Faculty Bibliography

BACKGROUND CONTEXT: Recent research describes the use of a nerve root sedimentation sign to diagnose lumbar spinal stenosis (LSS). The lack of sedimentation of the nerve roots (positive sedimentation sign) to the dorsal part of the dural sac is the characteristic feature of this new radiological parameter. PURPOSE: To demonstrate how the nerve root sedimentation sign compares with other more traditional radiological parameters in patients who have been operated for LSS. STUDY DESIGN/SETTING: A retrospective chart and image review. PATIENT SAMPLE: Preoperative magnetic resonance images (MRIs) were reviewed from 71 consecutive operative patients who presented with LSS and received spinal decompression surgery from 2006 to 2010. OUTCOME MEASURES: Preoperative T2-weighted MRIs were reviewed for each patient. METHODS: One hundred thirty-four vertebral levels from L1 to L5 were measured for: sedimentation sign, cross-sectional area (CSA) and anterior/posterior (A/P) diameter of the dural sac, thickness of the ligamentum flavum, and Fujiwara grade of facet hypertrophy. Radiological measurements were made using Surgimap 1.1.2.169 software (Nemaris, Inc., New York, NY, USA). Statistical analyses were performed using the SPSS 17.0 statistical software (SPSS Inc., Chicago, IL, USA). Significance was demonstrated using unpaired t tests and chi-squared tests. Study funding was departmental. There were no study-specific conflicts of interest-associated biases. RESULTS: A positive sedimentation sign was determined in 120 operated levels (89.5%), whereas 14 levels (10.5%) had no sign (negative sedimentation sign). The mean CSA and A/P diameter were 140.62 mm(2) (standard deviation [SD]=53) and 11.76 mm (SD=3), respectively, for the no-sign group; the mean CSA and A/P diameter were 81.87 mm(2) (SD=35) and 8.76 mm (SD=2.2), respectively, for the sedimentation sign group (p<.001). We found that 60% of levels with Fujiwara Grade A facet hypertrophy did not have a sedimentation sign, whereas 86.3% of levels with Grade B, 93.2% of levels with Grade C, and 100.0% of levels with Grade D did have a sedimentation sign (p<.001). CONCLUSIONS: The sedimentation sign is a new measurement tool that can enable physicians to objectively assess and quantify spinal stenosis. The sign is most often present in patients who have clinically significant lumbar stenosis and require surgery.

BACKGROUND CONTEXT: Adult spinal deformity (ASD) is commonly associated with disability and represents a challenging condition for physicians. Although surgical management has been reported as superior to conservative care, the choice of patient-specific optimal strategy has been poorly defined. A key question remains selection of fusion levels as this implies careful balance of risks and benefits. PURPOSE: The aim of this review is to propose an update on current knowledge related to optimal fusion levels in the surgical treatment of ASD. STUDY DESIGN: Literature review. METHODS: Based on a comprehensive literature search, recent studies focusing on the management of ASD were reviewed to establish current concepts on fusion levels in the management of symptomatic ASD. RESULTS: Despite numerous published studies, the management of ASD and specifically optimal fusion levels is incompletely defined. Described approaches carry benefits and risks. However, the need for detailed analysis and preoperative planning is confirmed as a prerequisite to obtaining realignment objectives and good outcomes. CONCLUSIONS: The treatment of ASD is emerging as an important health-care issue of the 21st century because of prevalence and cost. Despite technical advances related to ASD surgery, complication rates remain elevated, particularly in the older population. Recent research, mostly driven by outcome measures, has improved our understanding of optimal treatment approaches to ASD. The development of a widely accepted classification system will help to share knowledge and improve our ability to treat these complex patients.

STUDY DESIGN.: A retrospective review. OBJECTIVE.: To compare the radiographical and clinical profiles between 2 surgical approaches for the correction of sagittal plane spinal deformity. SUMMARY OF BACKGROUND DATA.: Sagittal plane decompensation is the radiographical parameter that carries the greatest impact on adverse outcomes. Surgical correction methods are heterogeneous, and opposing views pervade the spine community in consideration of the most effective approach and techniques to achieve correction. METHODS.: A total of 33 cases with sagittal spinal deformity were assessed according to their surgical approach, posterior only versus combined anteroposterior group. Comparison was based on the demographic data, and radiographical parameters included pelvic tilt, pelvic incidence, sacral slope, lumbar lordosis, thoracic kyphosis, and sagittal vertical axis. RESULTS.: Twenty two subjects were identified for the posterior-only and 11 subjects for the anteroposterior group. Average age was 58.7 years in the posterior-only and 55.7 years for the combined approach. Preoperative mean sagittal vertical axis was 186.6 and 147.7 mm, for the posterior-only and combined approaches, respectively (P = 0.1). Preoperative mean pelvic tilt was 34.2 degrees for the posterior-only and 36.9 degrees for the combined approach group (P = 0.5). A greater operative time for the combined approach was significant, 535 versus 333 minutes for the posterior-only approach (P < 0.001). In the posterior-only group, 8 of 22 patients and 7 of 11 patients in the combined-approach cohort experienced a postoperative complication (P = 0.16). The average follow-up was 41.8 and 47.7 months for the posterior-only and combined approaches, respectively (P = 0.4). CONCLUSION.: A posterior-only or combined surgical approach had comparable radiographical outcomes. Higher morbidity was significant in regard to operative time in the combined-approach group. Deciding on the approach best suited for achieving correction in the sagittal plane likely resides on the surgeon's experience and expertise.

Spine Tango is currently the only international spine registry in existence. It was developed under the auspices of Eurospine, the Spine Society of Europe, and is hosted at the University of Bern, Switzerland. The HJD Spine Center successfully tested Spine Tango during a 3-month pilot study and has since expanded documentation activities to more surgeons. Workflow integration and dedicated research staff are key factors for such an endeavor. Participation enables benchmarking against national and international peers and outcome research and quality assurance of surgical and non-surgical treatments.

BACKGROUND CONTEXT: Conjoined nerve roots are a relatively uncommon finding but are frequently undiagnosed on preoperative imaging studies. The presence of a conjoined root anomaly represents a significant potential for neurologic injury when nerve root mobilization is necessary during spinal procedures. PURPOSE: This comprehensive review of conjoined lumbar nerve roots encompasses preoperative diagnosis by physical examination and radiographic imaging studies, as well as the intraoperative management of conjoined nerve roots. STUDY DESIGN: Systematic review of existing literature. RESULTS: Findings have been described on standard magnetic resonance imaging (MRI) and computed tomography imaging to increase preoperative diagnosis rates. The literature lacks concrete recommendations regarding intraoperative techniques for conjoined root identification and management. CONCLUSIONS: Preoperative recognition and diagnosis of this anomaly has proven to be the best way to improve the chances of a successful procedure and avoid inadvertently damaging the nerve roots intraoperatively. Several radiographic signs of conjoined lumbar nerve roots have been described using standard MRI techniques including coronal T1- and T2-weighted sequences. Intraoperative management of conjoined nerve roots has not changed significantly since they were first identified, although diagnostic accuracy has improved with advanced MRI techniques.

BACKGROUND: Traditional surgical treatment of isthmic spondylolisthesis is posterior-lateral fusion, but the addition of anterior surgery has been explored. The purpose of this study was to evaluate the surgical and clinical outcomes of anterior-posterior surgical treatment for low-grade isthmic spondylolisthesis. METHODS: Retrospectively, we enrolled 23 consecutive patients (mean age of 50) who underwent surgical treatment for low grade isthmic spondylolisthesis. The mean follow-up was 10 months. Basic demographic and radiographic data was collected. Pre- and post-surgical clinical surveys (VAS, ODI, and SF-36) were collected. RESULTS: All 23 patients underwent anterior interbody fusion with a femoral ring allograft or ICBG in combination with posterior lumbar decompression and fusion with instrumentation. The average slip percentage decreased from 23.2% to 19.0% (p = 0.24) while slip angle increased from 9.8 degrees to 17.9 degrees (p < 0.001) and average disc height decreased from 1.9 cm to 0.80 cm (p < 0.001). VAS scores decreased from 7.1 to 2.4 (p < 0.001), ODI scores decreased from 52.5 to 28.1 (p < 0.001), and SF-36 scores increased in the Physical Component Scale (PCS) from 29.5 to 42.6 (p < 0.001). CONCLUSION: In our study, patients demonstrated an improvement in the ODI as well the physical component scores of the SF-36, thus having a good clinical outcome.

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

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