Prognostic Impact of Para-Aortic Lymph Node Metastasis in Resected Non-Pancreatic Periampullary Cancers.

BACKGROUND: Surgery remains debatable in para-aortic lymph node (PALN, station 16b1) metastasis in non-pancreatic periampullary cancer (NPPAC). This study examined the impact of PALN metastasis on outcomes following pancreaticoduodenectomy (PD) in NPPAC. METHODS: A retrospective analysis of patients with NPPAC who were explored for PD with PALN dissection was performed. Based on the extent of nodal involvement on final histopathology, they were stratified as node-negative (N0), regional node involved (N+) and metastatic PALN (N16+) and their outcomes were compared. RESULTS: Between 2011 and 2022, 153/887 PD patients underwent a PALN dissection, revealing N16+ in 42 patients (27.4%), of whom 32 patients underwent resection. The 3-years overall survival (OS) for patients with N16+ was 28% (95% confidence interval [CI] 13-60%), notably lower than the 67% (95% CI 53-83.5%; p = 0.007) for those without PALN metastasis. Stratified by nodal involvement, the median OS for N+ and N16+ patients was similar (28.4 months and 26.2 months, respectively). The N0 subgroup had a significantly longer 3-years OS of 87.5% (95% CI 79-96.7%; p = 0.0051). Interestingly, 10 patients not offered resection following N16+ identified on frozen section had a median survival of only 9 months. The perioperative morbidity and mortality in patients undergoing PD with PALN dissection were similar to standard resections. CONCLUSION: In a select group of patients with NPPAC, PD in isolated PALN metastasis was associated with improved OS. The survival in this group of patients was comparable with regional node-positive patients and significantly better than palliative treatment alone.

Factors Predicting Prognosis in Metastatic Grade 1 Gastro-entero-pancreatic Neuroendocrine Tumors.

INTRODUCTION: The incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NET) has steadily increased. These tumors are considered relatively indolent even when metastatic. What determines survival outcomes in such situations is understudied. MATERIALS AND METHODS: Retrospective analysis of a prospectively maintained NET clinic database, to include patients of metastatic grade 1 GEP-NET, from January 2018 to December 2021, to assess factors affecting progression-free survival (PFS). RESULTS: Of the 589 patients of GEP-NET treated during the study period, 100 were grade 1, with radiological evidence of distant metastasis. The median age was 50 years, with 67% being men. Of these, 15 patients were observed, while 85 patients received treatment in the form of surgery (n = 32), peptide receptor radionuclide therapy (n = 50), octreotide LAR (n = 22), and/or chemotherapy (n = 4), either as a single modality or multi-modality treatment. The median (PFS) was 54.5 months. The estimated 3-year PFS and 3-year overall survival rates were 72.3% (SE 0.048) and 93.4% (SE 0.026), respectively. On Cox regression, a high liver tumor burden was the only independent predictor of PFS (OR 3.443, p = 0.014). The 5-year OS of patients with concomitant extra-hepatic disease was significantly lower than that of patients with liver-limited disease (70.7% vs. 100%, p = 0.017). CONCLUSION: A higher burden of liver disease is associated with shorter PFS in patients with metastatic grade I GEP-NETs. The OS is significantly lower in patients with associated extrahepatic involvement. These parameters may justify a more aggressive treatment approach in metastatic grade 1 GEP-NETs.

Central versus distal pancreatectomy for low-grade and benign pancreatic neck-body tumours.

PURPOSE: Central pancreatectomy (CP) offers parenchymal preservation compared to conventional distal pancreato-splenectomy for pancreatic neck and body tumours. However, it is associated with more morbidity. This study is aimed at evaluating the peri-operative and long-term functional outcomes, comparing central and distal pancreatectomies (DPs). METHODS: Retrospective analysis of patients undergoing pancreatic resections for low-grade malignant or benign tumours in pancreatic neck and body was performed (from January 2007 to December 2022). Preoperative imaging was reviewed for all cases, and only patients with uninvolved pancreatic tail, whereby a CP was feasible, were included. Peri-operative outcomes and long-term functional outcomes were compared between CP and DP. RESULTS: One hundred twenty-two (5.2%) patients, amongst the total of 2304 pancreatic resections, underwent central or distal pancreatectomy for low-grade malignant or benign tumours. CP was feasible in 55 cases, of which 23 (42%) actually underwent CP and the remaining 32 (58%) underwent DP. CP group had a significantly longer operative time [370 min (IQR 300-480) versus 300 min (IQR 240-360); p = 0.002]; however, the major morbidity (43.5% versus 37.5%; p = 0.655) and median hospital stay (10 versus 11 days; p = 0.312) were comparable. The long-term endocrine functional outcome was favourable for the CP group [endocrine insufficiency rate was 13.6% in central versus 42.8% in distal (p = 0.046)]. CONCLUSION: Central pancreatectomy offers better long-term endocrine function without any increased morbidity in low malignant potential or benign pancreatic tumours of neck and body region.

Robotic Pancreaticoduodenectomy with 'SMA-First Approach (Posterior and Right Medial)' and 'Triangle Operation'.

BACKGROUND: Notable improvements in pancreatic cancer surgery have been due to utilization of the superior mesenteric artery (SMA)-first approach1 and triangle operation (clearance of triangle tissue between origin of SMA and celiac artery).2 The SMA-first approach was originally defined to assess resectability before taking the irreversible surgical steps. However, in the present era, resectability is judged by the preoperative radiology, and the benefit of the SMA-first approach is by improving the R0 resection rate and reducing blood loss. The basic principle is to identify the SMA at its origin and in the distal part, to guide the plane of uncinate dissection. This video demonstrates the combination of the posterior and right medial SMA-first approach along with triangle clearance during robotic pancreaticoduodenectomy (RPD). METHODS: The technique consisted of early dissection of SMA from the posterior aspect, by performing a Kocher maneuver using the 'posterior SMA-first approach'. The origin of the celiac artery, along with the SMA, was defined early in the surgery. During uncinate process dissection, the 'right/medial uncinate approach' was used to approach the SMA. 'Level 3 systematic mesopancreatic dissection' was performed along the SMA,3 culminating in the 'triangle operation'.2 RESULTS: The procedure was performed within 600 min, with a blood loss of 150 mL and no intraoperative or postoperative complications. The final histopathology report showed a moderately differentiated adenocarcinoma (pT2, pN2), with all resection margins free. CONCLUSION: The standardized technique of the SMA-first approach and triangle clearance during RPD is demonstrated in the video. Prospective studies should further evaluate the benefits of this procedure.

Outcomes following robotic assisted total knee arthroplasty compared to conventional total knee arthroplasty.

INTRODUCTION: This study elaborates on previous research to compare length of stay, complication rates, and total cost between patients undergoing robotic assisted total knee arthroplasty (rTKA) and conventional total knee arthroplasty (cTKA). We hypothesized that patients undergoing rTKA would have reduced length of stay, lower complication rates, improved perioperative outcomes, and higher total healthcare costs than those undergoing cTKA. METHODS: Data were collected from the National Inpatient Sample Database Healthcare Cost and Utilization Project between the years 2016-2019. Patients undergoing rTKA and cTKA were identified under International Classification of Diseases, 10th revision codes (ICD-10-CM/PCS). Length of stay, specific complications, and total costs were examined at time point. SPSS (v 27.0 8, IBM Corp. Armonk, NY) was utilized to compare demographic and analytical statistics between rTKA and cTKA. rTKA and cTKA were compared both before and after propensity matching. RESULTS: 17,249 rTKA (3.09%) and 541,122 cTKA (96.91%) were included. Compared to cTKA patients, rTKA patients had reduced average length of stay of 1.91 days (p < 0.001), higher average total cost of $67133.34 (p < 0.001), reduced periprosthetic infection (OR = 0.027, p < 0.001), periprosthetic dislocation (OR = 0.117, p < 0.001), periprosthetic mechanical complication (OR = 0.315, p < 0.001), pulmonary embolism (OR = 0.358, p < 0.001), transfusion (OR = 0.366, p < 0.001), pneumonia (OR = 0.468, p = 0.002), deep vein thrombosis (OR = 0.479, p = 0.001), and blood loss anemia (OR = 0.728, p < 0.001). These differences remained statistically significant even after propensity matching. CONCLUSIONS: This study supports our hypothesis that rTKA is associated with fewer complications, but higher average total cost than cTKA. Our study shows that rTKA can be safely performed in older and sicker patients. Future studies assessing the impacts of these findings on patient reported outcomes would provide further insight into the benefits of rTKA. Furthermore, identifying patient specific factors that place them at risk for increased complications with cTKA as opposed to rTKA could provide surgeons insight on the method of TKA that maximizes patient outcomes while minimizing healthcare cost.

Racial variations in complications and costs following total knee arthroplasty: a retrospective matched cohort study.

INTRODUCTION: In this study, we evaluate how race corresponds to specific complications and costs following total knee arthroplasty (TKA). Our hypothesis was that minority patients, comprising Black, Asian, and Hispanic patients, would have higher complication and revision rates and costs than White patients. METHODS: Data from 2014 to 2016 were collected from a large commercial insurance database. TKA patients were assigned under Current Procedural Terminology (CPT-27447) and International Statistical Classification of Diseases (ICD-9-P-8154) codes. Minority patients were compared to White patients before and after matching for age, gender, and tobacco use, diabetes, and obesity comorbidities. Standardized complications, revisions, and total costs at 30 days, 90 days, and 1 year were compared between the groups using unequal variance t tests. RESULTS: Overall, 140,601 White (92%), 10,247 Black (6.7%), 1072 Asian (0.67%), and 1725 Hispanic (1.1%) TKA patients were included. At baseline, minority patients had 7-10% longer lengths of stay (p = 0.0001) and Black and Hispanic patients had higher Charlson and Elixhauser comorbidity indices (p = 0.0001), while Asian patients had a lower Elixhauser comorbidity index (p < 0.0001). Black patients had significantly higher complication rates and higher rates of revision (p = 0.03). Minority patients were charged 10-32% more (p < 0.0001). Following matching, all minority patients had lengths of stay 8-10% longer (p = 0.001) and Black patients had higher Charlson and Elixhauser comorbidity indices (p < 0.0001) while Asian patients had a lower Elixhauser comorbidity index (p = 0.0008). Black patients had more equal complication rates and there was no significant difference in revisions in any minority cohort. All minority cohorts had significantly higher total costs at all time points, ranging from 9 to 31% (p < 0.0001). CONCLUSION: Compared to White patients, Black patients had significantly increased rates of complications, along with greater total costs, but not revisions. Asian and Hispanic patients, however, did not have significant differences in complications or revisions yet still had higher costs. As a result, this study corroborates our hypothesis that Black patients have higher rates of complications and costs than White patients following total knee arthroplasty and recommends efforts be taken to tackle health inequities to create more fairness in healthcare. This same hypothesis, however, was not supported when evaluating Asian and Hispanic patients, probably because of the few patients included in the database and deserves further investigation.

Big data and RCT's in surgical oncology: Impact on improving hepatopancreatobiliary cancer surgical care on the global stage.

Randomized controlled clinical trials (RCTs) are at the heart of "evidence-based" medicine. Conducting well-designed RCTs for surgical procedures is often challenged by inadequate recruitment accrual, blinding, or standardization of the surgical procedure, as well as lack of funding and evolution of the treatment strategy during the many years over which such trials are conducted. In addition, most clinical trials are performed in academic high-volume centers with highly selected patients, which may not necessarily reflect a "real-world" practice setting. Large databases provide easy and inexpensive access to data on a large and diverse patient population at a variety of treatment centers. Furthermore, large database studies provide the opportunity to answer questions that would be impossible or very arduous to answer using RCTs, including questions regarding health policy efficacy, trends in surgical practice, access to health care, the impact of hospital volume, and adherence to practice guidelines, as well as research questions regarding rare disease, infrequent surgical outcomes, and specific subpopulations. Prospective data registries may also allow for quality benchmarking and auditing. There are several high-quality RCTs providing evidence to support current practices in hepatopancreatobiliary (HPB) oncology. Evidence from big data bridges the gap in several instances where RCTs are lacking. In this article, we review the evidence from RCTs and big data in HPB oncology identify the existing lacunae, and discuss the future directions of research in HPB oncology.

Multiple genes in a single GWAS risk locus synergistically mediate aberrant synaptic development and function in human neurons.

The mechanistic tie between genome-wide association study (GWAS)-implicated risk variants and disease-relevant cellular phenotypes remains largely unknown. Here, using human induced pluripotent stem cell (hiPSC)-derived neurons as a neurodevelopmental model, we identify multiple schizophrenia (SZ) risk variants that display allele-specific open chromatin (ASoC) and are likely to be functional. Editing the strongest ASoC SNP, rs2027349, near vacuolar protein sorting 45 homolog (VPS45) alters the expression of VPS45, lncRNA AC244033.2, and a distal gene, C1orf54. Notably, the transcriptomic changes in neurons are associated with SZ and other neuropsychiatric disorders. Neurons carrying the risk allele exhibit increased dendritic complexity and hyperactivity. Interestingly, individual/combinatorial gene knockdown shows that these genes alter cellular phenotypes in a non-additive synergistic manner. Our study reveals that multiple genes at a single GWAS risk locus mediate a compound effect on neural function, providing a mechanistic link between a non-coding risk variant and disease-related cellular phenotypes.

Trapezoidal Wedge Osteotomy with Ligament Reconstruction for Chronic Instability following Failed ACLR.

We describe a case of a failed anterior cruciate ligament (ACL) reconstruction that underwent revision surgery. Lachman, anterior drawer and valgus stress tests were all grade 3, indicating ACL and medial collateral ligament (MCL) insufficiency. Posterior tibial slope (PTS) was 18° and coronal alignment was 5° valgus. The PTS and valgus alignment were possible contributing factors to the failure of the ACL reconstruction (ACLR). A novel approach was taken wherein an anterior closing wedge osteotomy (ACWO) and varising osteotomy were done after performing a tibial tuberosity (TT) osteotomy followed by revision ACLR and MCL reconstruction (MCLR). At 2-year follow-up, the coronal alignment changed to 1° varus and the tibial slope to 5°. The Knee Society Score improved from 34 pre-operatively to 90, with the patient returning to weightlifting and pre-injury activity levels.

Two-Year Clinical and Radiographic Outcomes for Percutaneous Lumbar Interbody Fusion With an Expandable Titanium Cage Through Kambin's Triangle Without Facetectomy.

BACKGROUND: There has been heightened interest in performing percutaneous lumbar interbody fusions (percLIFs) through Kambin's triangle, an anatomic corridor allowing entrance into the disc space. However, due to its novelty, there are limited data regarding the long-term benefits of this procedure. Our objective was to determine the long-term efficacy and durability of the percutaneous insertion of an expandable titanium cage through Kambin's triangle without facetectomy. METHODS: A retrospective review of patients undergoing percLIF via Kambin's triangle using an expandable titanium cage was performed. Demographics, visual analog scale (VAS) scores, Oswestry Disability Index (ODI), radiographic measurements, perioperative variables, and complications were recorded. VAS, ODI, and radiographic measurements were compared with baseline using the generalized estimating equations assuming normally distributed data. Fusion was assessed with computed tomography (CT) at 1 and 2 years after the procedure. RESULTS: A total of 49 patients were included. Spondylolisthesis, lumbar lordosis (LL), sacral slope, pelvic tilt, and anterior/posterior disc space height were all significantly improved postoperatively at each time point of 3, 6, 12, and 24 months (P < 0.001). Pelvic incidence-LL mismatch decreased significantly at each follow-up (P < 0.001) with a mean reduction of 4° by 24 months. VAS back scores reduced by >2 points at the 6, 12, and 24 month follow-ups. ODI scores reduced by >15 points at the 12- and 24-month follow-ups. Of the patients who had 1- and 2-year CT images, fusion rates at those time points were 94.4% (17/18) and 87.5% (7/8), respectively. The mean annual rate of surgically significant adjacent segment disease was 2.74% through an average follow-up of 2.74 years. CONCLUSION: These results highlight that percLIF, a procedure done without an endoscope or facetectomy, can be performed using an expandable titanium cage through Kambin's triangle with excellent radiographic and clinical results. CLINICAL RELEVANCE: percLIF via Kambin's triangle is a safe and succesful procedure with long-term improvements in both clinical and radiographic outcomes.

Complications and Costs Associated With Ethnicity Following Total Hip Arthroplasty: A Retrospective Matched Cohort Study.

BACKGROUND: Minority patients often have greater numbers of complications, revisions, and costs after total hip arthroplasty (THA). This study investigates how race correlates with specific surgical complications, revisions, and total costs following THA both before and after propensity matching. METHODS: Data from 2014-2016 were collected from a large commercial insurance database known as PearlDiver. THA patients were assigned under Current Procedural Terminology (CPT-27130) and International Statistical Classification of Diseases (ICD-9-P-8151) codes and then divided into groups based on racial status in the database. Patients of different ethnicities including White, Black, Asian, and Hispanic patients were compared in regard to age, gender, comorbidities, lengths of stay, and surgical complications and costs at thirty days, ninety days, and one year using unequal variance t-tests. Black, Asian, and Hispanic patients are collectively referred to as minority patients. Patient comparisons were done both before and after matching for age, gender, tobacco use, diabetes, and obesity comorbidities. RESULTS: A total of 73,688 White (93%), 4,822 Black (6%), 268 Asian (0.3%), and 420 Hispanic (0.5%) THA patients were included. Significantly more minority patients underwent THA under the age of 65 and had higher comorbidity indices and lengths of stay. Black patients had significantly higher complication rates, but there was no significant difference in rates of revision in any minority group. Minority patients were charged 9%-83% more. After matching, Black and Hispanic patients maintained higher comorbidity indices and lengths of stay. Black patients had a spectrum of complication rates but significantly decreased revision rates. Furthermore, after matching, minority patients were charged 5%-65% more. CONCLUSIONS: Black patients experienced significantly greater rates of complications and higher total costs; whereas, Asian and Hispanic patients did not have significant differences in complications but did have higher costs. Therefore, this study aligns with previous studies and supports our hypothesis that Black ethnicity patients have worse outcomes than White ethnicity patients after THA, advocating for reducing health disparities and establishing more equitable healthcare, but does not support our hypothesis for Asian and Hispanic patients, likely due to a small study population size, warranting further research into the topic.

Enterothecal fistula as a rare cause of adult pneumocephalus and meningitis: a case report.

Background: Enterothecal fistulas are pathological connections between the gastrointestinal system and subarachnoid space. These rare fistulas occur mostly in pediatric patients with sacral developmental anomalies. They have yet to be characterized in an adult born without congenital developmental anomaly yet must remain on the differential diagnosis when all other causes of meningitis and pneumocephalus have been ruled out. Good outcomes rely on aggressive multidisciplinary medical and surgical care, which are reviewed in this manuscript. Case Description: A 25-year-old female with history of a sacral giant cell tumor resected via anterior transperitoneal approach followed by posterior L4-pelvis fusion presented with headaches and altered mental status. Imaging revealed that a portion of small bowel had migrated into her resection cavity and created an enterothecal fistula resulting in fecalith within the subarachnoid space and florid meningitis. The patient underwent a small bowel resection for fistula obliteration, and subsequently developed hydrocephalus requiring shunt placement and two suboccipital craniectomies for foramen magnum crowding. Ultimately, her wounds became infected requiring washouts and instrumentation removal. Despite a prolonged hospital course, she made significant recovery and at 10-month following presentation, she is awake, oriented, and able to participate in activities of daily living. Conclusions: This is the first case of meningitis secondary to enterothecal fistula in a patient without a previous congenital sacral anomaly. Operative intervention for fistula obliteration is the primary treatment and should be performed at a tertiary hospital with multidisciplinary capabilities. If recognized quickly and appropriately treated, there is a possibility of good neurological outcome.

Novel Approach to Percutaneous Lumbar Surgeries via Kambin's Triangle-Radiographic and Surgical Planning Analysis with Nerve Segmentation Technology.

OBJECTIVE: While Kambin's Triangle has become an ever more important anatomic window given its proximity to the exiting nerve root, there have been limited studies examining the effect of disease on the corridor. Our goal was to better understand how pathology can affect Kambin's Triangle, thereby altering the laterality of approach for percutaneous lumbar interbody fusion (percLIF). METHODS: The authors performed a single-center retrospective review of patients evaluated for percLIF. The areas of Kambin's Triangle were measured without and with nerve segmentation. For the latter, the lumbosacral nerve roots on 3-dimensional T2 magnetic resonance imaging were manually segmented. Next, the borders of Kambin's Triangle were delineated, ensuring no overlap between the area and nerve above. RESULTS: Fifteen patients (67.5 ± 9.7 years, 46.7% female) were retrospectively reviewed. We measured 150 Kambin's Triangles. The mean areas from L1-S1 were 50.0 ± 12.3 mm2, 73.8 ± 12.5 mm2, 83.8 ± 12.2 mm2, 88.5 ± 19.0 mm2, and 116 ± 29.3 mm2, respectively. When pathology was present, the areas significantly decreased at L4-L5 (P = 0.046) and L5-S1 (P = 0.049). Higher spondylolisthesis and smaller posterior disk heights were linked with decreased areas via linear regression analysis (P < 0.05). When nerve segmentation was used, the areas were significantly smaller from L1-L5 (P < 0.05). Among 11 patients who underwent surgery, none suffered from postoperative neuropathies. CONCLUSIONS: These results illustrate the feasibility of preoperatively segmenting lumbosacral nerves and measuring Kambin's Triangle to help guide surgical planning and determine the ideal laterality of approach for percLIF.

What enhances the in-hospital mortality following total hip arthroplasty? A national inpatient sample-based study.

PURPOSE: With prolonged life expectancy and advancements in prosthetic designs, the proportion of patients belonging to diverse age groups undergoing total hip arthroplasty (THA) has progressively increased. In this context, the details regarding risk factors associated with mortality after THA, and its prevalence need to be clearly understood. This study sought to identify the possible co-morbidities associated with post-THA mortality. METHODS: Based on Nationwide Inpatient Sample (NIS) database, patients undergoing THA from 2016 to 2019 (using ICD-10CMP) were identified. The included cohort was stratified into two groups: "early mortality" and "no mortality" groups. The data regarding patients' demographics, co-morbidities, and associated complications were compared between the groups. RESULTS: Overall, 337,249 patients underwent THA, among whom, 332 (0.1%) died during their hospital admission ("early mortality" group). The remaining patients were included under "no mortality" group (336,917 patients). There was significantly higher mortality in the patients, who underwent emergent THA (as compared with elective THA: odd's ratio 0.075; p < 0.001). Based on multivariate analysis, presence of liver cirrhosis, chronic kidney disease (CKD) and previous history of organ transplant increased the odds of mortality {odds ratio [Exp (B)]} after THA by 4.66- (p < 0.001), 2.37-fold (p < 0.001) and 1.91-fold (p = 0.04), respectively. Among post-THA complications, acute renal failure (ARF), pulmonary embolism (PE), pneumonia, myocardial infarction (MI), and prosthetic dislocation increased the odds of post-THA mortality by 20.64-fold (p < 0.001), 19.35-fold (p < 0.001), 8.21-fold (p < 0.001), 2.71-fold (p = 0.05) and 2.54-fold (p < 0.001), respectively. CONCLUSION: THA is a safe surgery with low mortality rate during early post-operative period. Cirrhosis, CKD, and previous history of organ transplant were the most common co-morbidities associated with post-THA mortality. Among post-operative complications, ARF, PE, pneumonia, MI, and prosthetic dislocation substantially enhanced the odds of post-THA mortality.

Rescue of neuropsychiatric phenotypes in a mouse model of 16p11.2 duplication syndrome by genetic correction of an epilepsy network hub.

Neuropsychiatric disorders (NPDs) are frequently co-morbid with epilepsy, but the biological basis of shared risk remains poorly understood. The 16p11.2 duplication is a copy number variant that confers risk for diverse NPDs including autism spectrum disorder, schizophrenia, intellectual disability and epilepsy. We used a mouse model of the 16p11.2 duplication (16p11.2dup/+) to uncover molecular and circuit properties associated with this broad phenotypic spectrum, and examined genes within the locus capable of phenotype reversal. Quantitative proteomics revealed alterations to synaptic networks and products of NPD risk genes. We identified an epilepsy-associated subnetwork that was dysregulated in 16p11.2dup/+ mice and altered in brain tissue from individuals with NPDs. Cortical circuits from 16p11.2dup/+ mice exhibited hypersynchronous activity and enhanced network glutamate release, which increased susceptibility to seizures. Using gene co-expression and interactome analysis, we show that PRRT2 is a major hub in the epilepsy subnetwork. Remarkably, correcting Prrt2 copy number rescued aberrant circuit properties, seizure susceptibility and social deficits in 16p11.2dup/+ mice. We show that proteomics and network biology can identify important disease hubs in multigenic disorders, and reveal mechanisms relevant to the complex symptomatology of 16p11.2 duplication carriers.

A Comparison of Percutaneous Pedicle Screw Accuracy Between Robotic Navigation and Novel Fluoroscopy-Based Instrument Tracking for Patients Undergoing Instrumented Thoracolumbar Surgery.

BACKGROUND: The accuracy of pedicle screws placed with instrument tracking and robotic navigation are individually comparable or superior to placement using standard fluoroscopy, however head-to-head comparisons between these adjuncts in a similar surgical population have yet to be performed. METHODS: Consecutive patients undergoing percutaneous thoracic and lumbosacral spinal instrumentation were retrospectively enrolled. Instrumentation was performed using either fluoroscopy-based instrument tracking system (TrackX, TrackX Technologies) or robotic-navigation (ExcelsiusGPS, Globus Medical). Postinstrumentation computed tomography scans were graded for breach according to the Gertzbein-Robbins scale, with "acceptable" screws deemed as Grade A or B and "unacceptable" screws deemed as Grades C through E. Accuracy data was compared between both instrumentation modalities. RESULTS: Fifty-three patients, comprising a total of 250 screws (167 robot, 83 instrument tracking) were included. The overall accuracy between both modalities was similar, with 96.4% and 97.6% of screws with acceptable accuracy between instrument tracking and robotic navigation, respectively (I-squared 0.30, df = 1, P = 0.58). Between instrument tracking and robotic navigation, 92.8% and 95.8% of screws received Grade A, 3.6% and 1.8% a Grade B, 1.2% and 1.2% a Grade C, 1.2% and 0.6% a Grade D, and 1.2% and 0.6% a Grade E, respectively. The robot was abandoned intraoperatively in 2 cases due to unrecoverable registration inaccuracy or software failure, leading to abandonment of 8 potential screws (4.8%). CONCLUSIONS: In a similar patient population, there is a similarly high degree of instrumentation accuracy between fluoroscopy-based instrument tracking and robotic navigation. There is a rare chance for screw breach with either surgical adjunct.

True all inside meniscus repair using the popliteus tendon.

The popliteus tendon is a useful anchor point to repair the posterior horn of the lateral meniscus. We describe a new, economical technique that does not violate the neurovascular structures, using an antegrade suture passer and a 2-0 fiberwire to repair the posterior segment including posterior horn of the lateral meniscus taking bites through the capsule and meniscus or the popliteus tendon and meniscus with no anchors in the capsule or popliteus. 9 patients were operated upon using this technique and the mean IKDC score improved from 24.2 to 84, p < 0.01, mean pre op Tegner improved from 1.88 to 6.63 p < 0.01, median hop test from 0 to 4, p = 0 at a mean 15.2 months post surgery. 8 patients had a negative Lachman and 1 grade 2 Lachman at 12 months follow up but was asymptomatic. The Barret's criteria was negative for all 9 patients at latest follow up.

Ultrasound guided arthroscopic meniscus surgery.

Ultrasound is a useful adjunctive intra-operative imaging modality for soft tissue pathologies. It is readily available in the operating theater and has the distinct advantage of being more portable than an MRI, with no harmful radiation. It is especially useful for determining if any extra articular cysts have been decompressed through arthroscopic surgery, if a parameniscal cyst has been removed completely or if extrusion has been reduced adequately in a meniscus root repair. In our series, intra-operative ultrasound was used for two cases of medial meniscus horizontal tear with meniscus cyst excision, one case of lateral parameniscal cyst without a communicating tear, and five cases of meniscus root repairs. Ultrasound has the potential to be an important intra-operative diagnostic modality not only in diagnosing pathologies but also accurately localizing the soft tissue pathology, which is critical in arthroscopic surgery where the incisions are small. It also has the added advantage of guiding portal placements, especially in areas where there are neurovascular structures, to avoid injuring them. However, training in its effective use by the surgeon is important.