Features of the lumbar spine on magnetic resonance images following sectioning of filum terminale

Fibrofatty filum terminale: long-term outcomes from a Singapore children's hospital

OBJECTIVE

The role of prophylactic detethering a fibrofatty filum terminale (FFT) remains equivocal. Furthermore, long-term studies focusing on urological outcomes are sparse. The aims of this study were to present an institutional experience on the perioperative and long-term outcomes of FFT surgery and to assess for factors that contribute to postoperative clean intermittent catheterization (CIC).

METHODS

This was a single-institution, retrospective study conducted over a 20-year period. Patients younger than 19 years of age who underwent surgery for FFT were included. Variables of interest included patient demographics, clinical presentation, radiological findings, postoperative complications, and long-term need for CIC. Outcomes were measured using the Necker functional score and modified Hoffer Functional Ambulation scale score at 3, 6, and 12 months postdischarge.

RESULTS

A total of 164 surgeries were performed for FFT from 2000 to 2020. The median age at surgery was 1.1 years, and the mean follow-up duration was 8.3 years. There were 115 patients (70.1%) who underwent prophylactic-intent surgery and 49 patients (29.9%) who underwent therapeutic-intent surgery. The proportion of therapeutic-intent surgeries increased significantly with age percentiles (0-20th, 21.9%; 20th-40th, 9.1%; 40th-60th, 18.2%; 60th-80th, 36.4%; and 80th-100th, 63.6% [p < 0.001]). Thirty patients (18.3%) had an associated syndrome, the most common (n = 19, 11.6%) being VACTERL (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities). Forty-eight patients (29.3%) had an associated malformation (anorectal anomaly = 37, urogenital anomaly = 16, and sacral anomaly = 3). Cutaneous manifestation was the most common presentation (n = 96, 58.5%), followed by lower-limb neurological deficits (n = 21, 12.8%). A low-lying conus was present in 36.0% of patients (n = 59), and 16.5% had an associated syrinx (n = 27). There were 26 patients (18.8%) with an abnormal preoperative urodynamic study. Three patients (1.8%) had postoperative complications that required repeat surgery. There were no cases of CSF leakage. One patient (0.6%) developed retethering requiring another surgery. Postoperative CIC was required in 11 patients (6.7%). Multivariable analyses showed that an abnormal preoperative urodynamic study (adjusted OR 5.5 [95% CI 1.27-23.9], p = 0.023) and having an intraspinal syrinx (adjusted OR 5.29 [95% CI 1.06-26.4], p = 0.042) were associated with the need for CIC.

CONCLUSIONS

The authors' results demonstrate that detethering surgery for FFT is a relatively safe procedure and can be performed prophylactically. Nonetheless, the risks of postoperative CIC should be emphasized during the preoperative counseling process.

Epidural Placement in a Patient With a Type 2 Split Cord Malformation in the Interventional Pain Management Setting: A Case Report

Split cord malformations are rare spinal dysraphisms in which 2 separate spinal cords are present. Despite its diagnosis in all age groups, split cord malformations are not well described. The clinical presentation and symptom severity are highly variable. Anesthesiologists may encounter patients with known or unknown split cord malformations without much information to guide clinical decision-making and procedural risks of neuraxial anesthesia. This is the first case to the authors' knowledge of utilizing a caudal epidural injection for pain management in a patient with a diagnosed split cord malformation.

Is the Postoperative Horizontal Decubitus Position Following Transection of a Tight Filum Terminale in Pediatric Patients Necessary? - A Retrospective Cohort Study

After untethering surgery of a tethered spinal cord of a tight filum terminale, patients are usually kept in the horizontal decubitus position to prevent cerebrospinal fluid (CSF) leakage. However, the optimal period for keeping these patients in this position has not been established yet. Surgical results in two groups of pediatric patients with a tight filum terminale were retrospectively analyzed. Group A was maintained in the horizontal decubitus position for 72 h and group B was managed without being kept in this position postoperatively. A total of 313 patients underwent sectioning of a tight filum terminale. Of these patients, 144 were maintained horizontally for 72 h postoperatively (group A) and 169 were managed without this position (group B). Among the patients who were maintained horizontally for 72 h, one (0.7%) developed pseudomeningocele. No patients experienced CSF leakage in this group. Among the patients who were not horizontal, one (0.6%) developed CSF leakage and one (0.6%) developed pseudomeningocele. Maintaining patients without restriction of their position does not appear to change the rate of postoperative CSF leakage or pseudomeningocele. This suggests that maintaining patients horizontally after transection of a tight filum terminale is not necessary for preventing CSF leakage.

Long-Segment Fusion for Adult Spinal Deformity Correction Using Low-Dose Recombinant Human Bone Morphogenetic Protein-2

BACKGROUND:

Although use of very high-dose recombinant human bone morphogenetic protein-2 (rhBMP-2) has been reported to markedly improve fusion rates in adult spinal deformity (ASD) surgery, most centers use much lower doses due to cost constraints. How effective these lower doses are for fusion enhancement remains unclear.

OBJECTIVE:

To assess fusion rates using relatively low-dose rhBMP-2 for ASD surgery.

METHODS:

This was a retrospective review of consecutive ASD patients that underwent thoracic to sacral fusion. Patients that achieved 2-year follow-up were analyzed. Impact of patient and surgical factors on fusion rate was assessed, and fusion rates were compared with historical cohorts.

RESULTS:

Of 219 patients, 172 (78.5%) achieved 2-year follow-up and were analyzed. Using an average rhBMP-2 dose of 3.1 mg/level (average total dose = 35.9 mg/case), the 2-year fusion rate was 73.8%. Cancellous allograft, local autograft, and very limited iliac crest bone graft (&lt;20 mL, obtained during iliac bolt placement) were also used. On multivariate analysis, female sex was associated with a higher fusion rate, whereas age, comorbidity score, deformity type, and 3-column osteotomy were not. There were no complications directly attributable to rhBMP-2.

CONCLUSION:

Fusion rates for ASD using low-dose rhBMP-2 were comparable to those reported for iliac crest bone graft but lower than for high-dose rhBMP-2. Importantly, there were substantial differences between patients in the present series and those in the historical comparison groups that could not be fully adjusted for based on available data. Prospective evaluation of rhBMP-2 dosing for ASD surgery is warranted to define the most appropriate dose that balances benefits, risks, and costs.

Spinal cord abnormalities in sports

Many types of spinal abnormalities can have an impact on an athlete’s ability to participate in sports. One of the challenges in the current era is distinguishing the clinically relevant lesions from the incidental. Almost without exception, a Chiarimal formation, significant syringomyelia or other cyst compressing the spinal cord or nerve roots, tethered spinal cord, or spinal tumor should prompt referral to a neurosurgeon. However, tonsillar ectopia (descent of the cerebellum less than 5 mm beyond the foramen magnum) and small dilatations of the central canal, are very commonly seen and appear to represent normal anatomic variants that place athletes at no increased risk of spinal injury, and should not be considered a contraindication to play. The recommendations made in this article are largely based on consensus and experience, but as we gain more clinical experience to correlate with the increasingly sophisticated imaging findings, we hope that these recommendations can be refined further.