Christopher M. Bonfield

Complications and radiographic correction in adult scoliosis following combined transpsoas extreme lateral interbody fusion and posterior pedicle screw instrumentation.

OBJECT The authors recently used a combined approach of minimally invasive transpsoas extreme lateral interbody fusion (XLIF) and open posterior segmental pedicle screw instrumentation with transforaminal lumbar interbody fusion (TLIF) for the correction of coronal deformity. The complications and radiographic outcomes were compared with a posterior-only approach for scoliosis correction. METHODS The authors retrospectively reviewed all deformity cases that were surgically corrected at the University of Pittsburgh Medical Center Presbyterian Hospital between June 2007 and August 2009. Eight patients underwent combined transpsoas and posterior approaches for adult degenerative thoracolumbar scoliosis. The comparison group consisted of 4 adult patients who underwent a posterior-only scoliosis correction. Data on intra- and postoperative complications were collected. The pre- and postoperative posterior-anterior and lateral scoliosis series radiographic films were reviewed, and comparisons were made for coronal deformity, apical vertebral translation (AVT), and lumbar lordosis. Clinical outcomes were evaluated by comparing pre- and postoperative visual analog scale scores. RESULTS The median preoperative coronal Cobb angle in the combined approach was 38.5 degrees (range 18-80 degrees). Following surgery, the median Cobb angle was 10 degrees (p < 0.0001). The mean preoperative AVT was 3.6 cm, improving to 1.8 cm postoperatively (p = 0.031). The mean preoperative lumbar lordosis in this group was 47.3 degrees, and the mean postoperative lordosis was 40.4 degrees. Compared with posterior-only deformity corrections, the mean values for curve correction were higher for the combined approach than for the posterior-only approach. Conversely, the mean AVT correction was higher in the posterior-only group. One patient in the posterior-only group required revision of the instrumentation. One patient who underwent the transpsoas XLIF approach suffered an intraoperative bowel injury necessitating laparotomy and segmental bowel resection; this patient later underwent an uneventful posterior-only correction of her scoliotic deformity. Two patients (25%) in the XLIF group sustained motor radiculopathies, and 6 of 8 patients (75%) experienced postoperative thigh paresthesias or dysesthesias. Motor radiculopathy resolved in 1 patient, but persisted 3 months postsurgery in the other. Sensory symptoms persisted in 5 of 6 patients at the most recent follow-up evaluation. The mean clinical follow-up time was 10.5 months for the XLIF group and 11.5 months for the posterior-only group. The mean visual analog scale score decreased from 8.8 to 3.5 in the XLIF group, and it decreased from 9.5 to 4 in the posterior-only group. CONCLUSIONS Radiographic outcomes such as the Cobb angle and AVT were significantly improved in patients who underwent a combined transpsoas and posterior approach. Lumbar lordosis was maintained in all patients undergoing the combined approach. The combination of XLIF and TLIF/posterior segmental instrumentation techniques may lead to less blood loss and to radiographic outcomes that are comparable to traditional posterior-only approaches. However, the surgical technique carries significant risks that require further evaluation and proper informed consent.

Perioperative surgical complications of transforaminal lumbar interbody fusion: a single-center experience

OBJECT Since its original description in 1982, transforaminal lumbar interbody fusion (TLIF) has grown in popularity as a means for achieving circumferential fusion. The authors sought to define the perioperative complication rates of the TLIF procedure at a large academic medical center. METHODS For all eligible patients from a consecutive series of 531 TLIF procedures, the institutions complication database and the medical record were reviewed to identify complications. Medical, nonprocedure-related complications such as myocardial infarction and pulmonary embolism were excluded due to inconsistency in the recording of these complications in the database. Rates were calculated for each type of complication, and subgroup analysis was performed to investigate the effect of previous lumbar surgery, and of multilevel versus single-level interbody fusion on complication rates. Odds ratios were calculated and evaluated using chi-square analysis. RESULTS Five hundred thirty-one patients underwent a TLIF procedure during the study period. Two hundred forty-four patients (46%) had undergone a previous lumbar operation. Interbody fusion was performed at 1 level in 317 patients, at 2 levels in 188 patients, at 3 levels in 24 patients, and at 4 levels in 2 patients. One hundred thirty-five patients (25.4%) had at least one procedure-related complication. The most common complications were durotomy (14.3% of patients) and infection (3.8% of patients). Symptomatic screw misplacement (2.1% of patients) and interbody cage migration (1.8% of patients) were less common complications. The overall complication rate was greater in those patients who had undergone a previous operation (OR 1.75, 95% CI 1.18-2.59; p < 0.01) and in those who had multilevel surgery (OR 1.54, 95 % CI 1.04-2.28; p = 0.03), and the incidence of durotomy was higher in patients who had a previous operation (OR 1.75, 95% CI 1.07-2.87; p = 0.03). These differences were statistically significant. Durotomy also occurred more frequently in patients who had multilevel interbody fusion (OR 1.49, 95% CI 0.92-2.43; p = 0.13). A trend toward higher infection rates in those patients who underwent multilevel interbody fusion was observed (OR 1.5, 95% CI 0.62-3.68; p = 0.49), but this was not statistically significant. Infection rates did not differ between revision and first-time surgeries. CONCLUSIONS Transforaminal lumbar interbody fusion has gained widespread popularity as a procedure for achieving arthrodesis in the lumbar spine. Complications occurred more often in patients undergoing revision surgery or multilevel interbody fusion. Durotomy and infection were the most common complications in this series.

The use of a hybrid dynamic stabilization and fusion system in the lumbar spine: preliminary experience.

OBJECT The authors report the use and preliminary results of a novel hybrid dynamic stabilization and fusion construct for the surgical treatment of degenerative lumbar spine pathology. METHODS The authors performed a retrospective chart review of all patients who underwent posterior lumbar instrumentation with the Dynesys-to-Optima (DTO) hybrid dynamic stabilization and fusion system. Preoperative symptoms, visual analog scale (VAS) pain scores, perioperative complications, and the need for subsequent revision surgery were recorded. Each patient was then contacted via telephone to determine current symptoms and VAS score. Follow-up was available for 22 of 24 patients, and the follow-up period ranged from 1 to 22 months. Clinical outcome was gauged by comparing VAS scores prior to surgery and at the time of telephone interview. RESULTS A total of 24 consecutive patients underwent lumbar arthrodesis surgery in which the hybrid system was used for adjacent-level dynamic stabilization. The mean preoperative VAS score was 8.8, whereas the mean postoperative VAS score was 5.3. There were five perioperative complications that included 2 durotomies and 2 wound infections. In addition, 1 patient had a symptomatic medially placed pedicle screw that required revision. These complications were not thought to be specific to the DTO system itself. In 3 patients treatment failed, with treatment failure being defined as persistent preoperative symptoms requiring reoperation. CONCLUSIONS The DTO system represents a novel hybrid dynamic stabilization and fusion construct. The technique holds promise as an alternative to multilevel lumbar arthrodesis while potentially decreasing the risk of adjacent-segment disease following lumbar arthrodesis. The technology is still in its infancy and therefore follow-up, when available, remains short. The authors report their preliminary experience using a hybrid system in 24 patients, along with short-interval clinical and radiographic follow-up.

The impact of attention deficit hyperactivity disorder on recovery from mild traumatic brain injury

OBJECT Attention deficit hyperactivity disorder (ADHD) and traumatic brain injury (TBI) are significant independent public health concerns in the pediatric population. This study explores the impact of a premorbid diagnosis of ADHD on outcome following mild TBI. METHODS The charts of all patients with a diagnosis of mild closed head injury (CHI) and ADHD who were admitted to Childrens Hospital of Pittsburgh between January 2003 and December 2010 were retrospectively reviewed after institutional review board approval was granted. Patient demographics, initial Glasgow Coma Scale (GCS) score, hospital course, and Kings Outcome Scale for Childhood Head Injury (KOSCHI) score were recorded. The results were compared with a sample of age-matched controls admitted with a diagnosis of CHI without ADHD. RESULTS Forty-eight patients with mild CHI and ADHD, and 45 patients with mild CHI without ADHD were included in the statistical analysis. Mild TBI due to CHI was defined as an initial GCS score of 13-15. The ADHD group had a mean age of 12.2 years (range 6-17 years), and the control group had a mean age of 11.14 years (range 5-16 years). For patients with mild TBI who had ADHD, 25% were moderately disabled (KOSCHI Score 4b), and 56% had completely recovered (KOSCHI Score 5b) at follow-up. For patients with mild TBI without ADHD, 2% were moderately disabled and 84% had completely recovered at follow-up (p < 0.01). Patients with ADHD were statistically significantly more disabled after mild TBI than were control patients without ADHD, even when controlling for age, sex, initial GCS score, hospital length of stay, length of follow-up, mechanism of injury, and presence of other (extracranial) injury. CONCLUSIONS Patients who sustain mild TBIs in the setting of a premorbid diagnosis of ADHD are more likely to be moderately disabled by the injury than are patients without ADHD.

Radiographic and clinical outcomes following combined lateral lumbar interbody fusion and posterior segmental stabilization in patients with adult degenerative scoliosis

OBJECT A hybrid approach of minimally invasive lateral lumbar interbody fusion (LLIF) followed by supplementary open posterior segmental instrumented fusion (PSIF) has shown promising early results in the treatment of adult degenerative scoliosis. Studies assessing the impact of this combined approach on correction of segmental and regional coronal angulation, sagittal realignment, maximum Cobb angle, restoration of lumbar lordosis, and clinical outcomes are needed. The authors report their results of this approach for correction of adult degenerative scoliosis. METHODS Twenty-six patients underwent combined LLIF and PSIF in a staged fashion. The patient population consisted of 21 women and 5 men. Ages ranged from 40 to 77 years old. Radiographic measurements including coronal angulation, pelvic incidence, lumbar lordosis, and sagittal vertical axis were taken preoperatively and 1 year postoperatively in all patients. Concurrently, the visual analog score (VAS) for back and leg pain, the Oswestry Disability Index (ODI), and Short Form-36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores were used to assess clinical outcomes in 19 patients. RESULTS At 1-year follow-up, all patients who underwent combined LLIF and PSIF achieved statistically significant mean improvement in regional coronal angles (from 14.9° to 5.8°, p < 0.01) and segmental coronal angulation at all operative levels (p < 0.01). The maximum Cobb angle was significantly reduced postoperatively (from 41.1° to 15.1°, p < 0.05) and was maintained at follow-up (12.0°, p < 0.05). The mean lumbar lordosis-pelvic incidence mismatch was significantly improved postoperatively (from 15.0° to 6.92°, p < 0.05). Although regional lumbar lordosis improved (from 43.0° to 48.8°), it failed to reach statistical significance (p = 0.06). The mean sagittal vertical axis was significantly improved postoperatively (from 59.5 mm to 34.2 mm, p < 0.01). The following scores improved significantly after surgery: VAS for back pain (from 7.5 to 4.3, p < 0.01) and leg pain (from 5.8 to 3.1, p < 0.01), ODI (from 48 to 38, p < 0.01), and PCS (from 27.5 to 35.0, p = 0.01); the MCS score did not improve significantly (from 43.2 to 45.5, p = 0.37). There were 3 major and 10 minor complications. CONCLUSIONS A hybrid approach of minimally invasive LLIF and open PSIF is an effective means of achieving correction of both coronal and sagittal deformity, resulting in improvement of quality of life in patients with adult degenerative scoliosis.

Pediatric intracranial abscesses

Intracranial infections in children are a relatively rare, but potentially severe condition. Because of the potential for rapid deterioration, timely diagnosis and treatment are necessary. These infections are categorized based on their intracranial location: epidural abscess, subdural empyema, and brain abscess. They largely arise from direct extension of adjacent infection, hematogenous seeding, or trauma. Clinical presentations of intracranial infections also vary. However, common signs and symptoms include headache, fever, nausea and vomiting, altered mental status, focal neurologic deficits, and seizures. In general, MRI demonstrates a peripherally enhancing lesion with high signal on diffusion weighted imaging (DWI). Bacterial isolates vary, but most commonly are a single pathogen. Successful treatment requires a multidisciplinary team approach including such modalities as antibiotic therapy and surgical drainage. When possible, open surgical evacuation of the abscess is preferred, however, in cases of deep-seated lesions, or in unstable patients, aspiration has also been performed with good results.

Surgical management of post-traumatic syringomyelia

Study Design. Systematic review. Objective. To determine the indications for surgical intervention and optimal surgical treatment technique for patients with post-traumatic syringomyelia and spinal cord tethering. Summary of Background Data. The proper management strategy for post-traumatic syringomyelia has not been established. Most modern surgical series have documented improvement in symptomatic patients who have an internal decompression of their syrinx. Several options exist and include shunting the syrinx (to the subarachnoid space or to either the pleural or peritoneal cavities) as well as spinal cord untethering (with or without expansile duraplasty). Methods. A systematic review of literature followed by expert panel consensus was performed. English language literature published between 1980 and 2010 was gathered to examine articles search was conducted using the search terms syringomyelia, syrinx, spinal cord injury, traumatic syringomyelia, post-traumatic syringomyelia. Case reports and articles examining syrinx due to other cause were excluded. Articles were graded for strength of evidence according to the GRADE approach. The evidentiary tables were reviewed and approved by all 4 authors, and disagreements were resolved by consensus. Results. The literature search yielded a total of 296 abstracts, and 22 articles were found to fulfill all the criteria specified above. All identified articles were of low or very low evidence levels. The reported incidence of post-traumatic syringomyelia is 0.5% to 4.5%; the incidence is twice as common in complete versus incomplete injuries. The literature consistently demonstrated that surgery post-traumatic syringomyelia is effective at arresting or improving motor deterioration, but not sensory dysfunction or pain syndromes. The literature does not support surgical intervention for incidental, asymptomatic syrinx. The literature does not support one surgical technique as superior for the treatment of post-traumatic syringomyelia. Conclusion. The literature supports and the consensus panel recommended that there is no indication for direct decompression at the time of initial injury specifically for the purpose of limiting future risk of syringomyelia. The literature supports and the consensus panel gave a strong recommendation for surgical intervention in the setting of motor neurologic deterioration as a consequence of post-traumatic syrinx/tethered cord. The panel gave a weak recommendation against surgical intervention for patients developing sensory loss/pain syndrome or for asymptomatic but expanding syrinx. Finally, the literature does not provide strong evidence to support the superiority of one surgical technique over the others; however, the consensus panel gave a weak recommendation that spinal cord untethering with expansile duraplasty is the preferred first-line surgical technique.

Pediatric cerebellar astrocytoma: a review

IntroductionCerebellar astrocytomas (CA) are one of the most common posterior fossa tumors in children. The vast majority is low grade, and prognosis for long-term survival is excellent.MethodsRecent literature about CA was reviewed to provide an up to date overview of the epidemiology, pathology, molecular and cell biology, diagnosis, presentation, management, and long-term outcomes.ResultsSurgical resection remains the first-line treatment with complete removal of the tumor the goal. However, even when only subtotal resection has been achieved, there is a significant chance that the tumor will remain stable or will regress spontaneously. Adjuvant chemotherapy is reserved for those tumors that progress despite surgery, and more personalized chemotherapy is being pursued with better understanding of the molecular genetics of this tumor. Radiotherapy has generally not been recommended, but stereotactic radiotherapy and conformal proton beam radiotherapy may be reasonable options in the setting of relapse or progression. In the long term, permanent neurologic deficits, mainly cerebellar dysfunction, are common, but quality of life and cognitive function are generally good.ConclusionsLow-grade CA remains primarily a surgical disease, with excellent survival rates. Care must be taken with surgery and adjuvant treatments to preserve neurologic function to allow for optimal outcomes in the long term.

Extramedullary Ependymoma Near the Conus Medullaris With Lumbar Nerve Root Attachment: Case Report

BACKGROUND AND IMPORTANCE:Ependymomas are the most common primary spinal cord tumor, most frequently located near the cauda equina and conus medullaris. We believe that this is the first reported case of a low-grade, nonmyxopapillary (World Health Organization grade 2), intradural, extramedullary ependymoma involving a spinal nerve root. CLINICAL PRESENTATION:An 87-year-old woman presented with a chief complaint of acute onset of severe right hip and lateral thigh pain without midline back pain. She had baseline chronic bladder dysfunction, which remained unchanged. Her physical examination was significant for 4/5 strength in her right hip flexion (possibly related to pain), and 5 beats of clonus bilaterally. She had no point tenderness at the level of her compression fracture. Computed tomography of the patients lumbar spine revealed a well-corticated, chronic compression fracture of the L3 vertebral body. Magnetic resonance images demonstrated an ovoid-shaped, 1.5 × 1-cm, well-circumscribed, intradural, extramedullary lesion at the conus medullaris. The patient underwent an L1-3 laminectomy with intradural resection of the mass, which was found to be intricately involved with a single nerve root. The nerve root was coagulated and sectioned, and a gross total resection of the tumor was achieved. CONCLUSION:The patient tolerated the procedure well, with no complications or any postoperative neurological deficit. Her right-sided pain immediately resolved after surgery. Her strength and ambulation were normal after surgery. No adjuvant radiotherapy was offered to the patient. This case illustrates a unique tumor presentation and the successful surgical treatment of the condition.

Surgical treatment of sagittal synostosis by extended strip craniectomy: cranial index, nasofrontal angle, reoperation rate, and a review of the literature.

BACKGROUND Sagittal synostosis is the most common non-syndromic single suture craniosynostosis. Different techniques of surgical correction, including extended strip craniectomy (ESC), have been used to treat this condition. The aim of this study is to evaluate radiologic changes and rate of symptomatic restenosis after ESC in a large group of patients less than 12 months of age with non-syndromic sagittal synostosis. METHODS A retrospective study of patients from 1990 to 2012 was performed comparing cranial index (CI) and nasofrontal angle (NFA) before and after surgical correction by ESC. Also, the frequency of subsequent reoperations for symptomatic restricted head growth was determined. RESULTS A total of 238 patients underwent ESC. Follow-up information was available for 182 patients. The average age at the time of the operation was 4.5 months and the mean duration of follow-up was 49.6 months. The average post procedure radiologic follow-up (22 patients) was 40.7 months. CONCLUSIONS The mean CI increased from 0.68 to 0.75 (p < 0.001) after ESC. Also, mean NFA increased from 127 to 133° (p < 0.001). Five patients (2.7%) required a second operation due to symptomatic cranial growth restriction. Reoperation occurred at an average of 26.5 months after the initial procedure. The most common symptom reported was headache. ESC is effective in treating non-syndromic sagittal synostosis. It significantly improved NFA without the need for direct frontal bone resection or frontal orbital osteotomy and significantly increased CI without adjunctive helmet treatment. Patients should be followed for at least 5 years after surgical correction as symptomatic restenosis, although rare, can occur.