Does prone repositioning before posterior fixation produce greater lordosis in lateral lumbar interbody fusion (LLIF)?

STUDY DESIGN: Retrospective comparative radiographic review. OBJECTIVE: To determine if lateral to prone repositioning before posterior fixation confers additional operative level lordosis in lateral lumbar interbody fusion (LLIF) procedures. SUMMARY OF BACKGROUND DATA: In a review of 56 consecutive patients who underwent LLIF, there was no statistically significant change in segmental lordosis from lateral to prone once a cage is in place. The greatest lordosis increase was observed after cage insertion. METHODS: We reviewed 56 consecutive patients who underwent LLIF in the lateral position followed by posterior fixation in the prone position. Eighty-eight levels were fused. Disk space angle was measured on intraoperative C-arm images, and change in operative level segmental lordosis brought about by each of the following was determined: (1) cage insertion, (2) prone repositioning, and (3) posterior instrumentation. Paired t test was used to determine significance (α=0.05). RESULTS: Mean lordosis improvement brought about by cage insertion was 2.6 degrees (P=0.00005). There was a 0.1 degree mean lordosis change brought about by lateral to prone positioning (P=0.47). Mean lordosis improvement brought about by posterior fixation, including rod compression, was 1.0 degree (P=0.03). CONCLUSIONS: In LLIF procedures, the largest increase in operative level segmental lordosis is brought about by cage insertion. Further lordosis may be gained by placing posterior fixation, including compressive maneuvers. Prone repositioning after cage placement does not produce any incremental lordosis change. Therefore, posterior fixation may be performed in the lateral position without compromising operative level sagittal alignment.

"Quadruple-hit" primary testicular diffuse large B-cell lymphoma with MYD88 L265P mutation, IGH::MYC, and IRF4- and BCL6-rearrangements.

Classification of DLBCL relies on clinical, immunohistochemical, and genetic information. We report a case of primary testicular diffuse large B-cell lymphoma (PT-DLBCL) with a hitherto unreported constellation of pathologic findings to illustrate the challenges of DLBCL classification. A standard hematopathology workup was followed by gene expression profiling (GEP) to determine the DLBCL cell of origin (COO). A 75-year-old man presented with a unilateral testicular mass that had developed over the course of 1 month. Pathologic examination demonstrated involvement by DLBCL. Clinical staging revealed no systemic disease. Genetic testing showed an MYD88 mutation, as well as IGH::MYC and IRF4- and BCL6-rearrangements. Gene expression profiling demonstrated an activated B-cell expression profile. This case highlights the genetic complexity of DLBCL arising in the testis and questions the clinical significance of the identified genetic abnormalities.

The accuracy of navigation and 3D image-guided placement for the placement of pedicle screws in congenital spine deformity.

BACKGROUND: Treatment of congenital spine deformity has high surgical risk due to abnormal anatomy and dysmorphic pedicles. We hypothesized that an image-guided navigation system would result in a low rate of screw revision due to malposition. METHODS: From 2007 to 2010, 142 screws were placed in 14 consecutive patients with congenital spine deformity using an intraoperative computer tomography (CT) (O-arm) and image-guided navigation system (Stealth). Mean age was 8.8 years (range, 1 to 18 y). Deformities included scoliosis (12), kyphosis (1), and spinal dysgenesis (1). Screws were placed from T2 to S1. An intraoperative CT verified screw position. Need for intraoperative screw revision is the primary outcome measure. RESULTS: Of the 142 screws placed, 1 required revision intraoperatively due to malposition (99.3% screw accuracy rate). The screw was at L3 and was successfully redirected. There were no complications due to screw malposition. This navigated congenital screw accuracy rate (99.3%) is higher than the 94.9% accuracy rate reported for non-navigated screws in all children undergoing pedicle screw fixation in a recent systematic literature review and higher than the reported 96.4% accuracy rate for navigated pedicle screws in children. Kosmopoulos and colleagues found a lower accuracy rate (86.6%) in adult non-navigated screws (P<0.0001) and adult navigated screws (93.7%). Of note, 9 pedicles were noted on navigation to be absent. Despite the goal of bilateral screw placement at each fusion level, 31 of 173 pedicles were left unfilled due to technical impossibility based on intraoperative CT imaging. This represents an 18% screw dropout rate. CONCLUSIONS: CT-guided navigation resulted in the successful placement of 142 pedicle screws in patients with congenital deformity and altered anatomy, which represents a 99.3% screw accuracy rate. This is comparable with the screw accuracy rate of 93.7% reported for adult navigated pedicle screws. Further, navigation prevented attempts of screw placement at levels with absent or impassable pedicles. Image-guided navigation and intraoperative CT are valuable tools for the safe placement of pedicle screws in patients with significant congenital spine deformity and altered anatomy. LEVEL OF EVIDENCE: IV, Case Series.

Mitigation of SARS-CoV-2 transmission at a large public university.

In Fall 2020, universities saw extensive transmission of SARS-CoV-2 among their populations, threatening health of the university and surrounding communities, and viability of in-person instruction. Here we report a case study at the University of Illinois at Urbana-Champaign, where a multimodal "SHIELD: Target, Test, and Tell" program, with other non-pharmaceutical interventions, was employed to keep classrooms and laboratories open. The program included epidemiological modeling and surveillance, fast/frequent testing using a novel low-cost and scalable saliva-based RT-qPCR assay for SARS-CoV-2 that bypasses RNA extraction, called covidSHIELD, and digital tools for communication and compliance. In Fall 2020, we performed >1,000,000 covidSHIELD tests, positivity rates remained low, we had zero COVID-19-related hospitalizations or deaths amongst our university community, and mortality in the surrounding Champaign County was reduced more than 4-fold relative to expected. This case study shows that fast/frequent testing and other interventions mitigated transmission of SARS-CoV-2 at a large public university.

Deep learning for distinguishing normal versus abnormal chest radiographs and generalization to two unseen diseases tuberculosis and COVID-19.

Chest radiography (CXR) is the most widely-used thoracic clinical imaging modality and is crucial for guiding the management of cardiothoracic conditions. The detection of specific CXR findings has been the main focus of several artificial intelligence (AI) systems. However, the wide range of possible CXR abnormalities makes it impractical to detect every possible condition by building multiple separate systems, each of which detects one or more pre-specified conditions. In this work, we developed and evaluated an AI system to classify CXRs as normal or abnormal. For training and tuning the system, we used a de-identified dataset of 248,445 patients from a multi-city hospital network in India. To assess generalizability, we evaluated our system using 6 international datasets from India, China, and the United States. Of these datasets, 4 focused on diseases that the AI was not trained to detect: 2 datasets with tuberculosis and 2 datasets with coronavirus disease 2019. Our results suggest that the AI system trained using a large dataset containing a diverse array of CXR abnormalities generalizes to new patient populations and unseen diseases. In a simulated workflow where the AI system prioritized abnormal cases, the turnaround time for abnormal cases reduced by 7-28%. These results represent an important step towards evaluating whether AI can be safely used to flag cases in a general setting where previously unseen abnormalities exist. Lastly, to facilitate the continued development of AI models for CXR, we release our collected labels for the publicly available dataset.

Large Viable Fat Nodules, Months Post-Transfer, inside Radiated Breast Implant Pocket: A Case Report.

The cell survival theory and the cell replacement theory contribute to the current thinking regarding free adipose graft persistence after transplantation and influence the principles applied to autologous fat transfer procedures. Both theories necessitate the reestablishment of circulation for graft survival. To minimize ischemic death, according to Khouri, fat grafts should be injected with at most 1.6-mm-wide ribbons to optimize the graft-to-recipient interface for oxygen diffusion and neovascularization. The graft is eventually incorporated into the surrounding tissue. We present a curious intraoperative finding, in a 51-year-old woman 2.5 months post-grafting for failed implant reconstruction after radiation. Several large, well-circumscribed, clearly viable adipose tissue nodules, up to 2 cm in diameter, were present inside the capsule. These were so loosely attached to the capsule of the breast pocket that a mere gentle hand sweep and irrigation after opening the cavity caused them to dislodge and float to the surface of the irrigation fluid. This finding begs additional questions about the current understanding of the mechanisms of tissue viability after grafting. It raises the clinical possibility that larger aliquots of transferred fat can be viable than previously perceived.

Revision lumbar arthrodesis for the treatment of lumbar cage pseudoarthrosis: complications.

STUDY DESIGN: A study documenting major complications encountered in revision procedures for lumbar cage pseudoarthrosis. OBJECTIVE: To document the perioperative complications associated with revision surgery for threaded cylindrical cage pseudoarthrosis. SUMMARY OF BACKGROUND DATA: Pseudoarthrosis after cylindrical cage placement manifests as persistent or recurrent pain and disability after surgery. Revision strategies include isolated posterior stabilization and posterior bone grafting, versus circumferential revision where an attempt is made to remove the cages anteriorly, followed by posterior stabilization and fusion. Potential complications associated with these revision procedures have not been adequately documented in the past. METHODS: Forty-seven consecutive patients with the diagnosis of cylindrical cage pseudoarthrosis were surgically treated with either a circumferential revision (AP) or an isolated posterior instrumented fusion (P). All intraoperative and postoperative complications were documented. Radiographic interbody fusion rates and preoperative and postoperative visual analog scale (VAS) scores were documented. RESULTS: Three of the AP patients, all with anterior cage placement at L5-S1, had iliac vein lacerations requiring repair. A fourth patient had a ureteral injury requiring subsequent nephrectomy. Three patients who underwent circumferential revision and 2 patients who had an isolated posterior procedure had postoperative complications, including 2 infections (1 AP and 1 P), 1 radiculopathy (P), and 2 patients with prolonged ileus (both AP). There was a statistically significant decrease in overall VAS scores postoperatively for the 2 groups using the paired t test (P<0.0001). There was no difference in either the preoperative (P=0.22) or 2-year postoperative (P=0.30) VAS scores between the AP and P groups [rank-sum (Mann-Whitney) t tests]. Interbody fusion was achieved in 79% (30 of 38 levels) in the AP group. The interbody fusion rate was 37% (8 of 22) for the P group. CONCLUSIONS: Circumferential revision including cage removal, structural allograft placement, and posterior stabilization is associated with increased perioperative complications. Although an anterior approach showed increased interbody fusion rates, this technique did not lead to more superior clinical outcomes based on VAS scores. It remains to be shown by larger prospective studies if there is a true difference in outcome between these 2 groups that will justify the increased perioperative morbidity associated with attempted cage removal.

Comparison of allograft and polyetheretherketone (PEEK) cage subsidence rates in anterior cervical discectomy and fusion (ACDF).

Structural allografts and PEEK cages are commonly used interbody fusion devices in ACDF. The subsidence rates of these two spacers have not yet been directly compared. The primary aim of this study was to compare the subsidence rate of allograft and PEEK cage in ACDF. The secondary aim was to determine if the presence of subsidence affects the clinical outcome. We reviewed 67 cases (117 levels) of ACDF with either structural allograft or PEEK cages. There were 85 levels (48 cases) with PEEK and 32 levels (19 cases) with allograft spacers. Anterior and posterior disc heights at each operative level were measured at immediate and 6months post-op. Subsidence was defined as a decrease in anterior or posterior disc heights >2mm. NDI of the subsidence (SG) and non-subsidence group (NSG) were recorded. Chi-square test was used to analyze subsidence rates. T-test was used to analyze clinical outcomes (α=0.05). There was no statistically significant difference between subsidence rates of the PEEK (29%; 25/85) and allograft group (28%; 9/32) (p=0.69). Overall mean subsidence was 2.3±1.7mm anteriorly and 2.6±1.2mm posteriorly. Mean NDI improvement was 11.7 (from 47.1 to 35.4; average follow-up: 12mos) for the SG and 14.0 (from 45.8 to 31.8; average follow-up: 13mos) for the NSG (p=0.74). Subsidence rate does not seem to be affected by the use of either PEEK or allograft as spacers in ACDF. Furthermore, subsidence alone does not seem to be predictive of clinical outcomes of ACDF.

Do Lordotic Cages Provide Better Segmental Lordosis Versus Nonlordotic Cages in Lateral Lumbar Interbody Fusion (LLIF)?

STUDY DESIGN: A retrospective comparative radiographic review. OBJECTIVE: To evaluate the radiographic changes brought about by lordotic and nonlordotic cages on segmental and regional lumbar sagittal alignment and disk height in lateral lumbar interbody fusion (LLIF). SUMMARY OF BACKGROUND DATA: The effects of cage design on operative level segmental lordosis in posterior interbody fusion procedures have been reported. However, there are no studies comparing the effect of sagittal implant geometry in LLIF. METHODS: This is a comparative radiographic analysis of consecutive LLIF procedures performed with use of lordotic and nonlordotic interbody cages. Forty patients (61 levels) underwent LLIF. Average age was 57 years (range, 30-83 y). Ten-degree lordotic PEEK cages were used at 31 lumbar interbody levels, and nonlordotic cages were used at 30 levels. The following parameters were measured on preoperative and postoperative radiographs: segmental lordosis; anterior and posterior disk heights at operative level; segmental lordosis at supra-level and subjacent level; and overall lumbar (L1-S1) lordosis. Measurement changes for each cage group were compared using paired t test analysis. RESULTS: The use of lordotic cages in LLIF resulted in a significant increase in lordosis at operative levels (2.8 degrees; P=0.01), whereas nonlordotic cages did not (0.6 degrees; P=0.71) when compared with preoperative segmental lordosis. Anterior and posterior disk heights were significantly increased in both groups (P<0.01). Neither cage group showed significant change in overall lumbar lordosis (lordotic P=0.86 vs. nonlordotic P=0.25). CONCLUSIONS: Lordotic cages provided significant increase in operative level segmental lordosis compared with nonlordotic cages although overall lumbar lordosis remained unchanged. Anterior and posterior disk heights were significantly increased by both cages, providing basis for indirect spinal decompression.

Total knee arthroplasty in juvenile rheumatoid arthritis.

BACKGROUND: There is a paucity of reports regarding the long-term results of total knee arthroplasty in patients with juvenile rheumatoid arthritis. The purpose of this study was to evaluate the outcome of total knee arthroplasty in patients with juvenile rheumatoid arthritis who had been followed for a minimum of twelve years. METHODS: Eight consecutive patients (fifteen knees) with juvenile rheumatoid arthritis underwent total knee arthroplasty at an average age of 16.8 years. Clinical evaluation of pain status, range of motion, and the ability to walk and radiographic evaluation of the alignment of the knees and component loosening were performed preoperatively and at a mean of 15.5 years postoperatively. RESULTS: All patients had substantial pain and functional limitation before the surgery, and seven of the eight patients used a wheelchair. At the time of the latest follow-up, which was after revision surgery in three patients, all of the knees were pain-free and six patients were able to walk about the community. The mean arc of motion had increased from 36 degrees to 79 degrees . The final radiographic evaluation showed that thirteen of the fifteen knees were in neutral alignment and two were in valgus. Failure, defined as revision of any of the components or definite loosening as seen radiographically, occurred in three knees. CONCLUSIONS: Good results, in terms of pain relief and restoration of function, were seen at a minimum of twelve years following total knee arthroplasty in our series of patients with juvenile rheumatoid arthritis. This procedure is a reasonable option when nonoperative therapy has been inadequate for patients with severe disability and pain in this relatively young population.

Radiographic Comparison of Lateral Lumbar Interbody Fusion Versus Traditional Fusion Approaches: Analysis of Sagittal Contour Change.

BACKGROUND: Lateral approach to lumbar fusion has been gaining popularity in recent years. With increasing awareness of the significance of sagittal balance restoration in spinal surgery, it is important to investigate the potential of this relatively new approach in correcting sagittal deformities in comparison to conventional approaches. The aim of this study was to evaluate sagittal contour changes seen in lateral lumbar interbody fusion and compare them with radiographic changes in traditional approaches to lumbar fusion. METHODS: Lumbar fusion procedures from January 2008 to December 2009 were reviewed. Four approaches were compared: anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), transforaminal interbody fusion (TLIF) and posterior spinal fusion (PSF). Standing pre-operative and 6-week post-operative radiographs were measured in terms of operative level, suprajacent and subjacent level, and regional lumbar lordosis (L1-S1) as well as operative level anterior (ADH) and posterior disc heights (PDH). T-test was used to analyze differences between and within different approaches (α=0.05). RESULTS: A total of 147 patients underwent lumbar fusion at 212 levels. Mean operative level segmental lordosis change after each procedure is as follows: ALIF 3.8 ± 6.6° (p < 0.01); LLIF 3.2 ± 3.6° (p<0.01); TLIF 1.9 ± 3.9° (p<0.01); and PSF 0.7 ± 2.9° (p =0.13). Overall lumbar lordosis change after each procedure is as follows: ALIF 4.2 ± 5.8° (p < 0.01); LLIF 2.5 ± 4.1° (p<0.01); TLIF 2.1 ± 6.0 (p = 0.02); PSF -0.5 ± 6.2° (p = 0.66). There were no significant changes in the supradjcent and subjacent level lordosis in all approaches except in ALIF where a significant decrease in supradjecent level lordosis was seen. Mean ADH and PDH significantly increased for all approaches except in PSF where PDH decreased post-operatively. CONCLUSION: LLIF has the ability to improve sagittal contour as well as other interbody approaches and is superior to posterioronly approach in disc height restoration. However, ALIF provides the greatest amount of segmental and overall lumbar lordosis correction. LEVEL OF EVIDENCE: This is a Level III study. CLINICAL RELEVANCE: Regional lordosis correction may be effectively achieved with LLIF. This approach is a good addition to a surgeon's armamentarium in maintenance or restoration of normal lumbar sagittal alignment.

Response of Aneurysmal Bone Cyst to Denosumab.

STUDY DESIGN: Case report and literature review. OBJECTIVE: To describe a unique case of large sacral aneurysmal bone cysts (ABCs) treated with denosumab and review the literature on this rare entity. SUMMARY AND BACKGROUND DATA: ABCs are expansile osteolytic lesions that typically contain blood-filled spaces separated by fibrous septa. Standard treatment includes surgical resection or curettage and packing; however, for some spinal lesions, the standard approach is not optimal. One therapeutic strategy is to treat spinal ABC with an agent that targets a pathway that is dysregulated in a disease with similar pathophysiology. The bone destruction in both giant cell tumors of bone and ABCs is mediated by RANK ligand (RANKL) produced by the tumor cells. Denosumab, a human monoclonal antibody to RANKL, is effective in the treatment of giant cell tumors of bone. METHODS: We report a case of a large sacral ABC that responded to denosumab. A 27-year-old male developed increasing back pain. Imaging revealed a lytic lesion in the sacrum with no clear solid component and regions where the cortex was difficult to identify. ABC was diagnosed on biopsy. Surgery or radiation treatment was expected to be associated with serious morbidity; therefore, denosumab was given using the regimen for giant cell tumors of bone (120  mg monthly with a loading dose). RESULTS: The patient's pain gradually resolved after 2 months of treatment. New bone formation with a more clearly defined cortex was evident on computed tomographic scan at 16 weeks and continued to show evidence of improvement at 7 and 12 months. Biopsy at 12 months revealed a hypocellular fibrous stroma with new bone formation and no giant cells. CONCLUSION: We conclude that denosumab can result in symptomatic and radiological improvement in ABC and may be useful in select cases. LEVEL OF EVIDENCE: 5.

Comparison of open and percutaneous lumbar pedicle screw revision rate using 3-D image guidance and intraoperative CT.

Complications arising from a malpositioned screw can be both devastating and costly. The incidence of neurologic injury secondary to a malpositioned screw is reported to be as high as 7% to 12%. The advancement of image-guided technology has allowed surgeons to place screws more accurately and confirm correct placement prior to leaving the operating room. Only a small number of studies have examined image-guided pedicle screw accuracy in terms of intraoperative revision and reoperation rates. The purpose of this study was to determine the intraoperative revision and return to surgery rates for navigated lumbar pedicle screws and to compare navigated open and percutaneous techniques. The authors reviewed 199 cases of 3-dimensional image-guided lumbar pedicle screw instrumentation from November 2006 to December 2011. Screw or K-wire removal, repositioning, or eventual abandonment of insertion were noted. Chi-square test was used to determine statistical significance in rates between the 2 groups (alpha=0.05). The authors also noted return to surgery secondary to complications from a malpositioned screw. The overall intraoperative revision rate of navigated lumbar pedicle screws was 4.6%. There were significantly more revisions in the percutaneously inserted screws (7.5%) than with the open technique (2.7%) (P=.0004). If K-wire revisions are excluded, there was no statistically significant difference in intraoperative revision rates between the percutaneous and open groups (2.1% vs 2.7%, respectively) (P=.0004). No patients underwent reoperation for a malpositioned screw. This technology has virtually eliminated the need for reoperation for screw malposition. It may suggest a more cost-effective way of preventing neurovascular injuries and revision surgeries.

Comparison of nonnavigated and 3-dimensional image-based computer navigated balloon kyphoplasty.

Balloon kyphoplasty is a common treatment for osteoporotic and pathologic compression fractures. Advantages include minimal tissue disruption, quick recovery, pain relief, and in some cases prevention of progressive sagittal deformity. The benefit of image-based navigation in kyphoplasty has not been established. The goal of this study was to determine whether there is a difference between fluoroscopy-guided balloon kyphoplasty and 3-dimensional image-based navigation in terms of needle malposition rate, cement leakage rate, and radiation exposure time. The authors compared navigated and nonnavigated needle placement in 30 balloon kyphoplasty procedures (47 levels). Intraoperative 3-dimensional image-based navigation was used for needle placement in 21 cases (36 levels); conventional 2-dimensional fluoroscopy was used in the other 9 cases (11 levels). The 2 groups were compared for rates of needle malposition and cement leakage as well as radiation exposure time. Three of 11 (27%) nonnavigated cases were complicated by a malpositioned needle, and 2 of these had to be repositioned. The navigated group had a significantly lower malposition rate (1 of 36; 3%; P=.04). The overall rate of cement leakage was also similar in both groups (P=.29). Radiation exposure time was similar in both groups (navigated, 98 s/level; nonnavigated, 125 s/level; P=.10). Navigated kyphoplasty procedures did not differ significantly from nonnavigated procedures except in terms of needle malposition rate, where navigation may have decreased the need for needle repositioning.

Disc arthroplasty: lessons learned from total joint arthroplasty.

BACKGROUND CONTEXT: With the rapid emergence of new disc arthroplasty designs and ongoing clinical trials, there is great anticipation among clinicians. Inevitably there will be challenges associated with adoption of this new technology. Potential lessons learned from the extensive experience with extremity arthroplasty may predict some of the perils and pitfalls associated with motion-preserving devices in spinal applications. PURPOSE: To review the extremity total joint literature for lessons that may be transferable to disc arthroplasty and anticipate predictable problems that will occur. STUDY DESIGN/SETTING: A literature review and conjectural analysis of key lessons learned from the experience of extremity total joint arthroplasty and anterior lumbar interbody fusion devices with subsequent application of these lessons to disc arthroplasty in the lumbar spine. METHODS: Limited data are available on disc arthroplasty. RESULTS: Particular areas of controversy and uncertainty exist. The ongoing US Food and Drug Administration Investigational Device Exemption clinical trials may provide additional insight into these questions. CONCLUSIONS: Complications will occur. These will be approach related, device related and patient-selection related. Studying the experience of extremity joint arthroplasty may accelerate the learning curve for lumbar disc arthroplasty.

New generation intraoperative three-dimensional imaging (O-arm) in 100 spine surgeries: does it change the surgical procedure?

The O-arm (Medtronic Sofamor Danek, Inc., Memphis, TN, USA), an intraoperative CT scan imaging system, may provide high-quality imaging information to the surgeon. To our knowledge, its impact on spine surgery has not been studied. We reviewed 100 consecutive spine surgical procedures which utilized the new generation mobile intraoperative CT imaging system (O-arm). The most common diagnoses were degenerative conditions (disk disease, spondylolisthesis, stenosis and acquired kyphosis), seen in 49 patients. The most common indication for imaging was spinal instrumentation in 81 patients (74 utilized pedicle screws). In 52 (70%) of these, the O-arm was used to assess screw position after placement; in 22 (30%), it was coupled with Stealth navigation (Medtronic Sofamor Danek, Inc.) to guide screw placement. Another indication was to assess adequacy of spinal decompression in 38 patients; in 19 (50%) of these, intrathecal contrast material was used to obtain an intraoperative CT myelogram. In 20 patients O-arm findings led to direct surgeon intervention in the form of screw removal/repositioning (n=13), further decompression (n=6), interbody spacer repositioning (n=1), and removal of kyphoplasty trocar (n=1). In 20% of spine surgeries, the procedure was changed based on O-arm imaging findings. We found the O-arm to be useful for assessment of instrumentation position, adequacy of spinal decompression, and confirmation of balloon containment and cement filling in kyphoplasty. When used with navigation for image-guided surgery, it obviated the need for registration.

Comparison of cranial facet joint violation rates between open and percutaneous pedicle screw placement using intraoperative 3-D CT (O-arm) computer navigation.

STUDY DESIGN: Retrospective study comparing cranial facet joint violation rates of open and percutaneous pedicle screws inserted using 3-dimensional image-guidance. OBJECTIVE: To determine the rate of cranial facet joint violation in intraoperative computed tomography (CT) image-guided lumbar pedicle screw instrumentation and compare facet joint violation rates between CT image-guided open and percutaneous techniques. SUMMARY OF BACKGROUND DATA: Facet joint violation by pedicle screws can potentially result in a higher rate of adjacent segment degeneration. Reported cranial facet joint violation rates range from 7% to 100%. Intraoperative image-guidance, which has enhanced pedicle screw placement accuracy, may aid in avoiding impingement of the cranial facet joints. METHODS: We reviewed 188 cases of 3-dimensional image-guided lumbar pedicle screw instrumentation from November 2006 to December 2011. The cranial screws of each construct were graded by 3 reviewers according to the Seo classification (0 = no impingement; 1 = screw head in contact/suspected to be in contact with joint; 2 = screw clearly invaded the joint) on intraoperative axial CT images. If there was a difference in evaluation, a consensus was reached to arrive at a single grade. The χ2 test was used to determine significance between the open and percutaneous group (α = 0.05). RESULTS: A total of 370 screws (245 open, 125 percutaneous) were graded. Overall facet joint violation rate was 18.9% (grade 1 = 16.2%, grade 2 = 2.7%). Open technique (grade 1 = 22.4%, grade 2 = 4.1%) had a significantly higher violation rate than percutaneous technique (grade 1 = 4%, grade 2 = 0%) (P < 0.0001). There is a trend of an increasing likelihood of facet joint violation from L1 to L5. CONCLUSION: The use of intraoperative CT image-guidance in lumbar pedicle screw placement resulted in a facet joint violation rate at the lower end of the reported range in literature. The percutaneous technique has a significantly lower facet violation rate than the open technique. LEVEL OF EVIDENCE: 4.

Neck-shoulder crossover: how often do neck and shoulder pathology masquerade as each other?

Cases of consecutive new patients seen at orthopedic spine and shoulder clinics were reviewed. Four percent of spine patients had significant shoulder pathology, and 3.6% of shoulder patients had significant spine pathology. Identification of the correct pain generator is a prerequisite for effective treatment in patients with neck and/or shoulder problems. However, distinguishing between the two can be difficult. Relative frequencies of how often one is mistaken for the other have not been well established. Six hundred ninety-four new patients were seen at the orthopedic shoulder clinic (n = 452) or spine clinic (n = 242) at an academic institution during a 2-year period. One hundred seven patients had previous shoulder surgery, and 39 had previous neck surgery. The 548 patients (shoulder clinic, 345; spine clinic, 203) who had no previous surgery were reviewed with respect to workup performed, final diagnosis, subsequent operative procedures, and incidence of referral from the shoulder clinic to the spine clinic and vice versa. Among the patients seen at the shoulder clinic, 325 (94.2%) had shoulder pathology, 6 (1.7%) had neck but no shoulder pathology, 6 (1.7%) had shoulder and neck pathology, and 8 (2.3%) had an unidentifiable cause of pain. Of the 12 patients with neck pathology, none underwent neck surgery. Among the patients seen at the spine clinic, 182 (89.7%) had neck pathology, 5 (2.5%) had shoulder but no neck pathology, 3 (1.5%) had neck and shoulder pathology, and 13 (6.4%) had an unidentifiable cause of pain. Of the 8 patients with shoulder pathology, 1 (12.5%) underwent shoulder surgery. Our analysis suggests that for patients who present to a shoulder surgeon's clinic for shoulder pain, 3.6% will turn out to have neck pathology. For patients who present to a spine surgeon's clinic for neck pain, 4% may turn out to have shoulder pathology. Thus, approximately 1 in 25 patients seen at a surgeon's clinic for a presumed shoulder or neck problem may exhibit neck-shoulder crossover, in which pathology in one may be mistaken for or coexist with the other.

Adult Degenerative Scoliosis Surgical Outcomes: A Systematic Review and Meta-analysis.

INTRODUCTION: There is increasing awareness of adult degenerative or de novo scoliosis, and its surgical treatment when indicated can be challenging and resource intense. Surgical randomized controlled trials are rare, and observational studies pose limitations because of the heterogeneity of surgical practices, techniques, and patient populations. Pooled analysis of current literature may identify effective treatment strategies and guide future efforts at prospective clinical research. This study aimed to synthesize existing data on the outcomes of surgical intervention for adult degenerative scoliosis. METHODS: PubMed, Medline, Cochrane, and Web of Science databases were searched using key words and were limited to the English language. Spine surgeons reviewed abstracts and evaluated whether they contained surgically treated cohorts of adults (more than 18 years of age) with degenerative scoliosis. Full-text articles were reviewed in detail and data were abstracted. All meta-analyses were conducted using random effects models and heterogeneity was estimated with I2. Random-effects meta-regression models were used to investigate the association of treatment effects with baseline levels of each outcome. RESULTS: Of 482 articles, 24 (n = 805) met inclusion criteria Available outcomes included Cobb angle correction, coronal and sagittal balance, visual analog scale for pain (VAS), and Oswestry Disability Index. Despite significant heterogeneity among studies, random-effects meta-analysis showed significant improvements in Cobb angle (-11.1°; 95% confidence interval [CI], -13.86° to -8.40°), coronal balance (7.674 mm; 95% CI, -10.5 to -4.9), VAS (-3.24; 95% CI, -4.5 to -1.98), and Oswestry Disability Index (-27.18%; 95% CI, -34.22 to -20.15) postoperative treatment (p < .001). Meta-regression models showed that preoperative values for Cobb angle, coronal balance, and VAS were significantly associated with surgical treatment effect (p < .05). Changes in sagittal balance did not reach statistical significance although only 6 articles were included. CONCLUSIONS: Exhaustive literature review yielded 24 studies reporting preoperative and postoperative data regarding the surgical treatment of adult degenerative scoliosis. No randomized clinical trials (RCTs) were identified. Despite heterogeneity, a limited meta-analysis showed significant improvement in Cobb angle, coronal balance, and VAS after surgical treatment of adult degenerative scoliosis.