Cervical disc replacement - emerging equivalency to anterior cervical discectomy and fusion.

PURPOSE: Cervical disc replacement has become an acceptable alternative to anterior cervical fusion for the surgical treatment of cervical spine spondylosis resulting in radiculopathy or myelopathy following anterior discectomy and decompression. This concise overview considers the current state of knowledge regarding the continued debate of the role of cervical disc replacement with an update in light of the latest clinical trial results. METHODS: A literature review was performed identifying clinical trials pertaining to the use of cervical disc replacement compared to cervical discectomy and fusion. Single level disease and two level disease were considered. Outcome data from the major clinical trials was reviewed and salient points identified. RESULTS: With lengthier follow-up data becoming available, the equivalence of CDR in appropriately selected cases is becoming clear. This is chiefly manifested by reduced re-operation rates and reduced incidence of adjacent level disease in those treated with arthroplasty. CONCLUSION: Cervical disc replacement shows emerging equivalence in outcomes compared to the gold standard anterior cervical discectomy and fusion. Further longer term results are anticipated to confirm this trend.

Segmental Motion of Cervical Arthroplasty Leads to Decreased Adjacent-Level Degeneration: Analysis of the 7-Year Postoperative Results of a Multicenter Randomized Controlled Trial.

BACKGROUND: Cervical artificial disc replacement (C-ADR) has become a common and accepted surgical treatment for many patients with cervical disc degeneration/herniation and radiculopathy who have failed nonoperative treatment. Midterm follow-up studies of the original investigational device exemption trials comparing C-ADR to traditional anterior cervical discectomy and fusion (ACDF) have revealed C-ADR patients have less adjacent-level disease and fewer reoperations at 5 to 7 years. The purpose of this study was to examine the relationship of radiographic adjacent-level disease (R-ALD) with the amount of index-level segmental range of motion (ROM) in C-ADR patients using the long-term follow-up data from the ProDisc-C investigational device exemption trial. METHODS: This was a post hoc analysis of a 1:1 randomized controlled trial. The initial previously described Food and Drug Administration-approved 2-year study was extended, and consenting patients in the original study were followed at annual intervals up to 7 years. Logistic regression was used to assess any progression in adjacent-level disease (ALD). Ordinal logistic regression was also used to assess the relationship between any progressive R-ALD and final flexion extension (F/E) ROM in C-ADR patients. Spearman's rank-order correlation was used when R-ALD was kept as an ordinal variable to assess the same relationship. RESULTS: At the last follow-up visit, the rate of progressive R-ALD was significantly higher in ACDF patients than in C-ADR patients. When C-ADR patients were divided into 3 groups based on final F/E ROM, those with 0° to 3° (n = 19), 4° to 6° (n = 15), and 7° (n = 42) of segmental motion at the index procedure level, the rate of progressive R-ALD trended significantly with final ROM (P = 0.01). CONCLUSIONS: C-ADR leads to a significant decrease in R-ALD compared to ACDF. The difference in R-ALD is related to the preservation of motion at the index level and resultant preservation of kinematics and forces across the adjacent disc space.

The lumbar facet joint: a review of current knowledge: Part II: diagnosis and management.

This article is the second article in a two-part review on lumbar facet joint pathology. In this review, we discuss the current concepts and controversies regarding the proper diagnosis and management of patients presenting with presumed facet-mediated lower back pain. All efforts were made to include the most relevant literature from the fields of radiology, orthopaedics, physiatry, and pain management. Our focus in this article is on presenting the evidence supporting or refuting the most commonly employed injection-based therapies for facet-mediated lower back pain.

The lumbar facet joint: a review of current knowledge: part 1: anatomy, biomechanics, and grading.

We present a two-part review article on the current state of knowledge of lumbar facet joint pathology. This first article discusses the functional anatomy, biomechanics, and radiological grading systems currently in use in clinical practice and academic medicine. Facet joint degeneration is presented within the larger context of degenerative disc disease to enable the reader to better understand the anatomical changes underlying facet-mediated lower back pain. Other less-common, but equally important etiologies of lumbar facet joint degeneration are reviewed. The existing grading systems are discussed with specific reference to the reliability of CT and MR imaging in the diagnosis of lumbar facet osteoarthritis. It is hoped that this discussion will stimulate debate on how best to improve the diagnostic reliability of these tests so as to improve both operative and non-operative treatment outcomes.

Cervical fusion for treatment of degenerative conditions: development of appropriate use criteria.

BACKGROUND CONTEXT: High quality evidence is difficult to generate, leaving substantial knowledge gaps in the treatment of spinal conditions. Appropriate use criteria (AUC) are a means of determining appropriate recommendations when high quality evidence is lacking. PURPOSE: Define appropriate use criteria (AUC) of cervical fusion for treatment of degenerative conditions of the cervical spine. STUDY DESIGN/SETTING: Appropriate use criteria for cervical fusion were developed using the RAND/UCLA appropriateness methodology. Following development of clinical guidelines and scenario writing, a one-day workshop was held with a multidisciplinary group of 14 raters, all considered thought leaders in their respective fields, to determine final ratings for cervical fusion appropriateness for various clinical situations. OUTCOME MEASURES: Final rating for cervical fusion recommendation as either "Appropriate," "Uncertain" or "Rarely Appropriate" based on the median final rating among the raters. METHODS: Inclusion criteria for scenarios included patients aged 18 to 80 with degenerative conditions of the cervical spine. Key modifiers were defined and combined to develop a matrix of clinical scenarios. The median score among the raters was used to determine the final rating for each scenario. The final rating was compared between modifier levels. Spearman's rank correlation between each modifier and the final rating was determined. A multivariable ordinal regression model was fit to determine the adjusted odds of an "Appropriate" final rating while adjusting for radiographic diagnosis, number of levels and symptom type. Three decision trees were developed using decision tree classification models and variable importance for each tree was computed. RESULTS: Of the 263 scenarios, 47 (17.9 %) were rated as rarely appropriate, 66 (25%) as uncertain and 150 (57%) were rated as appropriate. Symptom type was the modifier most strongly correlated with the final rating (adjusted ρ2 = 0.58, p<.01). A multivariable ordinal regression adjusting for symptom type, diagnosis, and number of levels and showed high discriminative ability (C statistic = 0.90) and the adjusted odds ratio (aOR) of receiving a final rating of "Appropriate" was highest for myelopathy (aOR, 7.1) and radiculopathy (aOR, 4.8). Three decision tree models showed that symptom type and radiographic diagnosis had the highest variable importance. CONCLUSIONS: Appropriate use criteria for cervical fusion in the setting of cervical degenerative disorders were developed. Symptom type was most strongly correlated with final rating. Myelopathy or radiculopathy were most strongly associated with an "Appropriate" rating, while axial pain without stenosis was most associated with "Rarely Appropriate."

Revision of a lumbar disc arthroplasty following late infection.

Anterior removal of a lumbar total disc replacement implant is often a very technically demanding procedure. The anterior retroperitoneal anatomy is prone to scarring, limiting remobilization and making a direct anterior exposure above the L5-S1 level difficult if not impossible to achieve safely. Anterolateral approach strategies can be more safely achieved at L4-L5 and above, but may require vertebral osteotomy in order to remove a keeled prosthesis. Successful conversion to a fusion with implant removal can be achieved, even when osteotomy is needed for implant removal. This Grand Rounds case presentation involves an unusual late retroperitoneal abscess following two-level TDR with direct extension to one of the implants, and the subsequent nonoperative and operative management. Removal of a well-fixed keeled implant at the L4-L5 level following nonoperative treatment of a surrounding retroperitoneal abscess and conversion to fusion represents close to, if not a 'worst-case' scenario for revision TDR. However, with proper preoperative planning and surgical experience, a safe and successful procedure can be the end result.

Enhanced Recovery After Surgery Trends in Adult Spine Surgery: A Systematic Review.

BACKGROUND: Enhanced Recovery After Surgery (ERAS) is a multimodal, multidisciplinary approach to optimizing the postsurgical recovery process through preoperative, perioperative, and postoperative interventions. ERAS protocols are emerging quickly within orthopedic spine surgery, yet there is a lack of consensus on optimal ERAS practices. OBJECTIVE: The aim of this systematic review is to identify and discuss the trends in spine ERAS protocols and the associated outcomes. METHODS: A literature search on PubMed was conducted to identify clinical studies that implemented ERAS protocols for various spine procedures in the adult population. The search included English-language literature published through December 2019. Additional sources were retrieved from the reference lists of key studies. Studies that met inclusion criteria were identified manually. Data regarding the study population, study design, spine procedures, ERAS interventions, and associated outcome metrics were extracted from each study that met inclusion criteria. RESULTS: Of the 106 studies identified from the literature search, 22 studies met inclusion criteria. From the ERAS protocols in these studies, common preoperative elements include patient education and modified preoperative nutrition regimens. Perioperative elements include multimodal analgesia and minimally invasive surgery. Postoperative elements include multimodal pain management and early mobilization/rehabilitation/nutrition regimens. Outcomes from ERAS implementation include significant reductions in length of stay, cost, and opioid consumption. Although these trends were observed, there remained great variability among the ERAS protocols, as well as in the reported outcomes. CONCLUSIONS: ERAS may improve cost-effectiveness to varying degrees for spinal procedures. Specifically, the use of multimodal analgesia may reduce overall opioid consumption. However, the benefits of ERAS likely will vary based on the specific procedure. CLINICAL RELEVANCE: This review contributes to the assessment of ERAS protocol implementation in the field of adult spine surgery.

Three-dimensional printing in spine surgery: a review of current applications.

In recent years, the use of three-dimensional printing (3DP) technology has gained traction in orthopedic spine surgery. Although research on this topic is still primarily limited to case reports and small cohort studies, it is evident that there are many avenues for 3DP innovation in the field. This review article aims to discuss the current and emerging 3DP applications in spine surgery, as well as the challenges of 3DP production and limitations in its use. 3DP models have been presented as helpful tools for patient education, medical training, and presurgical planning. Intraoperatively, 3DP devices may serve as patient-specific surgical guides and implants that improve surgical outcomes. However, the time, cost, and learning curve associated with constructing a 3DP model are major barriers to widespread use in spine surgery. Considering the costs and benefits of 3DP along with the varying risks associated with different spine procedures, 3DP technology is likely most valuable for complex or atypical spine disorder cases. Further research is warranted to gain a better understanding of how 3DP can and will impact spine surgery.

The effect of vascular approach surgeons on perioperative complications in lateral transpsoas lumbar interbody fusions.

BACKGROUND CONTEXT: Lateral lumbar interbody fusion (LLIF) is a popular technique used in spine surgery. It is minimally invasive, provides indirect decompression, and allows for coronal plane deformity correction. Despite these benefits, the approach to LLIF has been linked to complications associated with the lumbosacral plexus and vascular anatomy. As a result, vascular surgeons may be recruited for the exposure portion of the procedure. PURPOSE: The purpose of this study was to compare exposure-related complication and postoperative (postop) neuropraxia rates between exposure (EXP) and spine surgeon only (SSO) groups while performing the approach for LLIF. STUDY DESIGN/SETTING: Retrospective analysis of patients treated at a single institution. PATIENT SAMPLE: Patients undergoing LLIF procedures between 2012 and 2018. OUTCOME MEASURES: Operative time, estimated blood loss, fluoroscopy, length of stay (LOS), intra- and postoperative complications, and physiologic measures including pre- and postoperative motor examinations and unresolved neuropraxia. METHODS: Patients who underwent LLIF were separated into EXP and SSO groups based on the presence or absence of vascular/general surgeon during the approach. The entire clinical history of patients with a decrease in pre- and postop motor examination was reviewed for the presence of neuropraxia. All other intra- and postop exposure-related complications were recorded for comparison. Propensity score matching (PSM) was performed to account for age, Charlson Comorbidity Index (CCI) percentage of LLIFs including L4-L5, and number of levels fused. Independent t test and chi-square analyses were used to identify significant differences between EXP and SSO groups. Statistical significance was set at p<.05. RESULTS: Two hundred and seventy-five patients underwent LLIF procedures, 155 SSO and 120 EXP. Postoperatively, 26 patients (11.1%) experienced a drop in any Medical Research Council (MRC) score, and two patients (0.7%) experienced unresolved quadriceps palsies. The mean recovery time for MRC scores was 84.4 days. Other complications included 2 pneumothoraces (0.7%), 1 iliac vein injury (0.4%), 14 cases of ileus (5.1%), 3 pulmonary emboli (1.1%), 2 deep vein thrombosis (0.7%), 3 cases of abdominal wall paresis (1.1%), and one abdominal hematoma (0.4%). After PSM, demographics including age, gender, body mass index, CCI, levels fused, and operative time were similar between cohorts. Twenty patients had changes in pre- to postop motor scores (SSO 9.4%, EXP 12.4%, p>.05). Iliopsoas motor scores decreased at the highest rate (EXP 12.4%, SSO 8.2%, p>.05) followed by quadriceps (EXP 5.2%, SSO 4.7%, p>.05). One SSO patient's postop course was complicated by a foot drop but returned to baseline within 1 year. One patient in EXP group developed an unresolved quadriceps palsy (EXP 1.0%, SSO 0.0%, p>.05). Intraoperative exposure complications included one pneumothorax (EXP 1.0%, SSO 0.0%, p>.05). There were no differences in PE/DVT, Ileus, or LOS. In the EXP cohort, three patients experienced abdominal wall paresis (EXP 2.9%, SSO 0.00%, p=.246). CONCLUSIONS: Comparing the LLIF exposures performed by EXP and SSO, we found no significant difference in the rates of complications. Additional research is needed to determine the etiology of the abdominal wall complications. In conclusion, neuropraxia- and approach-related complications are similarly low between exposure and spine surgeons.

The lumbar spine and low back pain in golf: a literature review of swing biomechanics and injury prevention.

BACKGROUND CONTEXT: The golf swing imparts significant stress on the lumbar spine. Not surprisingly, low back pain (LBP) is one of the most common musculoskeletal complaints among golfers. PURPOSE: This article provides a review of lumbar spine forces during the golf swing and other research available on swing biomechanics and muscle activity during trunk rotation. STUDY DESIGN: The role of "modern" and "classic" swing styles in golf-associated LBP, as well as LBP causation theories, treatment, and prevention strategies, are reviewed. METHODS: A PubMed literature search was performed using various permutations of the following keywords: lumbar, spine, low, back, therapy, pain, prevention, injuries, golf, swing, trunk, rotation, and biomechanics. Articles were screened and selected for relevance to injuries in golf, swing mechanics, and biomechanics of the trunk and lumbar spine. Articles addressing treatment of LBP with discussions on trunk rotation or golf were also selected. Primary references were included from the initial selection of articles where appropriate. General web searches were performed to identify articles for background information on the sport of golf and postsurgical return to play. RESULTS: Prospective, randomized studies have shown that focus on the transversus abdominus (TA) and multifidi (MF) muscles is a necessary part of physical therapy for LBP. Some studies also suggest that the coaching of a "classic" golf swing and increasing trunk flexibility may provide additional benefit. CONCLUSIONS: There is a notable lack of studies separating the effects of swing modification from physical rehabilitation, and controlled trials are necessary to identify the true effectiveness of specific swing modifications for reducing LBP in golf. Although the establishment of a commonly used regimen to address all golf-associated LBP would be ideal, it may be more practical to apply basic principles mentioned in this article to the tailoring of a unique regimen for the patient. Guidelines for returning to golf after spine surgery are also discussed.

Five-Year Reoperation Rates of 2-Level Lumbar Total Disk Replacement Versus Fusion: Results of a Prospective, Randomized Clinical Trial.

STUDY DESIGN: Long-term analysis of prospective randomized clinical trial data. SUMMARY OF BACKGROUND DATA: Lumbar total disk replacement (TDR) has been found to have equivalent or superior clinical outcomes compared with fusion and decreased radiographic incidence of adjacent level degeneration in single-level cases. OBJECTIVE: The purpose of this particular analysis was to determine the incidence and risk factors for secondary surgery in patients treated with TDR or circumferential fusion at 2 contiguous levels of the lumbar spine. METHODS: A total of 229 patients were treated and randomized to receive either TDR or circumferential fusion to treat degenerative disk disease at 2 contiguous levels between L3 and S1 (TDR, n=161; fusion, n=68). RESULTS: Overall, at final 5-year follow-up, 9.6% of subjects underwent a secondary surgery in this study. The overall rate of adjacent segment disease was 3.5% (8/229). At 5 years, the percentage of subjects undergoing secondary surgeries was significantly lower in the TDR group versus fusion (5.6% vs. 19.1%, P=0.0027).Most secondary surgeries (65%, 17/26) occurred at the index levels. Index level secondary surgeries were most common in the fusion cohort (16.2%, 11/68 subjects) versus TDR (3.1%, 5/161 subjects, P=0.0009). There no statistically significant difference in the adjacent level reoperation rate between TDR (2.5%, 4/161) and fusion (5.9%, 4/68). The most common reason for index levels reoperation was instrumentation removal (n=9). Excluding the instrumentation removals, there was not a significant difference between the treatments in index level reoperations or in reoperations overall. CONCLUSIONS: There were significantly fewer reoperations in TDR patients compared with fusion patients. However, most of the secondary surgeries were instrumentation removal in the fusion cohort. Discounting the instrumentation removals, there was no significant difference in reoperations between TDR and fusion. These results are indicative that lumbar TDR is noninferior to fusion.

The Effect of Smoking on Spinal Fusion.

BACKGROUND: Spinal fusion surgery is performed about half a million times per year in the United States and millions more worldwide. It is an effective method for reducing pain, increasing stability, and correcting deformity in patients with various spinal conditions. In addition to being a well-established risk factor for a variety of medical conditions, smoking has deleterious effects on the bone healing of spinal fusions. This review aims to specifically analyze the ways in which smoking affects the outcomes of spinal fusion and to explore ways in which these negative consequences can be avoided. PURPOSE: This article provides a complete understanding of the ways smoking affects spinal fusion from a biochemical and clinical perspective. Recommendations are also provided for ways in which surgeons can limit patient exposure to the most serious negative outcomes associated with cigarette smoking. STUDY DESIGN/SETTING: This study was a retrospective literature review done using the NCBI database. The research was compiled at NYU Hospital for Joint Diseases and the NYU Center for Musculoskeletal Care. METHODS: A comprehensive literature review was done spanning research on a variety of subjects related to smoking and spinal fusion surgery. The biochemistry of smoking and fusion healing were examined in great detail. In addition, both in vivo animal studies and human clinical studies were evaluated to explore fusion success related to the effects of smoking and its biochemical factors on spinal fusion surgery. RESULTS: Smoking significantly increases the risk of pseudoarthrosis for patients undergoing both lumbar and cervical fusions. In addition to nonunion, smoking also increases the risk of other perioperative complications such as infection, adjacent-segment pathology, and dysphagia. Treatment options are available that can be explored to reduce the risk of smoking-related morbidity, such as nicotine replacement therapy and use of bone morphogenetic proteins (BMPs). CONCLUSIONS: It has been clearly demonstrated from both a biochemical and clinical perspective that smoking increases the rate of perioperative complications for patients undergoing spinal fusion surgery, particularly pseudoarthosis. It has also been shown that there are certain approaches that can reduce the risk of morbidity. The most important recommendation is smoking cessation for four weeks after surgery. In addition, patients may be treated with certain surgical techniques, including the use of BMPs, to reduce the risk of pseudoarthrosis. Lastly, nicotine replacement therapy is an area of continued interest in relation to spinal fusion outcomes and more research needs to be done to determine its efficacy moving forward.

Laminoplasty: a review of its role in compressive cervical myelopathy.

BACKGROUND CONTEXT: The currently accepted surgical treatments for compressive cervical myelopathy include both anterior and posterior decompression. Anterior approaches including multilevel discectomy with fusion or vertebral corpectomy with strut grafting, both with and without instrumentation, have enjoyed successful outcomes, but have been associated with select postoperative complications. Laminoplasty has been developed to decompress the spine posteriorly while avoiding the spinal destabilization seen after laminectomy. PURPOSE: The purpose of this article is to provide a review of the various techniques, biomechanical basis, predictive value of imaging modalities, clinical outcomes, and postoperative complications associated with cervical laminoplasty. STUDY DESIGN: A review of the literature. METHODS: A comprehensive literature review using Medline was performed identifying relevant articles that addressed the techniques, clinical outcomes, and complications after cervical laminoplasty, as well as preoperative radiographic predictors of outcome. RESULTS: The various modifications of cervical laminoplasty have generally been associated with excellent clinical outcomes when used for myelopathy secondary to cervical spondylosis or ossification of the posterior longitudinal ligament (OPLL). Recent long-term studies have identified issues with this technique including axial neck pain, canal restenosis, nerve root palsy, diminished cervical motion, and loss of cervical lordotic alignment. CONCLUSIONS: Cervical laminoplasty remains a reliable procedure for posterior decompression of the spine, but the optimal approach to cervical myelopathy must take into account both patient and disease characteristics, as well as the capabilities and experience of the surgeon.

"Reverse Bohlman" technique for the treatment of high grade spondylolisthesis in an adult population.

BACKGROUND/AIMS: Surgical techniques for effective high-grade spondylolisthesis (HGS) remain controversial. This study aims to evaluate radiographic/clinical outcomes in HGS patients treated using modified "Reverse Bohlman" (RB) technique. METHODS: Review of consecutive HGS patients undergoing RB at a single university-center from 2006 to 2013. Clinical, surgical, radiographic parameters collected. RESULTS: Six patients identified: five with L5-S1 HGS with L4-L5 instability and one had an L4-5 isthmic spondylolisthesis and grade 1 L5-S1 isthmic spondylolisthesis. Two interbody graft failures and one L5-S1 pseudoarthrosis. Postoperative improvement of anterolisthesis (62.3% vs. 49.6%, p = 0.003), slip angle (10 vs. 5°, p = 0.005), and lumbar lordosis (49 vs. 57.5°, p = 0.049). CONCLUSIONS: RB technique for HGS recommended when addressing adjacent level instability/slip.

Cost-Effectiveness of Lumbar Spondylolisthesis Surgery at 2-Year Follow-up.

OBJECTIVES: The purpose of this study was to determine the cost/quality-adjusted life-year (QALY) of the operative treatment of lumbar spondylolisthesis and identify factors associated with cost-effectiveness at 2 years. METHODS: We evaluated patients who underwent surgery for spondylolisthesis. The QALY was determined from the EQ5D. Outcomes were also assessed using the Oswestry Disability Index (ODI). Surgical, neuromonitoring, and anesthesia Current Procedural Terminology (CPT) codes as well as hospital Diagnosis-Related Group codes were used to determine the Medicare direct care costs of surgery. Indirect costs were modeled based on existing literature. A discounting rate of 3% was applied. Analysis was performed to determine which factors were associated with a cost/QALY less than $100,000. RESULTS: There were 44 patients who underwent surgery for either degenerative (30) or isthmic spondylolisthesis (14). There were 27 women and 17 men, with an average age at surgery of 59.7 years (standard deviation [SD] = 14.69) and an average follow-up of 2 years (SD = 0.82). The average postoperative improvement in ODI was 24.77 (SD = 23.9), and change in QALY was 0.43 (SD = 0.30). The average cost/QALY at 2 years for direct care costs was $89,065. The average cost/QALY at 2 years for direct plus indirect costs was $112,588. Higher preoperative leg pain and greater leg pain change was associated with a cost/QALY <$100,000 (p < .005, p < .028). The cost-effective group had a higher proportion of patients with disease extent of two or more levels (p = .021). When comparing surgical techniques of anterior-posterior and posterior only, there was no difference in cost-effectiveness. CONCLUSIONS: Spondylolisthesis surgery is cost-effective at 2 years, with a QALY change of 0.43 and a direct cost/QALY of $89,065. Higher preoperative leg pain and larger extent of disease was associated with cost-effectiveness. LEVEL OF EVIDENCE: IV.

Analysis of Postoperative Thoracolumbar Spine Infections in a Prospective Randomized Controlled Trial Using the Centers for Disease Control Surgical Site Infection Criteria.

INTRODUCTION: Wound infections following spinal surgery place a high toll on both the patient and the healthcare system. Although several large series studies have examined the incidence and distribution of spinal wound infection, the applicability of these studies varies greatly since nearly every study is either retrospective and/or lacks standard inclusion criteria for defining surgical site infection. To address this void, we present results from prospectively gathered thoracolumbar spine surgery data for which the Centers for Disease Control (CDC) criteria were stringently applied to define a surgical site infection (SSI). METHODS: A prospective randomized trial of 314 patients who underwent multilevel thoracolumbar spinal surgery with instrumentation followed by postoperative drain placement was completed (Takemoto et al., 2015). The trial consisted of two antibiotic arms: one for 24-hours, and the other for the duration of the drain; no differences were found between the arms. All infections meeting CDC criteria for SSI were included. RESULTS: A total of 40 infections met CDC criteria for SSI, for an overall incidence of 12.7%. Of these, 20 (50%) were culture-positive. The most common organism was Staphylococcus aureus (4 total: methicillin-sensitive=2; methicillin-resistant=2), followed by coagulase-negative Staphylococcus (3 cases), Propionibacterium acnes and Escherichia coli (2 cases each). Six infections grew multiple organisms, most commonly involving coagulase-negative staphylococcus and enterococcus. CONCLUSIONS: Our findings indicate that thoracolumbar SSI occurs at the higher end of the range cited in the literature (2-13%), which is largely based on retrospective data not subjected to the inclusivity of SSI as defined by the CDC. The three most common organisms in our analysis (S. aureus, P. acnes, E. coli) are consistent with previous reports. Staphylococcus aureus continues to be the most common causative organism and continued vigilance and searching for preventive measures need to be a high priority. This study provides Level I evidence.

Embryology of the spine and associated congenital abnormalities.

BACKGROUND CONTEXT: The spine is a complex and vital structure. Its function includes not only structural support of the body as a whole, but it also serves as a conduit for safe passage of the neural elements while allowing proper interaction with the brain. Anatomically, a variety of tissue types are represented in the spine. Embryologically, a detailed cascade of events must occur to result in the proper formation of both the musculoskeletal and neural elements of the spine. Alterations in these embryologic steps can result in one or more congenital abnormalities of the spine. Other body systems forming at the same time embryologically can be affected as well, resulting in associated defects in the cardiopulmonary system and the gastrointestinal and genitourinary tracts. PURPOSE: This article is to serve as a review of the basic embryonic development of the spine. We will discuss the common congenital anomalies of the spine, including their clinical presentation, as examples of errors of this basic embryologic process. STUDY DESIGN/SETTING: Review of the current literature on the embryology of the spine and associated congenital abnormalities. METHODS: A literature search was performed on the embryology of the spine and associated congenital abnormalities. RESULTS: Development of the spine is a complex event involving genes, signaling pathways and numerous metabolic processes. Various abnormalities are associated with errors in this process. CONCLUSION: Physicians treating patients with congenital spinal deformities should have an understanding of normal embryologic development as well as common associated abnormalities.

Percutaneous treatment of vertebral body pathology.

Percutaneous vertebral body injection procedures currently are used to stabilize and reinforce weakened or fractured bone resulting from metastatic disease and severe osteoporosis. Both vertebroplasty and kyphoplasty can reinforce the structure of a vertebral body and provide pain relief, but the procedures have technical differences. Kyphoplasty improves vertebral height to varying degrees in nearly three quarters of patients. Kyphosis is improved more effectively when the procedure is performed within 3 months from the onset of fracture pain. To date, it is unknown whether vertebroplasty with preprocedure postural reduction can provide similar improvement of deformity. Complications are relatively infrequent with both vertebroplasty and kyphoplasty. Cement leakage from the vertebral body is more likely with vertebroplasty than with kyphoplasty. Leakage is more common in the treatment of pathologic fractures resulting from metastatic disease. Clinical complications caused by cement leakage and neural compression are infrequent. Specific indications for these injection procedures need to be more clearly refined. Long-term outcomes, including the fate of the injected material and the effect on adjacent vertebrae, have yet to be determined.

Systematic Review of Thigh Symptoms after Lateral Transpsoas Interbody Fusion for Adult Patients with Degenerative Lumbar Spine Disease.

BACKGROUND: Lateral transpsoas interbody fusion (LTIF) is a minimally invasive technique for achieving lumbar spinal fusion. While it has many advantages over open techniques it carries with it a distinct set of risks, most commonly post-operative ipsilateral thigh pain, weakness and sensory disturbances. It is vital for both the surgeon and patient to understand the risks for and outcomes of injury associated with this procedure. We conducted a systematic review of the literature to evaluate the incidence, risks, and long-term clinical outcomes of post-operative thigh symptoms in patients treated with LTIF. METHODS: We conducted a search of MEDLINE, EMBASE, CINAHL, Scopus, Web of Science and the Cochrane Collaboration Library, using keywords and MeSH terms, for English-language literature published through September 2014, as well as reference lists from key articles. Studies were then manually filtered to retrieve articles that met inclusion criteria. We were interested in studies that reported postoperative lower extremity symptoms after LTIF, such as pain, weakness and changes in sensation. The strength of evidence was determined based on precepts outlined by the Grades of Recommendation Assessment, Development and Evaluation Working Group (GRADE). RESULTS: A total of 392 articles were initially retrieved, with 24 ultimately meeting criteria for inclusion. The incidence of any post-operative thigh symptom varied, ranging as high as 60.7%, with 9.3% of patients experiencing a motor deficit related to direct nerve injury. Several studies reported cases of persistent symptoms at 6 months follow up. Additionally, inclusion of the L4-5 disc space and a longer duration of surgery were both identified as risks for developing postoperative thigh symptoms. CONCLUSION: The risk of postoperative thigh symptoms after LTIF is high. Thigh pain, paresthesias and weakness were the most commonly reported symptoms. While most patients' symptoms resolved by 6 months follow up, several studies reported patients with symptoms persistent as far as 12 months removed from surgery. Surgery at the L4-5 disc space and longer surgical duration place the patient at greater risk for developing postoperative and long-term thigh symptoms.

A Review of Symptomatic Lumbosacral Transitional Vertebrae: Bertolotti's Syndrome.

BACKGROUND: Lumbosacral transitional vertebrae (LSTV) are increasingly recognized as a common anatomical variant associated with altered patterns of degenerative spine changes. This review will focus on the clinical significance of LSTV, disruptions in normal spine biomechanics, imaging techniques, diagnosis, and treatment. METHODS: A Pubmed search using the specific key words "LSTV," "lumbosacral transitional vertebrae," and "Bertolotti's Syndrome" was performed. The resulting group of manuscripts from our search was evaluated. RESULTS: LSTV are associated with alterations in biomechanics and anatomy of spinal and paraspinal structures, which have important implications on surgical approaches and techniques. LSTV are often inaccurately detected and classified on standard AP radiographs and MRI. The use of whole-spine images as well as geometric relationships between the sacrum and lumbar vertebra increase accuracy. Uncertainty regarding the cause, clinical significance, and treatment of LSTV persists. Some authors suggest an association between LSTV types II and IV and low back pain. Pseudoarticulation between the transverse process and the sacrum creates a "false joint" susceptible to arthritic changes and osteophyte formation potentially leading to nerve root entrapment. The diagnosis of symptomatic LSTV is considered with appropriate patient history, imaging studies, and diagnostic injections. A positive radionuclide study along with a positive effect from a local injection helps distinguish the transitional vertebra as a significant pain source. Surgical resection is reserved for a subgroup of LSTV patients who fail conservative treatment and whose pain is definitively attributed to the anomalous pseudoarticulation. CONCLUSIONS: Due to the common finding of low back pain and the wide prevalence of LSTV in the general population, it is essential to differentiate between symptoms originating from an anomalous psuedoarticulation from other potential sources of low back pain. Further studies with larger sample sizes and longer follow-up time would better demonstrate the effectiveness of surgical resection and help guide treatment.