What are the predisposing factors for periprosthetic fractures following total hip arthroplasty? - a National Inpatient Sample-based study.

INTRODUCTION: With a progressive rise in the number of total hip arthroplasties (THA) over the past decades, the proportion of patients sustaining peri-prosthetic fractures (PPF) has been substantially increasing. In this context, the need for clearly understanding the factors predisposing patients to PPF following THA and the impact of these adverse complications on the overall healthcare burden cannot be understated. MATERIALS AND METHODS: Based upon the Nationwide Inpatient Sample (NIS) database, the patients who underwent THA in the United States between 2016 and2019 (with ICD-10 CMP code) were identified. The patients were divided into 2 groups; group A - patients who sustained PPF and group B - those who did not. The information about the patients' demographic profile, medical comorbidities; and hospital admission (including length of stay and expenditure incurred) were analysed; and compared between the 2 groups. RESULTS: Overall, 367,890 patients underwent THA, among whom 4,425 (1.2%) sustained PPF (group A). The remaining patients were classified under group B (363,465 patients). On the basis of multi-variate analysis (MVA), there was a significantly greater proportion of females, elderly patients, and emergent admissions (p < 0.001) in group A. The length of hospital stay, expenditure incurred and mortality were also significantly higher (p = 0.001) in group A. Based on MVA, Down's syndrome (odd's ratio 3.15, p = 0.01), H/O colostomy (odd's ratio 2.09, p = 0.008), liver cirrhosis (odd's ratio 2.01, p < 0.001), Parkinson's disease (odd's ratio 1.49, p = 0.004), morbid obesity (odd's ratio 1.44, p < 0.001), super obesity (odd's ratio 1.49, p = 0.03), and H/O CABG (coronary artery bypass graft; odd's ratio 1.21, p = 0.03) demonstrated significant association with PPF (group A). CONCLUSION: Patients with PPF require higher rates of emergent admission, longer hospital stay and greater admission-related expenditure. Female sex, advanced age, morbid or super obesity, and presence of medical comorbidities (such as Down's syndrome, cirrhosis, Parkinson's disease, previous colostomy, and previous CABG) significantly enhance the risk of PPF after THA. These medical conditions must be kept in clinicians' minds and close follow-up needs to be implemented in such situations so as to mitigate these complications.

Patient disposition after discharge following primary total hip arthroplasty: home versus skilled nursing facility-a study based on national inpatient sample database.

INTRODUCTION: In view of the shortened length of hospital stay following THA, an increasing proportion of patients have required transfer to "extended-care" (ECF) or "skilled nursing" facilities (SNF) over the past years. As a result, the expenditure related to postoperative care facility has been acknowledged as a crucial component of total economic burden associated with THA. In this context, the clinical and demographic factors leading to the need for transfer of patients to SNF following primary THA need to be clearly understood. METHODS: The NIS database was utilised to identify the patients, who underwent primary THA between 2016 and 2019. The patients were then grouped under two categories: group A-patients who required post-THA transfer to SNF; and group B-those who were discharged home. The details regarding patients' demographic profile, medical comorbidities and complication profile during the perioperative period were recorded; and compared between groups A and B. RESULTS: Based on the database, 368,431 patients underwent primary THA between 2016 and 2019; among whom, 67,498 (18.3%) were transferred to SNF (group A) following the surgery. Among the various comorbidities evaluated [on multivariate analysis (MVA)], uncomplicated DM (OR 1.45; p < 0.001), CKD (OR 1.47; p < 0.001), cirrhosis (OR 1.83; p < 0.001), Parkinson's disease (OR 3.94; p < 0.001), previous H/O dialysis (OR 2.84; p < 0.001), colostomy (OR 2.03; p < 0.001) or organ transplant (OR 1.42; p < 0.001); morbid obesity (OR 1.72; p < 0.001), cocaine abuse (OR 1.76; p < 0.001); and legal blindness (OR 2.58; p < 0.001) were associated with significantly greater need for post-THA transfer to SNF. Among the systemic complications reviewed (on MVA), pneumonia (odds ratio 3.2; p < 0.001), DVT (odds ratio 2.58; p < 0.001), higher need for blood transfusions (odds ratio 2.55; p < 0.001), ARF (odds ratio 2.32; p < 0.001), MI (odds ratio 2.2; p < 0.001), anaemia (odds ratio 1.65; p = 0.002) and PE (odds ratio 1.56; p < 0.001) significantly raised the probability of need for higher discharge destinations. In addition, prosthesis-related local complications such as prosthetic dislocation (OR 1.59; p < 0.001), fracture (OR 2.64; p < 0.001) or early peri-prosthetic infection (PPI; OR 1.71; p = 0.01) also necessitated specialised facilities of care following THA. CONCLUSION: We could observe that 0.2% of patients required transfer to SNF following primary THA. Comorbidities such as Parkinson's disease, previous H/O dialysis, legal blindness and H/O colostomy had the highest odds of necessitating patient disposition to SNF. The occurrence of one or more systemic complications including pneumonia, DVT, ARF, MI, PE, and blood loss anaemia (or need for blood transfusion) or local prosthesis-related complications (dislocation, fracture or infections) substantially increased the chances of requiring transfer to a specialised care facility.

What is the role of CT-based Hounsfield unit assessment in the evaluation of bone mineral density in patients undergoing 1- or 2-level lumbar spinal fusion for degenerative spinal pathologies? A prospective study.

BACKGROUND CONTEXT: Computed tomography-based vertebral attenuation values (CT-based HU) have been shown to correlate with T-scores on DEXA scan; and have been acknowledged as an independent factor for predicting fragility fractures. Most patients undergoing lumbar surgeries require CT as part of their preoperative evaluation. PURPOSE: The current study was thus planned to evaluate the role of lumbar CT as an opportunistic investigation in determining BMD preoperatively in patients undergoing lumbar fusion. STUDY DESIGN: Prospective cohort study. PATIENT SAMPLE: Patients older than 45 years, who underwent one- to two-level lumbar (L3-S1 levels) fusions. OUTCOME MEASURES: Comparison of the quantitative assessment of osteoporosis using Hounsfield Units (HU) on CT (L1-L5) and mean lumbar T-scores on DEXA (Dual Energy X-ray Absorptiometry). HYPOTHESIS: HU on CT is comparable to T-score on DEXA as a suitable modality for the assessment of osteoporosis in patients undergoing one- to two-level lumbar fusion. METHODS: A prospective cohort study was conducted between January and December 2021. Patients older than 45 years, who underwent one- to two-level lumbar (L3-S1 levels) fusions and had complete clinico-radiological records, were prospectively enrolled. A comparison was drawn between the HU (measured by placing an oval region of interest [ROI] over axial, sagittal and coronal images of lumbar vertebrae) on CT and T-scores on DEXA, and analyzed statistically. The HU values correlating best with normal (group A), osteopenia (B) and osteoporosis (C) categories (classified based on T-scores of lumbar spines) were determined statistically. RESULTS: Overall, 87 patients (mean age of 60.56±11.63 years; 63 [72.4%] female patients) were prospectively studied. There was a statistically significant difference in the mean age (p=.01) and sex distribution (predominantly female patients; p=.03) of patients belonging to groups B (osteopenic) and C (osteoporotic patients), as compared with group A. The greatest correlation between T-score (on DEXA) and HU (on CT) for differentiating osteopenia (group B) from group A was observed at levels L1 (p<.001), L2 (p<.001) and L3 (p<.001). Based on receiver-operating characteristic (ROC) curve analysis, the cut-off values for HU for identifying osteopenia were 159 (at L1; sensitivity 81.6 and specificity 80) and 162 (at L2; sensitivity 80 and specificity 71.1). In addition, there was statistically significant correlation between T-score (on DEXA) and HU at all the lumbar levels for distinguishing osteoporosis (group C), although the difference was most evident at the upper lumbar (L1 and L2) levels (p<.001). Based on ROC analysis, cut-off HU values for defining osteoporosis were 127 (at L1; sensitivity 71.3 and specificity 70) and 117 (at L2; sensitivity 65.5 and specificity 90). CONCLUSION: Based on our study, the measurement of HU on CT at upper lumbar levels can be considered as "surrogate marker" for BMD in the diagnosis of osteopenia (cut-off: 159 at L1, 162 at L2) and osteoporosis (cut-off: 127 at L1, 117 at L2) in patients undergoing lumbar fusion surgeries. The HU measurements on CT at the lower lumbar levels (L4 and L5) are less reliable in this preoperative scenario.

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.

How does sickle cell disease affect the peri-operative outcome in patients undergoing total knee arthroplasty? A large-scale, National Inpatient Sample-based study.

INTRODUCTION: In view of the vaso-occlusive pathophysiology affecting osseous micro-circulation, sickle cell disease (SCD) is well known to present with diverse skeletal and arthritic manifestations. With prolonged life-expectancy over the past decades, there has been a progressive increase in the proportion of SCD patients requiring joint reconstructions. Owing to the paucity of evidence in the literature, the post-operative complication rates and outcome in these patients following total knee arthroplasty (TKA) are still largely unknown. METHODS: Based on the National Inpatient Sample (NIS) database (using ICD-10 CMP code), patients who underwent TKA between 2016 and 2019 were identified. The cohort were classified into two groups: A-those with SCD; and B-those without. The data on patients' demographics, co-morbidities, details regarding hospital stay including expenditure incurred, and complications were analyzed and compared. RESULTS: Overall, 558,361 patients underwent unilateral, primary TKA; among whom, 493 (0.1%) were known cases of SCD (group A). Group A included a significantly greater proportion of younger (60.14 ± 10.87 vs 66.72 ± 9.50 years; p < 0.001), male (77.3 vs 61.5%; p < 0.001); and African-American (88.2 vs 8.3%B; p < 0.001) patients, in comparison with group B. Group A patients were also at a significantly higher risk for longer duration of peri-operative hospital stay (p < 0.001), greater health-care costs incurred (p < 0.001), and greater need for alternative step-down health-care facilities (p < 0.001) following discharge. Among the SCD patients, 24.7%, 20.9% and 24.9% developed acute chest syndrome, pain crisis and splenic sequestration crisis, respectively during the peri-operative period. Group A patients had a statistically greater incidence of acute renal failure (ARF; p = 0.014), need for blood transfusion (p < 0.001) and deep vein thrombosis (DVT; p = 0.03) during the early admission period. CONCLUSION: The presence of SCD substantially lengthens the duration of hospital stay and enhances health care-associated expenditure in patients undergoing TKA. SCD patients are at significantly higher risk for systemic complications including acute chest syndrome, pain crisis, splenic sequestration crisis, acute renal failure, higher need for blood transfusions and deep venous thrombosis during the initial peri-operative period following TKA.

Principles for Managing Patients with Spinal Ailments in the Coronavirus Disease 2019 Era: What Do We Know So Far? An Evidence-Based, Narrative Review.

The coronavirus disease 2019 (COVID-19) pandemic has significantly affected all specialty practices in medicine, including the field of spinal surgery. Spinal surgery is unique in that the procedures include not only fully elective and fully emergent interventions, but also involve a separate group of semi-emergent surgeries, where delayed intervention may lead to permanent neurological deficits. Here, we present an evidence-based review on the impact of the COVID-19 pandemic on spinal surgery and our current knowledge about this issue. We conducted a thorough search of the PubMed, Medline, and Google Scholar databases using the keywords, "COVID-19," "COVID-19 impact on spine surgery," "coronavirus impact on spine surgery," "COVID-19 impact on neurosurgery," "coronavirus impact on neurosurgery," "COVID-19 impact on spine surgeons," and "coronavirus impact on spine surgeons" on May 6, 2020. A total of 8,322 articles were identified in the initial search. Articles that were duplicated, those that did not pertain to COVID-19 or spine surgeries, those with details not pertaining to the current topic of interest, and those published in languages other than English were excluded from our analyses. After complete screening, six articles were included in this review. During the previous few weeks, the COVID pandemic has significantly influenced all major aspects of spine surgery across the world. Outpatient care has been gradually shifted from physical visits to tele-health and online consultations. General recommendations have favored the conservative approach over surgeries, although no patient should be deprived of standard care owing to concerns about COVID. The general principles followed by spine surgeons should include early detection of COVID symptomatology; triaging of patients based on underlying spinal pathology; prescription of appropriate investigations to confirm the COVID status; isolation, as needed; selection of optimal management method as per the guidelines; adherence to best intraoperative practices; and ensuring protective measures for non-infected patients, family members, fellow heath care providers, and themselves against the disease.

Nanotechnology in Spine Surgery: A Current Update and Critical Review of the Literature.

OBJECTIVE: Nanotechnology is a promising field with numerous applications across various branches of medicine. The unique innate physical, chemical, and biological properties of nanoparticles enable them to serve as appropriate agents performing diverse functions at cellular and subcellular levels. Spinal pathologies constitute one major field where its applications are being explored. METHODS: A critical review of literature was performed to identify the current role of nanotechnology in spine surgery. A PubMed search was done using the following key words: "nanotechnology in neurosurgery," "nanotechnology in surgery," "nanotechnology in spine," "nanotechnology in spine surgery," "nanotechnology in disc regeneration," "nanotechnology in spinal injury," "nanotechnology in spinal cord regeneration," "nanotechnology in spine fusion," "nanotechnology in osteoporosis," "nanotechnology in spinal drug delivery," and "nanotechnology in spinal infection." Initial search revealed 347 articles. Articles were further screened. Duplicate articles, articles on nonnanotechnologic topics, nonspine articles, or articles with details not pertaining to the current field of interest and non-English language studies were excluded. RESULTS: A total of 76 articles were finally included. Nanotechnologic advancements in spine surgery include applications in spinal fusion, central nervous system drug delivery, neuronal regeneration, disk regeneration, spinal infection prophylaxis, management of osteoporosis, sutureless vascular anastomosis, molecular imaging, and theranostic medicine. CONCLUSIONS: Nanotechnology in spine surgery is still in its early stages. Eventually, we may see the implementation of nanotechnology as an alternative to existing treatment options. Concerns regarding safety of this technology need to be addressed through future research projects. Although promising, the exact role of nanotechnology in spine surgery remains to be seen.

Comparison of Three Different Options for C7 Posterior Vertebral Anchor in the Indian Population-Lateral Mass, Pedicle, and Lamina: A Computed Tomography-Based Morphometric Analysis.

STUDY DESIGN: Radiological cohort study. PURPOSE: The options of posteriorly stabilizing C7 vertebra include using lateral mass, pedicle or lamina, as bony anchors. The current study is a computed tomography (CT)-based morphometric analysis of C7 vertebra of 100 Indian patients and discusses the feasibility of these different techniques. OVERVIEW OF LITERATURE: C7 is a peculiar vertebra with unique anatomy, which poses challenges for each of these fixation modalities. There are no reports available in the literature, which discuss and compare the feasibility of diverse posterior C7 fixation techniques in Indian population. METHODS: We included 100 consecutive cervical spine CT scans of Indian patients performed between July 2016 and September 2016. We excluded CT scans with any significant congenital anomaly or other pathological lesions of C7 and patients with non-Indian ethnicity. Regarding screw placement, we assessed and studied various dimensions of the C7 lateral mass, pedicles, and laminae in relevant sections. RESULTS: The mean age of our patients was 49.5±16.1 years. We included 56 male and 44 female patients. The mean anteroposterior and mediolateral dimensions of the lateral mass were 11.38±1.76 and 12.91±1.82 mm, respectively. The mean length of the lateral mass screw (Magerl technique) was 12.17±1.9 mm; 92% of patients could accommodate a lateral mass screw at least 10-mm long (unicortical), whereas 48% could accommodate a screw (unicortical) longer than 12 mm. Foramen transversarium was found in 30.5% of lateral masses. The mean outer and inner cortical widths of the pedicles were 6.5±0.71 mm and 3.72±0.61 mm, respectively. Approximately 58% of pedicles could accommodate 3.5-mm screws (based on the inner cortical pedicle width). The outer cortical and inner cortical widths of the laminae were 6.21±1.2 mm and 3.23±0.9 mm, respectively. Subsequently, 37% of the laminae could accommodate 3.5-mm screws. The mean angle of intralaminar screw trajectory was 50.7°±5.1°, and the mean length of the intralaminar screw was 32.6±3.05 mm. In addition, 96.4% and 60.7% of male patients could accommodate lateral mass screws longer than 10 mm and 12 mm, respectively. However, only 86.4% and 31.8% of female patients could accommodate 10- and 12-mm long lateral mass screws, respectively. Furthermore, 75% of male patients and 36% of female patients had pedicles that could accommodate 3.5-mm diameter screws, and 48.2% of male patients had laminae that could accommodate 3.5-mm screws; however, only 22.7% of female patients could accommodate 3.5-mm laminar screws. CONCLUSIONS: Based on our CT-guided morphometric analysis, 92% and 48% of Indian patients could accommodate at least 10- and 12-mm long lateral mass screws, and 58% of pedicles and 37% of laminae could accommodate 3.5-mm screws. Thus, lateral mass screws (between 10- and 12-mm long) seem to be the safest feasible option for C7 fixation. In case of the need for an alternative mode of stabilization (pedicle or intralaminar screw), particularly in female patients, careful preoperative planning with a CT scan is of utmost importance.

Symptomatic Unilateral Spondylolysis Associated With Nonspondylolytic Lateral Clefts in Adults: Review of an Infrequently Reported Pathology.

Nonspondylolytic lateral clefts of the lumbar neural arch (laminolysis and pediculolysis) are rare pathologies that usually occur consequent to repetitive stress injuries in patients with unilateral spondylolysis. These lesions are different from the usual bilateral spondylolytic defects, and their management depends upon the chronicity and the type of bony defect. We hereby discuss the verdict of current literature on underlying pathomechanics and ideal management guidelines of these rare lesions.