Mazda K. Turel, Mena G. Kerolus, Owoicho Adogwa, and Vincent C. Traynelis
The aim of this paper was to comprehensively review each of the Food and Drug Administration (FDA)–approved labels of 7 total cervical disc replacements, assess the exact methodology in which the trial was conducted, and provide a broad comparison of these devices to allow each surgeon to determine which disc best suits his or her specific treatment goals based on the specific labels and not the studies published.
The FDA-approved labels for each of the 7 artificial discs were obtained from the official FDA website. These labels were meticulously compared with regard to the statistical analysis performed, the safety and efficacy data, and the randomized controlled trial that each artificial disc was involved in to obtain the FDA approval for the product or device. Both single-level and 2-level approvals were examined, and primary and secondary end points were assessed.
In the single-level group, 4 of the 7 artificial discs—Prestige LP, Prestige ST, Bryan, and Secure-C—showed superiority in overall success. Prestige ST showed superiority in 3 of 4 outcome measures (neurological success, revision surgery, and overall success), while the other aforementioned discs showed superiority in 2 or fewer measures (Prestige LP, neurological and overall success; Bryan, Neck Disability Index [NDI] and overall success; Secure-C, revision surgery and overall success; Pro-Disc C, revision surgery). The PCM and Mobi-C discs demonstrated noninferiority across all outcome measures. In the 2-level group, Prestige LP and Mobi-C demonstrated superiority in 3 outcome measures (NDI, secondary surgery, and overall success) but not neurological success.
This paper provides a comprehensive analysis of 7 currently approved and distributed artificial discs in the United States. It compares specific outcome measures of these devices against those following the standard of care, which is anterior cervical discectomy and fusion. This information will provide surgeons the opportunity to easily answer patients' questions and remain knowledgeable when discussing devices with manufacturers.
Daniel B. Loriaux, Owoicho Adogwa, and Oren N. Gottfried
A true adult spinal lipoma is an exceedingly rare cause of lumbar compression neuropathy. Only 5 cases of true extradural intraforaminal lipomas have been documented in the medical literature. The diagnostic criteria and treatment guidelines for this specific lipoma have yet to be established. This report features 3 histologically confirmed cases of extradural intraforaminal spinal lipomas that recently presented to the authors’ practice. In addition, the literature was surveyed to include the 5 previously reported cases of true adult extradural intraforaminal spinal lipomas. The consistency in presentation, response to surgical intervention, and postoperative recovery in these 8 cases supports surgical intervention at the time of diagnosis. The authors’ findings support elevated clinical suspicion, efficient diagnosis based on MRI, and early surgical intervention for this rare pathological entity. All cases presented in this report were symptomatic and occurred in the absence of other significant pathologies such as general spinal epidural lipomatosis, intradural lesions, tethering, or severe degenerative stenosis or herniated discs. The clinical, neuroradiological, and histological findings characteristic of a true adult extradural intraforaminal lipoma are emphasized to differentiate this lesion from the more common etiologies for lumbar compression neuropathy. Heightened awareness and clinical suspicion for the focal, foraminal spinal lipoma as a cause of radiculopathy symptoms will enable more efficient diagnosis and treatment.
Christopher I. Shaffrey and Justin S. Smith
Syed I. Khalid, Ryan Kelly, Rita Wu, Akhil Peta, Adam Carlton, and Owoicho Adogwa
This study aims to assess the relationship of comorbidities and postoperative complications to rates of readmission for geriatric patients undergoing anterior cervical discectomy and fusion (ACDF) involving more than 2 levels on an inpatient or outpatient basis. With the rising costs of healthcare in the United States, understanding the safety and efficacy of performing common surgical interventions (including ACDF) as outpatient procedures could prove to be of great economic impact.Objective This study aims to assess the effect of comorbidities and postoperative complications on the rates of readmission of geriatric patients undergoing multilevel anterior cervical discectomy and fusion (ACDF) procedures (i.e., ACDF involving 3 or more levels) on an inpatient or outpatient basis. Same-day surgery has been demonstrated to be a safe and cost-effective alternative to the traditional inpatient option for many surgical interventions. With the rising costs of healthcare, understanding the safety and efficacy of performing common surgical interventions as outpatient procedures could prove to be of great economic impact.
The study population included total of 2492 patients: 2348 inpatients and 144 outpatients having ACDF procedures involving 3 or more levels in the Medicare Standard Analytical Files database. Age, sex, comorbidities, postoperative complications, readmission rates, and surgical procedure charges were compared between both cohorts. For selected variables, logistic regression was used to model odds ratios for various comorbidities against readmission rates for both inpatient and outpatient cohorts. Chi-square tests were also calculated to compare these comorbidities with readmission in each cohort.
Overall complication rates within 30 postoperative days were greater for inpatients than for outpatients (44.2% vs 12.5%, p < 0.001). More inpatients developed postoperative urinary tract infection (7.9% vs 0%, p < 0.001), and the inpatient cohort had increased risk of readmission with comorbidities of anemia (OR 1.52, p < 0.001), smoking (OR 2.12, p < 0.001), and BMI ≥ 30 (OR 1.43, p < 0.001). Outpatients had increased risk of readmission with comorbidities of anemia (OR 2.78, p = 0.047), diabetes mellitus type 1 or 2 (OR 3.25, p = 0.033), and BMI ≥ 30 (OR 3.95, p = 0.008). Inpatients also had increased readmission risk with a postoperative complication of surgical site infection (OR 2.38, p < 0.001). The average charges for inpatient multilevel ACDF were significantly higher than for multilevel ACDF performed on an outpatient basis ($12,734.27 vs $12,152.18, p = 0.0019).
This study suggests that ACDF surgery involving 3 or more levels performed as an outpatient procedure in the geriatric population may be associated with lower rates of readmissions, complications, and surgical charges.
Owoicho Adogwa, Isaac O. Karikari, Aladine A. Elsamadicy, Amanda R. Sergesketter, Diego Galan, and Keith H. Bridwell
Patient-reported outcomes (PROs) are often measured up to 2 years after surgery; however, prospective collection of longitudinal outcomes for 5 years postoperatively can be challenging due to lack of patient follow-up. The aim of this study was to determine whether PROs collected at 2-year follow-up accurately predict long-term PROs 5 years after complex spinal fusion (≥ 5 levels).
This was an ambispective study of 118 adult patients (≥ 18 years old) undergoing ≥ 5-level spinal arthrodesis to the sacrum with iliac fixation from January 2002 to December 2011. Patient demographics and radiographic parameters as well as intraoperative variables were collected. PRO instruments (Scoliosis Research Society [SRS]-22r function, self-image, mental health, pain, and Oswestry Disability Index [ODI]) were completed before surgery then at 2 and 5 years after surgery. Primary outcome investigated in this study was the correlation between SRS-22r domains and ODI collected at 2- and 5-year follow-up.
Of the 118 patients, 111 patients had baseline PROs, 105 patients had 2-year follow-up data, and 91 patients had 5-year follow-up PRO data with 72% undergoing revision surgery. The average pre- and postoperative major coronal curve Cobb angles for the cohort were 32.1° ± 23.7° and 19.8° ± 19.3°, respectively. There was a strong correlation between 2- and 5-year ODI (r2 = 0.80, p < 0.001) and between 2- and 5-year SRS-22r domains, including function (r2 = 0.79, p < 0.001), self-image (r2 = 0.82, p < 0.001), mental health (r2 = 0.77, p < 0.001), and pain (r2 = 0.79, p < 0.001). Of the PROs, ODI showed the greatest absolute change from baseline to 2- and 5-year follow-up (2-year Δ 17.6 ± 15.9; 5-year Δ 16.5 ± 19.9) followed by SRS-22r self-image (2-year Δ 1.4 ± 0.96; 5-year Δ 1.3 ± 1.0), pain (2-year Δ 0.94 ± 0.97; 5-year Δ 0.80 ± 1.0), function (2-year Δ 0.60 ± 0.62; 5-year Δ 0.49 ± 0.79), and mental health (2-year Δ 0.49 ± 0.77; 5-year Δ 0.38 ± 0.84).
Patient-reported outcomes collected at 2-year follow-up may accurately predict long-term PROs (5-year follow-up).
Owoicho Adogwa, Daniel R. Rubio, Jacob M. Buchowski, Alden D’Souza, Maksim A. Shlykov, and Jack W. Jennings
The population prevalence of non–small cell lung cancer (NSCLC) continues to increase; however, data are limited regarding the incidence rate of skeletal related events (SREs) (i.e., surgery to the spinal column, radiation to the spinal column, radiofrequency ablation, kyphoplasty/vertebroplasty, spinal cord compression, or pathological vertebral body fractures) and their impact on overall mortality. In this study, the authors sought to estimate the incidence rates of SREs in NSCLC patients and to quantify their impact on overall mortality.
This was a single-institution retrospective study of patients diagnosed with NSCLC between 2002 and 2014. The incidence rates for bone metastasis and subsequent SREs (per 1000 person-years) by time since lung cancer diagnosis were calculated and analyses were stratified separately for each histological type. Incidence rates for mortality at 1, 2, and 3 years from diagnosis stratified by the presence of SREs were also calculated. Kaplan-Meier survival curves were constructed to describe crude survival ratios in patients with spine metastasis and SREs and those with spine metastasis but without SREs. These curves were used to estimate the 1- and 2-year survival rates for each cohort.
We identified 320 patients with incident NSCLC (median follow-up 9.5 months). The mean ± SD age was 60.65 ± 11.26 years; 94.48% of patients were smokers and 60.12% had a family history of cancer. The majority of first-time SREs were pathological vertebral body compression fractures (77.00%), followed by radiation (35%), surgery (14%), and spinal cord compression (13.04%). Mortality rates were highest in NSCLC patients with spine metastasis who had at least 1 SRE. Stratifying by histological subtype, the incidence rate of mortality in patients with SRE was highest in the large cell cohort, 7.42 per 1000 person-years (95% CI 3.09–17.84 per 1000 person-years); followed by the squamous cell cohort, 2.49 per 1000 person-years (95% CI 1.87–3.32 per 1000 person-years); and lowest in the adenocarcinoma cohort, 1.68 per 1000 person-years (95% CI 1.46–1.94 per 1000 person-years). Surgery for decompression of neural structures and stabilization of the spinal column was required in 6% of patients.
SREs in NSCLC patients with bone metastasis are associated with an increased incidence rate of mortality.
Owoicho Adogwa, Scott L. Parker, Brandon J. Davis, Oran Aaronson, Clinton Devin, Joseph S. Cheng, and Matthew J. McGirt
Transforaminal lumbar interbody fusion (TLIF) for spondylolisthesis-associated back and leg pain is associated with improvement in pain, disability, and quality of life. However, given the rising health care costs associated with spinal fusion procedures and varying results of recent cost-utility studies, the cost-effectiveness of TLIF remains unclear. The authors set out to assess the comprehensive costs of TLIF at their institution and to determine its cost-effectiveness in the treatment of degenerative spondylolisthesis.
Forty-five patients undergoing TLIF for Grade I degenerative spondylolisthesis–associated back and leg pain after 6–12 months of conservative therapy were included. The authors assessed the 2-year back pain visual analog scale (VAS) score, leg pain VAS score, Oswestry Disability Index, and total back-related medical resource utilization, missed work, and health-state values (quality-adjusted life years [QALYs], calculated from EQ-5D with US valuation). Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). The mean total 2-year cost per QALY gained after TLIF was assessed.
Compared with preoperative health states reported after at least 6 months of medical management, a significant improvement in back pain VAS score, leg pain VAS score, and Oswestry Disability Index was observed 2 years after TLIF, with a mean 2-year gain of 0.86 QALYs. The mean ± SD total 2-year cost of TLIF was $36,836 ± $11,800 (surgery cost, $21,311 ± $2800; outpatient resource utilization cost, $3940 ± $2720; indirect cost, $11,584 ± $11,363). Transforaminal lumbar interbody fusion was associated with a mean 2-year cost per QALY gained of $42,854.
Transforaminal lumbar interbody fusion improved pain, disability, and quality of life in patients with degenerative spondylolisthesis–associated back and leg pain. The total cost per QALY gained for TLIF was $42,854 when evaluated 2 years after surgery with Medicare fees, suggesting that TLIF is a cost-effective treatment of lumbar spondylolisthesis.
Owoicho Adogwa, Aladine A. Elsamadicy, Victoria D. Vuong, Jared Fialkoff, Joseph Cheng, Isaac O. Karikari, and Carlos A. Bagley
Postoperative delirium is common in elderly patients undergoing spine surgery and is associated with a longer and more costly hospital course, functional decline, postoperative institutionalization, and higher likelihood of death within 6 months of discharge. Preoperative cognitive impairment may be a risk factor for the development of postoperative delirium. The aim of this study was to investigate the relationship between baseline cognitive impairment and postoperative delirium in geriatric patients undergoing surgery for degenerative scoliosis.
Elderly patients 65 years and older undergoing a planned elective spinal surgery for correction of adult degenerative scoliosis were enrolled in this study. Preoperative cognition was assessed using the validated Saint Louis University Mental Status (SLUMS) examination. SLUMS comprises 11 questions, with a maximum score of 30 points. Mild cognitive impairment was defined as a SLUMS score between 21 and 26 points, while severe cognitive impairment was defined as a SLUMS score of ≤ 20 points. Normal cognition was defined as a SLUMS score of ≥ 27 points. Delirium was assessed daily using the Confusion Assessment Method (CAM) and rated as absent or present on the basis of CAM. The incidence of delirium was compared in patients with and without baseline cognitive impairment.
Twenty-two patients (18%) developed delirium postoperatively. Baseline demographics, including age, sex, comorbidities, and perioperative variables, were similar in patients with and without delirium. The length of in-hospital stay (mean 5.33 days vs 5.48 days) and 30-day hospital readmission rates (12.28% vs 12%) were similar between patients with and without delirium, respectively. Patients with preoperative cognitive impairment (i.e., a lower SLUMS score) had a higher incidence of postoperative delirium. One- and 2-year patient reported outcomes scores were similar in patients with and without delirium.
Cognitive impairment is a risk factor for the development of postoperative delirium. Postoperative delirium may be associated with decreased preoperative cognitive reserve. Cognitive impairment assessments should be considered in the preoperative evaluations of elderly patients prior to surgery.
Scott L. Parker, Stephen K. Mendenhall, David N. Shau, Owoicho Adogwa, William N. Anderson, Clinton J. Devin, and Matthew J. McGirt
Spine surgery outcome studies rely on patient-reported outcome (PRO) measurements to assess treatment effect, but the extent of improvement in the numerical scores of these questionnaires lacks a direct clinical meaning. Because of this, the concept of a minimum clinically important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. As utilization of spinal fusion has increased over the past decade, so has the incidence of same-level recurrent stenosis following index lumbar fusion, which commonly requires revision decompression and fusion. The MCID remains uninvestigated for any PROs in the setting of revision lumbar surgery for this pathology.
In 53 consecutive patients undergoing revision surgery for same-level recurrent lumbar stenosis–associated back and leg pain, PRO measures of back and leg pain were assessed preoperatively and 2 years postoperatively, using the visual analog scale for back pain (VAS-BP) and leg pain (VAS-LP), Oswestry Disability Index (ODI), Physical and Mental Component Summary categories of the 12-Item Short Form Health Survey (SF-12 PCS and MCS) for quality of life, Zung Depression Scale (ZDS), and EuroQol-5D health survey (EQ-5D). Four established anchor-based MCID calculation methods were used to calculate MCID (average change; minimum detectable change; change difference; and receiver operating characteristic curve analysis) for 2 separate anchors (health transition index of the SF-36 and the satisfaction index).
All patients were available for 2-year PRO assessment. Two years after surgery, a significant improvement was observed for all PROs assessed. The 4 MCID calculation methods generated a range of MCID values for each of the PROs (VAS-BP 2.2–6.0, VAS-LP 3.9–7.5, ODI 8.2–19.9, SF-12 PCS 2.5–12.1, SF-12 MCS 7.0–15.9, ZDS 3.0–18.6, and EQ-5D 0.29–0.52). Each patient answered synchronously for the 2 anchors, suggesting both of these anchors are equally appropriate and valid for this patient population.
The same-level recurrent stenosis surgery-specific MCID is highly variable based on calculation technique. The “minimum detectable change” approach is the most appropriate method for calculation of MCIDs in this population because it was the only method to reliably provide a threshold above the 95% confidence interval of the unimproved cohort (greater than the measurement error). Based on this method, the MCID thresholds following neural decompression and fusion for symptomatic same-level recurrent stenosis are 2.2 points for VAS-BP, 5.0 points for VAS-LP, 8.2 points for ODI, 2.5 points for SF-12 PCS, 10.1 points for SF-12 MCS, 4.9 points for ZDS, and 0.39 QALYs for EQ-5D.