Surgical correction of scoliosis in Rett syndrome: cord monitoring and complications

Outcomes of Posterior Spinal Fusion in Pediatric Patients with Down Syndrome

BACKGROUND

Trisomy 21 or Down syndrome is associated with multiple orthopaedic manifestations. Although cervical instability is the most common spinal condition associated with Down syndrome, the prevalence of scoliosis has been estimated at 4.8% to 8.7%. Very few prior studies have documented the role of spinal fusion in this population, and all have included ≤10 patients.

METHODS

An institutional review board-approved multicenter retrospective analysis of patients with Down syndrome treated with spinal fusion between January 2009 and December 2019 was performed by cross-referencing Current Procedural Terminology (CPT) and International Classification of Diseases, Ninth and Tenth Revisions (ICD-9 and ICD-10) codes. Patients were followed for ≥2 years, with a mean follow-up of 3.77 years. Clinical and radiographic outcomes were collected, and complications were documented using the Clavien-Dindo-Sink (CDS) classification.

RESULTS

A total of 23 patients were included: 96% had ≥1 medical comorbidities, including 16 (70%) with congenital heart disease, of whom 88% had previous cardiac surgery, and 10 (44%) with thyroid disorders. All 23 patients underwent posterior spinal fusion. The mean estimated blood loss was 617 ± 459 mL, the mean length of the surgical procedure was 290 ± 92.7 minutes, and the mean length of hospital stay was 6.03 ± 2.91 days. The major Cobb angle measured 61.7° ± 17.6°, which corrected to 19.4° ± 14.8° (68.6% correction; p < 0.001), with well-maintained correction at 2 years of 22.0° ± 10.3° (64.3% correction; p = 0.158). Thirteen (57%) of 23 patients had a change in curve of >5°. There were no intraoperative complications; however, 12 patients (52%) sustained postoperative complications (e.g., need for reoperation, implant failure, and pulmonary complications), including 6 patients with CDS type 3 or 4 (e.g., wound dehiscence, late superficial abscess, pleural effusion, pseudarthrosis, and readmission for hypoxia). Four patients (17%) required a revision surgical procedure. One patient (4%) required an unplanned intensive care unit admission.

CONCLUSIONS

Although instrumented spinal fusion can effectively correct spinal deformity in these patients, complications are more frequent than in children with adolescent idiopathic scoliosis, with over half of patients sustaining a complication.

LEVEL OF EVIDENCE

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

Rett syndrome: think outside the (skull) box

Rett syndrome (RTT) is a severe X-linked neurodevelopmental disorder characterized by neurodevelopmental regression between 6 and 18 months of life and associated with multi-system comorbidities. Caused mainly by pathogenic variants in the MECP2 (methyl CpG binding protein 2) gene, it is the second leading genetic cause of intellectual disability in girls after Down syndrome. RTT affects not only neurological function but also a wide array of non-neurological organs. RTT-related disorders involve abnormalities of the respiratory, cardiovascular, digestive, metabolic, skeletal, endocrine, muscular, and urinary systems and immune response. Here, we review the different aspects of RTT affecting the main peripheral groups of organs and sometimes occurring independently of nervous system defects.

What's New in the Management of Neuromuscular Scoliosis

BACKGROUND

Patients with neuromuscular scoliosis (NMS) can pose treatment challenges related to medical comorbidities and altered spinopelvic anatomy. We reviewed the recent literature regarding evaluation and management of NMS patients and explored areas where further research is needed.

METHODS

We searched the PubMed database for all papers related to the treatment of NMS published from January 1, 2011 through July 31, 2014, yielding 70 papers.

RESULTS

A total of 39 papers contributed compelling new findings. Steroid treatment has been most promising in patients with Duchenne muscular dystrophy, leading to a significantly lower death rate, better pulmonary function, and longer independent ambulation. Growing rods in early-onset NMS were shown to result in significant improvements in major Cobb angles and pelvic obliquity, with low complication rates in patients with spinal muscular atrophy but high infection rates in those with cerebral palsy. Early reports of magnetic growing rods in NMS patients are favorable. Intraoperative neural monitoring is variable in this patient population; however, use of transcranial motor-evoked potentials in NMS patients seems to be safe. Blood loss is the highest in NMS patients when compared with all other diagnostic categories. However, tranexamic acid seems to significantly lower intraoperative blood loss. In a multicenter study, patients diagnosed with NMS had the highest surgical-site infection rate at 13.1%. Best-practice guidelines have been created regarding prevention of infection in NMS patients. Preoperative nutritional optimization and postoperative nutritional supplementation seem to help with lowering the infection rate in these patients.

CONCLUSIONS

There have been major advances in the management of NMS patients, but many challenges remain. Further multicenter studies and randomized clinical trials are needed, particularly in the areas of infection prophylaxis, nutritional optimization, improvement in intraoperative neural monitoring, and prevention of proximal junctional kyphosis.

LEVEL OF EVIDENCE

Level 4-literature review.

Validity and utility of monopolar spinal cord stimulation in pediatric scoliosis surgery

PURPOSE

To assess the validity and utility of monopolar stimulation (between a peridural needle and a large adhesive anode placed in the sternal area) for intraoperative monitoring in scoliosis surgery.

METHODS

This procedure was assessed during 41 operations involving either arthrodesis with posterior instrumentation or a Vertical Expandable Prosthetic Titanium Rib (VEPTR). Responses evoked by monopolar stimulation were compared with those evoked by bipolar stimulation between two epidural needle electrodes. Potentials evoked by monopolar stimulation in the upper limbs were compared with those evoked in the lower limbs during the same stimulation procedure.

RESULTS

Monopolar stimulation yielded equivalent and, if anything, more stable responses in the lower limbs. Recording in the upper limbs was satisfactory and allowed a decrease in responses to be detected in two patients. Acceptable thresholds for changes in amplitude relative to baseline were 40 % for upper limbs and 30 % for lower limbs.

CONCLUSIONS

Monopolar stimulation can be used to monitor the spinal cord during surgery for scoliosis correction. This procedure is more convenient for the surgeon and allows for the combined recording of responses in all four limbs, which can be useful in the case of surgical techniques such as those involving a VEPTR.

Minimally Invasive Scoliosis Surgery: A Novel Technique in Patients with Neuromuscular Scoliosis

Minimally invasive surgery (MIS) has been described in the treatment of adolescent idiopathic scoliosis (AIS) and adult scoliosis. The advantages of this approach include less blood loss, shorter hospital stay, earlier mobilization, less tissue disruption, and relatively less pain. However, despite these significant benefits, MIS approach has not been reported in neuromuscular scoliosis patients. This is possibly due to concerns with longer surgery time, which is further increased due to more levels fused and instrumented, challenges of pelvic fixation, size and number of incisions, and prolonged anesthesia. We modified the MIS approach utilized in our AIS patients to be implemented in our neuromuscular patients. Our technique allows easy passage of contoured rods, placement of pedicle screws without image guidance, partial/complete facet resection, and all standard reduction maneuvers. Operative time needed to complete this surgery is comparable to the standard procedure and the majority of our patients have been extubated at the end of procedure, spending 1 day in the PICU and 5-6 days in the hospital. We feel that MIS is not only a feasible but also a superior option in patients with neuromuscular scoliosis. Long-term results are unavailable; however, short-term results have shown multiple benefits of this approach and fewer limitations.