Management of mild degenerative cervical myelopathy and asymptomatic spinal cord compression: an international survey

STUDY DESIGN

Cross-sectional survey.

OBJECTIVE

Currently there is limited evidence and guidance on the management of mild degenerative cervical myelopathy (DCM) and asymptomatic spinal cord compression (ASCC). Anecdotal evidence suggest variance in clinical practice. The objectives of this study were to assess current practice and to quantify the variability in clinical practice.

METHODS

Spinal surgeons and some additional health professionals completed a web-based survey distributed by email to members of AO Spine and the Cervical Spine Research Society (CSRS) North American Society. Questions captured experience with DCM, frequency of DCM patient encounters, and standard of practice in the assessment of DCM. Further questions assessed the definition and management of mild DCM, and the management of ASCC.

RESULTS

A total of 699 respondents, mostly surgeons, completed the survey. Every world region was represented in the responses. Half (50.1%, n = 359) had greater than 10 years of professional experience with DCM. For mild DCM, standardised follow-up for non-operative patients was reported by 488 respondents (69.5%). Follow-up included a heterogeneous mix of investigations, most often at 6-month intervals (32.9%, n = 158). There was some inconsistency regarding which clinical features would cause a surgeon to counsel a patient towards surgery. Practice for ASCC aligned closely with mild DCM. Finally, there were some contradictory definitions of mild DCM provided in the form of free text.

CONCLUSIONS

Professionals typically offer outpatient follow up for patients with mild DCM and/or asymptomatic ASCC. However, what this constitutes varies widely. Further research is needed to define best practice and support patient care.

CT Scan in Subaxial Cervical Facet Injury: Is It Enough for Decision-Making?

STUDY DESIGN

Cross-sectional survey.

OBJECTIVES

Assessment of subaxial cervical facet injuries using the AO Spine Subaxial Cervical Spine Injury Classification System is based on CT scan findings. However, additional radiological evaluations are not directly considered. The aim of this study is to determine situations in which spine surgeons request additional radiological exams after a facet fracture.

METHODS

A survey was sent to AO Spine members from Latin America. The evaluation considered demographic variables, routine use of the Classification, as well as the timepoint at which surgeons requested a cervical MRI, a vascular study, and/ or dynamic radiographs before treatment of facet fractures.

RESULTS

There was 229 participants, mean age 42.9 ± 10.2 years; 93.4% were men. Orthopedic surgeons 57.6% with 10.7 ± 8.7 years of experience in spine surgery. A total of 86% used the Classification in daily practice. An additional study (MRI/vascular study/and dynamic radiographs) was requested in 53.3%/9.6%/43.7% in F1 facet injuries; 76.0%/20.1%/50.2% in F2; 89.1%/65.1%/28.4% in F3; and 94.8%/66.4%/16.6% in F4. An additional study was frequently required: F1 72.5%, F2 86.9%, F3 94.7%, and F4 96.1%.

CONCLUSIONS

Spine surgeons generally requested additional radiological evaluations in facet injuries, and MRI was the most common. Dynamic radiographs had a higher prevalence for F1/F2 fractures; vascular studies were more common for F3/F4 especially among surgeons with fewer years of experience. Private hospitals had a lower spine trauma cases/year and requested more MRI and more dynamic radiographs in F1/F2. Neurosurgeons had more vascular studies and dynamic radiographs than orthopedic surgeons in all facet fractures.

Risk Factors for Postoperative Complications After Surgical Treatment of Type B and C Injuries of the Thoracolumbar Spine

BACKGROUND

Unstable thoracolumbar spinal injuries benefit from surgical fixation. However, perioperative complications significantly affect outcomes in surgicallytreated spine patients. We evaluated associations between risk factors and postoperative complications in patients surgically treated for thoracolumbar spine fractures.

METHODS

We conducted a retrospective multicenter study collating data from 21 spine centers across 9 countries on the treatment of AOSpine types B and C injuries of the thoracolumbar spine treated via a posterior approach. Comparative analysis was performed between patients with postoperative complications and those without. Univariate and multivariable analyses were performed.

RESULTS

Among 535 patients, at least 1 complication occurred in 43%. The most common surgical complication was surgical-site infection (6.9%), while the most common medical complication was urinary tract infection (13.8%). Among 136 patients with American Spinal Injury Association (ASIA) Impairment Scalelevel A disability, 77.9% experienced at least 1 complication. The rate of complications also rose sharply among patients waiting >3 days for surgery (P<0.001), peaking at 68.4% among patients waiting ≥30 days. On multivariable analysis, significant predictors of complications were surgery at a governmental hospital (odds ratio = 3.38, 95% confidence interval = 1.73-6.60), having ≥1 comorbid illness (2.44, 1.61-3.70), surgery delayed due to health instability (2.56, 1.50-4.37), and ASIA Impairment Scalelevel A (3.36, 1.78-6.35), while absence of impairment (0.39, 0.22-0.71), ASIAlevel E (0.39, 0.22-0.67) and, unexpectedly, delay caused by operating room unavailability (0.60, 0.36-0.99) were protective.

CONCLUSIONS

Types B and C thoracolumbar spine injuries are associated with a high risk of postoperative complications, especially common at governmental hospitals, and among patients with comorbidity, health instability, longer delays to surgery, and worse preoperative neurologic status.

Minimally Invasive Versus Open Surgery for the Treatment of Types B and C Thoracolumbar Injuries: A PRISMA Systematic Review

BACKGROUND

Thoracic and lumbar spine injuries may require surgical management, particularly AO Spine types B and C injuries. Open reduction and fixation using pedicle screws, with or without fusion and/or decompression, is the gold standard surgical treatment for unstable injuries. Recent advances in instrumentation design have resulted in less-invasive surgeries. However, the literature is sparse about the effectiveness of these procedures for types B and C injuries. The objective is to compare the outcomes of conventional open surgery versus minimally invasive spine surgery (MISS) for the treatment of AO Spine types B and C thoracolumbar injuries.

METHODS

A systematic review of published literature in PubMed, Web of Science, and Scopus was performed to identify studies comparing outcomes achieved with open versus minimally invasive surgery in AO Spine types B and C thoracolumbar injury patients. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used.

RESULTS

Five retrospective case-control studies and 3 prospective studies met selection criteria. In general, most of the studies demonstrated that minimally invasive spine surgery is feasible for types B and C injuries, and associated with potential advantages like reduced blood loss, postoperative pain, and muscle injury, and shorter hospital stays. However, no differences were detected in major outcomes, like neurological status or disability.

CONCLUSIONS

Published literature currently suggests that minimally invasive spine surgery is a valid alternative for treating types B and C thoracolumbar injuries. However, further comparative prospective randomized clinical trials are necessary to establish the superiority of one approach over the other.

LEVEL OF EVIDENCE

3.

Time to Surgery for Unstable Thoracolumbar Fractures in Latin America-A Multicentric Study

OBJECTIVE

We sought to identify delays for surgery to stabilize unstable thoracolumbar fractures and the main reasons for them across Latin America.

METHODS

We reviewed the charts of 547 patients with type B or C thoracolumbar fractures from 21 spine centers across 9 Latin American countries. Data were collected on demographics, mechanism of trauma, time between hospital arrival and surgery, type of hospital (public vs. private), fracture classification, spinal level of injury, neurologic status (American Spinal Injury Association impairment scale), number of levels instrumented, and reason for delay between hospital arrival and surgical treatment.

RESULTS

The sample included 403 men (73.6%) and 144 women (26.3%), with a mean age of 40.6 years. The main mechanism of trauma was falls (44.4%), followed by car accidents (24.5%). The most frequent pattern of injury was B2 injuries (46.6%), and the most affected level was T12-L1 (42.2%). Neurologic status at admission was 60.5% intact and 22.9% American Spinal Injury Association impairment scale A. The time from admission to surgery was >72 hours in over half the patients and over a week in >25% of them. The most commonly reported reasons for surgical delay were clinical instability (22.9%), lack of operating room availability (22.7%), and lack of hardware for spinal instrumentation (e.g., screws/rods) (18.8%).

CONCLUSIONS

Timing for surgery in this sample of unstable fractures was over 72 hours in more than half of the sample and longer than a week in about a quarter. The main reasons for this delay were clinical instability and lack of economic resources. There is an apparent need for increased funding for the treatment of spinal trauma patients in Latin America.

The Relationship Between Preoperative Clinical Presentation and Quantitative Magnetic Resonance Imaging Features in Patients With Degenerative Cervical Myelopathy

BACKGROUND: Degenerative cervical myelopathy encompasses a group of conditions resulting in progressive spinal cord injury through static and dynamic compression. Although a constellation of changes can present on magnetic resonance imaging (MRI), the clinical significance of these findings remains a subject of controversy and discussion.

OBJECTIVE: To investigate the relationship between clinical presentation and quantitative MRI features in patients with degenerative cervical myelopathy.

METHODS: A secondary analysis of MRI and clinical data from 114 patients enrolled in a prospective, multicenter study was conducted. MRIs were assessed for maximum spinal cord compression (MSCC), maximum canal compromise (MCC), signal changes, and a signal change ratio (SCR). MRI features were compared between patients with and those without myelopathy symptoms with the use of t tests. Correlations between MRI features and duration of symptoms were assessed with the Spearman ρ.

RESULTS: Numb hands and Hoffmann sign were associated with greater MSCC (P &lt; .05); broad-based, unstable gait, impairment of gait, and Hoffmann sign were associated with greater MCC (P &lt; .05); and numb hands, Hoffmann sign, Babinski sign, lower limb spasticity, hyperreflexia, and T1 hypointensity were associated with greater SCR (P &lt; .05). Patients with a T2 signal hyperintensity had greater MSCC and MCC (P &lt; .001).

CONCLUSION: MSCC was associated with upper limb manifestations, and SCR was associated with upper limb, lower limb, and general neurological deficits. Hoffmann sign occurred more commonly in patients with a greater MSCC, MCC and SCR. The Lhermitte phenomenon presented more commonly in patients with a lower SCR and may be an early indicator of mild spinal cord involvement. Research to validate these findings is required.

Risk factors for the need of surgical treatment of a first recurrent lumbar disc herniation

PURPOSE

A recurrent lumbar disc herniation (RLDH) is the most prevalent cause for new radicular pain after surgery for disc herniation-induced sciatica. Reported risk factors include age, gender and smoking, while its surgical treatment is associated to a higher rate of complications and costs. The purpose of this study is to identify factors that increase the risk of requiring surgical treatment for a first RLDH in workers' compensation patients.

METHODS

Nested case-control: 109 patients operated for an RLDH (cases) between June 1st 1994 and May 31st 2011 (minimum follow-up 1 year) and 109 randomly selected patients operated for a first disc herniation with no recurrence during the study period (controls). Age, gender, smoking status, type of work and MRI characteristics of the index herniation were statistically evaluated as potential risk factors.

RESULTS

Patient's age of less than 35 years (p = 0.001) and a subligamentous herniation (p < 0.05) at the time of the index surgery were identified as risk factors for requiring surgical treatment of a first RLDH. No statistical differences were observed between both groups regarding the other evaluated variables.

CONCLUSION

A subligamentous disc herniation and patient's age inferior to 35 years at the time of the first surgery are risk factors for requiring surgical treatment of a first RLDH among workers' compensation patients.

Prevalence of Klippel-Feil Syndrome in a Surgical Series of Patients with Cervical Spondylotic Myelopathy: Analysis of the Prospective, Multicenter AOSpine North America Study

Study Design Prospective study. Objective To evaluate the prevalence of Klippel-Feil syndrome (KFS) in a prospective data set of patients undergoing surgical treatment for cervical spondylotic myelopathy (CSM) and to evaluate if magnetic resonance imaging (MRI) features in patients with KFS are more pronounced than those of non-KFS patients with CSM. Methods A retrospective analysis of baseline MRI data from the AOSpine prospective and multicenter CSM-North American study was conducted. All the patients presented with at least one clinical sign of myelopathy and underwent decompression surgery. The MRIs and radiographs were reviewed by three investigators. The clinical and imaging findings were compared with patients without KFS but with CSM. Results Imaging analysis discovered 5 of 131 patients with CSM (∼3.82%) had single-level congenital fusion of the cervical spine. The site of fusion differed for all the patients. One patient underwent posterior surgery and four patients received anterior surgery. Postoperative follow-up was available for four of the five patients with KFS and indicated stable or improved functional status. All five patients demonstrated pathologic changes of adjacent segments and hyperintensity signal changes in the spinal cord on T2-weighted MRI. Multiple MRI features, most notably maximum canal compromise (p = 0.05) and T2 signal hyperintensity area (p = 0.05), were worse in patients with CSM and KFS. Conclusions The high prevalence of KFS in our surgical series of patients with CSM may serve as an indication that these patients are prone to increased biomechanical use of segments adjacent to fused vertebra. This supposition is supported by a tendency of patients with KFS to present with more extensive MRI evidence of degeneration than non-KFS patients with CSM.

Role of magnetic resonance imaging in predicting surgical outcome in patients with cervical spondylotic myelopathy

STUDY DESIGN

Ambispective, retrospective cohort study from prospectively collected data.

SUMMARY OF BACKGROUND DATA

Cervical spondylotic myelopathy is the commonest cause of spinal cord impairment in the elderly population worldwide. Although magnetic resonance imaging (MRI) is the primary imaging modality for confirming the diagnosis, its role in predicting surgical outcome remains unclear.

METHODS

Two hundred seventy-eight patients with 1 or more clinical signs of myelopathy were enrolled; and they underwent decompression surgery. Complete baseline clinical and MRI data were available for 102 patients. MRI parameters measured included presence/absence of signal change on T1 and T2, T2 signal quantitative factors, and anatomical measurements. A dichotomized postoperative modified Japanese Orthopedic Association (mJOA) score at 6 months was used to characterize patients with mild myelopathy (≥16) and those with substantial residual neurological impairment (<16). Univariate analysis assessed the relationship between baseline parameters and outcome. Multivariate logistic regression was conducted after a conceptual division of variables into 3 groups: T1 signal analysis, T2 signal analysis, and anatomical measurements.

RESULTS

Baseline mJOA (P<0.001; odds ratio [OR]=1.644, 95% confidence interval [95% CI]: 1.326-2.037), maximum canal compromise (MCC) (P=0.0322; OR=0.965, 95% CI: 0.934-0.997), T2 hyperintensity region of interest area (P=0.0422; OR=0.67; 95% CI: 0.456-0.986), and sagittal extent (P=0.026; OR=0.673; 95% CI: 0.475-0.954) were significantly associated with outcome univariately. The final model was comprised of T1 hypointensity (P=0.029; OR=0.242; CI: 0.068-0.866), MCC (P=0.005; OR=0.940; CI: 0.90-0.982) and baseline mJOA (P<0.001; OR=1.743; CI: 1.353-2.245), yielding an area under the receiver operating characteristic curve (AUC) of 0.845.

CONCLUSION

Baseline mJOA is a strong predictor of postsurgical outcome in cervical spondylotic myelopathy at 6 months. However, a model inclusive of MCC and T1 hypointensity assessment provides superior predictive capacity. This suggests that MRI analysis has a significant role in predicting surgical outcome.

LEVEL OF EVIDENCE

3.

Isolated transverse sacral fractures

BACKGROUND CONTEXT

The limited literature available about transverse sacral fractures describes two populations of patients: one with severe associated injuries and neurologic impairment and another with insufficiency fractures after low-energy trauma. Nevertheless, we have observed that isolated sacral fractures can occur in a third group of patients without the previously described features.

PURPOSE

To describe the clinical features of a population of patients with isolated transverse sacral fractures and evaluate the results of their conservative treatment according to our experience.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Forty-two patients with isolated transverse sacral fractures with a mean follow-up of 22 months (range, 18-24 months).

OUTCOMES MEASURES

Neurologic recovery, pain relief, time out of work, and disability.

METHODS

We included all the patients admitted at our institution for an isolated transverse sacral fracture between 1996 and 2005. The information obtained from their medical records was analyzed using an electronic spreadsheet (Microsoft Excel for Mac v.2011; Microsoft, Redmond, WA, USA).

RESULTS

Thirty-four patients (80%) sustained a low-energy trauma, whereas only two (4.8%) presented transient neurologic impairment. Every fracture was confirmed with a sacrococcygeal computed tomography (CT) scan. All the patients referred no local pain 6 months after the accident and were able to return to their preinjury activity level. None of the patients required compensation for disability.

CONCLUSION

Transverse sacral fractures should be suspected in patients referring local pain after sustaining low-energy trauma, even in the absence of risk factors for an insufficiency fracture. These injuries are difficult to detect in plain X-rays, so a sacrococcygeal CT scan is recommended. Conservative treatment is associated with excellent results in this population of patients.