.

Diagnosis and management of Duchenne muscular dystrophy, part 2: implementation of multidisciplinary care

Optimum management of Duchenne muscular dystrophy (DMD) requires a multidisciplinary approach that focuses on anticipatory and preventive measures as well as active interventions to address the primary and secondary aspects of the disorder. Implementing comprehensive management strategies can favourably alter the natural history of the disease and improve function, quality of life, and longevity. Standardised care can also facilitate planning for multicentre trials and help with the identification of areas in which care can be improved. Here, we present a comprehensive set of DMD care recommendations for management of rehabilitation, orthopaedic, respiratory, cardiovascular, gastroenterology/nutrition, and pain issues, as well as general surgical and emergency-room precautions. Together with part 1 of this Review, which focuses on diagnosis, pharmacological treatment, and psychosocial care, these recommendations allow diagnosis and management to occur in a coordinated multidisciplinary fashion.

A Dutch guideline for the treatment of scoliosis in neuromuscular disorders

Background

Children with neuromuscular disorders with a progressive muscle weakness such as Duchenne Muscular Dystrophy and Spinal Muscular Atrophy frequently develop a progressive scoliosis. A severe scoliosis compromises respiratory function and makes sitting more difficult. Spinal surgery is considered the primary treatment option for correcting severe scoliosis in neuromuscular disorders. Surgery in this population requires a multidisciplinary approach, careful planning, dedicated surgical procedures, and specialized after care.

Methods

The guideline is based on scientific evidence and expert opinions. A multidisciplinary working group representing experts from all relevant specialties performed the research. A literature search was conducted to collect scientific evidence in answer to specific questions posed by the working group. Literature was classified according to the level of evidence.

Results

For most aspects of the treatment scientific evidence is scarce and only low level cohort studies were found. Nevertheless, a high degree of consensus was reached about the management of patients with scoliosis in neuromuscular disorders. This was translated into a set of recommendations, which are now officially accepted as a general guideline in the Netherlands.

Conclusion

In order to optimize the treatment for scoliosis in neuromuscular disorders a Dutch guideline has been composed. This evidence-based, multidisciplinary guideline addresses conservative treatment, the preoperative, perioperative, and postoperative care of scoliosis in neuromuscular disorders.

Scoliosis correction with pedicle screws in Duchenne muscular dystrophy

This report describes the spinal fixation with pedicle-screw-alone constructs for the posterior correction of scoliosis in patients suffering from Duchenne muscular dystrophy (DMD). Twenty consecutive patients were prospectively followed up for an average of 5.2 years (min 2 years). All patients were instrumented from T3/T4 to the pelvis. Pelvic fixation was done with iliac screws similar to Galveston technique. The combination of L5 pedicle screws and iliac screws provided a stable caudal foundation. An average of 16 pedicle screws was used per patient. The mean total blood loss was 3.7 l, stay at the intensive care unit was 77 h and hospital stay was 19 days. Rigid stabilisation allowed immediate mobilisation of the patient in the wheel chair. Cobb angle improved 77% from 44 degrees to 10 degrees, pelvic tilt improved 65% from 14 degrees to 3 degrees. Lumbar lordosis improved significantly from 20 degrees to 49 degrees, thoracic kyphosis remained unchanged. No problems related to iliac fixation, no pseudarthrosis or implant failures were observed. The average percentage of predicted forced vital capacity (%FVC) of the patients was 55% (22-94%) preoperatively and decreased to 44% at the last follow-up. There were no pulmonary complications. One patient with a known cardiomyopathy died intraoperatively due to a sudden cardiac arrest. The rigid primary stability with pedicle screws allowed early mobilisation of the patients, which helped to avoid pulmonary complications.