Characteristics and outcomes of patients undergoing lumbar spine surgery for axial back pain in the Michigan Spine Surgery Improvement Collaborative.

BACKGROUND CONTEXT: The indications for surgical intervention of axial back pain without leg pain for degenerative lumbar disorders have been limited in the literature, as most study designs allow some degree of leg symptoms in the inclusion criteria. PURPOSE: To determine the outcome of surgery (decompression only vs. fusion) for pure axial back pain without leg pain. STUDY DESIGN/SETTING: Prospectively collected data in the Michigan Spine Surgery Improvement Collaborative (MSSIC). PATIENT SAMPLE: Patients with pure axial back pain without leg pain underwent lumbar spine surgery for primary diagnoses of lumbar disc herniation, lumbar stenosis, and isthmic or degenerative spondylolisthesis ≤ grade II. OUTCOME MEASURES: Minimally clinically important difference (MCID) for back pain, Numeric Rating Scale of back pain, Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), MCID of PROMIS-PF, and patient satisfaction on the North American Spine Surgery Patient Satisfaction Index were collected at 90 days, 1 year, and 2 years after surgery. METHODS: Log-Poisson generalized estimating equation models were constructed with patient-reported outcomes as the independent variable, reporting adjusted risk ratios (RRadj). RESULTS: Of the 388 patients at 90 days, multi-level versus single level lumbar surgery decreased the likelihood of obtaining a MCID in back pain by 15% (RRadj=0.85, p=.038). For every one-unit increase in preoperative back pain, the likelihood for a favorable outcome increased by 8% (RRadj=1.08, p<.001). Of the 326 patients at 1 year, symptom duration > 1 year decreased the likelihood of a MCID in back pain by 16% (RRadj=0.84, p=.041). The probability of obtaining a MCID in back pain increased by 9% (RRadj=1.09, p<.001) for every 1-unit increase in baseline back pain score and by 14% for fusions versus decompression alone (RRadj=1.14, p=.0362). Of the 283 patients at 2 years, the likelihood of obtaining MCID in back pain decreased by 30% for patients with depression (RRadj=0.70, p<.001) and increased by 8% with every one-unit increase in baseline back pain score (RRadj=1.08, p<.001). CONCLUSIONS: Only the severity of preoperative back pain was associated with improvement in MCID in back pain at all time points, suggesting that surgery should be considered for selected patients with severe axial pain without leg pain. Fusion surgery versus decompression alone was associated with improved patient-reported outcomes at 1 year only, but not at the other time points.

Decompression of Lumbar Central Spinal Canal Stenosis Following Minimally Invasive Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: This was a retrospective clinical series. OBJECTIVE: The objective of this study was to evaluate radiologic changes in central spinal canal dimensions following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) with placement of a static or an expandable interbody device. SUMMARY OF BACKGROUND DATA: MIS-TLIF is used to treat lumbar degenerative diseases and low-grade spondylolisthesis. MIS-TLIF enables direct and indirect decompression of lumbar spinal stenosis, with patients experiencing relief from radiculopathy and neurogenic claudication. However, the effects of MIS-TLIF on the central spinal canal are not well-characterized. MATERIALS AND METHODS: We identified patients who underwent MIS-TLIF for degenerative lumbar spondylolisthesis and concurrent moderate to severe spinal stenosis. We selected patients who had both preoperative and postoperative magnetic resonance imaging (MRI) and upright lateral radiographs of the lumbar spine. Measurements on axial T2-weighted MRI scans include anteroposterior and transverse dimensions of the dural sac and osseous spinal canal. Measurements on radiographs include disk height, neural foraminal height, segmental lordosis, and spondylolisthesis. We made pairwise comparisons between each of the central canal dimensions and lumbar sagittal segmental radiologic outcome measures relative to their corresponding preoperative values. Correlation coefficients were used to quantify the association between changes in lumbar sagittal segmental parameters relative to changes in radiologic outcomes of central canal dimensions. Statistical analysis was performed for "all patients" and further stratified by interbody device subgroups (static and expandable). RESULTS: Fifty-one patients (age 60.4 y, 68.6% female) who underwent MIS-TLIF at 55 levels (65.5% at L4-L5) were included in the analysis. Expandable interbody devices were used in 45/55 (81.8%) levels. Mean duration from surgery to postoperative MRI scan was 16.5 months (SD 11.9). MIS-TLIF was associated with significant improvements in dural sac dimensions (anteroposterior +0.31 cm, transverse +0.38 cm) and osseous spinal canal dimensions (anteroposterior +0.16 cm, transverse +0.32 cm). Sagittal lumbar segmental parameters of disk height (+0.56 cm), neural foraminal height (+0.35 cm), segmental lordosis (+4.26 degrees), and spondylolisthesis (-7.5%) were also improved following MIS-TLIF. We did not find meaningful associations between the changes in central canal dimensions relative to the corresponding changes in any of the sagittal lumbar segmental parameters. Stratified analysis by interbody device type (static and expandable) revealed similar within-group changes as in the overall cohort and minimal between-group differences. CONCLUSIONS: MIS-TLIF is associated with radiologic decompression of neural foraminal and central spinal canal stenosis. The mechanism for neural foraminal and central canal decompression is likely driven by a combination of direct and indirect corrective techniques.

The influence of sagittal spinopelvic alignment on patient discharge disposition following minimally invasive lumbar interbody fusion.

BACKGROUND: The aim of this study was to investigate the changes to spinopelvic sagittal alignment following minimally invasive (MIS) lumbar interbody fusion, and the influence of such changes on postoperative discharge disposition. METHODS: The Michigan Spine Surgery Improvement Collaborative was queried for all patients who underwent transforaminal lumbar interbody fusion (TLIF)or lateral lumbar interbody fusion (LLIF) procedures for degenerative spine disease. Several spinopelvic sagittal alignment parameters were measured, including sagittal vertical axis (SVA), lumbar lordosis, pelvic tilt, pelvic incidence, and pelvic incidence-lumbar lordosis mismatch. Primary outcome measure-discharge to a rehabilitation facility-was expressed as adjusted odds ratio (ORadj) following a multivariable logistical regression. RESULTS: Of the 83 patients in the study population, 11 (13.2%) were discharged to a rehabilitation facility. Preoperative SVA was equivalent. Postoperative SVA increased to 8.0 cm in the discharge-to-rehabilitation division versus a decrease to 3.6 cm in the discharge-to-home division (P<0.001). The odds of discharge to a rehabilitation facility increased by 25% for every 1-cm increase in postoperative sagittal balance (ORadj =1.27, P=0.014). The strongest predictor of discharge to rehabilitation was increasing decade of life (ORadj =3.13, P=0.201). CONCLUSIONS: Correction of sagittal balance is associated with greater odds of discharge to home. These findings, coupled with the recognized implications of admission to a rehabilitation facility, will emphasize the importance of spine surgeons accounting for SVA into their surgical planning of MIS lumbar interbody fusions.

Relationship between initial opioid prescription size and likelihood of refill after spine surgery.

BACKGROUND CONTEXT: Best practices in opioid prescribing after elective surgery have been developed for most surgical subspecialties, including spine. However, some percentage of patients will become chronic users. PURPOSE: This study aimed to determine the relationship between the size of initial opioid prescription after surgery for degenerative spinal disease and the likelihood of refills. STUDY DESIGN/SETTING: Retrospective case-control study. PATIENT SAMPLE: Opioid-naïve patients aged 18 to 64 undergoing elective spinal procedures (anterior cervical discectomy and fusion, posterior cervical fusion, lumbar decompression, and lumbar fusion) from 2010 to 2015 filling an initial perioperative prescription using insurance claims from Truven Health MarketScan (n=25,329). OUTCOME MEASURES: Functional measure: health-care utilization. Primary outcome was occurrence of an opioid refill within 30 postoperative days. METHODS: We used logistic regression to examine the probability of an additional refill by initial opioid prescription strength, adjusting for patient factors. RESULTS: About 26.3% of opioid-naïve patients obtained refills of their opioid prescriptions within 30 days of surgery. The likelihood of obtaining a refill was unchanged with the size of the initial perioperative prescription across procedure categories. Patient factors associated with increased likelihood of refills included age 30 to 39 years (odds ratio [OR] 1.137, p=.007, 95% confidence interval [CI] 1.072-1.249), female gender (OR 1.137, p<.001, 95% CI 1.072-1.207), anxiety disorder (OR 1.141, p=.017, 95% CI 1.024-1.272), mood disorder (OR 1.109 p=.049, 95% CI 1.000-1.229), and history of alcohol/substance abuse (OR 1.445 p=.006, 95% CI 1.110-1.880). CONCLUSIONS: For opioid-naïve patients, surgeons can prescribe lower amounts of opioids after elective surgery for degenerative spinal disease without concern of increased need for refills.

Bone Marrow Aspirate in Spine Surgery: Case Series and Review of the Literature.

Background With the modernization of biotechnology, there has been a concerted effort to create novel biomaterials to promote arthrodesis for spine surgery. The novel use of the stem cells from bone marrow aspirate (BMA) to augment spine surgery is a burgeoning field because these cells are considered to be both osteoinductive and osteogenic. We sought to review the evidence behind the use of BMAs in spinal fusions and report the results of our own case series. Methods PubMed and EMBASE databases were searched for studies that investigated the use of stem cells for spine surgery. For our own case series, the medical records of 150 consecutive patients who underwent a lumbar spinal fusion with BMA were retrospectively reviewed for adverse events (AEs) for up to two years after surgery. Results In our case series, there were no AEs identified in 49% of our patients. Of the identified AEs, 61% were unrelated to the use of BMA (e.g., UTI and heart failure), with the remaining 39% likely unrelated to its use (e.g., back pain and anemia). There was a 92.8% arthrodesis rate with the use of BMA. Conclusions We reviewed the rationale, basic science, and clinical science for BMA usage in spine surgery and concluded that BMA is safe for use in spine surgery and is associated with a high rate of arthrodesis.

The Effect of Physical Therapy on Time to Discharge After Lumbar Interbody Fusion.

BACKGROUND: With a lesser degree of tissue destruction, patients undergoing minimally-invasive spine surgery are primed to benefit from early mobilization, which can further enhance recovery and hasten rehabilitation. We aimed to determine the role of physical therapy on earlier discharge after minimally-invasive transforaminal lumbar interbody fusion (TLIF). METHODS: Michigan Spine Surgery Improvement Collaborative (MSSIC) provided patients undergoing one- and two-level minimally-invasive TLIF for degenerative lumbar disease. The study population was divided into patients with a one-day length of stay (LOS 1), two days (LOS 2), and three or more days (LOS ≥ 3) to maintain three equal-time cohorts. On POD 0, physical therapy (or, in very rare circumstances, a spine-care-specialized nurse in patients arriving to the in-patient floors late after hours) must evaluate capacity to ambulate. RESULTS: Of the 101 patients, the median day of first ambulation statistically significantly increased from the LOS 1 to LOS ≥ 3 cohort (P = 0.007). Mean distance ambulated decreased from 156.5 ±â€¯123.1 feet in the LOS 1 group, 108.9 ±â€¯83.9 feet in the LOS 2 group, to 69.2 ±â€¯58.3 feet in the LOS ≥ 3 group (P = 0.002). Patient-reported outcomes did not differ among the three cohorts. Following a multivariable ordinal logistical regression controlling for disposition to rehab over home (ORadj = 5.47, P = 0.045), the odds of longer LOS decreased by 39% for every 50-feet ambulated (P = 0.002). CONCLUSIONS: Time to first ambulation independently increases the odds of earlier discharge, regardless of comorbidity burden and surgical determinants.

Sellar Atypical Teratoid/Rhabdoid Tumor Presenting with Subarachnoid and Intraventricular Hemorrhage.

BACKGROUND: Atypical teratoid/rhabdoid tumors (ATRT) are uncommon malignancies of the central nervous system and are often difficult to distinguish radiographically and pathologically from other common tumors. We present the first case of sellar ATRT presenting with subarachnoid hemorrhage (SAH) and intraventricular hemorrhage (IVH). CASE DESCRIPTION: A 62-year-old woman, who had presented with symptoms of headache, diabetes insipidus, hypothyroidism, and seizures, was found to have a sellar tumor with hemorrhagic transformation. Surgical resection was performed. The pathological examination findings were consistent with ATRT. Despite early surgical intervention, she later died before starting craniospinal radiotherapy and chemotherapy. CONCLUSION: To the best of our knowledge, although known to present with intratumoral hemorrhage, to date, no cases of sellar ATRT have presented with SAH or IVH have been reported. Considering our finding that ATRT can present with SAH and IVH, establishing the correct diagnosis using radiographic imaging, gender, pathological findings, and molecular markers is paramount for speedy treatment and management.

Concurrent Placement of Bilateral Suboccipital and Supraorbital Nerve Stimulators Using On-Q* Tunneler: Technical Note.

BACKGROUND: Stimulation of the occipital and supraorbital nerves is used to treat chronic migraine refractory to medical management. Placement of cranial leads is often challenging due to the rigid Touhy needle included in the kit for its placement. OBJECTIVE: To report the first case of concurrent placement of bilateral supraorbital (SNS) and occipital nerve stimulators (ONS) from a unilateral approach using the On-Q* Tunneler, (Halyard Health, Alpharetta, Georgia) a flexible, blunt tipped plastic tunneler with a tear-away sheath. METHODS: We present the case of a 49-yr-old female with debilitating daily holocephalic headaches who underwent placement of SNS and ONS through a cervical and left temporal incision at an outside hospital. She presented to our institution with purulent drainage from the temporal incision and the system was removed. We describe an alternative approach to bilateral SNS and ONS placement with a soft flexible tunneling device, which facilitated placement of the entire system through a right temporal incision, thereby avoiding her previously infected surgical sites. RESULTS: The patient reported complete resolution of her daily headaches and was able to resume her activities as a full-time student. CONCLUSION: The flexibility of the On-Q tunneler device (Halyard Health) allows the placement of bilateral SNS and ONS from a unilateral incision, thereby minimizing the cosmetic effect and infectious risk of this procedure.

Application of morphometrics as a predictor for survival in female patients with breast cancer spinal metastasis: a retrospective cohort study.

BACKGROUND CONTEXT: The current standard of care for prediction of survival of cancer staging is based on TNM staging. However, for patients with spinal metastasis, who all have identical stage IV disease, identifying accurate prognostic markers of survival would allow better treatment stratification between more aggressive treatment strategies or palliation. Analytical morphometrics enables physicians to quantify patient frailty by measuring lean muscle mass. Morphometrics also predicts survival in patients with lung cancer metastases to the spine. PURPOSE: Our study evaluates whether morphometrics is predictive of survival in patients with breast cancer spinal metastasis. DESIGN: This is an observational retrospective cohort study. PATIENT SAMPLE: This study includes female patients with breast cancer spinal metastases and patients who have undergone stereotactic body radiation therapy. OUTCOME MEASURES: Overall survival was the primary outcome measure. METHODS: Morphometric measurements of the psoas muscle were taken using computed tomography scans of the lumbar spine. We then stratified patients into tertiles based on the psoas muscle area. RESULTS: We identified 118 patients, with a median survival of 104 days (95% confidence interval [CI]=73-157 days). Overall survival was not associated with age, chemotherapy, or number of levels radiated. Patients in the lowest tertile of psoas size had significantly shorter survival compared with the highest tertile (68 days versus 148 days, hazard ratio 1.76 [95% CI=1.08-2.89], p=.024). The shorter survival was also true for the lowest tertile versus the middle tertile (68 days versus 167 days, hazard ratio 1.95 [95% CI=1.19-3.19], p=.007). Kaplan-Meier survival curves were used to visually illustrate the differences in survival between different tertiles. CONCLUSIONS: Morphometric analysis of the psoas muscle size in patients with breast cancer metastases to the spine was effective in identifying patients at risk of shorter survival. Further research is needed to validate these results, as well as to see if these methodologies can be applied to other cancer histologies.

Application of Morphometrics as a Predictor for Survival in Patients with Prostate Cancer Metastasis to the Spine.

BACKGROUND: Surgery for spinal metastases can improve survival but has high morbidity that can potentially diminish benefits. New objective methods of predicting overall survival would be beneficial for surgical decision making. Morphometrics quantifies patient frailty and has been successfully used to predict overall survival in patients with lung cancer spinal metastases. This study evaluated whether morphometrics can predict survival in patients with prostate cancer spinal metastases. METHODS: Using a retrospective registry of patients with spinal metastases who underwent stereotactic body radiation therapy, we identified patients with primary prostate cancer. Morphometric measurements of the psoas muscle were taken from most recent lumbar spine computed tomography. Patients were stratified into lowest, middle, and highest tertiles based on psoas muscle area. Primary outcome measure was overall survival from the date of computed tomography scan. RESULTS: We identified 92 patients. Median survival for all patients was 124 days (95% confidence interval, 98-197 days). Patients in the smallest third for average psoas size had significantly shorter survival compared with patients in the largest third: 117 days versus 302 days (hazard ratio 2.42; 95% confidence interval, 1.32-4.43; P = 0.004). Patients in the middle third for average psoas size also had shorter survival compared with patients in the largest third: 113 days versus 302 days (hazard ratio 2.31; 95% confidence interval, 1.25-4.25; P = 0.007). CONCLUSIONS: In patients with prostate cancer spinal metastases, morphometric analysis of psoas muscle size can identify patients at risk for shorter survival. This technique can aid in surgical decision making by weighing expected survival and fitness versus potential morbidity of intervention.

Assessment of radiographic and clinical outcomes of an articulating expandable interbody cage in minimally invasive transforaminal lumbar interbody fusion for spondylolisthesis.

OBJECTIVE 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.

Lateral Atlantoaxial Osteoarthritis: A Narrative Literature Review.

Lateral atlantoaxial osteoarthritis (AAOA), or C1-C2 lateral mass arthritis (LMA), is an unfamiliar degenerative cervical disease with a clinical presentation that markedly differs from subaxial spondylosis. The prevalence of LMA in the nonsurgical outpatient setting is 4%. Risk factors include age and occupation. The typical patient is between 50 and 90 years old, presents with upper cervical or occipital pain, has limited rotation, and has pain provocation during passive rotation to the affected side. Pain stems from degeneration of the lateral C1-C2 articulation and may be referred or radicular, through the greater occipital nerve. Although there is no consensus on diagnostic work-up, the disease is classically seen on the open-mouth odontoid radiograph. Computerized tomography, magnetic resonance imaging, bone scan, and diagnostic injections are also useful. Initial treatment is conservative, and upwards of two-thirds of LMA patients obtain lasting relief with noninvasive measures and injections. In patients with severe, recalcitrant pain, limited C1-C2 fusion offers satisfactory and reliable relief. The goals of this review article are to provide a synthesis of the literature on LMA, to offer a treatment approach to LMA, and to identify problems with the current state of knowledge on LMA.

Management of perisylvian arteriovenous malformations: a retrospective institutional case series and review of the literature.

OBJECT: Sylvian arteriovenous malformations (sAVMs) are challenging lesions of the central nervous system. The natural history of these unique lesions as well as clinical outcomes following treatment of sAVMs has been limited to case series owing to the rarity of these lesions. The authors present their experience with sAVMs and review the literature. METHODS: In accordance with the Henry Ford Institutional Review Board, medical records of patients with sAVMs treated from 2000 to 2012 were reviewed. Clinical data were retrospectively collected to calculate pre- and posttreatment modified Rankin Scale scores for all patients. RESULTS: The authors identified 15 patients with sAVMs who received treatment. Of these, 12 were female and 3 were male, and the average age at presentation was 39.6 ± 12.94 years (± SD). Two patients (13.3%) had Spetzler-Martin Grade I lesions, 6 patients (40%) had Grade II lesions, 5 patients (33.3%) had Grade III lesions, and another 2 (13.3%) harbored Grade IV arteriovenous malformations (AVMs). According to the Sugita classification, 6 patients (40%) had medial lesions, 6 (40%) had lateral lesions, 2 (13.3%) had deep lesions, and 1 patient (6.67%) had a pure sAVM. Eight patients (53.3%) underwent stereotactic radiosurgery while 7 patients (46.7%) had microsurgical resection; 1 patient underwent surgical extirpation after incomplete response following radiosurgery. After treatment, 9 patients were unchanged from pretreatment (60%), 3 patients worsened, and 2 patients had improved functional outcome (20% and 13.3%, respectively). The authors' literature search yielded 348 patients with sAVMs, most of them harboring Spetzler-Martin Grade II and III lesions. Approximately 98% of the patients underwent resection with excellent outcomes. CONCLUSIONS: While the ideal choice of therapeutic modality for cerebral AVMs remains controversial in light of the recent publication of the ARUBA (A Randomized trial of Unruptured Brain AVMs) trial, a multidisciplinary treatment approach for the management of sAVMs can lead to acceptable neurological outcome.