Kevin L. Ju

Differentiating Between Methicillin-Resistant and Methicillin-Sensitive Staphylococcus aureus Osteomyelitis in Children

BACKGROUND Although osteomyelitis was once commonly due to methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA)--which causes more virulent and invasive infections--has emerged as an increasingly important cause. Differentiating clinically between MRSA and MSSA can be challenging, but is necessary in order to promptly administer appropriate antibiotics and maintain vigilance against possible sequelae of MRSA osteomyelitis. The purpose of our study was to develop a clinical prediction algorithm to distinguish between MRSA and MSSA osteomyelitis in children. METHODS A retrospective review of 129 children presenting with culture-proven Staphylococcus aureus osteomyelitis between 2000 and 2009 was performed. The demographics, symptoms, vital signs, and laboratory test values in the MSSA group (n = 118) and the MRSA group (n = 11) were compared with use of univariate analysis. Multivariate logistic regression with backward stepwise selection was then used to identify independent multivariate predictors of MRSA osteomyelitis, and each of these predictors was subjected to receiver operating characteristic curve analysis to determine the optimal cutoff value. Finally, a prediction algorithm for differentiating between MRSA and MSSA osteomyelitis on the basis of these independent predictors was constructed. RESULTS Patients with MRSA osteomyelitis differed significantly from those with MSSA osteomyelitis with regard to non-weight-bearing status, antibiotic use at presentation, body temperature, hematocrit value, heart rate, white blood-cell count, platelet count, C-reactive protein level, and erythrocyte sedimentation rate. Four significant independent multivariate predictors were identified: a temperature of >38°C, a hematocrit value of <34%, a white blood-cell count of >12,000 cells/µL, and a C-reactive protein level of >13 mg/L. The predicted probability of MRSA osteomyelitis, determined on the basis of the number of these predictors that a child satisfied, was 92% for all four predictors, 45% for three, 10% for two, 1% for one, and 0% for zero predictors. Receiver operating characteristic curve analysis was used to evaluate the predictive accuracy of the number of multivariate predictors, and this analysis revealed a steep shoulder and an area under the curve of 0.94 (95% confidence interval, 0.88 to 1.00). CONCLUSIONS Our proposed set of four predictors provided excellent diagnostic performance in differentiating between MRSA and MSSA osteomyelitis in children, and thus would be able to guide patient management and facilitate timely antibiotic selection.Although osteomyelitis was once commonly due to methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA)—which causes more virulent and invasive infections—has emerged as an increasingly important cause. Differentiating clinically between MRSA and MSSA can be challenging, but is necessary in order to promptly administer appropriate antibiotics and maintain vigilance against possible sequelae of MRSA osteomyelitis. The purpose of our study was to develop a clinical prediction algorithm to distinguish between MRSA and MSSA osteomyelitis in children. A retrospective review of 129 children presenting with culture-proven Staphylococcus aureus osteomyelitis between 2000 and 2009 was performed. The demographics, symptoms, vital signs, and laboratory test values in the MSSA group (n = 118) and the MRSA group (n = 11) were compared with use of univariate analysis. Multivariate logistic regression with backward stepwise selection was then used to identify independent multivariate predictors of MRSA osteomyelitis, and each of these predictors was subjected to receiver operating characteristic curve analysis to determine the optimal cutoff value. Finally, a prediction algorithm for differentiating between MRSA and MSSA osteomyelitis on the basis of these independent predictors was constructed. Patients with MRSA osteomyelitis differed significantly from those with MSSA osteomyelitis with regard to non-weight-bearing status, antibiotic use at presentation, body temperature, hematocrit value, heart rate, white blood-cell count, platelet count, C-reactive protein level, and erythrocyte sedimentation rate. Four significant independent multivariate predictors were identified: a temperature of >38°C, a hematocrit value of 12,000 cells/μL, and a C-reactive protein level of >13 mg/L. The predicted probability of MRSA osteomyelitis, determined on the basis of the number of these predictors that a child satisfied, was 92% for all four predictors, 45% for three, 10% for two, 1% for one, and 0% for zero predictors. Receiver operating characteristic curve analysis was used to evaluate the predictive accuracy of the number of multivariate predictors, and this analysis revealed a steep shoulder and an area under the curve of 0.94 (95% confidence interval, 0.88 to 1.00). Our proposed set of four predictors provided excellent diagnostic performance in differentiating between MRSA and MSSA osteomyelitis in children, and thus would be able to guide patient management and facilitate timely antibiotic selection. Diagnostic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Independent predictors of failure of nonoperative management of spinal epidural abscesses

BACKGROUND CONTEXT The notion that all patients with spinal epidural abscess (SEA) require surgical decompression has been recently challenged by reports of successful medical management of select patients with SEA. PURPOSE The purpose of this study was to identify the independent variables that determine success or failure of medical management of SEA. STUDY DESIGN/SETTING This was a retrospective, case-control study. PATIENT SAMPLE Patients 18 years or older with diagnosis of SEA admitted to our institution during the study period were included in the sample. OUTCOME MEASURES The outcome measure was successful management of SEA by eradication of the infection without worsening of neurologic deficits. METHODS All patients admitted to our health-care system with a diagnosis of SEA from 1993 to 2011 were identified and the data were retrospectively collected. Patients 18 years or older diagnosed with SEA were included. Excluded were those with postsurgical SEA or phlegmon without an abscess and those with a complete spinal cord injury from SEA for longer than 48 hours. RESULTS A total of 355 patients with average age of 60 years met our inclusion criteria. Of the patients who initially underwent nonoperative treatment, 54 patients failed medical management and 73 patients were successfully treated without surgery. Univariate and multivariate analysis identified incomplete or complete spinal cord deficits as the most significant risk factor for failure of medical management. Age older than 65 years, diabetes, and methicillin-resistant Staphylococcus aureus (MRSA) were also independent risk factors for failure. An algorithm for probability of failed antibiotic management of spinal epidural abscess predicted 99% probability of failure for patients with all four of these risk factors. CONCLUSIONS SEA treated with medical management alone has a very high risk for failure if the patient is older than 65 years with diabetes, MRSA infection, or neurologic compromise. In the absence of these risk factors, nonoperative management of spinal epidural abscess may be considered as the initial line of treatment with close monitoring.

Differentiating between methicillin-resistant and methicillin-sensitive Staphylococcus aureus osteomyelitis in children: an evidence-based clinical prediction algorithm.

BACKGROUND Although osteomyelitis was once commonly due to methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA)--which causes more virulent and invasive infections--has emerged as an increasingly important cause. Differentiating clinically between MRSA and MSSA can be challenging, but is necessary in order to promptly administer appropriate antibiotics and maintain vigilance against possible sequelae of MRSA osteomyelitis. The purpose of our study was to develop a clinical prediction algorithm to distinguish between MRSA and MSSA osteomyelitis in children. METHODS A retrospective review of 129 children presenting with culture-proven Staphylococcus aureus osteomyelitis between 2000 and 2009 was performed. The demographics, symptoms, vital signs, and laboratory test values in the MSSA group (n = 118) and the MRSA group (n = 11) were compared with use of univariate analysis. Multivariate logistic regression with backward stepwise selection was then used to identify independent multivariate predictors of MRSA osteomyelitis, and each of these predictors was subjected to receiver operating characteristic curve analysis to determine the optimal cutoff value. Finally, a prediction algorithm for differentiating between MRSA and MSSA osteomyelitis on the basis of these independent predictors was constructed. RESULTS Patients with MRSA osteomyelitis differed significantly from those with MSSA osteomyelitis with regard to non-weight-bearing status, antibiotic use at presentation, body temperature, hematocrit value, heart rate, white blood-cell count, platelet count, C-reactive protein level, and erythrocyte sedimentation rate. Four significant independent multivariate predictors were identified: a temperature of >38°C, a hematocrit value of <34%, a white blood-cell count of >12,000 cells/µL, and a C-reactive protein level of >13 mg/L. The predicted probability of MRSA osteomyelitis, determined on the basis of the number of these predictors that a child satisfied, was 92% for all four predictors, 45% for three, 10% for two, 1% for one, and 0% for zero predictors. Receiver operating characteristic curve analysis was used to evaluate the predictive accuracy of the number of multivariate predictors, and this analysis revealed a steep shoulder and an area under the curve of 0.94 (95% confidence interval, 0.88 to 1.00). CONCLUSIONS Our proposed set of four predictors provided excellent diagnostic performance in differentiating between MRSA and MSSA osteomyelitis in children, and thus would be able to guide patient management and facilitate timely antibiotic selection.Although osteomyelitis was once commonly due to methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA)—which causes more virulent and invasive infections—has emerged as an increasingly important cause. Differentiating clinically between MRSA and MSSA can be challenging, but is necessary in order to promptly administer appropriate antibiotics and maintain vigilance against possible sequelae of MRSA osteomyelitis. The purpose of our study was to develop a clinical prediction algorithm to distinguish between MRSA and MSSA osteomyelitis in children. A retrospective review of 129 children presenting with culture-proven Staphylococcus aureus osteomyelitis between 2000 and 2009 was performed. The demographics, symptoms, vital signs, and laboratory test values in the MSSA group (n = 118) and the MRSA group (n = 11) were compared with use of univariate analysis. Multivariate logistic regression with backward stepwise selection was then used to identify independent multivariate predictors of MRSA osteomyelitis, and each of these predictors was subjected to receiver operating characteristic curve analysis to determine the optimal cutoff value. Finally, a prediction algorithm for differentiating between MRSA and MSSA osteomyelitis on the basis of these independent predictors was constructed. Patients with MRSA osteomyelitis differed significantly from those with MSSA osteomyelitis with regard to non-weight-bearing status, antibiotic use at presentation, body temperature, hematocrit value, heart rate, white blood-cell count, platelet count, C-reactive protein level, and erythrocyte sedimentation rate. Four significant independent multivariate predictors were identified: a temperature of >38°C, a hematocrit value of 12,000 cells/μL, and a C-reactive protein level of >13 mg/L. The predicted probability of MRSA osteomyelitis, determined on the basis of the number of these predictors that a child satisfied, was 92% for all four predictors, 45% for three, 10% for two, 1% for one, and 0% for zero predictors. Receiver operating characteristic curve analysis was used to evaluate the predictive accuracy of the number of multivariate predictors, and this analysis revealed a steep shoulder and an area under the curve of 0.94 (95% confidence interval, 0.88 to 1.00). Our proposed set of four predictors provided excellent diagnostic performance in differentiating between MRSA and MSSA osteomyelitis in children, and thus would be able to guide patient management and facilitate timely antibiotic selection. Diagnostic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Genomewide Linkage in a Large Caucasian Family Maps a New Locus for Intracranial Aneurysms to Chromosome 13q

Background and Purpose— Familial aggregation of intracranial aneurysms (IAs) indicates a genetic role in the pathogenesis of this disease. Despite a number of reported susceptibility loci, no disease-causing gene variants have been identified. In this study, we used a parametric genomewide linkage approach to search for new IA susceptibility loci in a large Caucasian family. Methods— The affection status of family members with clinical signs of IA was confirmed with medical records or through radiological or surgical examinations. All other relatives were screened using MR angiography. Genomewide linkage analysis was performed on 35 subjects using approximately 250 000 single nucleotide polymorphic markers. Results— Ten individuals had an IA. Linkage analysis using a dominant model showed significant linkage to a 7-cM region in 13q14.12–21.1 with a maximum logarithm of odds score of 4.56. Conclusion— A new IA susceptibility locus on 13q was identified, adding to the number of IA loci already reported. Given that no coding variants have been reported to date, it is possible that alternative genetic variants such as regulatory elements or copy number variation are important in IA pathogenesis. We are proceeding with attempts to identify such variants in our locus.

Predicting patients with concurrent noncontiguous spinal epidural abscess lesions

BACKGROUND CONTEXT Spinal epidural abscess (SEA) is a serious condition that can lead to significant morbidity and mortality if not expeditiously diagnosed and appropriately treated. However, the nonspecific findings that accompany SEAs often make its diagnosis difficult. Concurrent noncontiguous SEAs are even more challenging to diagnose because whole-spine imaging is not routinely performed unless the patient demonstrates neurologic findings that are inconsistent with the identified lesion. Failure to recognize a separate SEA can subject patients to a second operation, continued sepsis, paralysis, or even death. PURPOSE To formulate a set of clinical and laboratory predictors for identifying patients with concurrent noncontiguous SEAs. STUDY DESIGN A retrospective, case-control study. PATIENT SAMPLE Patients aged 18 years or older admitted to our institution during the study period who underwent entire spinal imaging and were diagnosed with one or more SEAs. OUTCOME MEASURES The presence or absence of concurrent noncontiguous SEAs on magnetic resonance imaging or computed tomography (CT)-myelogram. METHODS A retrospective review was performed on 233 adults with SEAs who presented to our health-care system from 1993 to 2011 and underwent entire spinal imaging. The clinical and radiographic features of patients with concurrent noncontiguous SEAs, defined as at least two lesions in different anatomical regions of the spine (ie, cervical, thoracic, or lumbar), were compared with those with a single SEA. Multivariate logistic regression identified independent predictors for the presence of a skip SEA, and a prediction algorithm based on these independent predictors was constructed. Institutional review board committee approval was obtained before initiating the study. RESULTS Univariate and multivariate analyses comparing patients with skip SEA lesions (n=22) with those with single lesions (n=211) demonstrated significant differences in three factors: delay in presentation (defined as symptoms for ≥7 days), a concomitant area of infection outside the spine and paraspinal region, and an erythrocyte sedimentation rate of >95 mm/h at presentation. The predicted probability for the presence of a skip lesion was 73% for patients possessing all three predictors, 13% for two, 2% for one, and 0% for zero predictors. Receiver operating characteristic curve analysis, used to evaluate the predictive accuracy of the model, revealed a steep shoulder with an area under the curve of 0.936 (p<.001). CONCLUSIONS The proposed set of three predictors may be a useful tool in predicting the risk of a skip SEA lesion and, consequently, which patients would benefit from entire spinal imaging.

The use of gait analysis in the assessment of patients afflicted with spinal disorders

PurposeUse gait analysis to establish and detail the clinically relevant components of normal human gait, analyze the gait characteristics for those afflicted with spinal pathology, and identify those aspects of human gait that correlate with pre- and postoperative patient function and outcomes.MethodsTwenty patients with adult degenerative scoliosis (ADS), 20 patients with cervical spondylotic myelopathy (CSM), and 15 healthy volunteers performed over-ground gait trials with a comfortable self-selected speed using video cameras to measure patient motion, surface electromyography (EMG) to record muscle activity, and force plates to record ground reaction force (GRF). Gait distance and temporal parameters, ankle, knee, hip, pelvic, and trunk range of motion (ROM), duration of lower extremity EMG activity and peak vertical GRF were measured.ResultsPatients with ADS and CSM exhibited a significantly slower gait speed, decrease in step length, cadence, longer stride time, stance time, double support time, and an increase in step width compared to those in the control group. These patients also exhibited a significantly different ankle, knee, pelvic, and trunk ROM. Moreover, spinal disorder patients exhibited a significantly longer duration of rectus femoris, semitendinosus, tibialis anterior and medial gastrocnemius muscle activity along with an altered vertical GRF pattern.ConclusionsGait analysis provides an objective measure of functional gait in healthy controls as well as those with ADS and CSM. This study established and detailed some of the important kinematic and kinetic variables of gait in patients with spinal disorders. We recommend that spine care providers use gait analysis as part of their clinical evaluation to provide an objective measure of function.Graphical abstractThese slides can be retrieved under Electronic Supplementary Material.

Surgery for Refractory Coccygodynia: Operative Versus Nonoperative Treatment

Study Design. This is a retrospective cohort study. Objective. To evaluate the long-term outcomes for patients with refractory coccygodynia treated with coccygectomy compared to a nonsurgical regimen of sitting aids, physical therapy, medications, and injections. Summary of Background Data. The surgical treatment of coccygodynia remains controversial. To date, there has only been one small comparative study of surgical versus nonsurgical treatment. Methods. From 2004 to 2014, 109 patients presenting with coccygodynia were treated with either total coccygectomy or a nonsurgical course of sitting aids, physical therapy, anti-inflammatory medications, and injections. All had at least 2 years of symptoms before surgery. The patient principally made the treatment decision, counseled by the treating physician. Before surgery, all subjects underwent at least 2 years of conservative treatment and three-dimensional imaging (computed tomography and/or magnetic resonance imaging). Subjects completed visual analog pain scales, EuroQol five-dimension, components of the PROMIS measure, and a novel Coccygodynia Disability Index evaluation. Work status, complications, and satisfaction were recorded. Results. A total of 61 patients received nonsurgical care; eight declined participation and five could not be located. Forty-eight patients underwent total coccygectomy; three declined participation and five could not be located. At an average 4.8 years of follow-up (range: 2–9), the nonsurgical visual analog pain scales was 5 and the surgical 2 (P = 0.001); 79% of surgically treated patients were improved at 2 years versus 43% for the nonsurgical group. EuroQol five-dimension (P = 0.002), Coccygodynia Disability Index (0.01), and PROMIS Pain interference scores (0.02) were also significantly improved in the surgical group. Eleven surgical patients (26%) had complications, all wound related with successful resolution; seven treated with dressing changes and four with surgical debridement. Conclusion. Total coccygectomy is a safe and effective surgical treatment of coccygodynia refractory to nonoperative care. Patient-reported outcome measures were improved after surgery compared with nonsurgical management. Postoperative wound care remains a concern. Level of Evidence: 4

Spine and lower extremity kinematics during gait in patients with cervical spondylotic myelopathy

BACKGROUND CONTEXT Cervical spondylotic myelopathy (CSM) typically manifests with a slow, progressive stepwise decline in neurologic function, including hand clumsiness and balance difficulties. Gait disturbances are frequently seen in patients with CSM, with more advanced cases exhibiting a stiff, spastic gait. PURPOSE To evaluate the spatiotemporal parameters and spine and lower extremity kinematics during the gait cycle of adult patients with CSM before surgical intervention. STUDY DESIGN Prospective cohort study. PATIENT SAMPLE Twenty-eight subjects with symptomatic CSM who have been scheduled for surgery and 30 healthy controls (HC). OUTCOME MEASURES Spine and lower extremity kinematics and spatiotemporal parameters. METHODS Clinical gait analysis was performed for patients with CSM and HC. The data were analyzed with a one-way analysis of variance. RESULTS Patients with CSM have significantly more anterior pelvis tilt (CSM: 13.97°, HC: 5.56°), larger lumbar lordosis (CSM: 8.59°, HC: 2.7°), smaller cervical lordosis (CSM: 6.02°, HC: 11.35°), and less head flexion (CSM: 0.69°, HC: 8.66°) at the beginning of the gait cycle. There was a decrease in knee range of motion in patients with CSM compared with controls (CSM: 36.31°, HC: 50.17°). Furthermore, patients with CSM presented with slower walking speed (CSM: 0.81 m/s, HC: 1.05 m/s), decreased cadence (CSM: 95.57 step/m, HC: 107.64 step/m), increased double support time (CSM: 0.40 s, HC: 0.28 s) and stride time (CSM:1.28 s, HC: 1.13 s), shorter stride length (CSM: 1.04 m, HC: 1.18 m) and step length (CSM:0.51 m, HC: 0.58 m), and wider width (CSM: 0.14 m, HC:0.11 m). CONCLUSIONS Our study shows that patients with CSM enter the gait cycle with a larger anterior pelvic tilt and lumbar lordosis as well as less cervical lordosis and head flexion. As a consequence of these abnormal spinal parameters at the onset of the gait cycle, lower extremity biomechanics are also altered. Our study is the first to demonstrate the relationship between aberrant spinal alignment and lower extremity function. Identification of this interrelationship as well as the specific gait and biomechanical disturbances seen in myelopathic patients can both inform our understanding of the disease and tailor rehabilitation protocols.

Progressive Bone Formation After Cervical Disc Replacement: Minimum of 5 Year Follow-up

Study Design. Retrospective review. Objective. Our objective was to examine the prevalence, clinical significance, ramifications, and possible etiology of postoperative bone formation at the index level after cervical disc replacement (CDR) with a minimum of 5 years of follow-up. Summary of Background Data. CDR can be complicated by postoperative ossification and unwanted ankylosis at the index level, which some authors have termed “heterotopic ossification.” This terminology may be inaccurate as it assumes the postoperative bone formation is unnatural and a consequence of the CDR surgery. We advocate that this phenomenon has more to do with individual patient factors rather than the surgery. Methods. Patients who underwent Bryan CDR for cervical myelopathy or radiculopathy between 12/2003 and 8/2008 with a minimum of 5-years follow-up were analyzed. They were divided into two groups, those with and without postoperative bone formation. Patient-reported outcomes (Japanese Orthopaedic Association score, Neck Disability Index, Visual Analogue Scale for neck and arm pain) and radiographic parameters were collected pre- and postoperatively and compared between groups. Results. Sixty-one patients (76 levels) were identified (mean follow-up 94.2 mo). The overall incidence of postoperative ossification was 50%. Both groups had sustained significant improvements across all patient-reported outcome measures at final follow-up. Notably, patients with more severe preoperative cervical spondylosis had higher rates of postoperative ossification (P = 0.036) and adjacent segment degeneration (P = 0.010). Conclusion. Although the long-term incidence of postoperative bone formation after CDR was relatively high, this did not adversely affect patient outcomes. Patients with more severe preoperative spondylosis had higher rates of postoperative ossification, suggesting that postoperative ossification at the CDR segment is likely one of progressive bone formation in individuals already predisposed to forming bone rather than one of alleged heterotopic ossification as a consequence of the surgery. Level of Evidence: 3

Anterior Cervical Discectomy and Fusion

Anterior cervical discectomy and fusion can be performed for a variety of pathologies but is most commonly used for the treatment of cervical radiculopathy or myelopathy. The procedure involves an anterior decompression of the disc space followed by interbody grafting and fusion. Supplemental anterior plating is commonly performed, and in certain circumstances, posterior instrumentation may provide additional fixation. The procedure includes the following steps: (1) The use of an anterior approach to the cervical spine, most commonly the Smith-Robinson approach medial to the sternocleidomastoid muscle and the carotid sheath. (2) Confirmation of the proper spinal level. (3) Elevation of the longus colli muscle, which acts as a cuff for the placement of retractors. (4) Removal of the involved disc and decompression of the spinal cord and nerve roots. This is facilitated by disc space distraction, most commonly via distraction pins. Osteophytes along the floor of the spinal canal impinging on the spinal cord are removed with a burr. Soft disc and anular material are also removed, usually with curets and rongeurs. Uncovertebral osteophyte resection and foraminotomies are completed to decompress the exiting nerve roots. (5) Carpentry and decortication of the end plates in preparation for fusion. (6) Sizing of the disc space followed by insertion of an interbody graft. (7) Anterior fixation, most commonly via application of a plate-and-screw construct. (8) Hemostasis and closure.