Trends in the presentation, surgical treatment, and outcomes of tethered cord syndrome: A nationwide study from 2001 to 2010

Diagnosis and Treatment of Tethered Spinal Cord: A Systematic Review

CONTEXT

Tethered cord syndrome is associated with motor and sensory deficits.

OBJECTIVE

Our objective was to summarize evidence regarding the diagnosis, prophylactic surgery, symptomatic treatment, and repeat surgery of tethered spinal cord in a systematic review (CRD42023461296).

DATA SOURCES AND STUDY SELECTION

We searched 13 databases, reference-mined reviews, and contacted authors to identify diagnostic accuracy studies and treatment studies published until March 2024.

DATA EXTRACTION

One reviewer abstracted data, and a content expert checked the data for accuracy. We assessed the risk of bias, strength of evidence (SoE), and applicability.

RESULTS

The evidence base includes 103 controlled studies, many with risk of bias and applicability concerns, and 355 case series providing additional clinical information. We found moderate SoE for MRI diagnosing tethered spinal cord, with medium to high diagnostic sensitivity and specificity. A small number of prophylactic surgery studies suggested motor function benefits and stability of neurologic status over time, but also complications such as surgical site infection (low SoE). A larger body of evidence documents treatments for symptomatic patients; studies revealed improvement in neurologic status after surgical detethering (low SoE), but also postoperative complications such as cerebrospinal fluid leakage (moderate SoE). A small body of evidence exists for retethering treatment (low or insufficient SoE for all outcomes).

LIMITATIONS

There was insufficient evidence for key outcomes (eg, over- or undertreatment, clinical impact of diagnostic modalities, ambulation, quality of life).

CONCLUSIONS

This comprehensive overview informs difficult clinical decisions that parents and their children with tethered spinal cords, as well as their health care providers, face.

Predictors of surgical treatment in children with tethered fibrofatty filum terminale

OBJECTIVE

Thickened or fatty filum terminale is an occult lesion that can cause tethered cord syndrome requiring surgical untethering. This study's objectives were to estimate the incidence of tethered fibrofatty filum terminale (TFFT) in a large insured pediatric population, identify predictors of surgery among those TFFT patients, and assess a diagnostic algorithm.

METHODS

TFFT was defined according to the ICD-9-CM code for cord tethering (742.59), after excluding codes for diastematomyelia, lipomyelomeningocele, terminal myelocystocele, meningocele, and myelomeningocele. Utilizing the Optum Insight database for 2001-2014, the authors identified pediatric patients (< 21 years) in the US who were diagnosed with a tethered cord and estimated the TFFT incidence rates in that source population and the surgical untethering probability among TFFT patients over the 14-year period. Logistic regression was used to estimate the effects (adjusted OR and 95% CI) of age at diagnosis, sex, Charlson Comorbidity Index (CCI) score, diagnosis of Chiari malformation type I, diagnosis of syrinx, and the probability of surgery by US census region. Lastly, to evaluate their algorithm for identifying TFFT from ICD-9 codes, the authors estimated its positive predictive value (PPV) among 50 children who were diagnosed at their institution and met the ICD-9-CM criteria.

RESULTS

There were 3218 diagnoses of TFFT, with 482 of these pediatric patients undergoing tethered cord release during the study period. The estimated incidence rate was 12.0 per 100,000/year (95% CI 11.6-12.4 per 100,000/year). The incidence rate was slightly higher in females than in males (12.7 vs 11.4 per 100,000/year). The probability of surgery in the total pediatric TFFT population was 15.0% (95% CI 13.8%-16.2%) and was greater in children with a syrinx (OR 2.2, 95% CI 1.6-3.0), children 7-11 years of age at diagnosis versus < 1 year (OR 1.5, 95% CI 1.1-2.0), CCI score ≥ 3 versus 0 (OR 2.3, 95% CI 1.4-3.8), and residents of the Western vs Northeastern US (OR 2.3, 95% CI 1.6-3.5). In the authors' own institution's database, the PPV of TFFT was 35/50 (70.0%, 95% CI 57.3%-82.7%) for identifying tethered cord due to fibrofatty filum terminale among childhood positives.

CONCLUSIONS

Patients with comorbidities or an associated syrinx showed a higher risk of untethering procedures for TFFT. Also, surgery was appreciably more frequent in the Western US. These findings signify the need for a collaborative prospective cohort study of long-term outcomes for TFFT patients with and without surgery to determine which patients should have surgery.

Pediatric tethered cord release: an epidemiological and postoperative complication analysis

Background

Tethered cord release (TCR) is a common procedure in pediatric neurosurgery. Despite a reputation for being relatively safe, the risk factors for postoperative complications are poorly understood.

Methods

In this study, the American College of Surgeons-National Surgical Quality Improvement Program Pediatric Database (ACS-NSQIP-P) was reviewed to identify the demographics, risk factors, and 30-day postoperative complications for tethered cord release using univariate and multivariate analysis. A detailed analysis of reasons for readmission and reoperation was also performed.

Results

Three thousand and six hundred eighty-two pediatric patients were studied. Males undergoing TCR were younger (5.6 vs. 6.1 years) and had a higher rate of pre-operative comorbidities but lower 30-day complication rate versus females. Patients who later developed complications were more likely to require a microscope intraoperatively, had longer operative times, and worse preoperative American Society of Anesthesiologists (ASA) class.

Conclusions

Despite being a relatively safe procedure, TCR in the pediatric population carries a finite risk of complications. In this large, international database study, males were found to have a greater number of risk factors prior to TCR, while females exhibit a higher risk of developing postoperative complications. This paper provides a large sample size of multi institutional pediatric patients undergoing TCR and may serve as a contemporary "snapshot" for future studies.

The Use of Prone Magnetic Resonance Imaging to Rule Out Tethered Cord in Patients With Structural Spine Anomalies: A Diagnostic Technical Note for Surgical Decision-making

Tethered cord syndrome (TCS) is a clinical diagnosis that can be difficult to establish, as symptoms do not always match classic radiological findings, such as a low-lying conus. Surgery for spinal detethering is not without risk and does not always result in clinical improvement. Prone magnetic resonance imaging (MRI) has been described as a tool to assess the mobility of the spine. This is a technical imaging report where prone imaging was a factor that influenced the decision to defer surgery in favor of conservative management. T1 and T2 sagittal and T1 axial MRI imaging were obtained with the patient supine, and then repeated in the prone position. An anteroposterior conus movement of >10% of the canal width was considered normal. There was significant anterior movement of the conus when switching to the prone position. Surgery was deferred, and the patient improved after a regimen of intensive physical therapy. Prone MRI can be a useful tool to have in our neurosurgical armamentarium when assessing spinal cord tethering. Surgery is not recommended when normal anteroposterior movement of the conus is present.