Perioperative Complications in Posterior Spinal Fusion Surgery for Neuromuscular Scoliosis

Scoliosis in spinal muscular atrophy in the era of disease-modifying therapy: a scoping review

Spinal muscular atrophy (SMA) frequently causes scoliosis (up to 90% of cases), due to weakened axial muscles impacting motor and respiratory function. While new SMA treatments improve motor function, their effect on scoliosis progression is unclear. This scoping review (2016-October 2024) analyzed literature from Pubmed, MEDLINE, EMBASE, and Scopus, focusing on studies of SMA, scoliosis, and treatment approaches. The aim of this work was to describe the clinical features and the possible therapeutic approaches of scoliosis in the "new population" of pharmacologically treated SMA patients. We included all types of SMA as well as all the approved disease modifying therapies (DMTs). The review found significant variability in scoliosis presentation and surgical intervention among different types of treated SMA patients. Early pharmacological treatment may slow scoliosis progression, particularly in Type II SMA. Interestingly, Type I SMA patients, who typically don't develop scoliosis due to severe hypotonia, showed an increased scoliosis onset. Larger studies are needed to fully evaluate the impact of different treatments on scoliosis progression in SMA, especially in Type I SMA patients, to establish updated standards of care.

Distal level in scoliosis surgery for non-ambulatory patients with cerebral palsy: is L5 an option? A case series study

PURPOSE

This study aimed to determine the radiographic outcomes of patients with cerebral palsy (CP) who underwent posterior spinal fusion from T2/3 to L5 at two quaternary hospitals.

METHODS

From January 2010 to January 2020, 167 non-ambulatory patients with CP scoliosis underwent posterior spinal fusion using pedicle screws from T2/3 to L5 in both centers, with a minimum of 2 years follow-up (FU). Radiological measurements and chart reviews were performed.

RESULTS

A total of 106 patients aged 15.6 ± 0.4 years were included. None of the patients was lost to FU. All patients had significant correction of the Cobb angle (MC) and pelvic obliquity (PO), thoracic kyphosis (TK), and lumbar lordosis (LL), without loss of correction at the last FU (LFU). The mean values for preoperative, immediate postoperative, and LFU were MC 93.4°, 37.5°, and 42.8°; PO 25.8°, 9.9°, and 12.7°; TK 52.2°, 44.3°, and 45°; and LL - 40.9°, - 52.4°, and - 52.9°, respectively. Higher residual PO at LFU was associated with more severe MC and PO baselines, lower implant density, and an apex located at L3.

CONCLUSIONS

CP scoliosis and PO can be corrected, and this correction is maintained over time with posterior spinal fusion using pedicle screws, with L5 as the lowest instrumented vertebra. Larger preoperative MC and PO values associated with the apex at L3 appear to be related to residual PO. Comparative large-scale studies of patient-related clinical outcomes are required to determine whether this intervention is associated with improved surgical outcomes and reduced complication rates.

LEVEL OF EVIDENCE

IV.

The indication of fusion to the pelvis in neuromuscular scoliosis is based on the underlying disease rather than on pelvic obliquity

INTRODUCTION

The decision to instrument to L5 or ilium, in NMS, is usually based on radiologic factors, including pelvic obliquity (PO) > 15°, apex of curvature < L3, and Cobb angle > 60°. Since scoliosis in these patients is caused by a neurologic disease, we based our decision to stop at L5 on the presence of spasticity or flaccidity.

PATIENTS & METHODS

The senior author did 109 primary fusions in NMS. Of those with DMD or SMA only 16% were instrumented to the ilium. The main factor for our decision was the correction potential of the truncal shift and PO in the supine traction radiographs and the absence of severe spasticity.

RESULTS

The 57 patients with DMD/SMA had a mean preoperative curvature of 68°, PO of 17°, and truncal shift of 20°. 74% should have been instrumented to the pelvis, but only 16% were. Those instrumented shorter as the rule, were corrected from 74° to 26° and had a postoperative PO of 8°. There was no significant difference in postoperative correction and PO compared to those instrumented to L5 on standard protocol. Subsequent extension to the pelvis was needed in 1 CP patient. There were no significant changes after 2 years. Of the 20 patients instrumented to the pelvis 11 had cerebral palsy and a preop curvature of 89°, a PO of 21° and a truncal shift of 25°.

DISCUSSION

The decision on instrumentation length should take flexibility and disease into consideration. If the trunk is centred over the pelvis, deterioration will not occur in absence of spasticity.

Posterior Spinal Fusion Surgery for Neuromuscular Disease Patients with Severe Scoliosis Whose Cobb Angle Was over 100 Degrees

Background and objectives: Patients with neuromuscular diseases usually have progressive neuromuscular scoliosis (NMS), requiring invasive surgery. Some patients present with severe scoliosis at the time of consultation and are difficult to treat. Posterior spinal fusion (PSF) surgery combined with anterior release and pre- or intraoperative traction would be effective for severe spinal deformities but would be invasive. This study aimed to evaluate the outcomes of PSF-only surgery for patients with severe NMS with a Cobb angle > 100°. Materials and Methods: Thirty NMS patients (13 boys and 17 girls; mean age 13.8 years) who underwent PSF-only surgery for scoliosis with a Cobb angle > 100° were included. We reviewed the lower instrumented vertebra (LIV), duration of surgery, blood loss, perioperative complications, preoperative clinical findings, and radiographic findings, including Cobb angle and pelvic obliquity (PO) in the sitting position pre- and postoperatively. The correction rate and correction loss of the Cobb angle and PO were also calculated. Results: The mean duration of surgery was 338 min, intraoperative blood loss was 1440 mL, preoperative %VC was 34.1%, FEV1.0 (%) was 91.5%, and EF was 66.1%. There were eight cases of perioperative complications. The Cobb angle and PO correction rates were 48.5% and 42.0%, respectively. We divided the patients into two groups: the L5 group, in which the LIV was L5, and the pelvis group, in which the LIV was the pelvis. The duration of surgery and PO correction rate in the pelvis group were significantly higher than those in the L5 group. Conclusions: Patients with severe NMS demonstrated severe preoperative restrictive ventilatory impairments. PSF surgery without anterior release or any intra-/preoperative traction showed satisfactory outcomes, including acceptable scoliosis correction and improved clinical findings, even in patients with extremely severe NMS. Instrumentation and fusion to the pelvis for severe scoliosis in patients with NMS showed good PO correction and low correction loss of Cobb angle and PO, but a longer duration of surgery.

Curve Characteristics and Surgical Outcomes in Scoliosis Associated With Childhood Sternotomy or Thoracotomy

BACKGROUND

The purpose of this study is to describe curve characteristics and postoperative outcomes in patients undergoing spinal fusion (SF) to treat thoracogenic scoliosis related to sternotomy and/or thoracotomy as a growing child.

METHODS

A retrospective review of electronic medical records of all patients with Post-Chest Incision scoliosis treated with SF was performed at 2 tertiary care pediatric institutions over a 19-year period. Curve characteristics, inpatient, and outpatient postoperative outcomes are reported.

RESULTS

Thirty-nine patients (62% female) were identified. Eighteen had sternotomy alone, 14 had thoracotomy alone, and 7 had both. Mean age at the time of first chest wall surgery was 2.5 years (range: 1.0 d to 14.2 y). Eighty-five percent of patients had a main thoracic curve (mean major curve angle 72 degrees, range: 40 to 116 degrees) and 15% had a main lumbar curve (mean major curve angle 76 degrees, range: 59 to 83 degrees). Mean thoracic kyphosis was 40 degrees (range: 4 to 84 degrees). Mean age at the time of SF was 14 years (range: 8.2 to 19.9 y). Thirty-six patients had posterior fusions and 3 had combined anterior/posterior. Mean coronal curve correction measured at the first postoperative encounter was 53% (range: 9% to 78%). There were 5 (13%) neuromonitoring alerts and 2 (5%) patients with transient neurological deficits. Mean length of hospital stay was 9±13 days. At an average follow-up time of 3.1±2.4 years, 17 complications (10 medical and 7 surgical) were noted in 9 patients for an overall complication rate of 23%. There was 1 spinal reoperation in the cohort. 2/17 (12%) complications were Clavien-Dindo-Sink class III and 5/17 (29%) were class IV.

CONCLUSION

Kyphotic thoracic curves predominate in patients with Post-Chest Incision scoliosis undergoing SF. Although good coronal and sagittal plane deformity can be expected after a fusion procedure, postoperative complications are not uncommon in medically complex patients, often necessitating longer postoperative stays.

LEVEL OF EVIDENCE

Level III.

The Early and Late Postoperative Complications of Pediatric Neuromuscular Scoliosis at King Abdulaziz Medical City, Riyadh, Saudi Arabia: A Case Series

Background 

Neuromuscular Scoliosis (NMS) is defined as “a coronal plane spinal curvature of 10 degrees or more, measured by the Cobb method, in the setting of muscle imbalance secondary to an underlying neuropathic or myopathic disease”. Patients who have the disease usually manifest with diminished balance, asymmetrical seating, abnormal gait, and decreased pulmonary function, which are related to the change in spine posture. Surgery benefits patients with NMS in terms of stopping disease advancement and improving quality of life, but is known to be associated with certain complications in this population. The aim of this study is to identify the most common complication in NMS patients after surgical correction.

Methods

This study is a chart review-based retrospective case series that has covered patients’ data going from 2015 to 2019. The study focused on patients who underwent scoliosis correction surgery of both genders and mainly of a single ethnicity, with the inclusion of patients aged 9 to 18 years old. Under consecutive sampling, the study has met a sample size of 14 patients. 

Results

Most of the study subjects nine (64%) were female. The age median was 13 years (2.25). The highest documented intraoperative complication was blood loss in 11 (79%) patients. The most prevalent early postoperative complication was urinary tract infection in two (14%) patients. No late postoperative complications were documented in the study.

Conclusion 

The study concluded that blood loss was the most common intraoperative complication. Pulmonary problems were one of the least reported complications. Possible reasons for these findings and prevention methods should be the focus of future studies.

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.

Neuromuscular Scoliosis: Comorbidities and Complications

Study Design

Single-center, retrospective cohort study conducted from 2013 to 2017.

Purpose

To determine the risk factors for surgical complications in neuromuscular scoliosis based on known patient comorbidities.

Overview of Literature

The concept of neuromuscular scoliosis includes a wide variety of pathologies affecting the neuromuscular system. Complications are numerous and are often difficult to predict.

Methods

A retrospective analysis of a single-center database was conducted from 2013 to 2017. Inclusion criteria were patients aged <25 years, diagnosis of neuromuscular scoliosis, and history of posterior fusion deformity surgery. A total of 64 patients (mean age, 15 years; 63% females) were included in this study. Clinical, radiological, and laboratory parameters in the preoperative, intraoperative, and postoperative settings were analyzed. Univariate analysis was performed using Student t -test for continuous variables, and a chi-square test was used for noncontinuous variables. Multivariate analysis was performed to identify predictors of major, mechanical, and total complications.

Results

Complications were found in 44% of patients, with 46.9% consisting of major complications, and 84.4% being early complications. Univariate analysis revealed that the presence of perinatal comorbidities, independent of other comorbidities, increased the risk for complications (p =0.029). Preoperative hypoglycemia, high number of instrumented levels, longer surgical time, use of an all-screw construct, lower preoperative pelvic obliquity, postoperative lower kyphosis, high thoracic spinopelvic angle (as measured by T9 spino-pelvic inclination), absence of deep drain, and use of superficial drain were associated with postoperative complications (all p <0.05). Logistic regression demonstrated that comorbidities, longer surgical time, hypoglycemia, and absence of deep drains are predictors of complications. Independent variables that predicted major complications were the number of levels fused, postoperative kyphosis (p =0.025; odds ratio [OR], 1.074), and high screw density (p =0.014; OR, 4.380).

Conclusions

Complications in neuromuscular scoliosis are increased by comorbidities, long surgical time, and inadequate correction. Preventative measures to decrease these complications include appropriate preoperative patient preparation and surgical planning.