The effect of chronic liver disease on acute outcomes following cervical spine trauma

BACKGROUND CONTEXT

The adverse impact of chronic liver diseases, including chronic hepatitis and cirrhosis, on outcomes following orthopedic surgery has been increasingly recognized in recent years. The impact of these conditions on acute outcomes following spinal trauma remains unknown.

STUDY DESIGN

This is a cohort control study that uses patient records in the Massachusetts Statewide Inpatient Dataset (2003-2010).

PURPOSE

The study aimed to evaluate whether chronic liver disease increased the odds of mortality, complications, failure to rescue (FTR), reoperation, and hospital length of stay (LOS) following cervical spine trauma.

PATIENT SAMPLE

The sample is composed of 10,841 patients with cervical spine trauma.

OUTCOME MEASURES

Posttreatment morbidity, mortality, reoperation, and LOS were the outcome measures.

METHODS

Differences between patients with and without chronic liver disease were evaluated using chi-square or Wilcoxon rank-sum tests. Logistic and negative binomial regression techniques were used to adjust for confounders, including whether a surgical intervention was performed. Receiver operator characteristic curves were used to assess final model discrimination.

RESULTS

There were 117 patients with chronic liver disease identified in the cohort. The rate of surgical intervention for cervical trauma was not significantly different between patients with and without chronic liver disease (odds ratio [OR]: 0.82, 95% confidence interval [CI]: 0.52-1.29). Mortality (OR: 2.12, 95% CI: 1.23-3.66), FTR (OR: 2.86, 95% CI: 1.34-6.11), complications (OR: 1.65, 95% CI: 1.12-2.45), and LOS (regression coefficients: 0.31, 95% CI: 0.14-0.48) were all significantly increased for patients with chronic liver disease in final adjusted models that controlled for differences in case-mix and whether a surgical procedure was performed. Final models explained approximately 72% of the variation in mortality and FTR.

CONCLUSIONS

Our novel findings indicate that patients with chronic liver disease may be at elevated risk of posttreatment morbidity and mortality following cervical spine trauma. Medical comanagement in the acute period following injury and optimization before surgery may diminish the potential for adverse events.

Idiopathic Spinal Epidural Lipomatosis in the Lumbar Spine

Overgrowth of epidural fat, known as spinal epidural lipomatosis (SEL), can cause symptomatic compression of the spinal cord, conus medullaris, or cauda equina. Suggested predisposing factors such as obesity, steroid use, and diabetes mellitus have been based on a few reported cases, many of which were not surgically confirmed. There is a paucity of epidemiological data in surgically confirmed cases for this disorder. The purpose of this independently reviewed, retrospective, matched cohort analysis was to compare the demographics and incidence of comorbidities of patients who underwent lumbar decompression for SEL vs degenerative stenosis without SEL. Two surgeons' databases were reviewed to identify patients older than 18 years who underwent decompression surgery for magnetic resonance imaging-verified, symptomatic lumbar SEL. A matched control group comprised an equal number of patients with degenerative stenosis (n=14). Demographic data, body mass index, symptom type/duration, comorbidities, complications, treatment history, and associated pathology were collected from medical records. Previously suggested risk factors, such as obesity, endocrinopathy, and epidural steroid injections, were not significantly different between the SEL and control groups. Furthermore, there were no differences in operative times, complications, or blood loss. The only noted difference between the 2 groups was the preoperative duration of symptoms, on average double in patients with SEL. This series represents the largest of its kind reported to date. Because symptom duration was the only difference noted, it is postulated to be the result of lack of awareness of SEL. Future prospective study in a larger group of patients is warranted. [Orthopedics. 2016; 39(3):163-168.].

The influence of race and hospital environment on the care of patients with cervical spine fractures

BACKGROUND

The influence of non-white race on outcomes following orthopedic injury has been described in the past. The impact of such factors on hospital processes and quality of care after spinal trauma is less well understood.

STUDY DESIGN

A cohort control study using the Massachusetts Statewide Inpatient Dataset (2003-2010) was used as the study design.

PURPOSE

This study aimed to determine whether (1) hospital processes and quality of care associated with the treatment of cervical spine fractures was significantly altered by non-white race and (2) whether findings were different among those treated at academic medical centers (AMCs).

SAMPLE

The study comprised 10,841 patients.

OUTCOMES

Surgical rate, postoperative morbidity, mortality, and length of stay (LOS) were the outcome measures.

METHODS

Baseline differences between cohorts were evaluated using chi-square or Wilcoxon rank sum tests. Logistic and negative binomial regression techniques were used to adjust for confounders, including whether a surgical intervention was performed. Subset analyses were performed to evaluate whether findings were different for individuals treated at AMCs.

RESULTS

The rate of surgical intervention was not significantly different between non-whites and whites (odds ratio [OR] 0.92, 95% confidence interval [CI] 0.82-1.04). LOS (regression coefficient [RC] 0.18, 95% CI 0.13-0.23), mortality (OR 1.49, 95% CI 1.20-1.85), and complications (OR 1.17, 95% CI 1.02-1.33) were significantly increased among non-white patients. These findings were largely preserved among those treated at AMCs.

CONCLUSIONS

Our results reinforce the fact that efforts at universal access to care may be insufficient to reduce differences in care among minority patients following cervical trauma. Future mixed-methods research is necessary to more effectively evaluate the etiologies behind health-care disparities associated with race in different health-care environments.

LEVEL OF EVIDENCE

The level of evidence is Level III, prognostic study.

The Quality and Readability of Information Available on the Internet Regarding Lumbar Fusion

Study Design An Internet-based evaluation of Web sites regarding lumbar fusion. Objective The Internet has become a major resource for patients; however, the quality and readability of Internet information regarding lumbar fusion is unclear. The objective of this study is to evaluate the quality and readability of Internet information regarding lumbar fusion and to determine whether these measures changed with Web site modality, complexity of the search term, or Health on the Net Code of Conduct certification. Methods Using five search engines and three different search terms of varying complexity ("low back fusion," "lumbar fusion," and "lumbar arthrodesis"), we identified and reviewed 153 unique Web site hits for information quality and readability. Web sites were specifically analyzed by search term and Web site modality. Information quality was evaluated on a 5-point scale. Information readability was assessed using the Flesch-Kincaid score for reading grade level. Results The average quality score was low. The average reading grade level was nearly six grade levels above that recommended by National Work Group on Literacy and Health. The quality and readability of Internet information was significantly dependent on Web site modality. The use of more complex search terms yielded information of higher reading grade level but not higher quality. Conclusions Higher-quality information about lumbar fusion conveyed using language that is more readable by the general public is needed on the Internet. It is important for health care providers to be aware of the information accessible to patients, as it likely influences their decision making regarding care.

Long Term Societal Costs of Anterior Discectomy and Fusion (ACDF) versus Cervical Disc Arthroplasty (CDA) for Treatment of Cervical Radiculopathy

BACKGROUND

Current literature suggests that anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) have comparable clinical outcomes for the treatment of cervical radiculopathy. Given similar outcomes, an understanding of differences in long-term societal costs can help guide resource utilization. The purpose of this study was to compare the relative long-term societal costs of anterior cervical discectomy and fusion (ACDF) to cervical disc arthroplasty (CDA) for the treatment of single level cervical disc disease by considering upfront surgical costs, lost productivity, and risk of subsequent revision surgery.

METHODS

We completed an economic and decision analysis using a Markov model to evaluate the long-term societal costs of ACDF and CDA in a theoretical cohort of 45-65 year old patients with single level cervical disc disease who have failed nonoperative treatment.

RESULTS

The long-term societal costs for a 45-year old patient undergoing ACDF are $31,178 while long-term costs for CDA are $24,119. Long-term costs for CDA remain less expensive throughout the modeled age range of 45 to 65 years old. Sensitivity analysis demonstrated that CDA remains less expensive than ACDF as long as annual reoperation rate remains below 10.5% annually.

CONCLUSIONS

Based on current data, CDA has lower long-term societal costs than ACDF for patients 45-65 years old by a substantial margin. Given reported reoperation rates of 2.5% for CDA, it is the preferred treatment for cervical radiculopathy from an economic perspective.

Virtually bloodless posterior midline exposure of the lumbar spine using the "para-midline" fatty plane

PURPOSE

The authors have developed a "para-midline" approach to the posterior lumbar spine using a virtually avascular surgical plane not previously described in the literature. It was their purpose to document consistent MRI presence of this plane and to prospectively evaluate its clinical use in terms of blood loss.

METHODS

Fifty consecutive patients undergoing primary lumbar surgery on 1-3 levels were prospectively enrolled from September 2014 to May 2015. The para-midline approach was used in all cases. The deep lumbar fascia is longitudinally incised on either side of the spinous processes instead of directly in the midline, which reveals the para-midline fatty plane. Blood loss during the approach and overall blood loss were recorded for all patients. MRIs from each patient were reviewed by an experienced neuroradiologist to determine the presence of the para-midline fatty plane.

RESULTS

There was no recorded blood loss during the approach for all procedures. The average overall blood loss was 60 cc (20-200 cc). No patient required a transfusion intraoperatively or postoperatively. The fatty para-midline plane was noted on preoperative MRI at all operated levels in all patients. The average width of this plane was 6.5 mm (2-17 mm).

CONCLUSIONS

The para-midline approach for lumbar surgery is associated with less blood loss than traditional, subperiosteal exposure techniques. The fatty interval through which this approach is made is universally present and identifiable on MRI. The authors offer this approach as a means of decreasing the risks associated with blood loss and transfusion with posterior lumbar surgery.

Academic productivity and contributions to the literature among spine surgery fellowship faculty

BACKGROUND CONTEXT

No previous study has considered academic productivity and contributions to the literature among the faculty members of spine fellowship programs.

PURPOSE

We sought to evaluate the total number of publications and measures of academic impact among faculty at spine surgical fellowship programs between 2011 and the present.

STUDY DESIGN

This study is based on a review of data publicly available on PubMed and Scopus.

PATIENT SAMPLE

Physicians listed as faculty at a spine fellowship program in the directory of the North American Spine Society (NASS).

OUTCOME MEASURES

The outcome measures were the number of publications between January 1, 2011 and August 31, 2014 and the h-index for 1996 to present (h-tot) and 2011 to present (h-pres) for faculty members.

METHODS

Fellowship programs and their characteristics were obtained from the directory of the NASS. Program-specific features, including academic affiliation, number of participating faculty, location, number of fellowship positions, dedicated research time, and presence of a research requirement for fellows, were abstracted. The number of publications for faculty at each program between January 1, 2011 and August 31, 2014 and the h-tot and h-pres were obtained from Scopus. Multivariable linear regression was used to identify statistically significant factors associated with increased academic productivity.

RESULTS

Among 75 fellowship programs, with 282 faculty members, there were 55 (73%) with academic affiliation. The average number of publications per faculty member (2011-2014) was 5.5 (standard deviation, 8.4; range, 0-54). The mean h-tot for programs was 13.6 (8.7, 0-37), and mean h-pres was 3.0 (2.2, 0-8.2). Academic affiliation (regression coefficient, 22.1; 95% confidence interval: 7.2, 37.0), and the number of fellows in a program (7.0, 0.9-13.2) was significantly associated with the total number of publications. Similar findings were encountered for average h-tot and h-pres.

CONCLUSIONS

The descriptive statistics presented can help surgeons benchmark their performance and that of their fellowship, compared with others in the field. Determinations regarding characteristics associated with academic productivity may also help programs' fashion future strategic initiatives.

The influence of adjacent level disc disease on discectomy outcomes

PURPOSE

The state of adjacent level discs and its impact on surgical outcomes following single-level lumbar discectomy have not been previously investigated. The purpose of the present study was to determine if a significant relationship exists between the degree of preoperative adjacent level disc degeneration and post-operative clinical outcomes following lumbar discectomy.

METHODS

This study retrospectively used preoperative magnetic resonance imaging (MRI) and prospectively collected data from a randomized clinical trial at two tertiary-care academic hospitals. Patients who underwent a primary, single-level lumbar discectomy were included. Exclusion criteria included prior lumbar surgery. Outcome measures were the Modified Oswestry Disability Index (ODI) score and Visual Analog Scale (VAS) scores for back and leg pain. These were recorded at baseline and at 3 months, 1, and 2 years postoperatively. An independent reviewer graded adjacent level disc degeneration on all preoperative MRIs using the Pfirrmann grading scale. These data were then analyzed for correlation with each outcome measure.

RESULTS

Forty-seven patients were included in the study. No statistically significant correlations were found when comparing preoperative 3-month or 1-year postoperative scores or change from baseline of any outcome measure between Pfirrmann grades. Only about half the patients had 2-year follow-up, but at that time point a statistically significant difference in back VAS scores was observed between Pfirrmann groups. No other significant differences were observed at that point.

CONCLUSIONS

The degree of preoperative adjacent level degeneration does not significantly affect functional or pain relief outcomes following lumbar discectomy up to 1 year after surgery.

Does Patient Sex Affect the Rate of Mortality and Complications After Spine Surgery? A Systematic Review

BACKGROUND

Available studies disagree regarding the influence of patient sex on mortality and complications after spine surgery. We sought to conduct a systematic review and pool the results of existing research to better understand this issue.

QUESTIONS/PURPOSES

We performed a systematic review to address two questions: (1) Does sex (male versus female) influence mortality after spine surgery? (2) Does sex impact the development of postoperative complications after spine surgery?

METHODS

This systematic review was performed through a query of PubMed using a structured search algorithm. Additional queries of Embase, SCOPUS, Web of Science, and the tables of contents of orthopaedic and neurosurgical journals were also conducted using search terms such as "sex factors", "male or female", "risk factors", and "spine surgery". Selected papers were independently abstracted by three of the authors (AJS, ENR, EIW) and pooling was performed. Our literature search returned 720 studies, of which 99 underwent full review. Of these, 50 were selected for final abstraction. The Cochrane Q test was used to assess study heterogeneity; significant study heterogeneity was present and so a random-effects model was used. A Harbord test was used to evaluate for the presence of publication bias; this analysis found no statistically significant evidence of publication bias.

RESULTS

Males were at increased odds of mortality after spine surgery (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.35-1.97; p<0.001). No differences between the sexes were identified for the odds of complications (OR, 1.04; 95% CI, 0.95-1.13; p=0.42).

CONCLUSIONS

Our results determined that males were at elevated odds of mortality but not of complications after spine surgery. These results should be used to inform preoperative discussion and decision-making at the time of surgical consent. Future work should be directed at determining the underlying factors responsible for increased mortality among males and prospective studies specifically designed to evaluate sex-based differences in outcomes after spine surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Does surgical timing influence functional recovery after lumbar discectomy? A systematic review

BACKGROUND

The impact of the duration of preoperative symptoms on outcomes after lumbar discectomy has not been sufficiently answered in a single study but is a potentially important clinical variable.

QUESTIONS/PURPOSES

A systematic review was performed to answer two questions: (1) Does symptomatic duration before surgery influence functional recovery after lumbar discectomy? (2) What is the time point for intervention beyond which the extent of postoperative recovery might be compromised?

METHODS

The systematic review began with a query of PubMed using a structured algorithm comprised of medical subject heading terms. This was supplemented by a keyword search in PubMed along with queries of Embase, Scopus, and Web of Science and searches of reference lists as well as the tables of contents of relevant journals. Eligible studies were those that evaluated aspects of recovery after elective discectomy and stratified duration of symptoms before surgery. Included papers were abstracted by two authors and determinations regarding the period of symptom duration and its impact on outcome were recorded. Eleven studies met all inclusion criteria. No prospectively randomized trials addressed our study questions.

RESULTS

Nine of 11 studies, four of which were prospective, maintained that longer symptom duration adversely impacted postsurgical recovery. There were substantial differences among the critical periods of symptom duration reported by individual studies, which ranged from 2 to 12 months. A preponderance of studies (five of nine) reported that surgical interventions could be performed at periods of 6 months or greater without impacting recovery.

CONCLUSIONS

Longer symptom duration had an adverse impact on results in most studies after lumbar discectomy. A possible point beyond which outcomes may be compromised is 6 months after symptom onset. Limitations in the literature surveyed, however, prevent firm conclusions.

Validation of multisociety combined task force definitions of abnormal disk morphology

BACKGROUND AND PURPOSE

The multisociety task force descriptively defined abnormal lumbar disk morphology. We aimed to use their definitions to provide a higher level of evidence for the validation of MR imaging in the evaluation of this pathology in patients who have undergone diskectomy by retrospectively classifying their preoperative MRI.

MATERIALS AND METHODS

This retrospective, institutional review board-approved study included 54 of 86 consecutive patients (47 men; average age, 44 years) enrolled in an ongoing prospective trial of surgically treated lumbar disk herniation who had preoperative MRI and documented intraoperative classification of the abnormal disk as protrusion, extrusion, or sequestration by the treating surgeon. Preoperative MRI was classified by 2 blinded radiologists; discrepancies were resolved by a third reader. Statistical analysis of interobserver agreement and imaging compared with surgical findings was performed.

RESULTS

The readers disagreed on only 1 of the 54 cases. The third reader resolved the disagreement. Eight protrusions and 46 extrusions were found on imaging, with no sequestrations. At surgery, there were 13 protrusions and 40 extrusions, with 2 of the extrusions also containing sequestrations; the remaining case had only sequestration. There were 16 discrepancies between imaging and surgery, resulting in 70% agreement.

CONCLUSIONS

This study, which was intended to validate the multisociety combined task force definitions of abnormal disk morphology by using MR imaging with a surgical criterion standard, found 70% agreement between imaging diagnosis and surgical findings. Although reasonable, this finding highlights differences that often exist between intraoperative and preoperative imaging findings of lumbar disk herniation.

Operative compared with nonoperative treatment of a thoracolumbar burst fracture without neurological deficit: a prospective randomized study with follow-up at sixteen to twenty-two years

BACKGROUND

Studies comparing operative with nonoperative treatment of a stable burst fracture of the thoracolumbar junction in neurologically intact patients have not shown a meaningful difference at early follow-up. To our knowledge, longer-term outcome data have not before been presented.

METHODS

From 1992 to 1998, forty-seven consecutive patients with a stable thoracolumbar burst fracture and no neurological deficit were evaluated and randomized to one of two treatment groups: operative treatment (posterior or anterior arthrodesis) or nonoperative treatment (a body cast or orthosis). We previously reported the results of follow-up at an average of forty-four months. The current study presents the results of long-term follow-up, at an average of eighteen years (range, sixteen to twenty-two years). As in the earlier study, patients at long-term follow-up indicated the degree of pain on a visual analog scale and completed the Roland and Morris disability questionnaire, the Oswestry Disability Index (ODI) questionnaire, and the Short Form-36 (SF-36) health survey. Work and health status were obtained, and patients were evaluated radiographically.

RESULTS

Of the original operatively treated group of twenty-four patients, follow-up data were obtained for nineteen; one patient had died, and four could not be located. Of the original nonoperatively treated group of twenty-three patients, data were obtained for eighteen; two patients had died, and three could not be located. The average kyphosis was not significantly different between the two groups (13° for those who received operative treatment compared with 19° for those treated nonoperatively). Median scores for pain (4 cm for the operative group and 1.5 cm for the nonoperative group; p = 0.003), ODI scores (20 for the operative group and 2 for the nonoperative group; p <0.001) and Roland and Morris scores (7 for the operative group and 1 for the nonoperative group; p = 0.001) were all significantly better in the group treated nonoperatively. Seven of eight SF-36 scores also favored nonoperative treatment.

CONCLUSIONS

While early analysis (four years) revealed few significant differences between the two groups, at long-term follow-up (sixteen to twenty-two years), those with a stable burst fracture who were treated nonoperatively reported less pain and better function compared with those who were treated surgically.

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.

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.

Traumatic thoracolumbar spine injuries: what the spine surgeon wants to know

The Thoracolumbar Injury Classification and Severity Score (TLICS) is a scoring and classification system developed by the Spine Trauma Study Group in response to the recognition that previous classification systems have limited prognostic value and generally do not suggest treatment pathways. The TLICS provides a spine injury severity score based on three components: injury morphology, integrity of the posterior ligamentous complex (PLC), and neurologic status of the patient. A numerical score is calculated for each category, with a lower point value assigned to a less severe or less urgent injury and a higher point value assigned to a more severe injury requiring urgent management. The total score helps guide decision making about surgical versus nonsurgical management. The TLICS also emphasizes the importance of magnetic resonance imaging in evaluating PLC injury and acknowledges that the primary driver of surgical intervention is the patient's neurologic status. Knowledge of PLC anatomy and its significance is essential in recognizing unstable injuries. Signs of PLC injury at computed tomography include interspinous distance widening, facet joint widening, spinous process fracture, and vertebral subluxation or dislocation. Familiarity with the TLICS will help radiologists who interpret spine trauma imaging studies to effectively communicate findings to spine trauma surgeons. The complete article is available online .

Mild diabetes is not a contraindication for surgical decompression in cervical spondylotic myelopathy: results of the AOSpine North America multicenter prospective study (CSM)

BACKGROUND CONTEXT

Cervical spondylotic myelopathy (CSM) is a chronic spinal cord disease and can lead to progressive or stepwise neurologic decline. Several factors may influence this process, including extent of spinal cord compression, duration of symptoms, and medical comorbidities. Diabetes is a systemic disease that can impact multiple organ systems, including the central and peripheral nervous systems. There has been little information regarding the effect of diabetes on patients with coexistent CSM.

PURPOSE

To provide empirical data regarding the effect of diabetes on treatment outcomes in patients who underwent surgical decompression for coexistent CSM.

STUDY DESIGN/SETTING

Large prospective multicenter cohort study of patients with and without diabetes who underwent decompressive surgery for CSM.

PATIENT SAMPLE

Two hundred thirty-six patients without and 42 patients with diabetes were enrolled. Of these, 37 were mild cases and five were moderate cases. Four required insulin. There were no severe cases associated with end-organ damage.

OUTCOME MEASURES

Self-report measures include Neck Disability Index and version 2 of 36-Item Short Form Health Survey (SF-36v2), and functional measures include modified Japanese Orthopedic Association (mJOA) score and Nurick grade.

METHODS

We compared presurgery symptoms and treatment outcomes between patients with and without diabetes using univariate and multivariate models, adjusting for demographics and comorbidities.

RESULTS

Diabetic patients were older, less likely to smoke, and more likely to be on social security disability insurance. Patients with diabetes presented with a worse Nurick grade, but there were no differences in mJOA and SF-36v2 at presentation. Overall, there was a significant improvement in all outcome parameters at 12 and 24 months. There was no difference in the level of improvement between the patients with and without diabetes, except in the SF-36v2 Physical Functioning, in which diabetic patients experienced significantly less improvement. There were no differences in surgical complication rates between diabetic patients and nondiabetic patients.

CONCLUSIONS

Except for a worse Nurick grade, diabetes does not seem to affect severity of symptoms at presentation for surgery. More importantly, with the exception of the SF-36v2 Physical Functioning scores, outcomes of surgical treatment are similar in patients with diabetes and without diabetes. Surgical decompression is effective and should be offered to patients with diabetes who have symptomatic CSM and are appropriate surgical candidates.

Closing the loop between evidence-based medicine and care delivery: a possible role for clinical audits in spinal surgery

BACKGROUND CONTEXT

Evidence-based medicine (EBM) should be the ultimate force driving change in clinical practice. This process generally occurs through a trickle-down phenomenon by which practice recommendations are revised, modified, and/or changed based on the best published data. Recommendations are subsequently incorporated by individual physicians. The fundamental assumption that drives this paradigm is that adopting evidence-based recommendations and/or treatment guidelines will result in improved outcomes. Unfortunately, to date, the paradigm does not have an effective feedback loop that would then evaluate whether the changes did, in fact, improve outcomes.

PURPOSE

To explore the process of clinical audits as a mechanism by which to provide a feedback loop to evaluate the results of spinal surgery on an individual basis and whether those results can be improved.

STUDY DESIGN

Review article, discussion.

METHODS

A literature review of the current data regarding clinical audits was performed, and a discussion of how they may apply to spinal surgery is offered.

RESULTS

Clinical audits have been used outside the United States, particularly in the United Kingdom, to fulfill this function. A clinical audit would allow a practicing spinal surgeon to examine his or her individual experience and determine if it is achieving the expected outcome based on published results. In the most important feature of a clinical audit, the reaudit, if an individual's results are found to be inconsistent with published results, it presents an opportunity to identify if there are reconcilable differences from which potential improvements can be made. Effectively, this "closes the loop" between EBM and actual clinical practice.

CONCLUSIONS

Documenting improved outcomes through the audit process can impact spinal care in several ways. Patients would receive a clear message that their doctors are interested in improving care. Hospitals will use the information to optimize treatment algorithms. Finally, insurers might make the audit process more tenable or attractive by indicating a physician's voluntary participation as a criterion to be a preferred provider.

Patient demographics, insurance status, race, and ethnicity as predictors of morbidity and mortality after spine trauma: a study using the National Trauma Data Bank

BACKGROUND CONTEXT

Predictors of complications and mortality after spine trauma are underexplored. At present, no study exists capable of predicting the impact of demographic factors, injury-specific predictors, race, ethnicity, and insurance status on morbidity and mortality after spine trauma.

PURPOSE

This study endeavored to describe the impact of patient demographics, comorbidities, injury-specific factors, race/ethnicity, and insurance status on outcomes after spinal trauma using the National Sample Program (NSP) of the National Trauma Data Bank (NTDB).

STUDY DESIGN

The weighted sample of 75,351 incidents of spine trauma in the NTDB was used to develop a predictive model for important factors associated with mortality, postinjury complications, length of hospital stay, intensive care unit (ICU) days, and time on a ventilator.

PATIENT SAMPLE

A weighted sample of 75,351 incidents of spine trauma as contained in the NTDB.

OUTCOME MEASURES

Mortality, postinjury complications, length of hospital stay, ICU days, and time on a ventilator as reported in the NTDB.

METHODS

The 2008 NSP of the NTDB was queried to identify patients sustaining spine trauma. Patient demographics, race/ethnicity, insurance status, comorbidities, injury-specific factors, and outcomes were recorded, and a national estimate model was derived. Unadjusted differences in baseline characteristics between racial/ethnic groups and insurance status were evaluated using the t test for continuous variables and Wald chi-square analysis for categorical variables with Bonferroni correction for multiple comparisons. Weighted logistic regression was performed for categorical variables (mortality and risk of one or more complications), and weighted multiple linear regression analysis was used for continuous variables (length of hospital stay, ICU days, and ventilator time). Initial determinations were checked against a sensitivity analysis using imputed data.

RESULTS

The weighted sample contained 75,351 incidents of spine trauma. The average age was 45.8 years. Sixty-four percent of the population was male, 9% was black/African American, 38% possessed private/commercial insurance, and 12.5% lacked insurance. The mortality rate was 6% and 16% sustained complications. Increased age, male gender, Injury Severity Score (ISS), and blood pressure at presentation were significant predictors of mortality, whereas age, male gender, other mechanism of injury, ISS, and blood pressure at presentation influenced the risk of one or more complications. Nonwhite and black/African American race increased risk of mortality, and lack of insurance increased mortality and decreased the number of hospital days, ICU days, and ventilator time.

CONCLUSIONS

This is the first study to postulate predictors of morbidity and mortality after spinal trauma in a national model. Race/ethnicity and insurance status appear to be associated with greater risk of mortality after spine trauma.

Evidence-based analysis of adjacent segment degeneration and disease after ACDF: a systematic review

BACKGROUND CONTEXT

Follow-up studies of patients undergoing anterior cervical discectomy and interbody fusion (ACDF) have demonstrated varying degrees of radiographic degeneration at adjacent levels, with most cases being asymptomatic (adjacent segment degeneration, ASDeg) and far fewer being symptomatic (adjacent segment disease, ASDz). Controversy remains as to whether these conditions are related to altered biomechanics or represent the natural history of cervical spondylosis at the adjacent segment.

PURPOSE

To provide an evidence-based analysis of the peer-reviewed literature on clinical studies of ASDeg and ASDz after ACDF.

STUDY DESIGN/SETTING

Systematic review of existing literature.

METHODS

The MEDLINE database was queried for clinical studies reporting ASDeg and/or ASDz after ACDF. Articles written in the English language with a minimum follow-up of 2 years were independently reviewed and analyzed by two authors, and the level of evidence was assigned. Data were pooled to generate summary outcomes and organized by number of levels, technique, and graft/implants.

RESULTS

Of the 238 articles returned from the MEDLINE database query, 14 met inclusion criteria. An average of 168 patients was enrolled per study with an average follow-up of 106.5 months. Graft materials, cage design, plate fixation system, and length of fusion varied widely. Additionally, no clear standard was seen for radiographic assessment modalities (eg, plain lateral radiograph, flexion-extension radiographs, computed tomography, or magnetic resonance imaging). Validated clinical outcome measures were used in 43% (6/14) of the studies. The average incidence of ASDeg was 47.33% (459.14/970) with a range from 16% to 96%. The frequency-weighted average for ASDz was 11.99% (263.70/2,199) with a range from 1.80% to 36.00%. Follow-up ranged from 24 to 296 months with no reliable commonalities, which prohibited a meta-analysis.

CONCLUSIONS

This review highlights the heterogeneous methodology of the peer-reviewed literature on ASDeg and ASDz after ACDF and the paucity of high-level clinical data published on these conditions. Despite the low level of evidence to define the incidence of ASDeg and ASDz, it is clear that radiographic ASDeg is more common than symptomatic ASDz, indicating that adjacent segment pathology remains subclinical in a large subset of patients. This analysis underscores the need for standardized radiographic measures in the assessment of ASDeg and validated clinical outcome measures for ASDz after ACDF. Consistent methodology and multi-surgeon collaboration may improve the quality of clinical data on ASDeg and ASDz and elucidate the true etiology and incidence of these conditions.

Patient factors, comorbidities, and surgical characteristics that increase mortality and complication risk after spinal arthrodesis: a prognostic study based on 5,887 patients

BACKGROUND CONTEXT

The impact of patient factors and medical comorbidities on the risk of mortality and complications after spinal arthrodesis has not been well described. Prior works have been limited by small sample size, single center data, or the inability to be broadly generalized.

PURPOSE

To determine if there is an association between the patient demographic factors, comorbidities, nutritional status, and surgical characteristics and the occurrence of mortality and complications after spinal arthrodesis.

STUDY DESIGN

Retrospective review of prospectively collected data in the National Surgical Quality Improvement Program (NSQIP).

PATIENT SAMPLE

Patients who underwent spinal arthrodesis and had data registered with the NSQIP between 2005 and 2010.

OUTCOME MEASURES

Primary outcomes were death or any complication after spinal arthrodesis. Secondary measures were the development of a specific complication, including wound infection, thromboembolic disease, or cardiac arrest/myocardial infarction.

METHODS

The data set of the NSQIP from 2005 to 2010 was queried to identify all patients who underwent spinal arthrodesis. Demographic information, body mass index (BMI), medical comorbidities, arthrodesis procedure, operative time, American Society of Anesthesiologists (ASA) classification, and preoperative albumin were recorded for all patients identified. Mortality, the development of postoperative complications, and the presence of specific complications were also abstracted. Risk factors for mortality and complications were initially evaluated using chi-square and univariate logistic regression analyses. The risk factors that maintained p values less than .2 in univariate analysis were then combined in a multivariate fashion that identified significant, independent, predictors of mortality and complications while controlling for other factors present in the model. Sensitivity analysis was also performed, discriminating between the impact of risk factors on major and minor complications and the relative contribution to overall risk of morbidity. Multivariate analysis resulted in odds ratios (ORs) with 95% confidence intervals (CIs) for each risk factor. Only those predictors with ORs and 95% CI exclusive of 1.0 and p values less than .05 were considered statistically significant.

RESULTS

In all, 5,887 patients who underwent spinal arthrodesis were identified. The average age of patients was 55.9 (±14.5) years. Twenty-five (0.42%) patients died after surgery, whereas 608 (10%) sustained a complication. Wound infection was the most common specific complication occurring in 2% of the cohort. Age (p=.03) and pulmonary conditions (p=.002) were found to have a significant association with the risk of mortality. Age exceeding 80 years was found to carry the highest risk of mortality. Age, pulmonary conditions, BMI, history of infection, ASA classification more than 2, neurologic conditions, resident (i.e., trainee) involvement, and procedural times exceeding 309 minutes increased the risk of complications. Body mass index, ASA classification more than 2, resident involvement, and procedural times exceeding 309 minutes were associated with the risk of infection. Although limited to univariate analysis, serum albumin 3.5 g/dL or less increased the risk of mortality, complications, wound infection, and thromboembolic disease. The OR for postoperative mortality among patients with albumin 3.5 g/dL or less was 13.8 (95% CI, 4.6-41.6; p<.001).

CONCLUSIONS

Several factors, including patients' age, BMI, ASA classification more than 2, pulmonary conditions, procedural times, and nutritional status likely influence the risk of postoperative morbidity to varying degrees. The risk factors identified here may be more generalizable to the American population as a whole because of the design and methodology of the NSQIP in comparison with previously published studies.

Efficacy and safety of surgical decompression in patients with cervical spondylotic myelopathy: results of the AOSpine North America prospective multi-center study

BACKGROUND

Cervical spondylotic myelopathy is the leading cause of spinal cord dysfunction worldwide. The objective of this study was to evaluate the impact of surgical decompression on functional, quality-of-life, and disability outcomes at one year after surgery in a large cohort of patients with this condition.

METHODS

Adult patients with symptomatic cervical spondylotic myelopathy and magnetic resonance imaging evidence of spinal cord compression were enrolled at twelve North American centers from 2005 to 2007. At enrollment, the myelopathy was categorized as mild (modified Japanese Orthopaedic Association [mJOA] score ≥ 15), moderate (mJOA = 12 to 14), or severe (mJOA < 12). Patients were followed prospectively for one year, at which point the outcomes of interest included the mJOA score, Nurick grade, Neck Disability Index (NDI), and Short Form-36 version 2 (SF-36v2). All outcomes at one year were compared with the preoperative values with use of univariate paired statistics. Outcomes were also compared among the severity classes with use of one-way analysis of variance. Finally, a multivariate analysis that adjusted for baseline differences among the severity groups was performed. Treatment-related complication data were collected and the overall complication rate was calculated.

RESULTS

Eighty-five (30.6%) of the 278 enrolled patients had mild cervical spondylotic myelopathy, 110 (39.6%) had moderate disease, and 83 (29.9%) had severe disease preoperatively. One-year follow-up data were available for 222 (85.4%) of 260 patients. There was a significant improvement from baseline to one year postoperatively (p < 0.05) in the mJOA score, Nurick grade, NDI score, and all SF-36v2 health dimensions (including the mental and physical health composite scores) except general health. With the exception of the change in the mJOA, the degree of improvement did not depend on the severity of the preoperative symptoms. These results remained unchanged after adjusting for relevant confounders in the multivariate analysis. Fifty-two patients experienced complications (prevalence, 18.7%), with no significant differences among the severity groups.

CONCLUSIONS

Surgical decompression for the treatment of cervical spondylotic myelopathy was associated with improvement in functional, disability-related, and quality-of-life outcomes at one year of follow-up for all disease severity categories. Furthermore, complication rates observed in the study were commensurate with those in previously reported cervical spondylotic myelopathy series.

Transforaminal lumbar interbody fusion: prognostic factors related to retention in an active duty military population

Little information is available regarding patient-based factors that may influence results following transforaminal lumbar interbody fusion (TLIF) in younger, high-demand individuals. A query of all TLIF procedures performed on active duty military personnel at our institution was conducted for the time period 2005 to 2008. Data was abstracted, including age, gender, military rank, preoperative diagnosis, complications, and ability to remain in the military. Favorable outcome was defined as the ability of the patient receiving TLIF to remain on active duty, without medical separation (Medical Evaluation Board [MEB]), at a minimum of 1 year postsurgery. Univariate analysis was conducted to identify potential risk factors for MEB. Factors with a univariate p value <0.2 were included in multivariate analysis and sensitivity testing to identify independent predictors of outcome. The cohort included 143 patients with an average age of 36.3 years and mean follow-up of 34.9 months. Younger age (odds ratio 0.93 per year increase in age; 95% confidence interval 0.87, 0.98) and Junior Enlisted rank (odds ratio 6.42; 95% confidence interval 2.20, 18.74) were found to increase the risk of MEB, and these relationships were maintained in the sensitivity analyses. These findings highlight the potential role of activity level and sociodemographic status in outcomes after TLIF in a military population.