Traumatic fractures of the thoracolumbar spine are relatively common occurrences that can be a source of pain and disability. Similarly, osteoporotic vertebral fractures are also frequent events and represent a significant health issue specific to the elderly. Neurologically intact patients with traumatic thoracolumbar fractures can commonly be treated nonoperatively with bracing. Nonoperative treatment is not suitable for patients with neurological deficits or highly unstable fractures. The role of operative versus nonoperative treatment of burst fractures is controversial, with high-quality evidence supporting both options. Osteoporotic vertebral fractures can be managed with bracing or vertebral augmentation in most cases. There is, however, a lack of high-quality evidence comparing operative versus nonoperative fractures in this population. Bracing is a low-risk, cost-effective method to treat certain thoracolumbar fractures and offers efficacy equivalent to that of surgical management in many cases. The evidence for bracing of osteoporotic-type fractures is less clear, and further investigation will be necessary to delineate its optimal role.
Victor Chang and Langston T. Holly
Victor Chang, Paul Hartzfeld, Marianne Langlois, Asim Mahmood and Donald Seyfried
Hemicraniectomy is a commonly practiced neurosurgical intervention with a wide range of indications and clinical data supporting its use. The extensive use of this procedure directly results in more cranioplasties to repair skull defects. The complication rate for cranial repair after craniectomy seems to be higher than that of the typical elective craniotomy. This finding prompted the authors to review their experience with patients undergoing cranial repair.
The authors performed a retrospective review of 212 patients who underwent cranial repair over a 13-year period at their institution. A database tracking age, presenting diagnosis, side of surgery, length of time before cranial repair, bone graft material used, presence of a ventricular shunt, presence of a postoperative drain, and complications was created and analyzed.
The overall complication rate was 16.4% (35 of 213 patients). Patients 0–39 years of age had the lowest complication rate of 8% (p = 0.028). For patients 40–59 years of age and older than 60, complication rates were 20 and 26%, respectively. Patients who originally presented with traumatic injuries had a lower rate of complications than those who did not (10 vs 20%; p = 0.049). Conversely, patients who presented with tumors had a higher complication rate than those without (38 vs 15%; p = 0.027). Patients who received autologous bone graft placement had a statistically significant lower risk of postoperative infection (4.6 vs 18.4%; p = 0.002). Patients who underwent cranioplasty with a 0–3 month interval between operations had a complication rate of 9%, 3–6 months 18.8%, and > 6 months 26%. Pairwise comparisons showed that the difference between the 0–3 month interval and the > 6-month interval was significant (p = 0.007). The difference between the 0–3 month interval and the 4–6 month interval showed a trend (p = 0.07). No difference was detected between the 4–6 month interval and > 6-month interval (p = 0.35).
The overall rate of complications related to cranioplasty after craniectomy is not negligible, and certain factors may be associated with increased risk. Therefore, when evaluating the need to perform a large decompressive craniectomy, the surgeon should also be aware that the patient is not only subject to the risks of the initial operation, but also the risks of subsequent cranioplasty.
Lara W. Massie, Hesham Mostafa Zakaria, Lonni R. Schultz, Azam Basheer, Morenikeji Ayodele Buraimoh and Victor Chang
The inability to significantly improve sagittal parameters has been a limitation of minimally invasive surgery for transforaminal lumbar interbody fusion (MIS TLIF). Traditional cages have a limited capacity to restore lordosis. This study evaluates the use of a crescent-shaped articulating expandable cage (Altera) for MIS TLIF.
This is a retrospective review of 1- and 2-level MIS TLIF. Radiographic outcomes included differences in segmental and lumbar lordosis, disc height, evidence of fusion, and any endplate violations. Clinical outcomes included the numeric rating scale for leg and back pain and the Oswestry Disability Index (ODI) for low-back pain.
Thirty-nine patients underwent single-level MIS TLIF, and 5 underwent 2-level MIS TLIF. The mean age was 63.1 years, with 64% women. On average, spondylolisthesis was corrected by 4.3 mm (preoperative = 6.69 mm, postoperative = 2.39 mm, p < 0.001), the segmental angle was improved by 4.94° (preoperative = 5.63°, postoperative = 10.58°, p < 0.001), and segmental height increased by 3.1 mm (preoperative = 5.09 mm, postoperative = 8.19 mm, p < 0.001). At 90 days after surgery the authors observed the following: a smaller postoperative sagittal vertical axis was associated with larger changes in back pain at 90 days (r = −0.558, p = 0.013); a larger decrease in spondylolisthesis was associated with greater improvements in ODI and back pain scores (r = −0.425, p = 0.043, and r = −0.43, p = 0.031, respectively); and a larger decrease in pelvic tilt (PT) was associated with greater improvements in back pain (r = −0.548, p = 0.043). For the 1-year PROs, the relationship between the change in PT and changes in ODI and numeric rating scale back pain were significant (r = 0.612, p = 0.009, and r = −0.803, p = 0.001, respectively) with larger decreases in PT associated with larger improvements in ODI and back pain. Overall for this study there was a 96% fusion rate.
Fourteen patients were noted to have endplate violation on intraoperative fluoroscopy during placement of the cage. Only 3 of these had progression of their subsidence, with an overall subsidence rate of 6% (3 of 49) visible on postoperative CT.
The use of this expandable, articulating, lordotic, or hyperlordotic interbody cage for MIS TLIF provides a significant restoration of segmental height and segmental lordosis, with associated improvements in sagittal balance parameters. Patients treated with this technique had acceptable levels of fusion and significant reductions in pain and disability.
Hesham Mostafa Zakaria, Lonni Schultz, Feras Mossa-Basha, Brent Griffith and Victor Chang
Improved objective assessments of perioperative risk after spine surgery are necessary to decrease postoperative morbidity and mortality rates. Morphometric analysis has proven utility in predicting postoperative morbidity and mortality in surgical disciplines. The aim of the present study was to evaluate whether morphometrics can be applied to the cases of patients undergoing lumbar spine surgery.
The authors performed a retrospective review of the perioperative course of 395 patients who underwent lumbar surgery at their institution from 2013 to 2014. Preoperative risk factors such as age, diabetes, smoking, coronary artery disease, and body mass index (BMI) were recorded. Preoperative MRI was used to measure the psoas muscle area at the L-4 vertebra and paraspinal muscle area at the T-12 vertebra. Primary outcomes included unplanned return to the operating room, 30- and 90-day readmissions, surgical site infection, wound dehiscence, new neurological deficit, deep vein thrombosis, pulmonary embolism, myocardial infarction, urinary tract infection, urinary retention, hospital-acquired pneumonia, stroke, and prolonged stay in the intensive care unit.
The overall rate of adverse events was 30%, the most common event being urinary retention (12%). Greater age (p = 0.015) and tobacco usage (p = 0.026) were both significantly associated with complications for all patients, while diabetes, coronary artery disease, and high BMI were not. No surgery-related characteristics were associated with postoperative morbidity, including whether surgery required instrumentation, whether it was a revision, or the number of vertebral levels treated. Using multivariate regression analysis, male and female patients with the lowest psoas tertile had an OR of 1.70 (95% CI 1.04–2.79, p = 0.035) for having postoperative complications. Male patients in the lowest psoas tertile had an OR of 2.42 (95% CI 1.17–5.01, p = 0.016) for having a postoperative complication. The paraspinal muscle groups did not provide any significant data for postoperative morbidity, even after multivariate analysis.
The morphometric measurement of psoas muscle size may be a sensitive predictive tool compared with other risk factors for perioperative morbidity in male patients undergoing lumbar surgery.
Hesham Mostafa Zakaria, Azam Basheer, David Boyce-Fappiano, Erinma Elibe, Lonni Schultz, Ian Lee, Farzan Siddiqui, Brent Griffith and Victor Chang
Predicting the survival rate for patients with cancer is currently performed using the TNM Classification of Malignant Tumors (TNM). Identifying accurate prognostic markers of survival would allow better treatment stratification between more aggressive treatment strategies or palliation. This is especially relevant for patients with spinal metastases, who all have identical TNM staging and whose surgical decision-making is potentially complex. Analytical morphometrics quantifies patient frailty by measuring lean muscle mass and can predict risk for postoperative morbidity after lumbar spine surgery. This study evaluates whether morphometrics can be predictive of survival in patients with spinal metastases.
Utilizing a retrospective registry of patients with spinal metastases who had undergone stereotactic body radiation therapy, the authors identified patients with primary lung cancer. Morphometric measurements were taken of the psoas muscle using CT of the lumbar spine. Additional morphometrics were taken of the L-4 vertebral body. Patients were stratified into tertiles based on psoas muscle area. The primary outcome measure was overall survival, which was measured from the date of the patient's CT scan to date of death.
A total of 168 patients were identified, with 54% male and 54% having multiple-level metastases. The median survival for all patients was 185.5 days (95% confidence interval [CI] 146–228 days). Survival was not associated with age, sex, or the number of levels of metastasis. Patients in the smallest tertile for the left psoas area had significantly shorter survival compared with a combination of the other two tertiles: 139 days versus 222 days, respectively, hazard ratio (HR) 1.47, 95% CI 1.06–2.04, p = 0.007. Total psoas tertiles were not predictive of mortality, but patients whose total psoas size was below the median size had significantly shorter survival compared with those greater than the median size: 146 days versus 253.5 days, respectively, HR 1.43, 95% CI 1.05–1.94, p = 0.025. To try to differentiate small body habitus from frailty, the ratio of psoas muscle area to vertebral body area was calculated. Total psoas size became predictive of mortality when normalized to vertebral body ratio, with patients in the lowest tertile having significantly shorter survival (p = 0.017). Left psoas to vertebral body ratio was also predictive of mortality in patients within the lowest tertile (p = 0.021). Right psoas size was not predictive of mortality in any calculations.
In patients with lung cancer metastases to the spine, morphometric analysis of psoas muscle and vertebral body size can be used to identify patients who are at risk for shorter survival. This information should be used to select patients who are appropriate candidates for surgery and for the tailoring of oncological treatment regimens.
Giacomo Pacchiarotti, Michael Y. Wang, John Paul G. Kolcun, Ken Hsuan-kan Chang, Motasem Al Maaieh, Victor S. Reis and Dao M. Nguyen
Solitary paravertebral schwannomas in the thoracic spine and lacking an intraspinal component are uncommon. These benign nerve sheath tumors are typically treated using complete resection with an excellent outcome. Resection of these tumors is achieved by an anterior approach via open thoracotomy or minimally invasive thoracoscopy, by a posterior approach via laminectomy, or by a combination of both approaches. These tumors most commonly occur in the midthoracic region, for which surgical removal is usually straightforward. The authors of this report describe 2 cases of paravertebral schwannoma at extreme locations of the posterior mediastinum, one at the superior sulcus and the other at the inferior sulcus of the thoracic cavity, for which the usual surgical approaches for safe resection can be challenging. The tumors were completely resected with robot-assisted thoracoscopic surgery. This report suggests that single-stage anterior surgery for this type of tumor in extreme locations is safe and effective with this novel minimally invasive technique.
Colin P. McDonald, Victor Chang, Michael McDonald, Nicole Ramo, Michael J. Bey and Stephen Bartol
Cervical arthroplasty with an artificial disc (AD) has emerged as an alternative to anterior cervical discectomy and fusion (ACDF) for the management of cervical spondylosis. This study aims to provide 3D motion analysis data comparing patients after ACDF and AD replacement.
Ten patients who underwent C5–6 ACDF and 7 who underwent C5–6 AD replacement were enrolled. Using biplanar fluoroscopy and a model-based track technique (accurate up to 0.6 mm and 0.6°), motion analysis of axial rotation and flexion-extension of the neck was performed. Three nonoperative segments (C3–4, C4–5, and C6–7) were assessed for both intervertebral rotation (coronal, sagittal, and axial planes) and facet shear (anteroposterior and mediolateral).
There was no difference in total neck motion comparing ACDF and AD replacement for neck extension (43.3° ± 10.2° vs 44.3° ± 12.6°, p = 0.866) and rotation (36.0° ± 6.5° vs 38.2° ± 9.3°, p = 0.576). For extension, when measured as a percentage of total neck motion, there was a greater amount of rotation at the nonoperated segments in the ACDF group than in the AD group (p = 0.003). When comparing specific motion segments, greater normalized rotation was seen in the ACDF group at C3–4 (33.2% ± 4.9% vs 26.8% ± 6.6%, p = 0.036) and C6–7 (28.5% ± 6.7% vs 20.5% ± 5.5%, p = 0.009) but not at C4–5 (33.5% ± 6.4% vs 31.8% ± 4.0%, p = 0.562). For neck rotation, greater rotation was observed at the nonoperative segments in the ACDF group than in the AD group (p = 0.024), but the differences between individual segments did not reach significance (p ≥ 0.146). Increased mediolateral facet shear was seen on neck extension with ACDF versus AD replacement (p = 0.008). Comparing each segment, C3–4 (0.9 ± 0.5 mm vs 0.4 ± 0.1 mm, p = 0.039) and C4–5 (1.0 ± 0.4 mm vs 0.5 ± 0.2 mm, p = 0.022) showed increased shear while C6–7 (1.0 ± 0.4 mm vs 1.0 ± 0.5 mm, p = 0.767) did not.
This study illustrates increased motion at nonoperative segments in patients who have undergone ACDF compared with those who have undergone AD replacement. Further studies will be required to examine whether these changes contribute to adjacent-segment disease.
Peng-Yuan Chang, Yu-Shu Yen, Jau-Ching Wu, Wen-Cheng Huang, Tsung-Hsi Tu, Li-Yu Fay and Henrich Cheng
Hesham Mostafa Zakaria, Michael Bazydlo, Lonni Schultz, Markian A. Pahuta, Jason M. Schwalb, Paul Park, Ilyas Aleem, David R. Nerenz, Victor Chang and for the MSSIC Investigators
The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a statewide, multicenter quality improvement initiative. Using MSSIC data, the authors sought to identify 90-day adverse events and their associated risk factors (RFs) after cervical spine surgery.
A total of 8236 cervical spine surgery cases were analyzed. Multivariable generalized estimating equation regression models were constructed to identify RFs for adverse events; variables tested included age, sex, diabetes mellitus, disc herniation, foraminal stenosis, central stenosis, American Society of Anesthesiologists Physical Classification System (ASA) class > II, myelopathy, private insurance, anterior versus posterior approach, revision procedures, number of surgical levels, length of procedure, blood loss, preoperative ambulation, ambulation day of surgery, length of hospital stay, and discharge disposition.
Ninety days after cervical spine surgery, adverse events identified included radicular findings (11.6%), readmission (7.7%), dysphagia requiring dietary modification (feeding tube or nothing by mouth [NPO]) (6.4%), urinary retention (4.7%), urinary tract infection (2.2%), surgical site hematoma (1.1%), surgical site infection (0.9%), deep vein thrombosis (0.7%), pulmonary embolism (0.5%), neurogenic bowel/bladder (0.4%), myelopathy (0.4%), myocardial infarction (0.4%), wound dehiscence (0.2%), claudication (0.2%), and ileus (0.2%). RFs for dysphagia included anterior approach (p < 0.001), fusion procedures (p = 0.030), multiple-level surgery when considering anterior procedures only (p = 0.037), and surgery duration (p = 0.002). RFs for readmission included ASA class > II (p < 0.001), while preoperative ambulation (p = 0.001) and private insurance (p < 0.001) were protective. RFs for urinary retention included increasing age (p < 0.001) and male sex (p < 0.001), while anterior-approach surgery (p < 0.001), preoperative ambulation (p = 0.001), and ambulation day of surgery (p = 0.001) were protective. Preoperative ambulation (p = 0.010) and anterior approach (p = 0.002) were protective of radicular findings.
A multivariate analysis from a large, multicenter, prospective database identified the common adverse events after cervical spine surgery, along with their associated RFs. This information can lead to more informed surgeons and patients. The authors found that early mobilization after cervical spine surgery has the potential to significantly decrease adverse events.
Victor Chang, Jason M. Schwalb, David R. Nerenz, Lisa Pietrantoni, Sharon Jones, Michelle Jankowski, Nancy Oja-Tebbe, Stephen Bartol and Muwaffak Abdulhak
Given the scrutiny of spine surgery by policy makers, spine surgeons are motivated to demonstrate and improve outcomes, by determining which patients will and will not benefit from surgery, and to reduce costs, often by reducing complications. Insurers are similarly motivated. In 2013, Blue Cross Blue Shield of Michigan (BCBSM) and Blue Care Network (BCN) established the Michigan Spine Surgery Improvement Collaborative (MSSIC) as a Collaborative Quality Initiative (CQI). MSSIC is one of the newest of 21 other CQIs that have significantly improved—and continue to improve—the quality of patient care throughout the state of Michigan.
MSSIC focuses on lumbar and cervical spine surgery, specifically indications such as stenosis, disk herniation, and degenerative disease. Surgery for tumors, traumatic fractures, deformity, scoliosis, and acute spinal cord injury are currently not within the scope of MSSIC. Starting in 2014, MSSIC consisted of 7 hospitals and in 2015 included another 15 hospitals, for a total of 22 hospitals statewide. A standardized data set is obtained by data abstractors, who are funded by BCBSM/BCN. Variables of interest include indications for surgery, baseline patient-reported outcome measures, and medical history. These are obtained within 30 days of surgery. Outcome instruments used include the EQ-5D general health state score (0 being worst and 100 being the best health one can imagine) and EQ-5D-3 L. For patients undergoing lumbar surgery, a 0 to 10 numeric rating scale for leg and back pain and the Oswestry Disability Index for back pain are collected. For patients undergoing cervical surgery, a 0 to 10 numeric rating scale for arm and neck pain, Neck Disability Index, and the modified Japanese Orthopaedic Association score are collected. Surgical details, postoperative hospital course, and patient-reported outcome measures are collected at 90-day, 1-year, and 2-year intervals.
As of July 1, 2015, a total of 6397 cases have been entered into the registry. This number reflects 4824 eligible cases with confirmed surgery dates. Of these 4824 eligible cases, 3338 cases went beyond the 120-day window and were considered eligible for the extraction of surgical details, 90-day outcomes, and adverse events. Among these 3338 patients, there are a total of 2469 lumbar cases, 862 cervical cases, and 7 combined procedures that were entered into the registry.
In addition to functioning as a registry, MSSIC is also meant to be a platform for quality improvement with the potential for future initiatives and best practices to be implemented statewide in order to improve quality and lower costs. With its current rate of recruitment and expansion, MSSIC will provide a robust platform as a regional prospective registry. Its unique funding model, which is supported by BCBSM/BCN, will help ensure its longevity and viability, as has been observed in other CQIs that have been active for several years.