Faculty Bibliography

PURPOSE:There is a paucity of literature describing Guillain-Barré syndrome (GBS) in the elective orthopedic patient. We aim to report one such case following spine surgery. METHODS:A morbidly obese 52-year-old male developed diminished reflexes as well as left upper and lower extremity weakness following surgical decompression and fusion at L4-5. The patient had persistent weakness and progressed to areflexia, at which point urgent lumbar puncture supported a diagnosis of GBS. RESULTS:The patient was promptly started on intravenous immunoglobulin and made significant clinical improvement with near-complete resolution of symptoms by 3-month follow-up visit. By the sixth month, he was able to function and ambulate without a cane. GBS is a rare and potentially critical cause of diminished reflexes and weakness in the post-operative elective orthopedic patient. We propose that morbid obesity may have contributed to the patient's susceptibility of developing GBS following surgery. CONCLUSION:Neurologic symptoms of this autoimmune condition may also mimic the clinical picture of an elective spine patient, thus confounding diagnosis. If imaging cannot explain exam findings or new neurologic symptoms post-operatively, rare disease processes should be considered in the differential diagnosis.

Little literature exists examining differences in presentation and outcomes between monomicrobial and polymicrobial vertebral infections. Seventy-nine patients treated for vertebral osteomyelitis between 2001 and 2011 were reviewed. Patients were divided into monomicrobial and polymicrobial cohorts based on type of infection. Various characteristics were compared between the 2 groups. The 26 patients with a polymicrobial infection were older and had a higher mortality rate, lower clearance of infection, larger infection, more vertebral instability, higher erythrocyte sedimentation rate at presentation, and longer mean length of stay. There were no significant differences in Oswestry Disability Index scores at final follow-up, but there were differences in presentation and clinical outcomes between monomicrobial and polymicrobial vertebral osteomyelitis. Patients may benefit from counseling regarding their disease type and potential prognosis. [Orthopedics. 2017; 40(2):e370-e373.].

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has been shown to have long-term clinical outcomes similar to those with open TLIF and decreased perioperative morbidity. This study assessed whether this procedure can be safely performed in outpatient settings. Ninety-six consecutive patients undergoing 1- or 2-level MIS-TLIFs were retrospectively reviewed. They were divided into inpatient and outpatient cohorts (36%). All had a minimum of 2 years of follow-up. Patient demographics, comorbidities, complications, and readmissions were examined. Early postoperative complications were stratified into wound related, infection, neurologic, implant related, and vascular injuries. Patients in the outpatient cohort were significantly younger, had lower American Society of Anesthesiologists physical status scores, and had lower Charlson Comorbidity Index scores than patients in the inpatient cohort. There were no statistically significant differences in overall postoperative complication rates, readmission rates, or final Oswestry Disability Index or visual analog scale scores between the 2 cohorts. The clinical outcomes of the outpatient TLIF procedure were similar to those of the inpatient procedure and it had an acceptable complication rate. [Orthopedics. 2016; 39(6):e1218-e1222.].

INTRODUCTION/BACKGROUND:Obtaining blood or tissue cultures prior to administration of antibiotics has been the standard of care in the treatment of osteomyelitis of the spine. A delay in diagnosis of vertebral osteomyelitis is the primary culprit for the inaccuracy of blood cultures and biopsies. The purpose of this study was to evaluate the outcomes of spinal osteomyelitis in patients where the infecting organism was identified through cultures in contrast to cases where the cultures continued to be negative. MATERIALS AND METHODS/METHODS:We retrospectively reviewed the database of spinal osteomyelitis cases presented at a high-volume institution from 2001-2011. This resulted in 91 patients (51 men and 40 women) who had a mean age of 59 years with a mean follow-up of four years. Delay in diagnosis was defined as greater than 2.5 months from first ER visit for non-specific back pain to diagnosis of osteomyelitis without antibiotic treatment in the interim. Nineteen patients had a delay in diagnosis (DD) and 72 were diagnosed early (ED). Outcomes evaluated include clearance of infection, clinical outcomes measured by Oswestry disability index scores (ODIs), and the efficacy of blood cultures and biopsies. RESULTS:The ED group had a higher odds ratio of osteomyelitis clearance compared to the delay in diagnosis group and this trended toward significance [p=0.08]. The mean improvements in ODIs were significantly greater in the ED group compared to the DD group. Positive blood cultures were more positive when drawn within one month compared to after one month [p=.001]. Percutaneous biopsy cultures were more positive when drawn within 2.5 months compared to after 2.5 months [p=.025]. Open biopsy cultures were more positive when drawn within 4.5 months compared to after that [p<0.001]. DISCUSSION/CONCLUSIONS:We found that delayed diagnosis may negatively affect the treatment outcome as evidenced by the greater improvements in ODI scores among those diagnosed early. Although we were unable to show a difference in clearance between early and delayed diagnosis, it is quite possible that larger cohorts may have shown this given the trend toward significance. CONCLUSION/CONCLUSIONS:Hence, an early diagnosis has improved vertebral osteomyelitis clearance and clinical outcomes, and blood cultures and biopsies may have a low yield if delayed.

BACKGROUND:How the relative volume of an epidural abscess on MRI affects outcomes with antibiotics alone has limited literature. The purpose of this study was to identify which infected epidural collections will reabsorb with antibiotics alone. Specifically, what is the critical size and enhancement on contrast MRIs to require a drainage procedure? MATERIALS AND METHODS/METHODS:A retrospective review of all spinal osteomyelitis patients from 2001-2012 was performed. Inclusion criteria included appropriate initial imaging, lab results, no drainage procedures of collections, and no treatment prior to admission at an outside institution. Large size epidural abscess was defined as abscesses with a volume greater than 1400 mm3. Clearance and mortality rates were evaluated. RESULTS:The cohort consisted of 128 patients including 76 men and 52 women who had a mean age of 62 years (range, 21 to 90 years) and had a mean follow-up of 38 months (range, 24 to 72 months). Patients with a large epidural abscess had a greater clearance rate of the infection and decreased mortality rate when treated with surgery or drainage compared to patients treated with antibiotics alone [clearance: p=0.048; mortality: p=0.048]. Those small epidural abscesses had similar clearance and mortality rates when treated with surgery or drainage compared to antibiotics alone [clearance: p=0.75; mortality: p=0.13]. Patients with non-enhancing epidural abscesses had similar clearance rates-but increased mortality rates-when treated with antibiotics alone compared to surgery or drainage [clearance: p>0.9; mortality: p=0.03]. Those with enhancing epidural collections had similar clearance and mortality rates when treated with antibiotics alone compared to surgery or drainage [clearance: p=0.08, mortality: p=0.10]. CONCLUSION/CONCLUSIONS:Large epidural infected collections require surgery or a percutaneous drainage procedure. Clearance rates are higher and mortality rates are lower compared to non-operative management in these instances. Neurologically intact patients with a small epidural collection can be treated with antibiotics alone with good expected outcomes.

The purpose of this study was to compare the outcomes of instrumented versus noninstrumented (decompression) surgical treatment of vertebral osteomyelitis. The study population included 104 patients with spinal osteomyelitis who were treated at the authors' institution between 2004 and 2012. This included 62 men and 42 women who underwent either instrumented (n=57) or noninstrumented (n=47) surgery. Mean patient age was 59 years, and mean follow-up was 38 months (range, 12-78 months). Specifically, the following criteria were assessed: mortality rates, infection clearance rates, clinical outcomes measured by Oswestry Disability Index (ODI), mean length of stay, and baseline differences between the 2 cohorts. Although patients in the instrumented cohort had more instability, more neurologic symptoms, and larger volume infection, they had similar clearance of infection (54% vs 42.5%; odds ratio [OR], 1.55; 95% confidence interval [CI], 0.61-3.9; P=.35), mortality rate (9% vs 17%; OR, 0.47; 95% CI, 0.14-1.54; P=.21), and ODI scores (40 vs 45 points; P=.32) compared with patients in the noninstrumented group. However, mean length of stay (19 vs 13 days; P=.02) was significantly higher for patients in the instrumented group. Even in more severe cases of vertebral osteomyelitis, instrumentation resulted in comparable outcomes to decompression. [Orthopedics. 2016; 39(3):e504-e508.].

Paraspinal muscles are commonly affected during spine surgery. The purpose of this study was to assess the potential factors that contribute to paraspinal muscle atrophy (PMA) after lumbar spine surgery. A comprehensive review of the available English literature, including relevant abstracts and references of articles selected for review, was conducted to identify studies that reported PMA after spinal surgery. The amount of postoperative PMA was evaluated in (1) lumbar fusion vs nonfusion procedures; (2) posterior lumbar fusion vs anterior lumbar fusion; and (3) minimally invasive (MIS) posterior lumbar decompression and/or fusion vs non-MIS equivalent procedures. In total, 12 studies that included 529 patients (262 men and 267 women) were reviewed. Of these, 365 patients had lumbar fusions and 164 had lumbar decompressions. There was a significantly higher mean postoperative volumetric PMA with fusion vs nonfusion procedures (P=.0001), with posterior fusion vs anterior fusion (P=.0001), and with conventional fusions vs MIS fusions (P=.001). There was no significant difference in mean volumetric lumbar PMA with MIS decompression vs non-MIS decompression (P=.56). There was significantly higher postoperative PMA with lumbar spine fusions, posterior procedures, and non-MIS fusions. [Orthopedics.].

The purpose of this study was to evaluate the long-term clinical and radiographic outcomes of posterolateral lumbar fusion for lumbar stenosis cases requiring bilateral facetectomy in conjunction with a laminectomy. The authors evaluated 34 consecutive patients who had undergone a lumbar laminectomy, bilateral partial facetectomy, and posterolateral fusion at a single institution between 1981 and 1996. They included 25 men and 9 women with a mean age of 42 years (range, 27-57 years). Twenty-three cases were instrumented and 11 were noninstrumented. Mean follow-up was 21 years (range, 15-29 years). Outcomes evaluated included reoperation rate, clinical outcomes evaluated by the Oswestry Disability Index (ODI) score, radiographic evaluations of adjacent segmental degeneration (ASD) and lumbar lordosis, and contributing demographic factors to disease progression. At final follow-up, 17 of the 34 patients had undergone reoperation (43% of the instrumented group and 64% of the noninstrumented group). There were no differences in the reoperation rate or ODI improvement between the instrumented and noninstrumented groups (P>.05). Female patients required more revisions, had less ODI improvement, had greater postoperative ASD, and had less maintenance of their postoperative lumbar lordosis. There was no difference in maintenance of postoperative lumbar lordosis or ASD between the instrumented and noninstrumented groups. Instrumentation did not improve revision rates, clinical outcomes, or radiographic outcomes in laminectomies requiring contemporaneous facetectomies. [Orthopedics. 2015; 38(12):e1104-e1109.].

This study evaluated the safety of 3-level anterior cervical diskectomy and fusion (ACDF) with ultra-low-dose recombinant bone morphogenetic protein-2 (rhBMP-2). Thirty-seven consecutive patients with cervical spondylotic myelopathy who were treated with 3-level ACDF and rhBMP-2 were evaluated. Complications such as airway or cervical swelling or hematoma were not observed. The rate of dysphagia was no different at 1, 2, and 6 months postoperatively compared with reports in the literature without rhBMP-2. There were significant improvements in VAS neck/arm pain, Oswestry Neck Disability Index, and cervical lordosis. The use of ultra-low-dose rhBMP-2 for 3-level ACDF may be efficacious for surgically addressing 3-level spondylotic myelopathy. [Orthopedics. 2015; 38(4):241-245.].

BACKGROUND CONTEXT: The role of magnetic resonance imaging (MRI) in neurologically intact cervical spine fractures is not well defined. To our knowledge, there are no studies that clearly identify the indications for MRI in this particular scenario. Controversy remains regarding the use of MRI in at-risk patients, primarily the obtunded and elderly patients. PURPOSE: The purpose of the present study was to examine the predisposing conditions where an MRI would provide additional findings that would affect management in acute cervical spine fractures. STUDY DESIGN: Retrospective cohort involving radiographic and clinical review. PATIENT SAMPLE: Consecutive patients with acute cervical injuries at a single institution. OUTCOME MEASURES: Neurologic recovery. METHODS: A review of 830 patients with cervical spinal injuries between 2006 and 2010 was performed. Clinical information was obtained for all the patients: Glasgow Coma Scale, mechanism of injury, major medical comorbidities, associated injuries, neurologic examination, neurologic symptoms, sex, age, and alertness. Two experienced fellowship-trained spine surgeons determined if the MRI study changed the management in the individual cases based on the Sub-axial Cervical Spine Injury classification system. RESULTS: Ninety-nine patients with a cervical fracture were included in the final analysis: median age 54 years (interquartile range, 42 years), mean Glasgow Coma Scale 13 (standard deviation+/-3.0), 68% males, 32% females, 42% older patients (age>60 years), 30% spondylosis, 27% polytrauma, 67% alert, 28% neurologic deficit. Major medical comorbidities, prior to injury level of activity, atlantoaxial versus subaxial, and gender were not associated with changes in diagnosis and management (p>.05). Age >60 years, neurologic deficit, polytrauma status, alertness, and spondylosis were associated with having additional clinically relevant findings seen on MRI and changes in management (p<.05). The majority of the changes in management were related to MRI's illustration of the spinal cord injury and not due to an occult instability. Eighty-one percent of the changes in management were related to the depiction of the spinal cord compression seen on MRI, whereas 19% of the changes in management were related to occult instability seen on MRI. CONCLUSIONS: Older age (>60 years), obtunded or temporary non-assessable status, cervical spondylosis, polytrauma, and neurologic deficit are predisposing factors for further injury found on MRI but missed on computed tomographic scan alone. These additional findings can affect the management in acute cervical spine fractures. The rational of the on-call spine surgeon to order an MRI for a cervical spine fracture is well founded and often that MRI will affect the fracture management. Magnetic resonance imaging particularly helps with better defining the type of spinal cord compression. Picking up occult instability missed on computed tomographic scan was possible with MRI but not as common.