Peter G. Campbell and James J. Evans
Peter G. Campbell, David A. Cavanaugh, Pierce Nunley, Philip A. Utter, Eubulus Kerr, Rishi Wadhwa, and Marcus Stone
The authors have provided a review of radiographic subsidence after lateral lumbar interbody fusion (LLIF) as a comparative analysis between titanium and polyetheretherketone (PEEK) cages. Many authors describe a reluctance to use titanium cages in spinal fusion secondary to subsidence concerns due to the increased modulus of elasticity of metal cages. The authors intend for this report to provide observational data regarding the juxtaposition of these two materials in the LLIF domain.
A retrospective review of a prospectively maintained database identified 113 consecutive patients undergoing lateral fusion for degenerative indications from January to December 2017. The surgeons performing the cage implantations were two orthopedic spine surgeons and two neurosurgeons. Plain standing radiographs were obtained at 1–2 weeks, 8–12 weeks, and 12 months postoperatively. Using a validated grading system, interbody subsidence into the endplates was graded at these time points on a scale of 0 to III. The primary outcome measure was subsidence between the two groups. Secondary outcomes were analyzed as well.
Of the 113 patients in the sample, groups receiving PEEK and titanium implants were closely matched at 57 and 56 patients, respectively. Cumulatively, 156 cages were inserted and recombinant human bone morphogenetic protein–2 (rhBMP-2) was used in 38.1%. The average patient age was 60.4 years and average follow-up was 75.1 weeks. Subsidence in the titanium group in this study was less common than in the PEEK cage group. At early follow-up, groups had similar subsidence outcomes. Statistical significance was reached at the 8- to 12-week and 52-week follow-ups, demonstrating more subsidence in the PEEK cage group than the titanium cage group. rhBMP-2 usage was also highly correlated with higher subsidence rates at all 3 follow-up time points. Age was correlated with higher subsidence rates in univariate and multivariate analysis.
Titanium cages were associated with lower subsidence rates than PEEK cages in this investigation. Usage of rhBMP-2 was also robustly associated with higher endplate subsidence. Each additional year of age correlated with an increased subsidence risk. Subsidence in LLIF is likely a response to a myriad of factors that include but are certainly not limited to cage material. Hence, the avoidance of titanium interbody implants secondary solely to concerns over a modulus of elasticity likely overlooks other variables of equal or greater importance.
Peter G. Campbell, Pascal Jabbour, Sanjay Yadla, and Issam A. Awad
Cerebral cavernous malformations (CCMs) are divided into sporadic and familial forms. For clinical imaging, T2-weighted gradient-echo sequences have been shown to be more sensitive than conventional sequences. Recently more advanced imaging techniques such as high-field and susceptibility-weighted MR imaging have been employed for the evaluation of CCMs. Furthermore, diffusion tensor imaging and functional MR imaging have been applied to the preoperative and intraoperative management of these lesions. In this paper, the authors attempt to provide a concise review of the emerging imaging methods used in the clinical diagnosis and treatment of CCMs.
Sonia G. Teufack, Peter Campbell, Pascal Jabbour, Mitchell Maltenfort, James Evans, and John K. Ratliff
The Centers for Medicare and Medicaid Services (CMS) have moved to limit hospital augmentation of diagnosis-related group billing for “never events” (adverse events that are serious, largely preventable, and of concern to the public and health care providers for the purpose of public accountability) and certain hospital-acquired conditions (HACs). Similar restrictions may be applied to physician billing. The financial impact of these restrictions may fall on academic medical centers, which commonly have populations of complex patients with a higher risk of HACs. The authors sought to quantify the potential financial impact of restrictions in never events and periprocedural HAC billing on a tertiary neurosurgery facility.
Operative cases treated between January 2008 and June 2008 were reviewed after searching a prospectively maintained database of perioperative complications. The authors assessed cases in which there was a 6-month lag time to allow for completion of hospital and physician billing. They speculated that other payers would soon adopt the present CMS restrictions and that procedure-related HACs would be expanded to cover common neurosurgery procedures. To evaluate the impact on physician billing and to directly contrast physician and hospital billing impact, the authors focused on periprocedural HACs, as opposed to entire admission HACs. Billing records were compiled and a comparison was made between individual event data and simultaneous cumulative net revenue and net receipts. The authors assessed the impact of the present regulations, expansion of CMS restrictions to other payers, and expansion to rehospitalization and entire hospitalization case billing due to HACs and never events.
A total of 1289 procedures were completed during the examined period. Twenty-five procedures (2%) involved patients in whom HACs developed; all were wound infections. Twenty-nine secondary procedures were required for this cohort. Length of stay was significantly higher in patients with HACs than in those without (11.6 ± 11.5 vs 5.9 ± 7.0 days, respectively). Fifteen patients required readmission due to HACs. Following present never event and HAC restrictions, hospital and physician billing was minimally affected (never event billing as percent total receipts was 0.007% for hospitals and 0% for physicians). Nonpayment for rehospitalization and reoperation for HACs by CMS and private payers yielded greater financial impact (CMS only, percentage of total receipts: 0.14% hospital, 0.2% physician; all payers: 1.56% hospital, 3.0% physician). Eliminating reimbursement for index procedures yielded profound reductions (CMS only as percentage of total receipts: 0.62% hospital, 0.8% physician; all payers: 5.73% hospital, 8.9% physician).
The authors found potentially significant reductions in physician and facility billing. The expansion of never event and HACs reimbursement nonpayment may have a substantial financial impact on tertiary care facilities. The elimination of never events and reduction in HACs in current medical practices are worthy goals. However, overzealous application of HACs restrictions may remove from tertiary centers the incentive to treat high-risk patients.
Peter G. Campbell, Sanjay Yadla, Jennifer Malone, Mitchell G. Maltenfort, James S. Harrop, Ashwini D. Sharan, and John K. Ratliff
Prospective examination of perioperative complications in spine surgery is limited in the literature. The authors prospectively collected data on patients who underwent spinal fusion at a tertiary care center and evaluated the effect of spinal fusion and comorbidities on perioperative complications.
Between May and December 2008 data were collected prospectively in 248 patients admitted to the authors' institution for spine surgery. The 202 patients undergoing spine surgery with instrumentation were further analyzed in this report. Perioperative complications occurring within the initial 30 days after surgery were included. All adverse occurrences, whether directly related to surgery, were included in the analysis.
Overall, 114 (56.4%) of 202 patients experienced at least one perioperative complication. Instrumented fusions were associated with more minor complications (p = 0.001) and more overall complications (0.0024). Furthermore, in the thoracic and lumbar spine, complications increased based on the number of levels fused. Advanced patient age and certain comorbidities such as diabetes, cardiac disease, or a history of malignancy were also associated with an increased incidence of complications.
Using a prospective methodology with a broad definition of complications, the authors report a significantly higher perioperative incidence of complications than previously indicated after spinal fusion procedures. Given the increased application of instrumentation, especially for degenerative disease, a better estimate of clinically relevant surgical complications could aid spine surgeons and patients in an individualized complication index to facilitate a more thorough risk-benefit analysis prior to surgery.
Peter G. Campbell, Sanjay Yadla, Rani Nasser, Jennifer Malone, Mitchell G. Maltenfort, and John K. Ratliff
Present attempts to control health care costs focus on reducing the incidence of complications and hospital-acquired conditions (HACs). One approach uses restriction or elimination of hospital payments for HACs. Present approaches assume that all HACs are created equal and that payment restrictions should be applied uniformly. Patient factors, and especially patient comorbidities, likely impact complication incidence. The relationship of patient comorbidities and complication incidence in spine surgery has not been prospectively reported.
The authors conducted a prospective assessment of complications in spine surgery during a 6-month period; an independent auditor and a validated definition of perioperative complications were used. Initial demographics captured relevant patient comorbidities. The authors constructed a model of relative risk assessment based on the presence of a variety of comorbidities. They examined the impact of specific comorbidities and the cumulative effect of multiple comorbidities on complication incidence.
Two hundred forty-nine patients undergoing 259 procedures at a tertiary care facility were evaluated during the 6-month duration of the study. Eighty percent of the patients underwent fusion procedures. One hundred thirty patients (52.2%) experienced at least 1 complication, with major complications occurring in 21.4% and minor complications in 46.4% of the cohort. Major complications doubled the median duration of hospital stay, from 6 to 12 days in cervical spine patients and from 7 to 14 days in thoracolumbar spine patients. At least 1 comorbid condition was present in 86% of the patients. An increasing number of comorbidities strongly correlated with increased risk of major, minor, and any complications (p = 0.017, p < 0.0001, and p < 0.0001, respectively). Patient factors correlating with increased risk of specific complications included systemic malignancy and cardiac conditions other than hypertension.
Comorbidities significantly increase the risk of perioperative complications. An increasing number of comorbidities in an individual patient significantly increases the risk of a perioperative adverse event. Patient factors significantly impact the relative risk of HACs and perioperative complications.
Cheerag D. Upadhyaya and Praveen V. Mumaneni
Sanjay Yadla, Jennifer Malone, Peter G. Campbell, Mitchell G. Maltenfort, James S. Harrop, Ashwini D. Sharan, and John K. Ratliff
The reported incidence of complications in spine surgery varies widely. Variable study methodologies may open differing avenues for potential bias, and unclear definitions of perioperative complication make analysis of the literature challenging. Although numerous studies have examined the morbidity associated with specific procedures or diagnoses, no prospective analysis has evaluated the impact of preoperative diagnosis on overall early morbidity in spine surgery. To accurately assess perioperative morbidity in patients undergoing spine surgery, a prospective analysis of all patients who underwent spine surgery by the neurosurgical service at a large tertiary care center over a 6-month period was conducted. The correlation between preoperative diagnosis and the incidence of postoperative complications was assessed.
Data were prospectively collected on 248 consecutive patients undergoing spine surgery performed by the neurosurgical service at the Thomas Jefferson University Hospital from May to December 2008. A standardized definition of minor and major complications was applied to all adverse events occurring within 30 days of surgery. Data on diagnosis, complications, and length of stay were retrospectively assessed using stepwise multivariate analysis. Patients were analyzed by preoperative diagnosis (neoplasm, infection, degenerative disease, trauma) and level of surgery (cervical or thoracolumbar).
Total early complication incidence was 53.2%, with a minor complication incidence of 46.4% and a major complication incidence of 21.3%. Preoperative diagnosis correlated only with the occurrence of minor complications in the overall cohort (p = 0.02). In patients undergoing surgery of the thoracolumbar spine, preoperative diagnosis correlated with presence of a complication and the number of complications (p = 0.003). Within this group, patients with preoperative diagnoses of infection and neoplasm were more often affected by isolated and multiple complications (p = 0.05 and p = 0.02, respectively). Surgeries across the cervicothoracic and thoracolumbar junctions were associated with higher incidences of overall complication than cervical or lumbar surgery alone (p = 0.04 and p = 0.03, respectively). Median length of stay was 5 days for patients without a complication. Length of stay was significantly greater for patients with a minor complication (10 days, p < 0.0001) and even greater for patients with a major complication (14 days, p < 0.0001).
The incidence of complications found in this prospective analysis is higher than that reported in previous studies. This association may be due to a greater accuracy of record-keeping, absence of recall bias via prospective data collection, high complexity of pathology and surgical approaches, or application of a more liberal definition of what constitutes a complication. Further large-scale prospective studies using clear definitions of complication are necessary to ascertain the true incidence of early postoperative complications in spine surgery.
Sanjay Yadla, George M. Ghobrial, Peter G. Campbell, Mitchell G. Maltenfort, James S. Harrop, John K. Ratliff, and Ashwini D. Sharan
Complications after spine surgery have an impact on overall outcome and health care expenditures. The increased cost of complications is due in part to associated prolonged hospital stays. The authors propose that certain complications have a greater impact on length of stay (LOS) than others and that those complications should be the focus of future targeted prevention efforts. They conducted a retrospective analysis of a prospectively maintained database to identify complications with the greatest impact on LOS as well as the predictive value of these complications with respect to 90-day readmission rates.
Data on 249 patients undergoing spine surgery at Thomas Jefferson University from May to December 2008 were collected by a study auditor. Any complications occurring within 30 days of surgery were recorded as was overall LOS for each patient. Stepwise regression analysis was performed to determine whether specific complications had a statistically significant effect on LOS. For correlation, all readmissions within 90 days were recorded and organized by complication for comparison with those complications affecting LOS.
The mean LOS for patients without postoperative complications was 6.9 days. Patients who developed pulmonary complications had an associated increase in LOS of 11.1 days (p < 0.005). The development of a urinary tract infection (UTI) was associated with an increase in LOS of 3.4 days (p = 0.002). A new neurological deficit was associated with an increase in LOS of 8.2 days (p = 0.004). Complications requiring return to the operating room (OR) showed a trend toward an increase in LOS of 4.7 days (p = 0.09), as did deep wound infections (3.3 days, p = 0.08). The most common reason for readmission was for wound drainage (n = 21; surgical drainage was required in 10 [4.01%] of these 21 cases). The most common diagnoses for readmission, in decreasing order of incidence, were categorized as hardware malpositioning (n = 4), fever (n = 4), pulmonary (n = 2), UTI (n = 2), and neurological deficit (n = 1). Complications affecting LOS were not found to be predictive of readmission (p = 0.029).
Postoperative complications in patients who have undergone spine surgery are not uncommon and are associated with prolonged hospital stays. In the current cohort, the occurrence of pulmonary complications, UTI, and new neurological deficit had the greatest effect on overall LOS. Further study is required to determine the causative factors affecting readmission. These specific complications may be high-yield targets for cost reduction and/or prevention efforts.
Peter G. Campbell, Pierce D. Nunley, David Cavanaugh, Eubulus Kerr, Philip Andrew Utter, Kelly Frank, and Marcus Stone
Recently, authors have called into question the utility and complication index of the lateral lumbar interbody fusion procedure at the L4–5 level. Furthermore, the need for direct decompression has also been debated. Here, the authors report the clinical and radiographic outcomes of transpsoas lumbar interbody fusion, relying only on indirect decompression to treat patients with neurogenic claudication secondary to Grade 1 and 2 spondylolisthesis at the L4–5 level.
The authors conducted a retrospective evaluation of 18 consecutive patients with Grade 1 or 2 spondylolisthesis from a prospectively maintained database. All patients underwent a transpsoas approach, followed by posterior percutaneous instrumentation without decompression. The Oswestry Disability Index (ODI) and SF-12 were administered during the clinical evaluations. Radiographic evaluation was also performed. The mean follow-up was 6.2 months.
Fifteen patients with Grade 1 and 3 patients with Grade 2 spondylolisthesis were identified and underwent fusion at a total of 20 levels. The mean operative time was 165 minutes for the combined anterior and posterior phases of the operation. The estimated blood loss was 113 ml. The most common cage width in the anteroposterior dimension was 22 mm (78%). Anterior thigh dysesthesia was identified on detailed sensory evaluation in 6 of 18 patients (33%); all patients experienced resolution within 6 months postoperatively. No patient had lasting sensory loss or motor deficit. The average ODI score improved 26 points by the 6-month follow-up. At the 6-month follow-up, the SF-12 mean Physical and Mental Component Summary scores improved by 11.9% and 9.6%, respectively. No patient required additional decompression postoperatively.
This study offers clinical results to establish lateral lumbar interbody fusion as an effective technique for the treatment of Grade 1 or 2 degenerative spondylolisthesis at L4–5. The use of this surgical approach provides a minimally invasive solution that offers excellent arthrodesis rates as well as favorable clinical and radiological outcomes, with low rates of postoperative complications. However, adhering to the techniques of transpsoas lateral surgery, such as minimal table break, an initial look-and-see approach to the psoas, clear identification of the plexus, minimal cranial caudal expansion of the retractor, mobilization of any traversing sensory nerves, and total psoas dilation times less than 20 minutes, ensures the lowest possible complication profile for both visceral and neural injuries even in the narrow safe zones when accessing the L4–5 disc space in patients with degenerative spondylolisthesis.