Chiari-related scoliosis: a single-center experience with long-term radiographic follow-up and relationship to deformity correction

OBJECTIVE Previous reports have addressed the short-term response of patients with Chiari-related scoliosis (CRS) to suboccipital decompression and duraplasty (SODD); however, the long-term behavior of the curve has not been well defined. The authors undertook a longitudinal study of a cohort of patients who underwent SODD for CRS to determine whether there are factors related to Chiari malformation (CM) that predict long-term scoliotic curve behavior and need for deformity correction. METHODS The authors retrospectively reviewed cases in which patients underwent SODD for CRS during a 14-year period at a single center. Clinical (age, sex, and associated disorders/syndromes) and radiographic (CM type, tonsillar descent, pBC2 line, clival-axial angle [CXA], syrinx length and level, and initial Cobb angle) information was evaluated to identify associations with the primary outcome: delayed thoracolumbar fusion for progressive scoliosis. RESULTS Twenty-eight patients were identified, but 4 were lost to follow-up and 1 underwent fusion within a year. Among the remaining 23 patients, 11 required fusion surgery at an average of 88.3 ± 15.4 months after SODD, including 7 (30%) who needed fusion more than 5 years after SODD. On univariate analysis, a lower CXA (131.5° ± 4.8° vs 146.5° ± 4.6°, p = 0.034), pBC2 > 9 mm (64% vs 25%, p = 0.06), and higher initial Cobb angle (35.1° ± 3.6° vs 22.8° ± 4.0°, p = 0.035) were associated with the need for thoracolumbar fusion. Multivariable modeling revealed that lower CXA was independently associated with a need for delayed thoracolumbar fusion (OR 1.12, p = 0.0128). CONCLUSIONS This investigation demonstrates the long-term outcome and natural history of CRS after SODD. The durability of the effect of SODD on CRS and curve behavior is poor, with late curve progression occurring in 30% of patients. Factors associated with CRS progression include an initial pBC2 > 9 mm, lower CXA, and higher Cobb angle. Lower CXA was an independent predictor of delayed thoracolumbar fusion. Further study is necessary on a larger cohort of patients to fully elucidate this relationship.

Fate of S2-Alar-Iliac Screws After 12-Month Minimum Radiographic Follow-up: Preliminary Results

BACKGROUND

S2-alar-iliac (S2AI) screws are 1 technique for lumbopelvic fixation to improve fusion rates across the lumbosacral junction that has gained wider acceptance. The S2AI screw crosses the cortical surfaces of the sacroiliac joint (SIJ), which may improve the biomechanical strength of the instrumentation.

OBJECTIVE

To report preliminary radiographic outcomes of patients who underwent lumbopelvic fixation with S2AI screws with a minimum 12-month follow-up.

METHODS

We retrospectively reviewed adult patients who underwent lumbopelvic fixation with S2AI screws. Patients with computed tomography (CT) scans obtained preoperatively and ≥12 months postoperatively were reviewed to determine whether there was S2AI screw backout or breakage, periscrew lucency, or SIJ degeneration, and to assess L5-S1 fusion status.

RESULTS

Twenty-six S2AI screws in 13 patients were evaluated (mean follow-up 24.8 months [14-52 months]). Nine patients had L5-S1 interbody grafts. Partial periscrew lucency was identified in 7 S2AI screws (27%) in 5 patients (38%), and L5-S1 fusion occurred in 92% of patients. L5-S1 nonunion was seen in 1 patient (8%), who had evidence of bilateral screw loosening in the sacral portion. Four patients with screw loosening had an osseous L5-S1 fusion. No patients had radiographic evidence of progression of SIJ degeneration, experienced screw backout or breakage, required reoperation for L5-S1 nonunion, or had S2AI screw-related complication.

CONCLUSION

S2AI screws maintained their integrity without causing SIJ degeneration or major screw-related complications in this small retrospective series with short follow-up. Long-term results are needed to evaluate the durability of S2AI screws over time.

Occipitocervical Instability After Far-Lateral Transcondylar Surgery: A Biomechanical Analysis

BACKGROUND

After a far-lateral transcondylar approach, patients may maintain neutral alignment in the immediate postoperative period, but severe occipitoatlantal subluxation may occur gradually with cranial settling and possible neurological injury. Previous research is based on assumptions regarding the extent of condylar resection and the change in biomechanics that produces instability.

OBJECTIVE

To quantify the extent of bone removal during a far-lateral transcondylar approach, determine the changes in range of motion (ROM) and stiffness that occur after condylar resection, and identify the threshold of condylar resection that predicts alterations in occipitocervical biomechanics.

METHODS

Nine human cadaveric specimens were biomechanically tested before and after far-lateral transcondylar resection extending into the hypoglossal canal (HC). The extent of condylar resection was quantified using volumetric comparison between pre- and postresection computed tomography scans. ROM and stiffness testing were performed in intact and resected states. The extent of resection that produced alterations in occipitocervical biomechanics was assessed with sensitivity analysis.

RESULTS

Bone removal during condylar resection into the HC was 15.4%-63.7% (mean 35.7%). Sensitivity analysis demonstrated that changes in biomechanics may occur when just 29% of the occipital condyle was resected (area under the curve 0.80-1.00).

CONCLUSION

Changes in occipitocervical biomechanics may be observed if one-third of the occipital condyle is resected. During surgery, the HC may not be a reliable landmark to guide the extent of resection. Patients who undergo condylar resections extending into or beyond the HC require close surveillance for occipitocervical instability.

Utility of intraoperative rotational thromboelastometry in thoracolumbar deformity surgery

OBJECTIVE Blood loss during surgery for thoracolumbar scoliosis often requires blood product transfusion. Rotational thromboelastometry (ROTEM) has enabled the more targeted treatment of coagulopathy, but its use in deformity surgery has received limited study. The authors investigated whether the use of ROTEM reduces transfusion requirements in this case-control study of thoracolumbar deformity surgery. METHODS Data were prospectively collected on all patients who received ROTEM-guided blood product management during long-segment (≥ 7 levels) posterior thoracolumbar fusion procedures at a single institution from April 2015 to February 2016. Patients were matched with a group of historical controls who did not receive ROTEM-guided therapy according to age, fusion segments, number of osteotomies, and number of interbody fusion levels. Demographic, intraoperative, and postoperative transfusion requirements were collected on all patients. Univariate analysis of ROTEM status and multiple linear regression analysis of the factors associated with total in-hospital transfusion volume were performed, with p < 0.05 considered to indicate statistical significance. RESULTS Fifteen patients who received ROTEM-guided therapy were identified and matched with 15 non-ROTEM controls. The mean number of fusion levels was 11 among all patients, with no significant differences between groups in terms of fusion levels, osteotomy levels, interbody fusion levels, or other demographic factors. Patients in the non-ROTEM group required significantly more total blood products during their hospitalization than patients in the ROTEM group (8.5 ± 4.2 units vs 3.71 ± 2.8 units; p = 0.001). Multiple linear regression analysis showed that the use of ROTEM (p = 0.016) and a lower number of fused levels (p = 0.022) were associated with lower in-hospital transfusion volumes. CONCLUSIONS ROTEM use during thoracolumbar deformity correction is associated with lower transfusion requirements. Further investigation will better define the role of ROTEM in transfusion during deformity surgery.

109 Impact of a More Restrictive Overlapping Surgery Policy An Analysis of Complication Rates, Resident Involvement, and Surgical Wait Times at a High-Volume Neurosurgical Department

INTRODUCTION

Recently, overlapping surgery has been a source of controversy both in the popular press and within the academic medical community. There have been no studies examining the possible effects of more stringent overlapping surgery restrictions. The authors examined the impact of a new overlapping surgery policy on complication rates, neurosurgical resident education, and wait times for neurosurgical procedures.

METHODS

The authors performed a retrospective chart review of nonemergent neurosurgical procedures performed over two periods from June 1, 2014, to October 31, 2014 (pre-policy change) and from June 1, 2016, to October 31, 2016 (post-policy change) by any of 4 senior neurosurgeons at a single institution who were authorized to schedule overlapping cases. Information on preoperative evaluation, patient demographics, premorbid conditions, surgical variables, and postoperative course were collected and analyzed.

RESULTS

>Six hundred fifty-three patients met inclusion criteria for complications analysis. Of these, 378 (57.9%) underwent surgery before the policy change. On multivariable regression analysis, neither overlapping surgery (OR 1.072, 95% CI 0.710-1.620) nor the overlapping surgery policy change (1.057, OR 0.700 1.596) was associated with overall complication rates. Similarly, neither overlapping surgery (OR 1.472, 95% CI 0.883 2.454) nor the overlapping surgery policy change (OR 1.251, 95% CI 0.748 2.091) was associated with numbers of serious complications. After the policy change, the percentage of procedures in which the senior assistant was a post-residency fellow increased significantly, from 11.9% to 34.2% (P< 0.001). In a multiple linear regression analysis of surgery wait time, patients undergoing surgery post-policy change had significantly longer delays from the decision to operate to the actual neurosurgical procedure (P< 0.001).

CONCLUSION

At our institution, further restriction of overlapping surgery was not associated with a reduction in overall or serious complications. Resident involvement in neurosurgical procedures decreased significantly after the policy change, and our study suggests that waiting times for neurosurgical procedures also significantly lengthened.

Multivariable analysis of factors affecting length of stay and hospital charges after single-level corpectomy

Anterior cervical corpectomy and fusion (ACCF) is commonly employed for treating myelopathy, deformity, and a variety of other cervical pathologies. Limited data are available on factors associated with longer hospitalization and higher hospital charges following ACCF. The purpose of this study was to evaluate the pre-, intra-, and postoperative variables that are associated with length of hospital stay and hospital charges for patients undergoing single-level anterior cervical corpectomy and fusion in a retrospective case series. We retrospectively identified from a clinical database 69 patients who underwent single-level ACCF at a single institution from 2010 through 2014. Demographic variables, clinical information, and intraoperative data were analyzed with respect to length of hospitalization and hospital charges. T-test and Chi-squared testing as well as univariate and multivariable analysis were performed with p<0.05 considered significant. On multivariable analysis, polytrauma, postoperative complications, lower postoperative hematocrit, and two-staged procedures were significantly associated with longer lengths of stay. Length of stay, postoperative complications, and two-staged procedures were significantly associated with higher hospital charges. Patients undergoing a two-staged procedure and those having postoperative complications experience a longer postoperative length of stay and incur higher hospital charges. Avoidance of postoperative anemia may help to reduce length of stay following ACCF.

Multivariable Analysis of Factors Affecting Length of Stay and Hospital Charges After Atlantoaxial Fusion

Background

Atlantoaxial fusion is an effective procedure for treating degenerative, traumatic, and congenital abnormalities that result in upper cervical instability; however, data on which factors affect the length of stay and hospitalization-related charges are limited. The purpose of this study was to evaluate the pre-, intra-, and postoperative variables that affect these healthcare cost factors for patients undergoing posterior atlantoaxial fusion.

Methods

We retrospectively identified from a clinical database 59 patients who underwent isolated posterior atlantoaxial fusion at a single institution from 2010 to 2015. Demographic, clinical, and surgical variables from a clinical database were analyzed with respect to the length of hospital stay and hospital charges. T-test and Chi-square testing, as well as univariate and multivariable analysis, were performed with p<0.05 considered significant.

Results

On multivariable analysis, a variety of preoperative, intraoperative, and postoperative variables were associated with prolonged hospitalization and higher hospital charges, including tobacco use, preoperative diagnosis, operating room time, and the need for intraoperative blood transfusion.

Conclusions

Varied preoperative, intraoperative, and postoperative factors are associated with increased length of hospitalization and higher hospital charges after atlantoaxial fusion. Familiarity with these factors may allow for improved surgical planning and patient counseling.

Anatomy of psoas muscle innervation: Cadaveric study

Hip flexion weakness is relatively common after lateral transpsoas surgery. Persistent weakness may result from injury to the innervation of the psoas major muscles (PMMs); however, anatomical texts have conflicting descriptions of this innervation, and the branching pattern of the nerves within the psoas major, particularly relative to vertebral anatomy, has not been described. The authors dissected human cadavers to describe the branching pattern of nerves supplying the PMMs. Sixteen embalmed cadavers were dissected, and the fine branching pattern of the innervation to the PMM was studied in 24 specimens. The number of branches and width and length of each branch of nerves to the PMMs were quantified. Nerve branches innervating the PMMs arose from spinal nerve levels L1-L4, with an average of 6.3 ± 1.1 branches per muscle. The L1 nerve branch was the least consistently present, whereas L2 and L3 branches were the most robust, the most numerous, and always present. The nerve branches to the psoas major commonly crossed the intervertebral (IV) disc obliquely prior to ramification within the muscle; 76%, 80%, and 40% of specimens had a branch to the PMM cross the midportion of the L2-3, L3-4, and L4-5 IV discs, respectively. The PMMs are segmentally innervated from the L2-L4 ventral rami branches, where these branches course obliquely across the L2-3, L3-4, and L4-5 IV discs. Knowledge of the mapping of nerve branches to the PMMs may reduce injury and the incidence of persistent weak hip flexion during lateral transpsoas surgery. Clin. Anat. 30:479-486, 2017. © 2017 Wiley Periodicals, Inc.

Comparing clinical outcomes of repeat discectomy versus fusion for recurrent disc herniation utilizing the N2QOD

OBJECTIVE

Recurrent lumbar disc herniation (RLDH) is a significant cause of morbidity in patients undergoing lumbar discectomy and has been reported to occur in up to 18% of cases. While repeat discectomy is often successful in treating these patients, concern over repeat RLDH may lead surgeons to advocate instrumented fusion even in the absence of instability. The authors' goal was to compare clinical outcomes for patients undergoing repeat discectomy versus instrumented fusion for RLDH.

METHODS

The authors used the National Neurosurgery Quality and Outcomes Database (N2QOD) to assess outcomes of patients who underwent repeat discectomy versus instrumented fusion at a single institution from 2012 to 2015. Primary outcomes included Oswestry Disability Index (ODI) score, visual analog scale (VAS) score, and quality-adjusted life year (QALY) measures. Secondary outcomes included hospital length of stay, discharge status, and hospital charges.

RESULTS

The authors identified 25 repeat discectomy and 12 instrumented fusion patients with 3- and 12-month follow-up records. The groups had similar ODI and VAS scores and QALY measurements at 3 and 12 months. Patients in the instrumented fusion group had significantly longer hospitalizations (3.7 days vs 1.0 days, p < 0.001) and operative times (229.6 minutes vs 82.7 minutes, p < 0.001). They were also more likely to be female (p = 0.020) and to be discharged to inpatient rehabilitation instead of home (p = 0.036). Hospital charges for the instrumented fusion group were also significantly higher ($54,458.29 vs $11,567.05, p < 0.001). Rates of reoperation were higher in the repeat discectomy group (12% vs 0%), but the difference was not statistically significant (p = 0.211).

CONCLUSIONS

Repeat discectomy and instrumented fusion result in similar clinical outcomes at short-term follow-up. Patients undergoing repeat discectomy had significantly shorter operative times and length of stay, and they incurred dramatically lower hospital charges. They were also less likely to require acute rehabilitation postoperatively. Further research is needed to compare these two management strategies.

Managing overlapping surgery: an analysis of 1018 neurosurgical and spine cases

OBJECTIVE Overlapping surgery-the performance of parts of 2 or more surgical procedures at the same time by a single lead surgeon-has recently come under intense scrutiny, although data on the effects of overlapping procedures on patient outcomes are lacking. The authors examined the impact of overlapping surgery on complication rates in neurosurgical patients. METHODS The authors conducted a retrospective review of consecutive nonemergent neurosurgical procedures performed during the period from May 12, 2014, to May 12, 2015, by any of 5 senior neurosurgeons at a single institution who were authorized to schedule overlapping cases. Overlapping surgery was defined as any case in which 2 patients under the care of a single lead surgeon were under anesthesia at the same time for any duration. Information on patient demographics, premorbid conditions, surgical variables, and postoperative course were collected and analyzed. Primary outcome was the occurrence of any complication from the beginning of surgery to 30 days after discharge. A secondary outcome was the occurrence of a serious complication-defined as a life-threatening or life-ending event-during this same period. RESULTS One thousand eighteen patients met the inclusion criteria for the study. Of these patients, 475 (46.7%) underwent overlapping surgery. Two hundred seventy-one patients (26.6%) experienced 1 or more complications, with 134 (13.2%) suffering a serious complication. Fourteen patients in the cohort died, a rate of 1.4%. The overall complication rate was not significantly higher for overlapping cases than for nonoverlapping cases (26.3% vs 26.9%, p = 0.837), nor was the rate of serious complications (14.7% vs 11.8%, p = 0.168). After adjustments for surgery type, surgery duration, body mass index, American Society of Anesthesiologists (ASA) physical classification grade, and intraoperative blood loss, overlapping surgery remained unassociated with overall complications (OR 0.810, 95% CI 0.592-1.109, p = 0.189). Similarly, after adjustments for surgery type, surgery duration, body mass index, ASA grade, and neurological comorbidity, there was no association between overlapping surgery and serious complications (OR 0.979, 95% CI 0.661-1.449, p = 0.915). CONCLUSIONS In this cohort, patients undergoing overlapping surgery did not have an increased risk for overall complications or serious complications. Although this finding suggests that overlapping surgery can be performed safely within the appropriate framework, further investigation is needed in other specialties and at other institutions.

Return to Play after Cervical Spine Injuries: A Consensus of Opinion

Study Design Survey. Objective Sports-related spinal cord injury (SCI) represents a growing proportion of total SCIs but lacks evidence or guidelines to guide clinical decision-making on return to play (RTP). Our objective is to offer the treating physician a consensus analysis of expert opinion regarding RTP that can be incorporated with the unique factors of a case for clinical decision-making. Methods Ten common clinical scenarios involving neurapraxia and stenosis, atlantoaxial injury, subaxial injury, and general cervical spine injury were presented to 25 spine surgeons from level 1 trauma centers for whom spine trauma is a significant component of their practice. We evaluated responses to questions about patient RTP, level of contact, imaging required for a clinical decision, and time to return for each scenario. The chi-square test was used for statistical analysis, with p < 0.05 considered significant. Results Evaluation of the surgeons' responses to these cases showed significant consensus regarding return to high-contact sports in cases of cervical cord neurapraxia without symptoms or stenosis, surgically repaired herniated disks, and nonoperatively healed C1 ring or C2 hangman's fractures. Greater variability was found in recommendations for patients showing persistent clinical symptomatology. Conclusion This survey suggests a consensus among surgeons for allowing patients with relatively normal imaging and resolution of symptoms to return to high-contact activities; however, patients with cervical stenosis or clinical symptoms continue to be a challenge for management. This survey may serve as a basis for future clinical trials and consensus guidelines.

Vitamin D status in cervical spondylotic myelopathy: comparison of fusion rates and patient outcome measures

BACKGROUND

Patients undergoing elective spinal fusion have an alarming rate of vitamin D deficiency, but its impact on bone fusion and patient outcomes is unclear. We investigated the association of perioperative vitamin D levels, fusion rates, and patient-reported outcome in patients undergoing spinal fusion for cervical spondylotic myelopathy.

METHODS

In this one-year, prospective, single-center observational study, serum 25-OH vitamin D levels were measured perioperatively in adult patients. Serum vitamin D levels <30 ng/mL were considered abnormal. The primary outcome measures were postoperative patient-reported outcomes (Neck Disability Index, Visual Analog Scale, EuroQol EQ-5D-3L, EQ-VAS). Secondary outcome measures were the presence of and time to solid bony fusion, controlling for Body Mass Index (BMI), age, and number of motion segments.

RESULTS

Forty-one of 58 patients (71%) had laboratory-confirmed abnormal vitamin D levels. Patients with low vitamin D were younger (P<0.05) and had a higher BMI (P<0.05) than patients with adequate vitamin D, but the groups were otherwise similar. There were no differences in mean time to fusion between the two groups, but patients with low vitamin D reported more postoperative disability (P<0.05). Multivariate model analysis demonstrated an independent, significant association between normal vitamin D and lower postoperative neck disability index (P=0.05) and EQ-5D-3L (P=0.03).

CONCLUSIONS

Vitamin D deficiency (<30 ng/mL) is highly prevalent in patients undergoing elective spinal fusion for cervical myelopathy. Low vitamin D levels were associated with worse patient-reported outcomes and were an independent predictor of greater disability, which suggests vitamin D supplementation may offer some benefit in these patients.

Unusual brachial plexus lesion: Hematoma masquerading as a peripheral nerve sheath tumor

Background:

Malignant peripheral nerve sheath tumors (MPNSTs) of the brachial plexus have unique radiographic and clinical findings. Patients often present with progressive upper extremity paresthesias, weakness, and pain. On magnetic resonance (MR) imaging, lesions are isointense on T1-weighted and hyperintense on T2-weighted sequences, while also demonstrating marked enhancement on MR studies with gadolinium diethylenetriamine pentaacetic acid. On the basis of their characteristic MR imaging features and rapid clinical progression, two brachial plexus lesions proved to be organizing hematomas rather than MPNST.

Methods:

A 51-year-old male and a 31-year-old female were both assessed for persistent and worsened left-sided upper extremity pain, paresthesias, and weakness. In both cases, the MR imaging of the brachial plexus demonstrated an extraspinal enhancing lesion located within the left C7–T1 neuroforamina.

Results:

Although the clinical and radiographic MR features for these 2 patients were consistent with MPNSTs, both lesions proved to be benign organizing hematomas.

Conclusions:

These two case studies emphasize that brachial plexus hematomas may mimic MPNSTs on MR studies. Accurate diagnosis of these lesions is critical for determining the appropriate management options and treatment plans. Delaying the treatment of a highly aggressive nerve sheath tumor can have devastating consequences, whereas many hematomas resolve without surgery. Therefore, if the patient has stable findings on neurological examination and a history of trauma, surgical intervention may be delayed in favor of repeat MR imaging in 2–3 months to re-evaluate the size of the mass.

Bow hunter's syndrome revisited: 2 new cases and literature review of 124 cases

Rotational occlusion of the vertebral artery (VA), or bow hunter's syndrome, is a rare yet surgically treatable cause of vertebrobasilar insufficiency. The underlying pathology is dynamic stenosis of the VA by osteophytes, fibrous bands, or lateral disc herniation with neck rotation or extension. The authors present 2 previously unreported cases of bow hunter's syndrome and summarize 124 cases identified in a literature review. Both patients in the new cases were treated by VA decompression and fusion of the subaxial spine. Each had > 50% occlusion of the left VA at the point of entry into the transverse foramen with a contralateral VA that ended in the posterior inferior cerebellar artery. Analyzing data from 126 cases (the 2 new cases in addition to the previously published 124), the authors report that stenosis was noted within V1 in 4% of cases, in V2 in 58%, in V3 in 36%, and distal to C-1 in 2%. Patients presented in the 5th to 7th decade of life and were more often male than female. The stenotic area was decompressed in 85 (73%) of the 116 patients for whom the type of treatment was reported (V1, 4 [80%] of 5; V2, 52 [83%] of 63; V3/V4, 29 [60%] of 48). Less commonly, fusion or combined decompression and fusion was used (V2, 7 [11%] of 63; V3/V4, 14 [29%] of 48). Most patients reported complete resolution of symptoms. The authors conclude that patients with bow hunter's syndrome classically have an impaired collateral blood flow to the brainstem. This condition carries an excellent prognosis with decompression, fusion, or combined surgery, and individual patient characteristics should guide the choice of therapy.

Primary repair of open neural tube defect in adulthood: case example and review of management strategies

BACKGROUND CONTEXT

Neural tube defects are congenital malformations that develop when the neural plate fails to close during embryogenesis. The most common open neural tube defect, myelomeningocele (MMC), is declining in frequency in North America. If identified, an MMC must be closed in the perinatal period to prevent lethal complications. Lesions presenting in older adults are, thus, very uncommon.

PURPOSE

The purpose of this study was to describe the surgical management of an adult with an unrepaired ulcerated lumbosacral MMC who presented with persistent cerebrospinal fluid (CSF) leakage and to review the management strategies for adult patients with unrepaired MMC.

STUDY DESIGN

A case report was used for this study.

METHODS

The patient was a 62-year-old woman with an unrepaired ulcerated lumbosacral MMC and associated lower extremity weakness. She sought medical care for persistent lumbar tenderness and ulceration after sustaining a fall 4 months before admission. Physical and radiological assessment revealed a lumbosacral MMC at the L5 and S1 levels and a tethered cord. Surgical resection of the placode and de-tethering were performed.

RESULTS

One week after repair of the lumbosacral MMC, the patient was readmitted for management of continued CSF leakage and hydrocephalus, requiring external ventricular drainage, wound revision, and placement of lumboperitoneal shunt. The patient experienced complete resolution of back pain without additional episodes of CSF leakage.

CONCLUSIONS

This rare case and review of management strategies suggests that proper surgical management of open MMC in adulthood can successfully be performed and improve patient symptoms and prevent further complications.

Rigid Posterior Lumbopelvic Fixation without Formal Debridement for Pyogenic Vertebral Diskitis and Osteomyelitis Involving the Lumbosacral Junction: Technical Report

Background

Pelvic fixation with S2-alar-iliac (S2AI) screws can increase the rigidity of a lumbosacral construct, which may promote bone healing, improve antibiotic delivery to infected tissues, and avoid L5–S1 pseudarthrosis.

Purpose

To describe the use of single-stage posterior fixation without debridement for the treatment of pyogenic vertebral diskitis and osteomyelitis (PVDO) at the lumbosacral junction.

Study design

Technical report.

Methods

We describe the management of PVDO at the lumbosacral junction in which the infection invaded the endplates, disk space, vertebrae, prevertebral soft tissues, and epidural space. Pedicle involvement precluded screw fixation at L5. Surgical management consisted of a single-stage posterior operation with rigid lumbopelvic fixation augmented with S2-alar-iliac screws and without formal debridement of the infected area, followed by long-term antibiotic treatment.

Results

At 2-year follow-up, successful fusion and eradication of the infection were achieved.

Conclusion

PVDO at the lumbosacral junction may be treated successfully using rigid posterior-only fixation without formal debridement combined with antibiotic therapy.

Unplanned reoperation after lumbopelvic fixation with S-2 alar-iliac screws or iliac bolts

OBJECT

S-2 alar-iliac (S2AI) screws are an attractive alternative to conventional fixation with iliac bolts because they are lower profile, require less muscle dissection, and have greater pullout strength. Few studies, however, compare outcomes between these techniques.

METHODS

The authors conducted a retrospective cohort study of consecutive adult patients at a single institution from December 2009 to March 2012 who underwent lumbopelvic fixation using S2AI screws or iliac bolts. Medical records were reviewed for patients with clinical failure, defined as an unplanned reoperation because of instrumentation failure and/or wound-related complications. Univariate, multivariate, and survival analyses were used to compare patients who required reoperation with those who did not. Method of pelvic fixation was the main predictor variable of interest, and the authors adjusted for potential confounding risk factors.

RESULTS

Of the 60 patients included, 23 received S2AI screws. Seventeen patients (28%) underwent an osteotomy. The mean follow-up was 22 months. A Kaplan-Meier survival model was used to evaluate the time to reoperation from the initial placement of lumbopelvic instrumentation. The failure-free rate was 96.6% at 6 months, 87.0% at 1 year, and 73.5% at 2 years. Reoperation was more common in patients with iliac bolts than in those with S2AI screws (13 vs 2; p = 0.031). Univariate analysis identified potential risk factors for unplanned reoperation, including use of iliac bolts (p = 0.031), absence of L5–S1 interbody graft (p = 0.048), previous lumbar fusion (p = 0.034), and pathology other than degenerative disease or scoliosis (p = 0.034). After adjusting for other risk factors, multivariate analysis revealed that the use of S2AI screws (OR 8.1 [1.5–73.5]; p = 0.030) was the only independent predictor for preventing unplanned reoperation.

CONCLUSIONS

Both S2AI screws and iliac bolts were effective at improving fusion rates at the lumbosacral junction. The use of S2AI screws, however, was independently associated with fewer unplanned reoperations for wound-related complications and instrumentation failures than the use of iliac bolts.

Comparison of structural allograft and traditional autograft technique in occipitocervical fusion: radiological and clinical outcomes from a single institution

OBJECT The authors' objectives were to compare the rate of fusion after occipitoatlantoaxial arthrodesis using structural allograft with the fusion rate from using autograft, to evaluate correction of radiographic parameters, and to describe symptom relief with each graft technique. METHODS The authors assessed radiological fusion at 6 and 12 months after surgery and obtained radiographic measurements of C1-2 and C2-7 lordotic angles, C2-7 sagittal vertical alignments, and posterior occipitocervical angles at preoperative, postoperative, and final follow-up examinations. Demographic data, intraoperative details, adverse events, and functional outcomes were collected from hospitalization records. Radiological fusion was defined as the presence of bone trabeculation and no movement between the graft and the occiput or C-2 on routine flexion-extension cervical radiographs. Radiographic measurements were obtained from lateral standing radiographs with patients in the neutral position. RESULTS At the University of Utah, 28 adult patients underwent occipitoatlantoaxial arthrodesis between 2003 and 2010 using bicortical allograft, and 11 patients were treated using iliac crest autograft. Mean follow-up for all patients was 20 months (range 1-108 months). Of the 27 patients with a minimum of 12 months of follow-up, 18 (95%) of 19 in the allograft group and 8 (100%) of 8 in the autograft group demonstrated evidence of bony fusion shown by imaging. Patients in both groups demonstrated minimal deterioration of sagittal vertical alignment at final follow-up. Operative times were comparable, but patients undergoing occipitocervical fusion with autograft demonstrated greater blood loss (316 ml vs 195 ml). One (9%) of 11 patients suffered a significant complication related to autograft harvesting. CONCLUSIONS The use of allograft in occipitocervical fusion allows a high rate of successful arthrodesis yet avoids the potentially significant morbidity and pain associated with autograft harvesting. The safety and effectiveness profile is comparable with previously published rates for posterior C1-2 fusion using allograft.

Increased spasticity from a fracture in the baclofen catheter caused by Charcot spine: case report

In patients with Charcot spine, a loss of normal feedback response from the insensate spine results in spinal neuropathy. Increasing deformity, which can manifest as sitting imbalance, crepitus, or increased back pain, can result. We present the case of a patient with a high-thoracic spinal cord injury (SCI) who subsequently developed a Charcot joint at the T10-11 level that resulted in a dramatic increase in previously controlled spasticity after fracture of an existing baclofen catheter. The 68-year-old man with T4 paraplegia presented with increasing baclofen requirements and radiographic evidence of fracture of the intrathecal baclofen catheter with an associated Charcot joint with extensive bony destruction. The neuropathic spinal arthropathy caused mechanical baclofen catheter malfunction and resulting increased spasticity. The patient was found to have transected both his spinal cord and the baclofen catheter. Treatment consisted of removal of the catheter and stabilization with long-segment instrumentation and fusion from T6 to L2. Follow-up radiographs obtained a year and a half after surgery showed no evidence of hardware failure or significant malalignment. The patient has experienced resolution of symptoms and does not require oral or intrathecal baclofen. This is the only reported case of a Charcot spine causing intrathecal catheter fracture, leading to increased spasticity. This noteworthy case suggests that late spinal instability should be considered in the setting of SCI and increased spasticity.