Sina Pourtaheri

The role of magnetic resonance imaging in acute cervical spine fractures

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 MRIs 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.

Paraspinal Muscle Atrophy After Lumbar Spine Surgery

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.

Minimally Invasive Transforaminal Lumbar Interbody Fusion in the Outpatient Setting.

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.].

Cervical Corpectomy With Ultra-low-dose rhBMP-2 in High-risk Patients: 5-year Outcomes

Twenty-four consecutive patients with cervical spondylosis who were treated with cervical corpectomy and recombinant human bone morphogenetic protein-2 (rhBMP-2) with standalone anterior instrumentation were evaluated. Mean number of levels fused was 2.4. There were significant improvements in visual analog scale neck pain and Oswestry Disability Index scores and cervical lordosis. Cervical corpectomy with a lower dose of rhBMP-2 was found to be safe and efficacious for patients who are at a higher risk for pseudarthrosis.

Intraoperative Neuromonitoring for Anterior Cervical Spine Surgery: What is the Evidence?

Study Design. Systematic review and meta-analysis. Objective. The goal of this study was to (i) assess the risk of neurological injury after anterior cervical spine surgery (ACSS) with and without intraoperative neuromonitoring (ION) and (ii) evaluate differences in the sensitivity and specificity of ION for ACSS. Summary of Background Data. Although ION is used to detect impending neurological injuries in deformity surgery, its utility in ACSS remains controversial. Methods. A systematic search of multiple medical reference databases was conducted for studies on ION use for ACSS. Studies that included posterior cervical surgery were excluded. Meta-analysis was performed using the random-effects model for heterogeneity. Outcome measure was postoperative neurological injury. Results. The search yielded 10 studies totaling 26,357 patients. The weighted risk of neurological injury after ACSS was 0.64% (0.23–1.25). The weighted risk of neurological injury was 0.20% (0.05–0.47) for ACDFs compared with 1.02% (0.10–2.88) for corpectomies. For ACDFs, there was no difference in the risk of neurological injury with or without ION (odds ratio, 0.726; confidence interval, CI, 0.287–1.833; P = 0.498). The pooled sensitivities and specificities of ION for ACSS are 71% (CI: 48%–87%) and 98% (CI: 92%–100%), respectively. Unimodal ION has a higher specificity than multimodal ION [unimodal: 99% (CI: 97%–100%), multimodal: 92% (CI: 81%–96%), P = 0.0218]. There was no statistically significant difference in sensitivities between unimodal and multimodal [68% vs. 88%, respectively, P = 0.949]. Conclusion. The risk of neurological injury after ACSS is low although procedures involving a corpectomy may carry a higher risk. For ACDFs, there is no difference in the risk of neurological injury with or without ION use. Unimodal ION has a higher specificity than multimodal ION and may minimize “subclinical” intraoperative alerts in ACSS. Level of Evidence: 3

Routine Use of Intraoperative Neuromonitoring During ACDFs for the Treatment of Spondylotic Myelopathy and Radiculopathy Is Questionable: A Review of 15,395 Cases.

Study Design. A retrospective database study. Objective. The goal of this study was to (1) evaluate the trends in the use of intraoperative neuromonitoring (ION) for anterior cervical discectomy and fusion (ACDF) surgery in the United States and (2) assess the incidence of neurological injuries after ACDFs with and without ION. Summary of Background Data. Somatosensory-evoked potentials (SSEPs) and motor-evoked potentials (MEPs) are the commonly used ION modalities for ACDFs. Controversy exists on the routine use of ION for ACDFs and there is limited literature on national practice patterns of its use. Methods. A retrospective review was performed using the PearlDiver Patient Record Database to identify cases of spondylotic myelopathy and radiculopathy that underwent ACDF from 2007 to 2014. The type of ION modality used and the rates of neurological injury after surgery were assessed. Results. During the study period, 15,395 patients underwent an ACDF. Overall, ION was used in 2627 (17.1%) of these cases. There was a decrease in the use of ION for ACDFs from 22.8% in 2007 to 4.3% use in 2014 (P < 0.0001). The ION modalities used for these ACDFs were quite variable: SSEPs only (48.7%), MMEPs only (5.3%), and combined SSEPs and MMEPs (46.1%). Neurological injuries occurred in 0.23% and 0.27% of patients with and without ION, respectively (P = 0.84). Younger age was associated with a higher utility of ION (<45: 20.3%, 45–54: 19.3%, 55–64: 16.6%, 65–74: 14.3%, and >75: 13.6%, P < 0.0001). Significant regional variability was observed in the utility of ION for ACDFs across the country (West; 21.9%, Midwest; 12.9% (P < 0.0001). Conclusion. There has been a significant decrease in the use of ION for ACDFs. Furthermore, there was significant age and regional variability in the use of ION for ACDFs. Use of ION does not further prevent the rate of postoperative neurological complications for ACDFs as compared with the cases without ION. The utility of routine ION for ACDFs is questionable. Level of Evidence: 3

Effectiveness of Reoperations for Adjacent Segment Disease Following Lumbar Spinal Fusion

Although several options are available to address adjacent segment disease (ASD), the most effective surgical treatment has not been determined. In addition, it is important to subdivide ASD into stenosis with or without instability to determine if a decompression alone vs an extension of fusion is necessary. A systematic search of multiple medical reference databases was conducted for studies on surgical treatment of ASD. The primary outcome measures used were radiographic and clinical success rates. Meta-analysis was completed to determine effect summary values, 95% confidence intervals, and Q statistic and I2 values, using the random effects model for heterogeneity. The search yielded 662 studies, of which 657 were excluded. A total of 5 (level IV) studies with a total of 118 patients were included in this review. In 2 studies (46 patients), stenosis without instability was the indication for reoperation for ASD. However, extension of fusion was the modality of choice for the treatment of ASD in all studies. Overall clinical improvement (in back and/or leg pain scores) was noted in 71.3% of patients (95% confidence interval, 37.4-100), while radiographic fusion was noted in 89.3% of patients (95% confidence interval, 51.2-100). Following reoperation for ASD, revision surgery rates ranged from 4.5% to 23.1% at last clinical follow-up. There is variability in the clinical improvement following lumbar fusion for ASD. In addition, little literature exists regarding the optimal treatment options for patients with ASD for stenosis with or without instability. [Orthopedics. 2018; 41(2):e161-e167.].

Ultra-Low-Dose Recombinant Human Bone Morphogenetic Protein-2 for 3-Level Anterior Cervical Diskectomy and Fusion

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.

Bilateral Femur Fractures Associated With Short-term Bisphosphonate Use

Bisphosphonates are the most commonly prescribed drugs to treat osteoporosis because they have been proposed to prevent bone loss. Nevertheless, in up to 0.1% of patients, long-term use may cause atypical stress or insufficiency femoral fractures. Bilateral femoral shaft fractures have been reported after long-term use of bisphosphonates; however, there is limited evidence of the effect of short-term use. The current study reports a case of bilateral femoral fractures after a low-energy fall in a 56-year-old woman and provides a review of the literature on bilateral femoral shaft fractures after long-term use of bisphosphonates. Patients should be educated about the potential for stress fractures with the use of this treatment. In patients with thigh pain, a thorough history and physical examination, including the contralateral thigh, may be beneficial to detect bilateral traumatic or atypical stress fracture patterns. More studies with larger sample sizes are necessary to better identify patients who may be at risk for fracture, including histomorphometric evidence of low bone turnover in patients with unfortunate bilateral cases.

Clinical Differences Between Monomicrobial and Polymicrobial Vertebral Osteomyelitis

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.].