Paul W. Millhouse

Anterior lumbar spine surgery: a systematic review and meta-analysis of associated complications

BACKGROUND CONTEXT The anterior approach to the lumbar spine is increasingly used to accomplish various surgical procedures. However, the incidence and risk factors for complications associated with anterior lumbar spine surgery (ALS) have not been fully elucidated. PURPOSE To identify and document types of complications and complication rates associated with ALS, determine risk factors for these events, and evaluate the effect of measures used to decrease complication rates. STUDY DESIGN Systematic review and meta-analysis. METHODS A systematic review of the English-language literature was conducted for articles published between January 1992 and December 2013. A MEDLINE search was conducted to identify articles reporting complications associated with ALS. For each complication, the data were combined using a generalized linear mixed model with a binomial probability distribution and a random effect based on the study. Predictors used were the type of procedure (open, minimally invasive, or laparoscopic), the approach used (transperitoneal vs. retroperitoneal), use of recombinant bone morphogenetic protein-2, use of preoperative computed tomography angiography (CTA), and the utilization of an access surgeon. Open surgery was used as a reference category. RESULTS Seventy-six articles met final inclusion criteria and reported complication rates in 11,410 patients who underwent arthrodesis and/or arthroplasty via laparoscopic, mini-open, and open techniques. The overall complication rate was 14.1%, with intraoperative and postoperative complication rates of 9.1% and 5.2%, respectively. Only 3% of patients required reoperation or revision procedures. The most common complications reported were venous injury (3.2%), retrograde ejaculation (2.7%), neurologic injury (2%), prosthesis related (2%), postoperative ileus (1.4%), superficial infection (1%), and others (1.3%). Laparoscopic and transperitoneal procedures were associated with higher complication rates, whereas lower complication rates were observed in patients receiving mini-open techniques. Our analysis indicated that the use of recombinant bone morphogenetic protein-2 was associated with increased rates of retrograde ejaculation; however, there may be limitations in interpreting these data. Data regarding the use of preoperative CTA and an access surgeon were limited and demonstrated mixed benefit. CONCLUSIONS Overall complication rates with ALS are relatively low, with the most common complications occurring at a rate of 1% to 3%. Complication rates are related to surgical technique, approach, and implant characteristics. Further randomized controlled trials are needed to validate the use of preventative measures including CTA and the use of an access surgeon.

L5/S1 Fusion Rates in Degenerative Spine Surgery: A Systematic Review Comparing ALIF, TLIF, and Axial Interbody Arthrodesis.

Study Design:Systematic review. Objective:To determine the fusion rate of an anterior lumbar interbody fusion (ALIF), transforaminal lumbar interbody fusion (TLIF), and axial arthrodesis at the lumbosacral junction in adult patients undergoing surgery for 1- and 2-level degenerative spine conditions. Summary of Background Data:An L5/S1 interbody fusion is a commonly performed procedure for pathology such as spondylolisthesis with stenosis; however, it is unclear if 1 technique leads to superior fusion rates. Materials and Methods:A systematic search of MEDLINE was conducted for literature published between January 1, 1992 and August 17, 2014. All peer-reviewed articles related to the fusion rate of L5/S1 for an ALIF, TLIF, or axial interbody fusion were included. Results:In total, 42 articles and 1507 patients were included in this systematic review. A difference in overall fusion rates was identified, with a rate of 99.2% (range, 96.4%–99.8%) for a TLIF, 97.2% (range, 91.0%–99.2%) for an ALIF, and 90.5% (range, 79.0%–97.0%) for an axial interbody fusion (P=0.005). In a paired analysis directly comparing fusion techniques, only the difference between a TLIF and an axial interbody fusion was significant. However, when only cases in which bilateral pedicle screws supported the interbody fusion, no statistical difference (P>0.05) between the 3 techniques was identified. Conclusions:The current literature available to guide the treatment of L5/S1 pathology is poor, but the available data suggest that a high fusion rate can be expected with the use of an ALIF, TLIF, or axial interbody fusion. Any technique-dependent benefit in fusion rate can be eliminated with common surgical modifications such as the use of bilateral pedicle screws.

Bone substitutes and expanders in Spine Surgery: A review of their fusion efficacies

Study Design A narrative review of literature. Objective This manuscript intends to provide a review of clinically relevant bone substitutes and bone expanders for spinal surgery in terms of efficacy and associated clinical outcomes, as reported in contemporary spine literature. Summary of Background Data Ever since the introduction of allograft as a substitute for autologous bone in spinal surgery, a sea of literature has surfaced, evaluating both established and newly emerging fusion alternatives. An understanding of the available fusion options and an organized evidence-based approach to their use in spine surgery is essential for achieving optimal results. Methods A Medline search of English language literature published through March 2016 discussing bone graft substitutes and fusion extenders was performed. All clinical studies reporting radiological and/or patient outcomes following the use of bone substitutes were reviewed under the broad categories of Allografts, Demineralized Bone Matrices (DBM), Ceramics, Bone Morphogenic proteins (BMPs), Autologous growth factors (AGFs), Stem cell products and Synthetic Peptides. These were further grouped depending on their application in lumbar and cervical spine surgeries, deformity correction or other miscellaneous procedures viz. trauma, infection or tumors; wherever data was forthcoming. Studies in animal populations and experimental in vitro studies were excluded. Primary endpoints were radiological fusion rates and successful clinical outcomes. Results A total of 181 clinical studies were found suitable to be included in the review. More than a third of the published articles (62 studies, 34.25%) focused on BMP. Ceramics (40 studies) and Allografts (39 studies) were the other two highly published groups of bone substitutes. Highest radiographic fusion rates were observed with BMPs, followed by allograft and DBM. There were no significant differences in the reported clinical outcomes across all classes of bone substitutes. Conclusions There is a clear publication bias in the literature, mostly favoring BMP. Based on the available data, BMP is however associated with the highest radiographic fusion rate. Allograft is also very well corroborated in the literature. The use of DBM as a bone expander to augment autograft is supported, especially in the lumbar spine. Ceramics are also utilized as bone graft extenders and results are generally supportive, although limited. The use of autologous growth factors is not substantiated at this time. Cell matrix or stem cell-based products and the synthetic peptides have inadequate data. More comparative studies are needed to evaluate the efficacy of bone graft substitutes overall.

Variation in the management of thoracolumbar trauma and postoperative infection.

Study Design: Multinational survey of spine trauma surgeons. Objectives: To survey spine trauma surgeons, examine the variety of management practices for thoracolumbar fractures, and investigate the need for future areas of study. Background: Attempts to develop a universal thoracolumbar classification system represent the first step in standardizing treatment of thoracolumbar injuries, but there is little consensus regarding diagnosis and management of these injuries. Methods: A survey questionnaire regarding a fictional neurologically intact patient with a burst fracture was administered to 46 spine surgeons. The questionnaire consisted of 2 domains: management of thoracolumbar fractures and management of postoperative infection. Survey results were compiled and evaluated and consensus arbitrarily assumed when the majority of surgeons agreed on a single question answer. Results: Although majority consensus was reached on most questions, the interobserver reliability was poor. Consensus was achieved that magnetic resonance imaging should be performed during initial imaging. The majority would also operate regardless of magnetic resonance imaging findings, and would not operate at night. The favored technique was a posterior approach with decompression. Percutaneous fusion was considered a viable option by the majority of surgeons. No consensus was reached regarding instrumentation levels or construct length. The majority would use posterolateral bone grafting, and would not remove instrumentation nor perform an anterior reconstruction. Consensus was reached that postoperative bracing is unnecessary. Regarding management of infection, consensus was reached to use intraoperative vancomycin powder but not culture the nares before surgery. The majority used a set time period for antibiotic treatment when a drain was required, and would not apply supplementary bone graft at the time of final debridement and closure. Conclusions: There is lack of consensus regarding the appropriate management of thoracolumbar fractures. In the future, multicenter prospective studies are necessary to establish guidelines for the management of thoracolumbar fractures.

Diagnosis and neurologic status as predictors of surgical site infection in primary cervical spinal surgery.

BACKGROUND CONTEXT Surgical site infection (SSI) incidence after cervical spinal surgery ranges from 0.1% to 17%. Although the general risk factors for SSI have been discussed, the relationship of neurologic status and trauma to SSI has not been explicitly explored. PURPOSE This study aimed to study associated risk factors and to report the incidence of SSI in patients who have undergone cervical spinal surgery with the following four preoperative diagnoses: (1) degenerative disease with no myelopathy (MP), (2) degenerative disease with MP, (3) traumatic cervical injury without spinal cord injury (SCI), (4) traumatic cervical injury with SCI. We hypothesize that SSI incidence would increase from Group (1) to Group (4). STUDY DESIGN Retrospective database analysis was carried out. PATIENTS SAMPLE We used International Classification of Diseases codes to identify the four groups of patients in the U.S. Nationwide Inpatient Sample (NIS) from the years 2000 to 2011. We complemented this study with a similar search in our institutional database (ID) from the years 2000 to 2013. Patients with concomitant congenital deformity, infection, inflammatory disease, and neoplasia were excluded, as were revision surgeries. OUTCOME MEASURES The primary outcome studied was the occurrence of SSI. Statistical analyses included bivariate comparisons and chi-square distribution of demographic data and multivariable regression for demographic, surgical, and outcome variables. RESULTS A total of 1,247,281 and 5,540 patients met inclusion criteria in the NIS database and the ID, respectively. Overall SSI incidence was 0.73% (NIS) versus 1.75% (ID). Surgical site infection incidence increased steadily from 0.52% in Group (1) to 1.97% in Group (4) in the NIS data and from 0.88% to 5.54% in the ID. Differences between diagnostic groups and cohorts reached statistical significance. Surgical site infection was predicted significantly by status (odds ratio [OR] 1.69, p<.0001) and trauma (OR 1.30, p=.0003) in the NIS data. Other significant predictors included the following: approach, number of levels fused, female gender, black race, medium size hospital, rural hospital, large hospital, western US hospital and Medicare coverage. In the ID, only trauma (OR 2.11, p=.03) reached significance when accounting for comorbidities. CONCLUSIONS Both primary diagnosis (trauma vs. degenerative) and neurologic status (MP or SCI) were found to be strong and independent predictors of SSI in cervical spine surgery.

Lateral Mass Fixation in the Subaxial Cervical Spine.

The use of lateral mass screws and rods in the subaxial spine has become the standard method of fixation for posterior cervical spine fusions. Multiple techniques have been described for the placement of lateral mass screws, including the Magerl, the Anderson, and the An techniques. While these techniques are all slightly different, the overall goal is to obtain solid bony fixation while avoiding the neurovascular structures. The use of lateral mass screws has been shown to be a safe and effective technique for achieving a posterior cervical fusion.

Managing the Delivery of Health Care: What Can Health Care Learn From the Business Community?

The passage of the Patient Protection and Affordable Care Act in March 2010 has resulted in dramatic changes to the delivery of health care in the United States toward a value-based system. While this is a significant change from the previous model, it presents an opportunity for high-quality health care providers to improve patient outcomes while also increasing revenue. However, those that lack a clear strategy to effectively implement change and communicate the increased value to the patients likely will suffer, regardless of how successful or prestigious they seem today.

The Role of Strategy in Health Care.

Significant changes are occurring in the health care field, and spine surgeons must have an understanding of business strategy if they are going to adapt to the new health care environment. Spine surgeons will be required to demonstrate how their service provides a unique value to their patients or else the patients will obtain care from competitors. Classic methods for demonstrating value such as academic prestige and superior clinical outcomes may no longer be sufficient in the evolving health care field, and surgeons will need to demonstrate a comprehensive and cost-effective treatment algorithm for a diagnosis. This article will discuss the basics of business strategy for the spine surgeon, and ways in which the surgeon may demonstrate value to their patients.

Magnetic Resonance Imaging Following Spine Trauma

Magnetic resonance imaging (MRI) provides high-resolution images without ionizing radiation. It has substantially improved our diagnostic capability following spine trauma, especially for assessing soft-tissue structures. Strong, changing magnetic fields are used to generate cross-sectional images on the basis of the anatomy and chemical composition of the tissues. Nevertheless, compared with radiographs and computed tomography (CT) scans, MRI has several disadvantages, including inadequate visualization of bones, the considerable amount of time required for the procedure (rendering this method impractical in emergency situations), logistical considerations (including the availability of infrastructure and skilled technicians and the necessity for patient transfer), and high cost. Moreover, MRI is routinely performed with the patient in the supine position and therefore may not detect instability associated with loading (upright) positions. Finally, MRI is contraindicated for patients …

Guidelines on What Constitutes Plagiarism and Electronic Tools to Detect it.

Plagiarism is a serious ethical problem among scientific publications. There are various definitions of plagiarism, and the major categories include unintentional (unsuitable paraphrasing or improper citations) and intentional. Intentional plagiarism includes mosaic plagiarism, plagiarism of ideas, plagiarism of text, and self-plagiarism. There are many Web sites and software packages that claim to detect plagiarism effectively. A violation of plagiarism laws can lead to serious consequences including author banning, loss of professional reputation, termination of a position, and even legal action.