Intraspinal Pathology Associated With Pediatric Scoliosis: A Ten-year Review Analyzing the Effect of Neurosurgery on Scoliosis Curve Progression

Pre-operative clinical deterioration and long-term surgical outcomes in 41 patients with split cord malformation type 1

PURPOSE

To document the pre-operative rate of clinical deterioration in a cohort of patients with split cord malformation type 1 (SCM 1) and the early- and long-term surgical outcome in these patients.

METHODS

Data from 41 patients with SCM 1 operated upon by the same surgeon (VR) between January 2008 to June 2023 were retrospectively reviewed with respect to history of clinical deterioration prior to surgery and early and long-term surgical outcomes.

RESULTS

The mean age of the patients at presentation was 79.3 months and the male to female ratio was 1:1.93. Twelve (29%) patients had congenital deficits whereas 4 (10%) patients had no neurological deficits. Twenty-six (63%) patients had kyphoscoliosis and 25 (61%) patients had motor dysfunction. Thirty-three (81%) patients (8/12 (67%) with congenital deficits) had clinical deterioration prior to surgery. By the age of 2 years, 56% of patients had clinical deterioration. After surgery, 18 (55%) patients with progressive symptoms had improvement in one or more of their symptoms on long-term follow-up (mean, 63.4 months). There were no predictors of surgical outcome.

CONCLUSIONS

Since over half of our patients with SCM 1 developed progression of congenital deficits or developed deficits by the age of 2 years, surgery should be performed as soon as possible in these children. On long-term follow-up after surgery, improvement can be expected in over half the patients.

Classification of and individual treatment strategies for complex tethered cord syndrome

Objective

To study the classification, diagnosis, and treatment strategies of complex tethered cord syndrome (C-TCS) on the basis of the patients' clinical symptoms, imaging findings, and therapeutic schedule.

Methods

The clinical data of 126 patients with C-TCS admitted to our department from January 2015 to December 2020 were retrospectively analyzed. Classification criteria for C-TCS were established by analyzing the causes of C-TCS. Different surgical strategies were adopted for different types of C-TCS. The Kirollos grading, visual analogue scale (VAS), critical muscle strength, and Japanese Orthopaedic Association (JOA) scores were used to evaluate the surgical outcomes and explore individualized diagnosis and treatment strategies for C-TCS.

Results

C-TCS was usually attributable to three or more types of tether-causing factors. The disease mechanisms could be categorized as pathological thickening and lipomatosis of the filum terminal (filum terminal type), arachnoid adhesion (arachnoid type), spina bifida with lipomyelomeningocele/meningocele (cele type), spinal lipoma (lipoma type), spinal deformity (bone type), and diastomyelia malformation (diastomyelia type). Patients with different subtypes showed complex and varied symptoms and required individualized treatment strategies.

Conclusion

Since C-TCS is attributable to different tether-related factors, C-TCS classification can guide individualized surgical treatment strategies to ensure complete release of the tethered cord and reduce surgical complications.

Younger age at spinal cord detethering is potentially associated with a reduced risk of curve progression in children with early onset scoliosis

PURPOSE

In children with early onset scoliosis (EOS) who have tethered spinal cord (TSC), spinal cord detethering is commonly performed prior to spinal deformity correction (SDC). The purpose of this study was to investigate whether age or curve magnitude at the time of detethering is associated with curve progression at a follow-up of at least 2 years. It was hypothesized that patients who undergo detethering at a younger age, or those with a smaller curve magnitude, would experience a reduced rate of curve progression when compared with those who are older or with larger curves.

METHODS

Patients with EOS who underwent detethering at least 2 years prior to SDC were identified in a multicenter international registry. Radiographs were assessed just prior to the detethering procedure (pre-detether) and at the most recent visit prior to SDC (most recent post-detether). The rate of curve progression > 10° was examined. Owing to unequal follow-up in individual patients, Cox regression was used to investigate associations between primary variables (age and magnitude of major coronal curve) and rate of curve progression.

RESULTS

37 patients met inclusion criteria and 18 (mean age: 3.7 ± 2.9 years, 66.7% female, mean follow-up: 3.4 ± 1.3 years) had radiographic data available for analysis. Pre-detether and most recent post-detether major coronal curves were 44.8° ± 18.5° and 47.6° ± 23.9°, respectively. 5 (27.8%) patients had curve progression > 10° at a follow-up of 3.2 ± 1.2 years. Patients with progression > 10° were older at the time of detethering when compared with those without (5.6 ± 2.8 vs. 3 ± 2.7 years, p = 0.084). Regression analysis demonstrated that as age at detethering increased by 1 year, the rate of curve progression > 10° increased by 28.6% [95% confidence interval (CI) 0.899; 1.839, p = 0.169]. There was no evidence of an association between pre-detethering curve magnitude and rate of curve progression > 10° [HR: 1.027, 95% CI 0.977; 1.079, p = 0.297].

CONCLUSION

In a small multicenter cohort of EOS patients with TSC, younger age, but not curve size, at the time of detethering was associated with a lower rate of scoliosis progression. Although these results indicate a potential role for early spinal cord detethering in the EOS population, they require further prospective investigation with a larger number of patients.

LEVEL OF EVIDENCE

Level II.

Reduced complication rate with simultaneous detethering and spinal deformity correction surgery compared to staged surgeries in patients with early onset scoliosis

PURPOSE

In patients with early onset scoliosis (EOS) and intraspinal anomalies, surgery may be necessary for both the tethered spinal cord (TSC) and spinal deformity. The purpose of this study was to determine if there is a difference in complications when TSC release and surgery for spinal deformity correction (SDC) are performed separately compared simultaneously.

METHODS

EOS patients with TSC who underwent detethering and SDC surgeries were identified through a multicenter registry. Patients were stratified into two groups. The simultaneous cohort consisted of patients receiving both detethering and SDC surgeries in a single anesthetic event on the same day, and the staged cohort consisted of patients undergoing detethering and SDC on two separate occasions. Postoperative complications up to 180 days for either surgery were assessed.

RESULTS

Twenty five (65.8%) patients were staged and 13 (34.2%) underwent a simultaneous approach. Percent curve correction following SDC surgery did not significantly differ between the groups (p = 0.36). Within 90 days postoperatively, 16 complications in 11 patients (44.0%) occurred in the staged group, whereas no complications occurred in the simultaneous cohort (p = 0.006). From 90-days to 180-days postoperatively, 4 additional complications in 3 patients (12.0%) occurred in the staged group, with no complications reported in the same timeframe for the simultaneous cohort.

CONCLUSION

To our knowledge, this is the largest multicenter comparative study to date, and it suggests that a simultaneous approach can be performed safely for EOS patients undergoing detethering and SDC surgeries, with a potentially lower risk profile than the traditional staged approach to these pathologies.

LEVEL OF EVIDENCE

Level III.

Scoliosis with Chiari I malformation without associated syringomyelia

PURPOSE

Many patients with presumed idiopathic scoliosis are found to have Chiari I malformation (CM-I) on MRI. The objective of this study is to report on scoliosis progression in CM-I with no syringomyelia.

METHODS

A retrospective review of patients with scoliosis and CM-I was conducted from 1997 to 2015. Patients with syringomyelia and/or non-idiopathic scoliosis were excluded. Clinical and radiographic characteristics were recorded at presentation and latest follow-up. CM-I was defined as the cerebellar tonsil extending 5 mm or more below the foramen magnum on MRI.

RESULTS

Thirty-two patients (72% female) with a mean age of 11 years (range 1-16) at scoliosis diagnosis were included. The average initial curve was 30.3° ± SD 16.3. The mean initial Chiari size was 9.6 mm SD ± 4.0. Fifteen (46.9%) experienced Chiari-related symptoms, and three (9%) patients underwent Posterior Fossa Decompression (PFD) to treat these symptoms. 10 (31%) patients went on to fusion, progressing on average 13.6° (95% CI 1.6-25.6°). No association was detected between decompression and either curve progression or fusion (p = 0.46, 0.60). For those who did not undergo fusion, curve magnitude progressed on average 1.0° (95% CI - 4.0 to 5.9°). There was no association between age, Chiari size, presence of symptoms, initial curve shape, or bracing treatment and fusion.

CONCLUSION

Patients with CM-I and scoliosis may not require surgical treatment, including PFD and fusion. Scoliosis curvature stabilized in the non-surgical population at an average progression of 1.0°. These results suggest that CM-I with no syringomyelia has minimal effect on scoliosis progression.

Increased cautiousness in adolescent idiopathic scoliosis patients concordant with syringomyelia fails to improve overall patient outcomes

Background:

Adolescent idiopathic scoliosis (AIS) is a common cause of spinal deformity in adolescents. AIS can be associated with certain intraspinal anomalies such as syringomyelia (SM). This study assessed the rate o f SM in AIS patients and compared trends in surgical approach and postoperative outcomes in AIS patients with and without SM.

Methods:

The database was queried using ICD-9 codes for AIS patients from 2003–2012 (737.1–3, 737.39, 737.8, 737.85, and 756.1) and SM (336.0). The patients were separated into two groups: AIS-SM and AIS-N. Groups were compared using t-tests and Chi-squared tests for categorical and discrete variables, respectively.

Results:

Totally 77,183 AIS patients were included in the study (15.2 years, 64% F): 821 (1.2%) – AIS-SM (13.7 years, 58% F) and 76,362 – AIS-N (15.2 years, 64% F). The incidence of SM increased from 2003–2012 (0.9 to 1.2%, P = 0.036). AIS-SM had higher comorbidity rates (79 vs. 56%, P < 0.001). Comorbidities were assessed between AIS-SM and AIS-N, demonstrating significantly more neurological and pulmonary in AIS-SM patients. 41.2% of the patients were operative, 48% of AIS-SM, compared to 41.6% AIS-N. AIS-SM had fewer surgeries with fusion (anterior or posterior) and interbody device placement. AIS-SM patients had lower invasiveness scores (2.72 vs. 3.02, P = 0.049) and less LOS (5.0 vs. 6.1 days, P = 0.001). AIS-SM patients underwent more routine discharges (92.7 vs. 90.9%). AIS-SM had more nervous system complications, including hemiplegia and paraplegia, brain compression, hydrocephalous and cerebrovascular complications, all P < 0.001. After controlling for respiratory, renal, cardiovascular, and musculoskeletal comorbidities, invasiveness score remained lower for AIS-SM patients (P < 0.001).

Conclusions:

These results indicate that patients concordant with AIS and SM may be treated more cautiously (lower invasiveness score and less fusions) than those without SM.

Spinal-Shortening Process Positively Improves Associated Syringomyelia in Patients with Scoliosis After Single-Stage Spinal Correction

OBJECTIVE

Single-stage spinal correction without previous neurosurgical intervention has been attempted in patients with scoliosis associated with syringomyelia (SM). However, evidence to demonstrate its potential influence on associated SM from direct spinal correction is still lacking. The aim of the present study was to explore the role of spinal shortening in the prognosis of SM-associated scoliosis after single-stage spinal correction without previous neurosurgical intervention.

METHODS

Patients with SM-associated scoliosis without previous neurological intervention, who had undergone posterior direct instrumental correction (PDIC) without osteotomy and posterior vertebral column resection (PVCR) at a single center, were selected for comparative analysis. The basic demographic and pre- and postoperative imaging data of the spinal deformity and SM at the final follow-up were compared separately for the 2 different spinal correction procedures.

RESULTS

A total of 23 patients were included in the final analysis: 13 had undergone PDIC and 10 had undergone PVCR. The mean follow-up period was 6.2 years (range, 5-9 years). At the final follow-up, the mean corrective rate of scoliosis and kyphosis was 65.7% and 48.4%, respectively. Obvious SM reduction was achieved in 11 patients (47.8%), with an average reduction of 37.3%. No patient experienced neurologic deterioration or had required further neurosurgical intervention for SM during follow-up. The patients who had undergone PVCR had had much more severe scoliosis (98.8° vs. 60.5°; P = 0.000) and kyphosis (74.8° vs. 43.6°; P = 0.032). Moreover, 80.0% of the patients who had undergone PVCR had experienced obvious SM improvement compared with 23.1% of those who had undergone PDIC (P = 0.007).

CONCLUSIONS

The reduction of spinal cord tension is an important factor influencing SM improvement. As the most powerful spinal-shortening osteotomy, PVCR can effectively correct severe spinal deformities and improve associated SM. Single-stage posterior spinal correction can be a potential choice for selected patients with scoliosis and untreated SM using strict inclusion criteria, which will not only achieve safe spinal correction but could also steadily improve and stabilize SM.

Are craniocervical angulations or syrinx risk factors for the initiation and progression of scoliosis in Chiari malformation type I?

The pathophysiology behind the instigation and progression of scoliosis in Chiari malformation type I (CMI) patients has not been elucidated yet. This study aims to explore the initiating and progressive factors for scoliosis secondary to CMI. Pediatric patients with CMI were retrospectively reviewed for radiological characteristics of tonsillar herniation, craniocervical anomaly, syrinx morphology, and scoliosis. Subgroup analyses of the presence of syrinx, scoliosis, and curve progression were also performed. A total of 437 CMI patients were included in the study; 62% of the subjects had syrinx, and 25% had scoliosis. In the subgroup analysis of 272 CMI patients with syrinx, 78 of them (29%) had scoliosis, and multiple logistic regression analysis showed that tonsillar herniation ≥ 10 mm (OR 2.13; P = 0.033) and a clivus canal angle ≤ 130° (OR 1.98; P = 0.025) were independent risk factors for scoliosis. In the subgroup analysis of 165 CMI patients without syrinx, 31 of them (19%) had scoliosis, and multiple logistic regression analysis showed that a clivus canal angle ≤ 130° (OR 3.02; P = 0.029) was an independent risk factor for scoliosis. In the subgroup analysis of curve progression for 97 CMI patients with scoliosis, multiple logistic regression analysis showed that anomalies of the craniocervical junction and syrinx were not risk factors for curve progression. Many complex factors including craniocervical angulation, tonsillar herniation, and syrinx might participate in the instigation of scoliosis for CMI patients, and the relationship between craniocervical angulation and scoliosis deserves further study.

Effect of simultaneous surgical treatment in scoliosis associated with intraspinal abnormalities: A retrospective study

To evaluate the outcomes of single-stage surgical treatment for spinal deformity and coexisting intraspinal pathologies, 12 patients who underwent single-stage surgical treatment for spinal deformity and co-existing intraspinal abnormalities between October 2016 and January 2017 were enrolled in the present study. Treatment for intraspinal abnormalities, posterior correction, osteotomy and internal fixation were performed simultaneously. The clinical and radiological outcomes, surgical details, complications and postoperative outcomes were evaluated. The mean fusion length was 11.0±2.8. Both scoliosis Cobb angle (pre-surgery 65.9±13.4 vs. post-surgery 21.7±9.4) and kyphosis (pre-surgery 71.1±19.5 vs. post-surgery 31.4±10.4) were significantly improved post-surgery. Tethered cords were released and epidermoid cysts, gangliogliomas, meningiomas and lipomas were resected. Muscle strength in all patients was improved. The muscular tone of 8 patients was improved. No severe complications occurred postoperatively. None of the patients experienced deterioration in their neurological status nor loss of correction during the 12-24 months' follow-up. The simultaneous surgical treatment for spinal deformity and intraspinal pathology seems to be a safe and effective approach. Neurological deficits were improved postoperatively. Osteotomy produces satisfactory correction results.

Perioperative Halo-Gravity Traction in the Treatment of Scoliosis with Intraspinal Anomalies

OBJECTIVE

To investigate the efficacy and safety of preoperative halo-gravity traction and 1-stage posterior surgery for the treatment of scoliosis with intramedullary anomalies.

METHODS

A total of 11 patients with scoliosis with intramedullary anomalies were evaluated. All patients were treated with preoperative halo-gravity traction and 1-stage posterior surgery. The average age was 11.4 years (range, 7-21 years). All patients were followed-up for at least 2 years (mean, 3.5 years; range, 2-5 years). Their radiologic presentations and complications were reviewed.

RESULTS

The operating time was 7.9 hours, and the intraoperative bleeding amount was 1890 mL. Both the Cobb angle of scoliosis and kyphosis were significantly improved after halo-gravity traction and the operation (P < 0.05). Tethered cords were released, and intraspinal masses (neurofibromatosis and lipoma) were excised. Syringomyelia and split spinal cord malformations were left untreated. None of the patients experienced deterioration in their neurologic status after surgery. No severe complications, such as infection, cerebrospinal fluid leakage, failed internal fixation, or fractured pedicle screws or rods occurred after the operation. There was no deterioration of neurologic function, delayed infection, or pseudoarthrosis during the follow-up visits.

CONCLUSIONS

Preoperative halo-gravity traction and 1-stage posterior surgery provided patients who had scoliosis and intramedullary anomalies an effective and safe treatment option with few complications.

Cervical Abnormalities in Severe Spinal Deformity: A 10-year MRI Review

Objective

To investigate the incidence of cervical anomalies (CA), including cervical intraspinal neural axis abnormalities (CIINAA) and/or cervical osseous abnormalities (COA), and the clinical relevance in severe spinal deformities (SSD) at a single center.

Methods

A retrospective study of SSD admitted for spinal surgery from January 2003 to January 2015 was conducted at a single center. Inclusion criteria: patients who present with coronal Cobb over 90° (and/or sagittal cobb ≥90°); and patients with complete imaging and clinical data preoperatively. Exclusion criteria: ankylosing spondylitis, adult onset scoliosis, scoliosis secondary to bone destruction. There were 108 SSD patients who fulfilled the criteria in this research (41 males and 67 females). The mean age of the patients was 18.1 ± 2.7 years (range, 10–45 years). The clinical and radiological data of these patients were reviewed to identify CA and to analyze the relationship between clinical and radiographic characteristics in the population of SSD.

Results

The major curves of scoliosis and segmental kyphosis were 109.1° ± 24.7° and 91.2° ± 29.1°. Cervical abnormalities were detected in 56 patients (51.85%) with 9 different CA, including 28 patients (25.9%) with 6 different COA, 21 patients (19.4%) with 3 different CIINAA, and 7 patients (6.5%) with a combination of COA and cervical intraspinal neural axis abnormalities (CINAA). Basilar invagination and Klippel–Feil syndrome were the most frequent COA. Syringomyelia was the most frequent CINAA. SSD with COA in upper vertebral levels (UVL) had a higher incidence of CINAA than those in subaxial vertebral levels (SVL) (P = 0.024) and SSD with multiple COA (mCOA) in UVL had a higher incidence of CINAA than those with single COA (sCOA) (P = 0.029). In the present study, 83.9% of the SSD with CA were asymptomatic.

Conclusion

The incidence of CA in SSD was 51.85%, with most presenting with intact neurologic status. As the diversity of COA increased, we found a higher incidence of CINAA, especially in UVL.

Continuous Hypodynamic Change of Cerebrospinal Fluid Flow as A Potential Factor Working for Experimental Scoliotic Formation

Scoliosis is often associated with syringomyelia (SM). As an important role in SM formation, the influence from abnormal cerebrospinal fluid (CSF) flow is still unclear to scoliosis. The aim of this experimental work is to explore the connection between CSF flow and scoliosis through imaging and histological analysis on the basis of a kaolin-induced scoliotic rabbit model. For imaging observation, in 40 kaolin-induced rabbits by C7 spinal cord injection, through pre- and postoperative MRI and radiography, CSF flow and scoliosis formation were detected at consecutive phases. According to the final formation of scoliosis until postoperative week 12, the kaolin-induced rabbits were divided into 2 groups. Through comparing the 2 groups, the relationship between the changes of CSF flow velocity and scoliosis formation were reviewed and analyzed. For histological observation, another 20 kaolin-induced rabbits were used for consecutive histological observations of spinal cord at postoperative 3-day, 2-week, 4-week and 6-week. After kaolin-induction, abnormal spinal coronal curve was observed from postoperative week 6 in the 37 survived rabbits. At postoperative week 12, scoliosis formation was detected in 73.0% kaolin-induced rabbits and the mean Cobb angle was 27.4°. From the comparison between scoliotic and non-scoliotic groups, the difference of the velocities of CSF flow was more obviously from postoperative week 4 to 12, especially after week 6. In the scoliotic group, the peak velocity of CSF flow was diseased gradually following scoliosis formation after induction. Moreover, the decrease of the peak velocities of CSF flow from preoperation to postoperative 12 weeks (ΔVmax), including up-flow (ΔVUmax) and down-flow (ΔVDmax), were positively correlated to the final scoliotic Cobb angle (P < 0.01). Through histological observation at different phases, the distinctive pathological changes of the spinal cord included early inflammatory reaction, adhesion and blockage in the subarachnoid space and the central canal, perivascular space enlargement, central canal expansion, which suggested the CSF flow being blocked by multiple ways after kaolin-induction. In conclusion, experimental scoliosis can be successfully induced by intraspinal kaolin injection. In this model, continuous hypodynamic change of CSF flow was correlated to the formation of scoliosis, which could be an important factor of scoliotic pathogenesis being explored furtherly.

Chiari I malformations with syringomyelia: long-term results of neurosurgical decompression

STUDY DESIGN

Retrospective case series.

OBJECTIVES

The objective was to assess the long-term outcomes on scoliosis following Chiari-I (CM-I) decompression in patients with CM-I and syringomyelia (SM). A secondary objective was to identify risk factors of scoliosis progression.

BACKGROUND

The association between CM-I with SM and scoliosis is recognized, but it remains unclear if CM-I decompression alters the long-term evolution of scoliosis in patients with associated syringomyelia.

METHODS

A retrospective review of children with scoliosis, CM-I, and SM during 1997-2015 was performed. Congenital, syndromic, and neuromuscular scoliosis were excluded. Clinical and radiographic characteristics were recorded at presentation, pre-decompression, after 1-year, and latest follow-up. A scale to measure syringomyelia area on MRI was used to evaluate SM changes post-decompression.

RESULTS

65 children with CM-I, SM, and scoliosis and a mean age of 8.9 years (range 0.7-15.8) were identified. Mean follow-up was 6.9 years (range 2.0-20.4). Atypical curves were present in 28 (43%) children. Thirty-eight patients (58%) underwent decompression before 10 years. Syringomyelia size reduced a mean of 70% after decompression (p < 0.001). Scoliosis improved in 26 (40%), stabilized in 17 (26%), and progressed in 22 (34%) cases. Early spinal fusion was required in 7 (11%) patients after a mean of 0.5 ± 0.37 years and delayed fusion in 16 (25%) patients after 6.0 ± 3.24 years. The remaining 42 (65%) patients were followed for a median of 6.1 years (range 2.0-12.3) without spine instrumentation or fusion. Fusion patients experienced less improvement in curve magnitude 1-year post-decompression (p < 0.001) and had larger curves at presentation (43° vs. 34°; p = 0.004).

CONCLUSIONS

Syringomyelia size decreased by 70% after CM-I decompression and scoliosis stabilized or improved in two-thirds of patients. Greater curve improvement within the first year post-decompression and smaller curves at presentation decreased the risk of spinal fusion. Neurosurgical decompression is recommended in children with CM-I, SM, and scoliosis with the potential to treat all three conditions.

LEVEL OF EVIDENCE

Level IV.

Comparison of Radiological Features and Clinical Characteristics in Scoliosis Patients With Chiari I Malformation and Idiopathic Syringomyelia: A Matched Study

STUDY DESIGN

Retrospective study.

OBJECTIVE

To compare syrinx characteristics, scoliotic parameters, and neurological deficits between Chiari I malformation (CIM) and idiopathic syringomyelia (IS) in the scoliotic population.

SUMMARY OF BACKGROUND DATA

CIM and IS are common in neuromuscular scoliosis patients; however, differences in syrinx characteristics, scoliotic parameters, and neurological deficits between CIM and IS are unclear.

METHODS

Thirty-six patients with scoliosis secondary to CIM were enrolled retrospectively and matched with 36 IS patients for sex, age, scoliosis classification, and Cobb angle. Information on radiographic features of scoliosis and syrinx and neurological deficits was systematically collected.

RESULTS

Sex, age, and coronal, and sagittal scoliosis parameters did not differ between the CIM and IS groups. The CIM group had a longer syrinx (12.9 ± 4.0 vertebral levels vs. 8.7 ± 5.5 vertebral levels, P < 0.001), a higher cranial extent (3.6 ± 2.2 vs. 5.2 ± 3.5, P = 0.027), and a lower caudal extent (15.6 ± 2.9 vs. 13.0 ± 4.6, P = 0.006) than the IS group, despite no differences in syrinx/cord (S/C) ratio or syrinx classification. No differences in neurological deficits were identified between the CIM and IS patients.

CONCLUSION

With demographic and scoliotic coronal parameters matched, the CIM patients had a longer syrinx, located at a higher cranial and lower caudal level, compared with the IS group. No significant differences in syrinx S/C ratio, sagittal features of scoliosis, or neurological deficits were detected between the two groups.

LEVEL OF EVIDENCE

3.

Long-term evaluation of intraoperative neurophysiological monitoring-assisted tethered cord surgery

PURPOSE

Patients with tethered spinal cord have been investigated for short-term effects after tethered spinal cord surgery in the past. However, little is known about the long-term effects in this patient group. In this retrospective, longitudinal, observational study, a patient sample of a previous report of 65 patients was reassessed to observe the long-term effects of intraoperative neurophysiological monitoring-assisted tethered cord surgery.

METHODS

With the use of patient charts and a survey, patients were scored on four domains: (1) neurological deficits, (2) urological deficits, (3) pain symptoms, and (4) orthopedic deficits. Measurements were performed at four moments in time: (1) preoperatively, (2) postoperatively, (3) follow-up 1 (4.6 years), and (4) follow-up 2 (11.2 years). Besides this, a subgroup analysis and a quality of life questionnaire were performed.

RESULTS

When observing the symptom domains in the long-term, the pain domain appeared to improve most postoperatively after which it remained stable over time. The neurological and urological domains showed a stable, slightly decreasing trend in the long-term follow-up. The orthopedic domain showed a significant increase of the number of patients with scoliosis during the long-term follow-up.

CONCLUSIONS

Lasting effects of stability in the neurological, urological, and pain domains were observed. Close monitoring during follow-up might contribute to early recognition of progressive scoliosis, in spite of detethering, in a risk group defined by females who underwent tethered cord surgery at or under the age of 12 years old with either lipomyelomeningocele, split cord malformation, or myelomeningocele. Detethering does not appear to protect these patients against progressive scoliosis.