Risk factors for progressive neuromuscular scoliosis requiring posterior spinal fusion after selective dorsal rhizotomy

Cervicothoracic ventral-dorsal rhizotomy for treatment of brachial hypertonia in cerebral palsy

PURPOSE

Cervicothoracic ventral-dorsal rhizotomy (VDR) is a potential treatment of medically refractory hypertonia in patients who are not candidates for intrathecal baclofen, particularly in cases of severe upper limb hypertonia with limited to no function. A longitudinal cohort was identified to highlight our institutional safety and efficacy using cervicothoracic VDR for the treatment of hypertonia.

METHODS

Retrospective data analysis was performed for patients that underwent non-selective cervicothoracic VDR between 2022 and 2023. Non-modifiable risk factors, clinical variables, and operative characteristics were collected.

RESULTS

Six patients (three female) were included. Four patients underwent a bilateral C6-T1 VDR, one patient underwent a left C7-T1 VDR, and another underwent a left C6-T1 VDR. Three patients had quadriplegic mixed hypertonia, one patient had quadriplegic spasticity, one patient had triplegic mixed hypertonia, and one patient had mixed hemiplegic hypertonia. The mean difference of proximal upper extremity modified Ashworth scale (mAS) was - 1.4 ± 0.55 (p = 0.002), and - 2.2 ± 0.45 (p < 0.001) for the distal upper extremity. Both patients with independence noted quality of life improvements as well as increased ease with dressing and orthotics fits. Caregivers for the remaining four patients noted improvements in caregiving provision, mainly in dressing, orthotics fit, and ease when transferring.

CONCLUSION

Cervicothoracic VDR is safe and provides tone control and quality of life improvements in short-term follow-up. It can be considered for the treatment of refractory hypertonia. Larger multicenter studies with longer follow-up are necessary to further determine safety along with long-term functional benefits in these patients.

Pre-op considerations in neuromuscular scoliosis deformity surgery: proceedings of the half day course at the 58th annual meeting of the Scoliosis Research Society

Scoliosis is a common complication of neuromuscular disorders. These patients are frequently recalcitrant to nonoperative treatment. When treated surgically, they have the highest risk of complications of all forms of scoliosis. While recent studies have shown an improvement in the rate of complications, they still remain high ranging from 6.3 to 75% depending upon the underlying etiology and the treatment center (Mohamad et al. in J Pediatr Orthop 27:392-397, 2007; McElroy et al. in Spine, 2012; Toll et al. in J Neurosurg Pediatr 22:207-213, 2018; Cognetti et al. in Neurosurg Focus 43:E10, 2017). For those patients who are able to recover from the perioperative period without major complications, several recent studies have shown decreased long-term mortality and improved health-related quality of life in neuromuscular patients who have undergone spine fusion (Bohtz et al. in J Pediatr Orthop 31:668-673, 2011; Ahonen et al. in Neurology 101:e1787-e1792, 2023; Jain et al. in JBJS 98:1821-1828, 2016). It is critically important to optimize patients preoperatively to minimize the risk of post-operative complications and maximize long-term outcomes. In order to do so, one must familiarize themselves with the common complications and their treatment. The most common complications are pulmonary in nature. With reported rates as high as 23-29%, pre-operative optimization should be employed for these patients to minimize the risk of post-operative complications (Sharma et al. in Eur Spine J 22:1230-1249, 2013; Rumalla et al. in J Neurosurg Spine 25:500-508, 2016). The next most common cause of complications are implant related, with 13-23% of patients experiencing an implant-related complication that may require a second procedure (Toll et al. in J Neurosurg Pediatr 22:207-213, 2018; Sharma et al. in Eur Spine J 22:1230-1249, 2013) Therefore optimization of bone quality prior to surgical intervention is important to help minimize the risk of instrumentation failure. Optimization of muscle tone and spasticity may help to decrease the risk of instrumentation complications, but may also contribute to the progression of scoliosis. While only 3% of patients have neurologic complication, significant equipoise remains regarding whether or not patients should undergo prophylactic detethering procedures to minimize those risks (Sharma et al. in Eur Spine J 22:1230-1249, 2013). Although only 1.8% of complications are classified as cardiac related, they can be among the most devastating (Rumalla et al. in J Neurosurg Spine 25:500-508, 2016). Simply understanding the underlying etiology and the potential risks associated with each condition (i.e., conduction abnormalities in a patient with Rett syndrome or cardiomyopathies patients with muscular dystrophy) can be lifesaving. The following article is a summation of the half day course on neuromuscular scoliosis from the 58th annual SRS annual meeting, summarizing the recommendations from some of the world's experts on medical considerations in surgical treatment of neuromuscular scoliosis.

A systematic review of complications following selective dorsal rhizotomy in cerebral palsy

PURPOSE

The literature lacks a concise overview of complications secondary to selective dorsal rhizotomy (SDR). The aim of this study was to systematically review the literature regarding post-SDR complications, and to present them concisely.

METHODS

The protocol of the review was registered on Open Science Framework. Studies on SDR in cerebral palsy were included. The studies to be included used SDR for management of spasticity in patients with cerebral palsy. The long-term complications of SDR mentioned in the articles were inventoried.

RESULTS

Thirty studies were included for qualitative review. Twenty-one types of complication were identified. Structural complications were the commonest: scoliosis (214/1,043, 20.5%), hyperlordosis (101/552, 18.2%), spondylolysis (55/574, 9.5%) and kyphosis (67/797, 8.4%). Neurological complications comprised constipation (70/485, 14.4%), hip subluxation (3/29, 10.3%), spastic syndrome (4/47, 8.5%), sensory changes (106/1290, 8.2%) and urinary incontinence (61/1013, 6%).

CONCLUSION

This review should help surgeons and parents alike to know about the potential complications of SDR. Complications may affect quality of life and should be weighed. Although the majority of these complications were managed conservatively, there would still be a physical, psychological and financial burden which should be taken into account. Screening should be continued vigorously throughout skeletal growth and at reduced frequency thereafter, for timely intervention in case of structural complications.

Hospital Burdens of Patients With Cerebral Palsy Undergoing Posterior Spinal Fusion for Scoliosis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Many patients undergoing posterior spinal fusion (PSF) for scoliosis have concurrent cerebral palsy (CP), which is associated with many medical comorbidities and inherent operative risk. We aimed to quantify the contribution of CP to increased cost, length of stay (LOS), and complication rates in patients with scoliosis undergoing PSF.

METHODS

Using the National Inpatient Sample database, we collected data regarding patient demographics, hospital characteristics, comorbidities, in-hospital complications, and mortality. Primary outcomes included complications, hospital LOS, and total hospital costs. Multivariate regression models assessed the contribution of CP to in-hospital complications, discharge status, and mortality. Linear regression identified the contribution of a diagnosis of CP on hospital LOS and inflation-adjusted cost.

RESULTS

Cerebral palsy was an independent predictor of several complications. The most striking differences were seen for mortality (odds ratio [OR]: 3.40, P < .001), a postoperative requirement for total parenteral nutrition (OR: 3.16, P < .001), urinary tract infection (OR: 2.75, P < .001), surgical site infection (OR: 2.67, P < .001), and pneumonia (2.21, P < .001). Patients with CP ultimately cost an additional $13 482 (P < .001) with a 2.07-day greater LOS (P < .001) than patients without CP.

CONCLUSION

Most complications were seen in higher rates in the CP cohort, with higher cost and LOS in patients with CP versus those with idiopathic scoliosis (IS). Our findings represent important areas of emphasis during preoperative consultations with patients with CP and their families. Extra care in patient selection and multifaceted treatment protocols should continue to be implemented with further investigation on how to mitigate common complications.

Efficacy of Selective Dorsal Rhizotomy and Intrathecal Baclofen Pump in the Management of Spasticity

BACKGROUND

Neurosurgical indications and interventions provided in the management of spasticity have evolved significantly over time. Selective dorsal rhizotomy (SDR) and intrathecal baclofen (ITB) pumps have been used to improve mobility, reduce lower extremity spasticity, and increase quality of life in patients with various diagnoses.

METHODS

Studies describing ITB and SDR outcomes in adult and pediatric patients were identified from Medline and Embase databases. Only publications between January 1990 to January 2021 were included. Combinations of search terms 'Selective Dorsal Rhizotomy', 'Selective Posterior Rhizotomy', 'functional posterior rhizotomy', 'intrathecal baclofen pump', and 'spasticity' were used. Only studies in English language and those that included parameters for lower extremity outcome (i.e., spasticity, ambulation) were included. Only studies describing follow-up 12 months or greater were included. Case reports, reviews without primary data, or inaccessible publications were excluded.

RESULTS

Two hundred and ninety publications between January 1990 to January 2021 were identified. Of these, 62 fit inclusion and exclusion criteria for a total of 1291 adult and 2263 patients. Etiologies in adult and pediatric populations varied substantially with multiple sclerosis, cerebral palsy, and trauma comprising the majority of causes for spasticity in adult patients. In pediatric patients, cerebral palsy was the predominant etiology of spasticity. While outcomes after SDR and ITB varied, both are effective for long-term tone reduction. SDR appeared to have a greater effect on function compared to baseline when comparing relatively similar subgroups. The complication rates for either intervention were significant; ITB had a much greater incidence of wound and hardware adverse events, whereas SDR was associated with a not insignificant incidence of new bladder or sensory deficit.

CONCLUSION

ITB and SDR have demonstrated efficacy and utility for tone reduction in a variety of conditions. The selection of a specific intervention may have a variety of determining features including the etiology of spasticity, age of patient, as well as balancing benefit and complication profiles of each technique. Appropriate patient selection is essential for providing optimal patient outcomes.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Palliative Rhizotomy: A Novel Technical Application

BACKGROUND

Spastic cerebral palsy is caused by an insult to the developing brain. Various medical and surgical procedures are used to reduce tone.

OBJECTIVE

To describe a novel method of magnetic resonance-guided laser interstitial thermal ablation for palliative rhizotomy.

METHODS

Patients treated at a single institution with percutaneous rhizotomy using magnetic resonance-guided laser interstitial thermal therapy were identified. Preoperative and postoperative Modified Ashworth Scale scores were collected as well as procedural information.

RESULTS

Two male children (7.8 and 19 yr, respectively) with spastic quadriparesis were treated using this technique. Neither patient experienced surgical or perioperative complications, and both were discharged from the hospital within 48 h. Each of them demonstrated improvement in his Modified Ashworth Scale score with no need for retreatment for spasticity at last follow-up.

CONCLUSION

These 2 cases illustrate a novel technique for treating spasticity in the setting of cerebral palsy. Further study of this technique in additional patients, and comparison with traditional methods of surgical tone reduction, are warranted.

Intraoperative electrophysiology during single-level selective dorsal rhizotomy: technique, stimulation threshold, and response data in a series of 145 patients

OBJECTIVE

Selective dorsal rhizotomy (SDR) is effective at permanently reducing spasticity in children with spastic cerebral palsy. The value of intraoperative neurophysiological monitoring in this procedure remains controversial, and its robustness has been questioned. This study describes the authors' institutional electrophysiological technique (based on the technique of Park et al.), intraoperative findings, robustness, value to the procedure, and occurrence of new motor or sphincter deficits.

METHODS

The authors analyzed electrophysiological data of all children who underwent SDR at their center between September 2013 and February 2019. All patients underwent bilateral SDR through a single-level laminotomy at the conus and with transection of about 60% of the L2-S2 afferent rootlets (guided by intraoperative electrophysiology) and about 50% of L1 afferent roots (nonselectively).

RESULTS

One hundred forty-five patients underwent SDR (64% male, mean age 6 years and 7 months, range 2 years and 9 months to 14 years and 10 months). Dorsal roots were distinguished from ventral roots anatomically and electrophysiologically, by assessing responses on free-running electromyography (EMG) and determining stimulation thresholds (≥ 0.2 mA in all dorsal rootlets). Root level was determined anatomically and electrophysiologically by assessing electromyographic response to stimulation. Median stimulation threshold was lower in sacral compared to lumbar roots (p < 0.001), and 16% higher on the first operated (right) side (p = 0.023), but unrelated to age, sex, or functional status. Similarly, responses to tetanic stimulation were consistent: 87% were graded 3+ or 4+, with similar distributions between sides. This was also unrelated to age, sex, and functional status. The L2-S2 rootlets were divided (median 60%, range 50%-67%), guided by response to tetanic stimulation at threshold amplitude. No new motor or sphincter deficits were observed, suggesting sparing of ventral roots and sphincteric innervation, respectively.

CONCLUSIONS

This electrophysiological technique appears robust and reproducible, allowing reliable identification of afferent nerve roots, definition of root levels, and guidance for rootlet division. Only a direct comparative study will establish whether intraoperative electrophysiology during SDR minimizes risk of new motor or sphincter worsening and/or maximizes functional outcome.

Long-term effects of selective dorsal rhizotomy in children with cerebral palsy: a systematic review

AIM

To evaluate the long-term effects of selective dorsal rhizotomy (SDR) 10 years or more after the procedure and complications observed any time after SDR in children with cerebral palsy (CP).

METHOD

Embase, PubMed, and the Cochrane Library were searched from their individual dates of inception through 1st June 2018 for full-text original articles in English that described long-term follow-up after SDR in children with CP. The authors independently screened publications to determine whether they met inclusion criteria; thereafter all authors extracted data on patient characteristics, the proportion of the original cohort being followed-up, and the reported outcomes.

RESULTS

Of the 199 studies identified, 16 were included in this evaluation: 14 were case series and two studies reported a retrospectively assigned comparison group. Evidence concerning function was limited by study design differences, clinical variability, loss to follow-up, and heterogeneity across trials.

INTERPRETATION

At 10 years or more follow-up, available studies generate low-level evidence with considerable bias. No functional improvement of SDR over routine therapy is documented. Furthermore, the long-term effects of SDR with respect to spasticity reduction is unclear, with many studies reporting a high amount of add-on spasticity treatment. More long-term follow-up using robust scientific protocols is required before it can be decided whether the use of SDR as routine therapy for children with CP is to be recommended or not.

WHAT THIS PAPER ADDS

Ten years after selective dorsal rhizotomy, available studies supply inconclusive evidence on functional outcomes. The long-term effect on spasticity is uncertain, studies reported a substantial need for add-on treatment. Short- and long-term complications seem frequent but are not reported in a consistent manner.

Selective dorsal rhizotomy: an illustrated review of operative techniques

OBJECTIVE

Selective dorsal rhizotomy (SDR) is a procedure primarily performed to improve function in a subset of children with limitations related to spasticity. There is substantial variability in operative techniques among centers and surgeons. Here, the authors provide a technical review of operative approaches for SDR.

METHODS

Ovid MEDLINE, Embase, and PubMed databases were queried in accordance with PRISMA guidelines. All studies included described a novel surgical technique. The technical nuances of each approach were extracted, including extent of exposure, bone removal, and selection of appropriate nerve roots. The operative approach preferred at the authors' institution (the "2 × 3 exposure") is also detailed.

RESULTS

Five full-text papers were identified from a total of 380 articles. Operative approaches to SDR varied significantly with regard to level of exposure, extent of laminectomy, and identification of nerve roots. The largest exposure involved a multilevel laminectomy, while the smallest exposure involved a keyhole interlaminar approach. At the Hospital for Sick Children, the authors utilize a two-level laminoplasty at the level of the conus medullaris. The benefits and disadvantages of the spectrum of techniques are discussed, and illustrative figures are provided.

CONCLUSIONS

Surgical approaches to SDR vary considerably and are detailed and illustrated in this review as a guide for neurosurgeons. Future studies should address the long-term impact of these techniques on functional outcomes and complications such as spinal deformity.

Intrathecal baclofen versus selective dorsal rhizotomy for children with cerebral palsy who are nonambulant: a systematic review

OBJECTIVE

Cerebral palsy (CP) is the most common childhood physical disability. Historically, children with hypertonia who are nonambulatory (Gross Motor Function Classification System [GMFCS] level IV or V) were considered candidates for intrathecal baclofen (ITB) therapy to facilitate care and mitigate discomfort. Selective dorsal rhizotomy (SDR) was often reserved for ambulant children to improve gait. Recently, case series have suggested SDR as an alternative to ITB in selected children functioning at GMFCS level IV/V. The objective for this study was to systematically review the evidence for ITB and SDR in GMFCS level IV or V children.

METHODS

Medline, Embase, Web of Science, and Cochrane databases were systematically searched. Articles were screened using the following inclusion criteria: 1) peer-reviewed articles reporting outcomes after SDR or ITB; 2) outcomes reported using a quantifiable scale or standardized outcome measure; 3) patients were < 19 years old at the time of operation; 4) patients had a diagnosis of CP; 5) patients were GMFCS level IV/V or results were reported based on GMFCS status and included some GMFCS level IV/V patients; 6) article and/or abstract in English; and 7) primary indication for surgery was hypertonia. Included studies were assessed with the Risk of Bias in Non-Randomized Studies - of Interventions (ROBINS-I) tool.

RESULTS

Twenty-seven studies met inclusion criteria. The most commonly reported outcomes were spasticity (on the Mean Ashworth Scale) and gross motor function (using the Gross Motor Function Measure), although other outcomes including frequency of orthopedic procedures and complications were also reported. There is evidence from case series that suggests that both ITB and SDR can lower spasticity and improve gross motor function in this nonambulatory population. Complication rates are decidedly higher after ITB due in part to the ongoing risk of device-related complications. The heterogeneity among study design, patient selection, outcome selection, and follow-up periods was extremely high, preventing meta-analysis. There are no comparative studies, and meaningful health-related quality of life outcomes such as care and comfort are lacking. This review is limited by the high risk of bias among included studies. Studies of SDR or ITB that did not clearly describe patients as being GMFCS level IV/V or nonambulatory were excluded.

CONCLUSIONS

There is a lack of evidence comparing the outcomes of ITB and SDR in the nonambulatory CP population. This could be overcome with standardized prospective studies using more robust methodology and relevant outcome measures.

Australian children undergoing selective dorsal rhizotomy: protocol for a national registry of multidimensional outcomes

INTRODUCTION

Selective dorsal rhizotomy (SDR) is a neurosurgical intervention intended to permanently reduce spasticity in the lower limbs and improve mobility in selected children with cerebral palsy (CP). Despite SDR having been performed worldwide for the past 30 years, there is moderate quality of evidence that SDR is effective in reducing spasticity with low to very low evidence of its effectiveness in improving gait, function and participation, using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system. Published studies have described outcomes for groups that differ in selection, surgical technique and postoperative rehabilitation making it difficult for clinicians to use this information to advise families on best management. There is substantial community interest in SDR. A small number of children with CP undergo SDR in Australia each year and some families seek the intervention at international sites. Capturing clinical outcomes and adverse event (AE) data for Australian children undergoing SDR will provide clinicians with information to help guide families considering SDR.

METHODS AND ANALYSIS

The Australian SDR Research Registry is a national registry of multidimensional outcomes for Australian children undergoing SDR in an Australian or overseas centre. Data will be collected for up to 10 years following the surgery, to include surgery and admission details, surgical and long-term AEs, and outcome measures across the body structure and functions, activity and participation domains of the International Classification of Functioning, Disability and Health. Data will be collected at baseline, during inpatient admission and at 1, 2, 5 and 10 years post. The aim of collecting these data is to improve understanding of short-, medium- and long-term outcomes and adverse effects of the intervention.

ETHICS AND DISSEMINATION

This study was approved by the individual Human Research and Ethics committees at the five Australian tertiary hospitals involved. Results will be disseminated via peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12618000985280; Pre-results.