Spine-shortening vertebral osteotomy for tethered cord syndrome: report of three cases

Disparities in Indications and Outcomes Reporting for Spinal Column Shortening for Tethered Cord Syndrome: The Need for a Standardized Approach

STUDY DESIGN

Systematic review.

OBJECTIVE

To identify commonly reported indications and outcomes in spinal column shortening (SCS) procedures.

BACKGROUND

SCS is a surgical procedure used in patients with tethered cord syndrome-characterized by abnormal attachment of neural components to surrounding tissues-to shorten the vertebral column, release tension on the spinal cord/neural elements, and alleviate associated symptoms.

PATIENTS AND METHODS

PubMed and EMBASE searches captured SCS literature published between 1950 and 2023. Prospective/retrospective cohort studies and case series were included without age limit or required follow-up period. Review articles without new patient presentations, meta-analyses, systematic reviews, conference abstracts, and letters were excluded. Studies included adult and pediatric patients.

RESULTS

The 29 identified studies represented 278 patients (aged 5-76 yr). In 24.1% of studies, patients underwent primary tethered cord syndrome intervention through SCS. In 41.4% of studies, patients underwent SCS after failed previous primary detethering (24.1% of studies were mixed and 10.3% were unspecified). The most commonly reported nongenitourinary/bowel surgical indications were back pain (55.2%), lower-extremity pain (48.3%), lower-extremity weakness (48.3%), lower-extremity numbness (34.5%), and lower-extremity motor dysfunction (34.5%). Genitourinary/bowel symptoms were most often described as nonspecific bladder dysfunction (58.6%), bladder incontinence (34.5%), and bowel dysfunction (31.0%). After SCS, nongenitourinary/bowel outcomes included lower-extremity pain (44.8%), back pain (31.0%), and lower-extremity sensory and motor function (both 31.0%). Bladder dysfunction (79.3%), bowel dysfunction (34.5%), and bladder incontinence (13.8%) were commonly reported genitourinary/bowel outcomes. In total, 40 presenting surgical indication categories and 33 unique outcome measures were reported across studies. Seventeen of the 278 patients (6.1%) experienced a complication.

CONCLUSION

The SCS surgical literature displays variability in operative indications and postoperative outcomes. The lack of common reporting mechanisms impedes higher-level analysis. A standardized outcomes measurement tool, encompassing both patient-reported outcome measures and objective metrics, is necessary.

LEVEL OF EVIDENCE

Level IV.

New Spinal Shortening Technique for Tethered Cord Syndrome: A Technical Note

Background and Objectives: To present a new spinal shortening technique for tethered cord syndrome. Tethered cord syndrome (TCS) is a debilitating condition leading to progressive neurological decline. Surgical detethering for TCS is the gold standard of treatment. However, symptomatic retethering of TCS has been reported in 5%-50% of patients after initial release. To solve this problem, posterior spinal shortening osteotomy has been reported. This technique has risks of massive blood loss and neurological deterioration. The authors hereby report a new safe spinal shortening technique for tethered cord syndrome. Materials and Methods: A 31-year-old man with gait disturbance was referred to our hospital. After the delivery of treatment, he underwent surgical untethering of the spinal cord in another hospital. He had hyperreflexia of the Achilles tendon reflex and bilateral muscle weakness of the legs (MMT 3-4). He also had urinary and bowel incontinence, and total sensory loss below L5. An anteroposterior lumbar radiogram indicated partial laminectomy of L3 and L4. Lumbar MRI showed retethering of spinal cord. Results: The patient underwent a new spinal shortening technique for tethered cord syndrome under the guidance of O-arm navigation. First, from the anterior approach, disectomy from T12 to L3 was performed. Second, from the posterior approach, Ponte osteotomy was performed from T12 to L3, shortening the spinal column by 15 mm. The patient was successfully treated surgically. Postoperative lumbar MRI showed that the tension of the spinal cord was released. Manual muscle testing results and the sensory function of the left leg had recovered almost fully upon final follow-up at one year. Conclusions: A retethered spinal cord after initial untethering is difficult to treat. This new spinal shortening technique can represent another good option to release the tension of the spinal cord.

Surgical technique of spine-shortening vertebral osteotomy for adult tethered cord syndrome: a case report and review of the literature

BACKGROUND

Miyakoshi et al. reported three cases of tethered cord syndrome treated by spine-shortening vertebral osteotomy, which provided relief of the patients' symptoms with no complications. Although the details of these cases were described in a previous report, the surgical technique was not thoroughly explained. In the present report, we describe the details of our procedure with reference to a fourth case.

CASE PRESENTATION

A 47-year-old Asian woman was admitted to our hospital with a 1-year history of worsening leg numbness and urinary dysfunction. Magnetic resonance imaging revealed a low-lying conus medullaris extending to the level of S2 and surrounded by fat tissue at that level. We diagnosed her condition as adult tethered cord syndrome, and spine-shortening vertebral osteotomy was planned. The target level for the osteotomy was L2. Bilateral pedicle screw implants were placed at L1 and L3 using an anterior-posterior image intensifier. In this procedure, it is essential to use monoaxial screws inserted exactly parallel to the rostral endplates of each vertebral body; this ensures appropriate alignment between the L1 caudal endplate and the L2 osteotomy surface. The upper one-third of the lamina of L2 was resected, and the bilateral two-thirds of the pedicle of L2 was removed with a surgical air drill. After exposure of the lateral side of the L1-2 disc, discectomy was performed with a knife and curette. Following complete discectomy of L1-2, the upper vertebral body of L2 was removed with a surgical air drill. After complete removal of the vertebral body, a straight rod was connected to two screws and applied pressure between the screws. Two polyethylene tapes were applied to the L2 lamina and bilateral rods.

CONCLUSION

Spine-shortening osteotomy that preserves the caudal one-third of the pedicle and lamina with one-above and one-below instrumentation successfully reduced the spinal cord tension without causing neural damage.

Spinal column shortening for tethered cord syndrome: a systematic review and individual patient data meta-analysis

OBJECTIVE

Tethered cord release (TCR) is the gold standard treatment for tethered cord syndrome (TCS); however, there are significant shortcomings including high rates of retethering, especially in complex and recurrent cases. Spinal column shortening (SCS) is an alternative treatment for TCS intended to avoid these shortcomings. Early studies were limited to case reports and smaller case series; however, in recent years, larger case series and small cohort studies have been conducted. Given the increase in available data, a repeat systematic review and meta-analysis is warranted to assess the safety and efficacy of SCS for TCS.

METHODS

The authors conducted a systematic review using MEDLINE (OVID), Embase (Elsevier), and Web of Science records dating from 1944 to July 2021 to identify all articles investigating SCS for TCS. They performed standard and individual patient data (IPD) meta-analyses, with 2 independent reviewers using PRISMA-IPD guidelines. Primary outcomes were improvement of preoperative clinical symptoms of pain, motor weakness, and bladder and bowel dysfunction, and also surgical complication rate. Secondary outcomes included urodynamic improvement and health-related quality-of-life outcomes determined using patient-reported outcome tools. Individual study quality assessment was performed using a standardized assessment tool for case reports/series, and publication bias was assessed using funnel plot analyses.

RESULTS

The review yielded 15 studies with 191 cases of TCS treated with SCS. IPD were available in 11 studies with 89 cases. The average age at time of surgery was 28.0 years (range 5-76 years). The average follow-up time was 33.2 months (range 7-132 months). Improvement was observed at last follow-up in 60 of 70 (85.7%) patients with preoperative pain, in 38 of 60 (60.3%) patients with preoperative weakness, and in 36 of 76 (47.4%) patients with preoperative bladder or bowel dysfunction. Complications of CSF leak, new neurological deficit, wound infection, or reoperation occurred in 4 of 89 (4.5%) patients.

CONCLUSIONS

SCS may be considered a safe and efficacious treatment option for TCS in children and adults (level C evidence; class IIb recommendation), especially for recurrent and complex cases. Current evidence is likely to be affected by selection and publication bias. Prospective comparative studies of SCS and TCR for TCS are recommended to determine long-term duration of outcomes, long-term safety in skeletally immature children, and exact indications of SCS versus traditional TCR.

Spinal shortening osteotomy for adult tethered cord syndrome evaluated by intraoperative ultrasonography

BACKGROUND

Spinal shortening osteotomy (SSO) reduces the tension indirectly in the spinal cord and minimizes perioperative complications. However, the most effective and safe length to which the spine can be shortened is still unknown. In our practice, we use somatosensory-evoked potentials, motor-evoked potentials, and intraoperative ultrasonography when performing SSO. This study aimed to introduce the clinical outcomes of our SSO technique for tethered cord syndrome (TCS) in adults.

METHODS

This retrospective study included 7 adult patients (2 males and 5 females) with TCS treated between December 2010 and December 2018. The average age and average preoperative duration were 40 and 5 years, respectively. All patients received SSO with somatosensory-evoked potentials, motor-evoked potentials, and ultrasonography. After surgery, all patients were followed for an average of 4 years.

RESULTS

The mean operation time was 328 (284-414) min for SSO. The mean blood loss was 828 ml (501-1252 ml). Postoperative bony fusion was confirmed in all patients. Postoperative computed tomography (CT) demonstrated an average of 16 mm (11-20 mm) of spinal column shortening, compared with preoperative CT. Clinical improvements were obtained in all 7 cases, and there was no case of exacerbation. An indicator of shortening is that the ultrasonography gives pulsation and relaxation of the spinal cord. There were no abnormalities observed while monitoring the spinal cord.

CONCLUSIONS

Spinal shortening should be done under somatosensory-evoked potentials, motor-evoked potentials, and intraoperative ultrasonography to obtain safe and sufficient shortening.

Spinal column shortening versus revision detethering for recurrent adult tethered cord syndrome: a preliminary comparison of perioperative and clinical outcomes

OBJECTIVE

Recurrent tethered cord syndrome (TCS), believed to result from tension on the distal portion of the spinal cord, causes a constellation of neurological symptoms. Detethering surgery has been the traditional treatment for TCS. However, in cases of recurrent TCS, there is a risk of new neurological deficits developing, and subsequent retethering is difficult to prevent. Spinal column shortening has been proposed as an alternative technique to reduce the tension on the spinal cord without incurring the morbidity of revision surgery on the spinal cord. The authors compared the perioperative outcomes and morbidity of patients who were treated with one or the other procedure.

METHODS

The medical records of 16 adult patients with recurrent TCS who were treated between 2005 and 2018 were reviewed. Eight patients underwent spinal column shortening, and 8 patients underwent revision detethering surgery. Patient demographics, clinical outcomes, and perioperative factors were analyzed. The authors include a video to illustrate their technique of spinal column shortening.

RESULTS

Within the spinal column shortening group, no patients experienced any complications, and all 8 patients either improved or stabilized with regard to lower-extremity and bowel and bladder function. Within the revision detethering group, 2 patients had worsening of lower-extremity strength, 3 patients had worsening of bowel and bladder function, and 1 patient had improvement in bladder function. Also, 3 patients had wound-related complications. The median estimated blood loss was 731 ml in the shortening group and 163 ml in the revision detethering group. The median operative time was 358 minutes in the shortening group and 226 minutes in the revision detethering group.

CONCLUSIONS

Clinical outcomes were comparable between the groups, but none of the spinal column shortening patients experienced worsening, whereas 3 of the revision detethering patients did and also had wound-related complications. Although the operative times and blood loss were higher in the spinal column shortening group, this procedure may be an alternative to revision detethering in extremely scarred or complex wound revision cases.

The Treatment of Severe Congenital Scoliosis Associated With Type I Split Cord Malformation: Is a Preliminary Bony Septum Resection Always Necessary?

BACKGROUND

Single-stage spine-shortening osteotomy without treating spinal cord malformations may have potential advantages for the treatment of severe congenital scoliosis (CS) with type I split spinal cord malformation (SSCM); however, the study of this technique was limited.

OBJECTIVE

To evaluate the safety and efficacy of a single-stage spine-shortening osteotomy in the treatment of severe CS associated with type I SSCM.

METHODS

A retrospective study was designed to compare 2 case series including 12 severe CS patients with type I SSCM and 26 patients with type A cord function (without spinal cord malformations, evoked potential abnormalities, and neurological dysfunctions preoperatively) treated with a single-stage spine-shortening posterior vertebral column resection (PVCR). Patient demographic, clinical, operative, and radiographic data were obtained and compared between groups.

RESULTS

The surgical procedure was successfully performed in both groups, and the patients were observed for an average of 44.9 mo (range 25-78 mo) after the initial surgery. The radiographic parameters, intraoperative data, and new neurological deficits showed no difference, while deformity angular ratio (SSCM group: control group = 16.6 ± 3.6: 20.1 ± 3.9, P = .01) and corrective rate (SSCM group: control group = 50%: 58%, P = .046) of the main curve were statistically different between groups. All of the new neurological deficits were recovered within 1 yr.

CONCLUSION

The single-stage spine-shortening PVCR with moderate correction could be applied to the treatment of CS associated with type I SSCM. This strategy can achieve safe spinal deformity correction while obviate the neurological complications brought by the detethering procedures, which merits further clinical investigation.

Spinal Shortening for Recurrent Tethered Cord Syndrome via a Lateral Retropleural Approach: A Novel Operative Technique

Spine shortening via vertebral osteotomy (SSVO) for recurrent tethered cord syndrome (TCS) is a novel surgical technique that avoids the complication profile associated with revision detethering. While SSVO has previously been described via a posterior approach, we describe a lateral retropleural approach for SSVO in recurrent TCS in a 21-year-old female.

Our patient presented with progressive lower extremity weakness, bowel and bladder incontinence, and back pain in the setting of childhood repair of myelomeningocele and two previous detethering procedures. SSVO was offered to the patient as further detethering was deemed to have significant risk. A discectomy at T11-T12 via the lateral retropleural approach was performed, followed by a T12 partial corpectomy removing the vertebral body down to the inferior aspect of the T12 pedicle, followed by the removal of the ipsilateral pedicle. The T10, T11, L1, and L2 pedicle screws were then placed in the prone position and temporary rods were placed for temporary stability, followed by a laminectomy at T12 and a facetectomy for posterior element release. The remaining pedicle was removed, permanent rods were sequentially placed, and spinal column shortening was achieved by compression against the rods. Standing lateral radiographs demonstrated 19 millimeters (mm) of shortening after the intervention. The patient remained at her neurologic baseline postoperatively. At the six-month follow-up, the patient reported decreased lower extremity radicular pain and improved bowel and bladder function.

This operative report demonstrates that SSVO via a lateral retropleural approach is a viable treatment for the recurrence of TCS. The advantages of this minimally invasive approach compared to the posterior approach are direct access to the vertebral body and disc space, avoiding the need to operate around the spinal cord. Further studies are necessary to assess this minimally invasive approach to spinal shortening and to see if a complete minimally invasive approach is possible.

Computed Tomography Based Three-dimensional Measurements of Spine Shortening Distance After Posterior Three-column Osteotomies for the Treatment of Severe and Stiff Scoliosis

STUDY DESIGN

Retrospective study.

OBJECTIVES

This study is to measure and analyze the changes of three-dimensional (3D) distances of spinal column and spinal canal at the three-column osteotomy sites and address their clinical and neurologic significance.

SUMMARY OF BACKGROUND DATA

Three-column osteotomies were developed to treat severe and stiff spine deformities with insufficient understanding on the safe limit of spine shortening and the relationship between the shortening distance of the spinal column and that of the spinal canal.

METHODS

Records of 52 continuous patients with severe and stiff scoliosis treated with three-column spine osteotomies at our institution from July 2013 to June 2015 were reviewed. The preoperative spinal cord function classification were type A in 31 cases, type B in 10 cases, and type C in 11 cases. The types of osteotomies carried out were extended pedicle subtraction osteotomy in nine patients and posterior vertebral column resection in 43 patients. Multimodality neuromonitoring strategies were adopted intraoperatively. 3D pre- and postoperative spine models were reconstructed from the computed tomography (CT) scans. The distances of convex and concave spinal column and the spinal canal shortening were measured and analyzed.

RESULTS

The spinal column shortening distance (SCSD) measured on the 3D models (27.8 mm) were statistically shorter than those measured intraoperatively (32.8 mm) (P < 0.05); however, they were strongly correlated statistically (r = 0.82). The central spinal canal shortening distance (CCSD) was significantly shorter than the convex SCSD (P < 0.05). The convex SCSD and CCSD were significantly shorter in cases with anterior column strut graft than in those with bone-on-bone fusion (P < 0.05).

CONCLUSION

The shortening distance of the convex spinal column cannot represent that of the central spinal canal in patients with severe scoliosis. The spinal column shortening procedure in appropriately selected patient groups with bone-on-bone fusion is a viable option with the CCSD being significantly shorter than the convex SCSD.

LEVEL OF EVIDENCE

4.

Comparative Study of Untethering and Spine-Shortening Surgery for Tethered Cord Syndrome in Adults

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVE

Although untethering surgery has been a standard treatment in patients with adult tethered cord syndrome (TCS), spine-shortening osteotomy (SSO) has recently been performed as an alternative technique. The purpose of this study was to compare the clinical outcomes of the two procedures for TCS in adults.

METHODS

Fourteen patients (37.7 ± 12.5 years) with TCS were enrolled at 6 hospitals. Their clinical charts, operative records, and follow-up data were reviewed. The categories of tethering lesions were tight terminal filum in 1 patient, lipoma in 5 patients, and lipomyelomeningocele in 8 patients. Eleven patients underwent untethering surgery, and 3 patients underwent SSO surgery.

RESULTS

There were no significant differences in age, sex, types of preoperative symptoms, or duration of follow-up between the two groups. The preoperative duration of symptoms was significantly longer (25 ± 12.4 years) and the percentage of those with prior surgery was higher in the SSO group (66.7%). The preoperative pathology was lipomeningocele in all SSO group and lipoma or tight terminal filum in the untethering group. Cerebrospinal fluid leakage and urinary infection occurred in 1 patient each among those with untethering, and massive intraoperative bleeding occurred in 1 patient with SSO. SSO provided better clinical improvement than untethering surgery (p = 0.003).

CONCLUSIONS

Based on this small retrospective case series, SSO appears to provide clinical improvement at least comparable to the untethering procedure, especially in more challenging cases.

Surgical Treatment of Congenital Scoliosis Associated With Tethered Cord by Thoracic Spine-shortening Osteotomy Without Cord Detethering

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To investigate the safety and efficacy of spine-shortening osteotomy for congenital scoliosis with tethered cord.

SUMMARY OF BACKGROUND DATA

Conventional surgery for congenital scoliosis associated with tethered cord risks the complications of detethering. Spine-shortening osteotomy holds the potential to correct scoliosis and decrease spinal cord tension simultaneously without an extra detethering procedure, but no data on this issue is available.

METHODS

21 patients (14 females and 7 males, average age 15.4 yr) underwent spine-shortening osteotomy without detethering. All of the patients had tethered cord. Patients with main curve more than 90° underwent vertebral column resection (VCR), whereas the others had pedicle subtraction osteotomy (PSO) performed. The average postoperative follow-up period was 45.2 months.

RESULTS

The mean operation time was 544.5 min with average blood loss of 2769.1 ml. The deformity correction was 61.3% in the coronal plane and 43.9° in the sagittal plane. 10 patients had neurological deficits preoperatively. At the final follow-up, the deficits in 8 (80%) patients were significantly improved, whereas 2 (20%) remained unchanged. At final follow-up, 71.4% (5/7) patients reported improvement in motor function, 100% (3/3) had improved pain scores, and 75% (3/4) reported better sensory function after the spine-shortening osteotomy. Urinary dysfunction and bowel incontinence present preoperatively in 3 patients all recovered by final follow-up. 5 (23.8%) patients incurred complications including temporary neurological deterioration in 1 patient, urinary tract infection in 2 patients, cerebrospinal fluid leakage in 1 patient, and blood loss more than 5000 ml in 1 patient.

CONCLUSION

Spine-shortening osteotomy is a safe and effective procedure for congenital scoliosis associated with tethered cord. Spine-shortening osteotomy at the thoracic apical vertebrae level not only corrects the spine deformity but also simultaneously releases the tension of the tethered cord, resulting in improved neurologic function.

Safety and Efficacy of One-stage Spinal Osteotomy for Severe and Rigid Congenital Scoliosis Associated with Split Spinal Cord Malformation

STUDY DESIGN

Retrospective clinical study.

OBJECTIVE

To retrospectively evaluate the safety and efficacy of one-stage spinal osteotomy in the treatment of severe and progressive congenital scoliosis (CS) associated with split spinal cord malformation (SSCM).

SUMMARY OF BACKGROUND DATA

For severe and rigid spinal deformity, spinal osteotomies are often advocated for correcting the deformity. However, the safety and efficacy of one-stage spinal osteotomy in the treatment of severe and rigid CS with SSCM have been unclear thus far.

METHODS

Patients were treated by one-stage spinal osteotomy between September 2007 and June 2011 in our hospital. The clinical records were reviewed for demographic and radiographical data, operative time, intraoperative blood loss, blood transfusion, perioperative complications, and functional outcomes.

RESULTS

There were 18 females and 11 males with an average age of 15.5 ± 3.6 years (range, 12-28 yr). Spinal cord was longitudinally split by a bony spur in 11 patients (type I SSCM) and by a fibrous band in 18 patients (type II SSCM). Patients were observed for a minimum of 24 months after initial surgical treatment with an average follow-up of 43.0 ± 17.1 months (range 24-68 mo) from September 2007 to June 2013. The mean operative time and average blood loss of type ISSCM was significantly greater than those of type II SSCM (P < 0.05). The major curve was corrected from an average of 97.2°± 17.8° to 35.7°± 15.9°, a mean correction rate of 64.3% ± 11.0%. The average loss of correction at final follow-up was 2.9% for major curves. The overall complication rate was 24.1%, including transient neurological deterioration in 3 patients, cerebrospinal fluid leakage in 2 patients, urinary tract infection in 1 patient and pleural rupture in 1 patient.

CONCLUSION

Relative to multistage corrective surgery, one-stage spinal osteotomy is effective for the correction of severe CS and SSCM without increasing the rate of surgical complications. However, surgical treatment of type I SSCM does require more operating time and blood loss.

LEVEL OF EVIDENCE

4.

The effect of spinal osteotomies on spinal cord tension and dural buckling: a cadaveric study

OBJECT

The standard surgical release of a tethered cord may result in recurrent scar formation and occasionally be associated with retethering. The application of spinal shortening procedures to this challenging problem potentially can reduce tension on the retethered spinal cord while minimizing the difficulties inherent in traditional lumbosacral detethering revision. Although spinal shortening procedures have proven clinical benefit in patients with a recurrent tethered cord, it is unclear how much shortening is required to achieve adequate reduction in spinal cord tension or what impact these osteotomies have on dural buckling.

METHODS

The authors calculated mean values from 4 human cadavers to evaluate the effect of 3 different spinal shortening procedures--Smith-Petersen osteotomy (SPO), pedicle subtraction osteotomy (PSO), and vertebral column resection (VCR)--on spinal cord tension and dural buckling. Three cadavers were dedicated to the measurement of spinal cord tension, and 3 other cadavers were devoted to myelography to measure dural buckling parameters.

RESULTS

The SPO was associated with a maximal decrease in spinal cord tension of 16.1% from baseline and no dural buckling with any degree of closure. The PSO led to a mean maximal decrease in spinal cord tension of 63.1% from baseline at 12 mm of closure and demonstrated a direct linear relationship between dural buckling and increasing osteotomy closure. Finally, VCR closure correlated with a mean maximal decrease in spinal cord tension of 87.2% from baseline at 10 mm of closure and also showed a direct linear relationship between dural buckling and increases in osteotomy closure.

CONCLUSIONS

In this cadaveric experiment, the SPO did not lead to appreciable tension reduction, while a substantial response was seen with both the PSO and VCR. The rate of tension reduction may be steeper for the VCR than the PSO. Adequate tension relief while minimizing dural buckling may be optimal with 12-16 mm of posterior osteotomy closure based on this cadaveric experiment.

Successful treatment of a patient with congenital kyphoscoliosis associated with tethered cord

Tethered cord is a common finding in congenital scoliosis. The most frequently advocated approach for this condition is to perform prophylactic detethering of the cord before scoliosis corrective surgery. The authors report on a 14-year-old patient with congenital thoracic kyphoscoliosis associated with a tethered cord, who developed progressive paraparesis and was successfully treated by posterior spine shortening osteotomy alone without prophylactic untethering. The patient had a 103° scoliotic curve together with a 93° kyphotic curve with an apical vertebra of T-7. Furthermore, he developed a significant progression of neurological deficits, including weakness of both legs and urinary and bowel incontinence. Preoperative MRI revealed that the spinal cord was entrapped by the apical vertebra and the low-placed conus medullaris was at approximately L-5. A posterior vertebral column resection of T-7 was performed for the purpose of simultaneously correcting the kyphoscoliosis and releasing tension on the tethered cord without a true detethering surgery. The patient's spinal cord function recovered completely from Frankel D to Frankel E by 6 months after the procedure. Evaluation at 31 months after surgery showed maintenance of good curve correction and normal neurological function.

Spine-shortening osteotomy for patients with tethered cord syndrome caused by lipomyelomeningocele

OBJECTIVE

Tethered cord syndrome (TCS) is a disorder involving an abnormal stretching of the tethered spinal cord caused by several pathological conditions and presents with a variety of neurological symptoms. Untethering (tethered cord release) is the gold standard treatment for TCS. However, untethering carries risks of spinal cord injury and postoperative retethering. To avoid these potential risks, the authors applied spine-shortening osteotomy to adult patients with TCS, and report on the surgical procedure and treatment outcomes.

METHODS

Eight patients with TCS caused by a lipomyelomeningocele were surgically treated by the authors' original procedure of spine-shortening osteotomy. Six patients were male and 2 were females; average age at the time of surgery was 31 years old. Spine-shortening osteotomy was performed at the level of L-1 in all but 2 patients, in whom it was performed at T-12, with spinal fusion between T-12 and L-2 or T-11 and L-1 using a pedicle screw-rod system. The average follow-up period was 6.2 years and the patients' pre- and postoperative conditions were evaluated clinically and radiologically.

RESULTS

Preoperatively, all patients displayed severe neurological deficits such as motor disturbance, muscle atrophy, and bladder dysfunction. Several months before surgery, all showed progressive symptoms. Those symptoms showed initial improvement in 6 patients and stabilized in 2 postoperatively, but the improved symptoms worsened again in 4 of the 6 patients. The osteotomized vertebrae were shortened by 21 mm on average, and all spines showed complete bone union without loss of correction. At the final follow-up evaluations, 6 patients showed stabilization as per the modified Japanese Orthopaedic Association score for thoracic myelopathy.

CONCLUSIONS

Spine-shortening osteotomy successfully helps reduce the spinal cord tension without causing direct neural damage. At minimum, it stabilized the patients' symptoms and/or helped delay neurological deterioration for a period of time. Spine-shortening osteotomy might be a feasible mode of treatment for adult TCS caused by a spinal lipoma.

Treatment of myelomeningocele: a review of outcomes and continuing neurosurgical considerations among adults

OBJECT

Myelomeningocele is the most severe congenital malformation of the CNS that is compatible with survival. From the time of the development of practical treatment for hydrocephalus in the late 1950s, affected individuals began to survive into adulthood in substantial numbers. Data on the neurological status of these individuals are sparse, as are descriptions of their continuing requirements for neurosurgical care.

METHODS

A review of the literature was undertaken using the PubMed database maintained by the National Library of Medicine. Formal grading of the quality of evidence was not attempted, but methodological issues affecting validity or generalizability were noted.

RESULTS

Observations from 2 major longitudinal studies of cohorts of patients treated without selection using contemporary neurosurgical techniques have been published at intervals beginning in the mid-1970s. Numerous cross-sectional, institutional reviews have focused on neurosurgical issues in adulthood: hydrocephalus, Chiari malformation Type II and syringomyelia, and secondary spinal cord tethering. The organization of medical services for adults with myelomeningocele has received limited study.

CONCLUSIONS

Surviving adults with myelomeningocele achieve a wide range of neurological and functional outcomes, the most critical and adverse determinant of which is symptomatic CSF shunt failure. From a neurosurgical standpoint, adults with myelomeningocele remain clinically active indefinitely, and they deserve periodic neurosurgical surveillance.

Management of recurrent adult tethered cord syndrome

Recurrent tethered cord syndrome (TCS) can lead to significant progressive disability in adults. The diagnosis of TCS is made with a high degree of clinical suspicion. In the adult population, many patients receive inadequate care unless they are seen at a multidisciplinary clinic. Successful detethering procedures require careful intradural dissection and meticulous wound and dural closure. With multiple revision procedures, vertebral column shortening has become an appropriate alternative to surgical detethering.

Posterior vertebral column subtraction osteotomy for the treatment of tethered cord syndrome: review of the literature and clinical outcomes of all cases reported to date

Tethered cord syndrome (TCS) is a debilitating condition of progressive neurological decline caused by pathological, longitudinal traction on the spinal cord. Surgical detethering of the involved neural structures is the classic method of treatment for lumbosacral TCS, although symptomatic retethering has been reported in 5%–50% of patients following initial release. Subsequent operations in patients with complex lumbosacral dysraphic lesions are fraught with difficulty, and improvements in neurological function are modest while the risk of complications is high. In 1995, Kokubun described an alternative spine-shortening procedure for the management of TCS. Conducted via a single posterior approach, the operation relies on spinal column shortening to relieve indirectly the tension placed on the tethered neural elements. In a cadaveric model of TCS, Grande and colleagues further demonstrated that a 15–25-mm thoracolumbar subtraction osteotomy effectively reduces spinal cord, lumbosacral nerve root, and filum terminale tension. Despite its theoretical appeal, only 18 reports of the use of posterior vertebral column subtraction osteotomy for TCS treatment have been published since its original description. In this review, the authors analyze the relevant clinical characteristics, operative data, and postoperative outcomes of all 18 reported cases and review the role of posterior vertebral column subtraction osteotomy in the surgical management of primary and recurrent TCS.