Risk Factors for Peripheral Nerve Injury Following Revision Total Knee Arthroplasty in 132,960 Patients.

BACKGROUND: Peripheral nerve injury (PNI) following revision total knee arthroplasty (rTKA) is a potentially devastating injury for patients. This study assessed the frequency of and risk factors for postoperative PNI following rTKA. METHODS: Patients who underwent rTKA from 2003 to 2015 were identified using the National Inpatient Sample. Demographics, medical histories, surgical details, and complications were compared between patients who sustained a PNI and those who did not to identify risk factors for the development of PNI after rTKA. RESULTS: Overall, 132,960 patients who underwent rTKA were identified, and 737 (0.56%) sustained a postoperative PNI. After adjusting for confounders, patients with a history of a spine condition (adjusted odds ratio [aOR]: 1.7, 95%-confidence interval 1.2 to 2.4, P = .003) and postoperative anemia (aOR: 1.3, 95%-CI: 1.1 to 1.5, P = .004) had higher risk of PNI following rTKA. Intraoperative periprosthetic fracture (aOR: 1.3, 0.78 to 2.2, P = .308), rheumatoid arthritis (aOR: 1.0, 95%-CI: 0.68 to 1.6, P = .865), and history of knee dislocation (aOR: 1.1, 95%-CI: 0.85 to 1.5, P = .412), were not significantly associated with higher risk for PNI. CONCLUSIONS: This study found a 0.56% incidence of PNI following rTKA, and patients who had preexisting spine conditions or postoperative anemia were at an increased risk for this complication. Orthopedic surgeons may use the results of this study to appropriately counsel patients on the potential for a PNI following rTKA.

Is the Rise of Medicare Advantage Impacting the Fidelity of Traditional Medicare Claims Data? Implications for Reporting of Long-Term Total Hip Arthroplasty Survivorship.

BACKGROUND: Arthroplasty registries often use traditional Medicare (TM) claims data to report long-term total hip arthroplasty (THA) survivorship. The purpose of this study was to determine whether the large number of patients leaving TM for Medicare Advantage (MA) has compromised the fidelity of TM data. METHODS: We identified 10,962 THAs in 9,333 Medicare-eligible patients who underwent primary THA from 2000 to 2020 at a single institution. Insurance type was analyzed, and 83% of patients had TM at the time of THA. Survivorship free from any revision or reoperation was calculated for patients who have TM. The same survivorship end points were recalculated with censoring performed when a patient transitioned to an MA plan after their primary THA to model the impact of losing patients from the TM dataset. Differences in survivorship were compared. The mean follow-up was 7 years. RESULTS: From 2000 to 2020, there was a decrease in TM insurance (93 to 73%) and a corresponding increase in MA insurance (0 to 19%) among THA patients. Following THA, 23% of TM patients switched to MA. For patients who had TM at the time of surgery, 15-year survivorship free from any reoperation or revision was 90% and 93%, respectively. When censoring patients upon transition from TM to MA, survivorship free from any reoperation became significantly higher (92 versus 90% at 15 years; hazard ratio = 1.16, P = .033), and there was a trend toward higher survivorship free from any revision (95 versus 93% at 15 years; hazard ratio = 1.16, P = .074). CONCLUSIONS: Approximately 1 in 4 patients left TM for MA after primary THA, effectively making them lost to follow-up within TM datasets. The mass exodus of patients out of TM appears to have led to a slight overestimation of survivorship free from any reoperation and trended toward overestimating survivorship free from any revision. If MA continues to grow, efforts to obtain MA data will become even more important.

Merkel cell carcinoma of unknown primary: Clinical presentation and outcomes.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous malignancy that usually occurs in the head/neck or extremities. However, there are reports of MCC developing in the lymph nodes or parotid gland without evidence of a primary cutaneous lesion. METHODS: We reviewed 415 patients with biopsy-proven MCC. Patients with MCC of unknown primary (n = 37, 9%, MCCUP) made up the study cohort. The primary endpoints of the study were rate of recurrence, disease-free survival, and overall survival. RESULTS: Patients with MCCUP presented with tumors in lymph nodes (n = 34) or parotid gland (n = 3). Nodal disease was most commonly detected in the inguinal/external iliac (n = 15) or axillary (n = 14) regions. The mean age at diagnosis was 70 years and 24% were female. Patients presented with distant metastases in 24.3% of cases. Patients with stage IIIA disease treated with regional lymph node dissection (RLND) had a lower risk of disease recurrence (hazard ratio 0.26, p = 0.046). Recurrence-free survival was 59.3% at 5 years. Disease-specific survival was 63.3% at 5 years. CONCLUSION: Patients with MCCUP have a high risk of recurrence and mortality. The optimal treatment for MCCUP has yet to be elucidated, although therapeutic RLND appears beneficial for these patients.

The impact of frailty on postoperative complications in geriatric patients undergoing multi-level lumbar fusion surgery.

STUDY DESIGN: Retrospective Cohort Study. PURPOSE: This study evaluates the impact of patient frailty status on postoperative complications in those undergoing multi-level lumbar fusion surgery. METHODS: The Nationwide Readmission Database (NRD) was retrospectively queried between 2016 and 2017 for patients receiving multi-level lumbar fusion surgery. Demographics, frailty status, and relevant complications were queried at index admission and readmission intervals. Primary outcome measures included perioperative complications and 30-, 90-, and 180-day complication and readmission rates. Perioperative complications of interest were infection, urinary tract infection (UTI), and posthemorrhagic anemia. Secondary outcome measures included inpatient length of stay (LOS), adjusted all-payer costs, and discharge disposition. Nearest-neighbor propensity score matching for demographics was implemented to identify non-frail patients with similar diagnoses and procedures. Subgroup analysis of minimally invasive surgery (MIS) versus open surgery within frail and non-frail cohorts was conducted to evaluate differences in surgical and medical complication rates. The analysis used nonparametric Mann-Whitney U testing and odds ratios. RESULTS: Frail patients encountered higher rates perioperative complications including posthemorrhagic anemia (OR: 1.73, 95%CI 1.50-2.00, p < 0.0001), infection (OR: 2.94, 95%CI 2.04-4.36, p < 0.0001), UTI (OR: 2.57, 95%CI 2.04-3.26, p < 0.0001), and higher rates of non-routine discharge (OR: 2.07, 95%CI 1.80-2.38, p < 0.0001). Frail patients had significantly greater LOS and total all-payer inpatient costs compared to non-frail patients (p < 0.0001). Frailty was associated with significantly higher rates of 90- (OR: 1.43, 95%CI 1.18-1.74, p = 0.0003) and 180-day (OR: 1.28, 95%CI 1.03-1.60, p = 0.02) readmissions along with higher rates of wound dehiscence (OR: 2.21, 95%CI 1.17-4.44, p = 0.02) at 90 days. Subgroup analysis revealed that frail patients were at significantly higher risk for surgical complications with open surgery (16%) compared to MIS (0%, p < 0.0001). No significant differences were found between surgical approaches with respect to medical complications in both cohorts, nor surgical complications in non-frail patients. CONCLUSIONS: Frailty was associated with higher odds of all perioperative complications, LOS, and all-payer costs following multi-level lumbar fusion. Frail patients had significantly higher rates of 90 and 180-day readmission and higher rates of wound disruption at 90-days. On subgroup analysis, MIS was associated with significantly reduced rates of surgical complications specifically in frail patients. Our results suggest frailty status to be an important predictor of perioperative complications and long-term readmissions in geriatric patients receiving multi-level lumbar fusions. Frail patients should undergo surgery utilizing minimally invasive techniques to minimize risk of surgical complications. Future studies should explore the utility of implementing frailty in risk stratification assessments for patients undergoing spine surgery.

Identifying risks factors in thoracolumbar anterior fusion surgery through predictive analytics in a nationally representative inpatient sample.

PURPOSE: Anterior thoracolumbar (TL) surgical approaches provide more direct trajectories compared to posterior approaches. Proper patient selection is key in identifying populations that may benefit from anterior TL fusion. Here, we utilize predictive analytics to identify risk factors in anterior TL fusion in patients with trauma and deformity. METHODS: In this retrospective cohort study of patients receiving anterior TL fusion (between and including T12/L1), population-based regression models were developed to identify risk factors using the National Readmission Database 2016-2017. Readmissions were analyzed at 30- and 90-day intervals. Risk factors included hypertension, obesity, malnutrition, smoking, alcohol use, long-term opioid use, and frailty. Multivariate regression models were developed to determine the influence of each risk factor on complication rates. RESULTS: A total of 265 and 375 patients were identified for the scoliosis and burst fracture cohorts, respectively. In patients with scoliosis, alcohol use was found to increase the length of stay (LOS) (p = 0.00061) and all-payer inpatient cost following surgery (p = 0.014), and frailty was found to increase the inpatient LOS (p = 0.0045). In patients with burst fractures, malnutrition was found to increase the LOS (p < 0.0001) and all-payer cost (p < 0.0001), obesity was found to increase the all-payer cost (p = 0.012), and frailty was found to increase the all-payer cost (p = 0.031) and LOS (p < 0.0001). DISCUSSION: Patient-specific risk factors in anterior TL fusion surgery significantly influence complication rates. An understanding of relevant risk factors before surgery may facilitate preoperative patient selection and postoperative patient triage and risk categorization.

Impact of diagnosis and type of sacroiliac joint fusion on postoperative complications.

PURPOSE: Two main surgical approaches are available for fusing the sacroiliac joint (SIJ): an open or minimally invasive (MIS) approach. The purpose of this study was to analyze the associated total hospital charges and postoperative complications of the MIS and open approach. METHODS: Using the 2016 and 2017 National Readmission Database, we conducted a retrospective cohort analysis of 2521 patients who received a SIJ fusion with an open (N = 1990) or MIS (N = 531) approach for diagnosed sacrum pain, sacroiliitis, sacral instability, or spondylosis. Each cohort was analyzed for postoperative complications. RESULTS: We identified 604 patients diagnosed with sacrum pain, 1142 with sacroiliitis, 315 with spondylosis, and 288 with sacral instability. Patients who received the open approach for sacrum pain had significantly higher rates of novel post-procedural pain (p = 0.045) and novel lumbar pathology (p = 0.015) within 30 days. On 30-day follow-up, patients with sacroiliitis treated with open SIJ fusion had significantly higher rates of novel postprocedural pain compared to those treated with MIS fusion (p = 0.045). Patients who received the open approach for spondylosis resulted in significantly higher rates of non-elective readmission within 30 days compared to the MIS approach (p < 0.0001). In addition, the open technique for spondylosis resulted in significantly higher rates of non-elective readmissions for infection within 30 days (p = 0.014). On 30-day follow-up, patients with sacral instability treated with open SIJ fusion had significantly higher rates of UTI (p = 0.045). CONCLUSION: Our study suggests that there exist unique postoperative complications that arise after SIJ fusion specific to preoperative diagnosis and surgical approach.

Midterm Survivorship of Robotic-Assisted Lateral Unicompartmental Knee Arthroplasty.

BACKGROUND: Lateral unicompartmental knee arthroplasty (UKA) is a popular alternative to total knee arthroplasty (TKA) for patients with isolated lateral compartment osteoarthritis. Few studies have investigated outcomes following robotic-assisted lateral UKA. The purpose of this study is to evaluate mid-term survivorship and patient-reported outcomes of robotic-assisted lateral UKA. METHODS: A retrospective case series was conducted on all robotic-assisted lateral UKAs performed by a single surgeon between 2013 and 2019. Patient demographics, surgical variables, and Kozinn and Scott criteria were collected. Implant survivorship was estimated using the Kaplan-Meier method with all-cause reoperation and conversion to TKA as endpoints. Participating patients were assessed for patient satisfaction and the Forgotten Joint Score-12. Correlations between patient demographics and patient outcome scores were investigated. RESULTS: In total, 120 lateral UKAs were identified, 84 of which met inclusion criteria, with a mean follow-up of 4.0 years (range 2.0-7.0). Five-year survivorship was 92.9% (95% confidence interval [CI] 84.5-96.7) with all-cause reoperation as the endpoint, and 100% (95% CI 95.0-100) with conversion to TKA as the endpoint. One patient was converted to TKA after the 5-year mark, resulting in a 6-year survival for conversion to TKA of 88.9% (95% CI 44.9-98.5). Average Forgotten Joint Score-12 score was 82.7/100, and patient satisfaction 4.7/5. Mean coronal plane correction was 2.5° ± 1.9° toward the mechanical axis. Neither final postoperative alignment nor failure to meet classic Kozinn and Scott criteria for UKA resulted in differences in patient-reported outcomes. CONCLUSION: The current study demonstrates high mid-term survivorship and excellent patient-reported outcomes with robotic-assisted lateral UKA. Robotic-assisted lateral UKA is a viable treatment option for isolated lateral compartment arthritis even in patients who do not meet classic indications.

The influence of frailty on postoperative complications in geriatric patients receiving single-level lumbar fusion surgery.

PURPOSE: This study evaluates the influence of patient frailty status on postoperative complications in those receiving single-level lumbar fusion surgery. METHODS: The nationwide readmission database was retrospectively queried between 2016 and 2017 for all patients receiving single-level lumbar fusion surgery. Readmissions were analyzed at 30, 90, and 180 days from primary discharge. Demographics, frailty status, and relevant complications were queried at index admission and all readmission intervals. Complications of interest included infection, urinary tract infection (UTI), posthemorrhagic anemia, inpatient length of stay (LOS), and adjusted all-payer costs. Nearest-neighbor propensity score matching for demographics was implemented to identify non-frail control patients with similar diagnoses and procedures. The analysis used nonparametric Mann-Whitney U testing and odds ratios. RESULTS: Comparing propensity-matched cohorts revealed significantly greater LOS and total all-payer inpatient costs in frail patients than non-frail patients with comparable demographics and comorbidities (p < 0.0001 for both). Furthermore, frail patients encountered higher rates of UTI (OR: 3.97, 95%CI: 3.21-4.95, p < 0.0001), infection (OR: 6.87, 95%CI: 4.55-10.86, p < 0.0001), and posthemorrhagic anemia (OR: 1.94, 95%CI: 1.71-2.19, p < 0.0001) immediately following surgery. Frail patients had significantly higher rates of 30-day (OR: 1.24, 95%CI: 1.02-1.51, p = 0.035), 90-day (OR: 1.38, 95%CI: 1.17-1.63, p < 0.001), and 180-day (OR: 1.55, 95%CI: 1.30-1.85, p < 0.0001) readmissions. Lastly, frail patients had higher rates of infection at 30-day (OR: 1.61, 95%CI: 1.05-2.46, p = 0.027) and 90-day (OR: 1.51, 95%CI: 1.07-2.16, p = 0.020) readmission intervals. CONCLUSIONS: Patient frailty status may serve as an important predictor of postoperative outcomes in patients receiving single-level lumbar fusion surgery.

The Efficacy of Platelet-Rich Plasma for Improving Pain and Function in Lateral Epicondylitis: A Systematic Review and Meta-analysis with Risk-of-Bias Assessment.

PURPOSE: To assess the efficacy of platelet-rich plasma (PRP) for lateral epicondylitis and evaluate its impact on pain and functional outcomes. METHODS: This study followed Preferred Reporting Items and Systematic Reviews and Meta-Analyses guidelines. A comprehensive literature search was conducted in September 2019 and repeated in April 2020 using electronic databases PubMed, MEDLINE, and the Cochrane Library. Baseline and 3-, 6-, and 12-month data were extracted for visual analog scale (VAS), Disabilities of the Arm, Shoulder, and Hand (DASH), and modified Mayo Clinic performance index for the elbow (MAYO) scores. Only level 1 studies with patients who had not undergone surgery were included. Outcomes data, study design, demographic variables, PRP formulation, and comparator treatments were recorded. Statistical analyses of pooled weighted mean differences (WMDs) were performed and compared with estimated minimal clinically important difference (MCID) values. The Coleman Methodology Score (CMS) was used to assess methodological quality, and the Cochrane risk-of-bias assessment was performed. RESULTS: This review included 16 level I studies, 9 of which (581 total patients, 281 receiving single injections of PRP) were quantitatively analyzed. The average age was 41.5 years, 56.8% of patients were female, and mean follow-up was 7.5 months. The mean CMS was 78.94 ± 12.74 (range 59 to 97), and 5 of 16 studies were at low risk for bias. Patients who received PRP had significantly improved VAS scores at 3 months (WMD -0.85; 95% confidence interval [CI] -1.03, -0.66; P < .01) and 6 months (WMD -0.74; 95% CI -0.98, -0.50; P < .01) compared with those who received autologous whole blood, though MAYO scores were statistically equivalent. Comparing PRP to corticosteroids, VAS and DASH scores were not significantly different at 3 months, although PRP was superior at 6 months for VAS (WMD -1.70; 95% CI -2.65, -0.75; P < .01) and DASH (WMD -6.23; 95% CI -10.78, -1.69; P < .01). Most differences in VAS and DASH scores exceeded the 5% absolute difference estimate for their respective MCIDs but fell short of the 10% estimate. CONCLUSION: Considering the small number of comparable studies, lack of quantification of specific PRP content, considerable heterogeneity between randomized control trials, and most effect sizes being equivocal within the framework of 2 estimated MCID values, the authors can neither scientifically support nor discourage the usage of PRP for lateral epicondylitis despite finding statistically significant improvements in pain and functional outcomes. LEVEL OF EVIDENCE: I, prognostic.

Cemented Vs Cementless Femoral Fixation for Total Hip Arthroplasty After Displaced Femoral Neck Fracture: A Nationwide Analysis of Short-Term Complications and Readmission Rates.

BACKGROUND: Active patients with displaced femoral neck fractures are often treated with total hip arthroplasty (THA). However, optimal femoral fixation in these patients is controversial. The purpose of this study was to compare early complication and readmission rates in patients with hip fracture treated with THA receiving cemented vs cementless femoral fixation. METHODS: The National Readmissions Database was queried to identify patients undergoing primary THA for femoral neck fracture from 2016 to 2017. Postoperative complications and unplanned readmissions at 30, 90, and 180 days were compared between patients treated with cemented and cementless THA. Univariate and multivariate analyses were performed to compare differences between groups and account for confounding variables. RESULTS: Of 17,491 patients identified, 4427 (25.3%) received cemented femoral fixation and 13,064 (74.7%) cementless. The cemented group was significantly older (77.2 vs 71.1, P < .001), had more comorbidities (Charlson comorbidity index: 4.44 vs 3.92, P < .001), and had a greater proportion of women (70.5% vs 65.2%, P < .001) compared with the cementless group. On multivariate analysis, cemented fixation was associated with reduced rates of periprosthetic fracture (odds ratio: 0.052, 95% confidence interval: 0.003-0.247, P = .004) at 30 days but similar readmission rates at 30, 90, and 180 days (odds ratio range: 1.012-1.114, P > .05) postoperatively compared with cementless fixation. Cemented fixation was associated with greater odds of medical complications at 180 days postoperatively (odds ratio:: 1.393, 95% confidence interval: 1.042-1.862, P = .025). CONCLUSION: Cemented femoral fixation was associated with a lower short-term incidence of periprosthetic fractures, higher incidence of medical complications, and equivalent unplanned readmission rates within 180 days postoperatively compared with cementless fixation in patients undergoing THA for femoral neck fracture. LEVEL OF EVIDENCE: Level III.

The role of frailty in geriatric cranial neurosurgery for primary central nervous system neoplasms.

OBJECTIVE: Frailty is a clinical state of increased vulnerability due to age-associated decline and has been well established as a perioperative risk factor. Geriatric patients have a higher risk of frailty, higher incidence of brain cancer, and increased postoperative complication rates compared to nongeriatric patients. Yet, literature describing the effects of frailty on short- and long-term complications in geriatric patients is limited. In this study, the authors evaluate the effects of frailty in geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm. METHODS: The authors conducted a retrospective cohort study of geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm between 2010 and 2017 by using the Nationwide Readmission Database. Demographics and frailty were queried at primary admission, and readmissions were analyzed at 30-, 90-, and 180-day intervals. Complications of interest included infection, anemia, infarction, kidney injury, CSF leak, urinary tract infection, and mortality. Nearest-neighbor propensity score matching for demographics was implemented to identify nonfrail control patients with similar diagnoses and procedures. The analysis used Welch two-sample t-tests for continuous variables and chi-square test with odds ratios. RESULTS: A total of 6713 frail patients and 6629 nonfrail patients were identified at primary admission. At primary admission, frail geriatric patients undergoing cranial neurosurgery had increased odds of developing acute posthemorrhagic anemia (OR 1.56, 95% CI 1.23-1.98; p = 0.00020); acute infection (OR 3.16, 95% CI 1.70-6.36; p = 0.00022); acute kidney injury (OR 1.32, 95% CI 1.07-1.62; p = 0.0088); urinary tract infection prior to discharge (OR 1.97, 95% CI 1.71-2.29; p < 0.0001); acute postoperative cerebral infarction (OR 1.57, 95% CI 1.17-2.11; p = 0.0026); and mortality (OR 1.64, 95% CI 1.22-2.24; p = 0.0012) compared to nonfrail geriatric patients receiving the same procedure. In addition, frail patients had a significantly increased inpatient length of stay (p < 0.0001) and all-payer hospital cost (p < 0.0001) compared to nonfrail patients at the time of primary admission. However, no significant difference was found between frail and nonfrail patients with regard to rates of infection, thromboembolism, CSF leak, dural tear, cerebral infarction, acute kidney injury, and mortality at all readmission time points. CONCLUSIONS: Frailty may significantly increase the risks of short-term acute complications in geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm. Long-term analysis revealed no significant difference in complications between frail and nonfrail patients. Further research is warranted to understand the effects and timeline of frailty in geriatric patients.

Risk Factors for Peripheral Nerve Injury Following Revision Total Hip Arthroplasty in 112,310 Patients.

Background: Peripheral nerve injury (PNI) following revision total hip arthroplasty (rTHA) can be a devastating complication. This study assessed the frequency of and risk factors for postoperative PNI following rTHA. Methods: Patients who underwent rTHA from 2003 to 2015 were identified using the National Inpatient Sample (NIS). Demographics, medical history, surgical details, and complications were compared between patients who sustained a PNI and those who did not, to identify risk factors for the development of PNI after rTHA. Results: Overall, 112,310 patients who underwent rTHA were identified, 929 (0.83%) of whom sustained a PNI. Univariate analysis found that younger patients (p < 0.0001), females (p = 0.025), and those with a history of flexion contracture (0.65% vs. 0.22%, p = 0.005), hip dislocation (24.0% vs. 18.0%, p < 0.001), and spine conditions (4.8% vs. 2.7%, p < 0.001) had significantly higher rates of PNI. In-hospital complications associated with PNI included postoperative hematoma (2.6% vs. 1.2%, p < 0.0001), postoperative seroma (0.75% vs. 0.30%, p = 0.011), superficial wound dehiscence (0.65% vs. 0.23%, p = 0.008), and postoperative anemia (36.1% vs. 32.0%, p = 0.007). Multivariate analysis demonstrated that a history of pre-existing spine conditions (aOR: 1.7; 95%-CI: 1.3-2.4, p < 0.001), prior dislocation (aOR 1.5; 95%-CI: 1.3-1.7, p < 0.001), postoperative anemia (aOR 1.2; 95%-CI: 1.0-1.4, p = 0.01), and hematoma (aOR 2.1; 95%-CI: 1.4-3.2, p < 0.001) were associated with increased risk for PNI. Conclusions: Our findings align with the existing literature, affirming that sciatic nerve injury is the prevailing neuropathic complication after total hip arthroplasty (THA). Furthermore, we observed a 0.83% incidence of PNI following rTHA and identified pre-existing spine conditions, prior hip dislocation, postoperative anemia, or hematoma as risk factors. Orthopedic surgeons may use this information to guide their discussion of PNI following rTHA, especially in high-risk patients.

Metal artifact reduction sequence-MRI abnormalities in asymptomatic patients with dual-mobility hip prostheses.

Aims: Modular dual-mobility (DM) articulations are increasingly used during total hip arthroplasty (THA). However, concerns remain regarding the metal liner modularity. This study aims to correlate metal artifact reduction sequence (MARS)-MRI abnormalities with serum metal ion levels in patients with DM articulations. Methods: A total of 45 patients (50 hips) with a modular DM articulation were included with mean follow-up of 3.7 years (SD 1.2). Enrolled patients with an asymptomatic, primary THA and DM articulation with over two years' follow-up underwent MARS-MRI. Each patient had serum cobalt, chromium, and titanium levels drawn. Patient satisfaction, Oxford Hip Score, and Forgotten Joint Score-12 (FJS-12) were collected. Each MARS-MRI was independently reviewed by fellowship-trained musculoskeletal radiologists blinded to serum ion levels. Results: Overall, two patients (4.4%) had abnormal periprosthetic fluid collections on MARS-MRI with cobalt levels > 3.0 µg/l. Four patients (8.9%) had MARS-MRI findings consistent with greater trochanteric bursitis, all with cobalt levels < 1.0 µg/l. A seventh patient had a periprosthetic fluid collection with normal ion levels. Of the 38 patients without MARS-MRI abnormalities, 37 (97.4%) had cobalt levels < 1.0 µg/l, while one (2.6%) had a cobalt level of 1.4 µg/l. One patient (2.2%) had a chromium level > 3.0 µg/l and a periprosthetic fluid collection. Of the 41 patients with titanium levels, five (12.2%) had titanium levels > 5.0 µg/l without associated MARS-MRI abnormalities. Conclusion: Periprosthetic fluid collections associated with elevated serum cobalt levels in patients with asymptomatic DM articulations occur infrequently (4.4%), but further assessment is necessary due to implant heterogeneity.

The Effect of Modifiable Risk Factors on Postoperative Complications in Lumbar Spine Fusions.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The impact of modifiable risk factors (MRFs) on complications, costs, and readmission rates at 30, 90, and 180-days following lumbar spine fusion. METHODS: Patients with lumbar spine fusions within the 2016-2017 Nationwide Readmissions Database (NRD). Patients were stratified by the following MRFs: Alcohol use, tobacco/nicotine use, nutritional malnourishment, dyslipidemia, and primary hypertension. Differences in complications, non-elective readmission rates, costs, and length of stay were compared between MRFs and the non-MRF group. Statistical analysis was conducted using Tukey multiple comparisons of means, 1-way ANOVA, Wald testing, unpaired Welch 2-sample t-tests, multivariate analysis, and predictive modeling. RESULTS: The final analysis included 297,579 lumbar fusion patients. At 30 and 90 days, patients with nutritional malnutrition, dyslipidemia, and primary hypertension had significantly greater readmission rates than patients without MRFs (all P<0.01). At 180-days, all MRFs had significantly greater readmission rates than the non-MRF group (all P<0.001). Dyslipidemia demonstrated significantly greater rates of myocardial infarction at 90 days compared to all groups (all P<0.02). Nutritional malnutrition was associated with a significantly greater mortality rate than primary hypertension, non-MRF, and tobacco/nicotine use at 90 days (P<0.001) and only tobacco/nicotine use at 180 days (P=0.007). Predictive modeling showed increases of 0.77%, 1.70%, and 2.44% risk of readmission at 30, 90, and 180-days respectively per additional MRF (all P<0.001). CONCLUSIONS: These findings highlight the negative impact each MRF has on patients following lumbar spinal fusion. Further longitudinal research is necessary to comprehensively characterize the effects of various MRFs on spine surgery outcomes.

Multidisciplinary Treatment of Merkel Cell Carcinoma of the Extremities: Outcomes and Factors Associated with Poor Survival in Nodal Disease.

Merkel cell carcinoma (MCC) has a tendency for lymphatic spread and locoregional recurrence, although there is little data examining the risk factors for patients with lymph node-positive extremity lesions. The purpose of the current study was to examine the outcomes and risk factors associated with nodal metastasis in extremity MCC. We retrospectively reviewed the medical record of 120 patients with extremity MCC evaluated at our institution between 1994 and 2021. The mean age of this cohort was 71 years; 33% of patients were female; and 98% were Caucasian. Seventy-eight (65%) patients presented with localized disease. Thirty-seven (31%) patients had stage III disease, and five (4%) patients had stage IV disease. Treatment of primary lesions consisted primarily of margin-negative excision and adjuvant radiotherapy. Nodal metastases were most treated with adjuvant radiation or completion lymph node dissection. Five-year disease-specific survival in our series was 88% for patients with localized disease, 89% for stage IIIa disease, 40% for stage IIIb disease and 42% for stage IV. Factors associated with worse survival included immunosuppression and macroscopic nodal disease. In conclusion, extremity MCC has a low rate of local recurrence when treated with margin-negative excision and adjuvant radiation. However, treatment of nodal metastases remains a challenge with high rates of recurrence and mortality, particularly for patients who are immunosuppressed or who have macroscopic nodal disease.

Outcome of Multidisciplinary Treatment of Merkel Cell Carcinoma of the Hand and Wrist.

BACKGROUND/AIM: Skin cancers are the most common malignancy of the hand and wrist. Merkel cell carcinoma (MCC) is a rare, aggressive non-melanoma skin cancer arising from cutaneous neuroendocrine cells and is known for local and distant recurrence. The purpose of the current study was to examine the treatment outcome of patients with MCC of the hand and wrist. PATIENTS AND METHODS: We reviewed 25 patients (18 males:7 females) with MCC that occurred in the hand and wrist. The mean age at the time of biopsy of 71±11 years. RESULTS: Tumors were located on the hand (n=13), finger/thumb (n=9), and wrist (n=3). Local control included wide local excision (n=22). This included 21 non-amputation resections and one 5th digit ray amputation. Sentinel lymph node biopsy was performed in 21 patients with positive nodal disease in seven cases. Adjuvant radiotherapy was delivered to the primary site in 17 patients and additionally to the regional lymph node basin in six patients. Recurrence within five years was noted in 40% of patients (mean time to recurrence 18.4±20.6 months). Recurrence-free and disease-specific survival rates at 5-years were 54.8% and 67.6%. CONCLUSION: MCC is a rare cutaneous neuroendocrine carcinoma with a high propensity for regional nodal spread. Despite aggressive local treatment, adjuvant radiotherapy to the primary site and regional nodes, MCC of the hand and wrist has a high rate of recurrence and mortality within five years of diagnosis.

Cemented versus Cementless Femoral Fixation for Elective Primary Total Hip Arthroplasty: A Nationwide Analysis of Short-Term Complication and Readmission Rates.

Cementless fixation during total hip arthroplasty (THA) is the predominant mode of fixation utilized for both acetabular and femoral components during elective primary THAs performed in the United States. This study aims to compare early complication and readmission rates between primary THA patients receiving cemented versus cementless femoral fixation. The 2016-2017 National Readmissions Database was queried to identify patients undergoing elective primary THA. Postoperative complication and readmission rates at 30, 90, and 180 days were compared between cemented and cementless cohorts. Univariate analysis was conducted to compare differences between cohorts. Multivariate analysis was performed to account for confounding variables. Of 447,902 patients, 35,226 (7.9%) received cemented femoral fixation, while 412,676 (92.1%) did not. The cemented group was older (70.0 vs. 64.8, p < 0.001), more female (65.0% vs. 54.3%, p < 0.001), and more comorbid (CCI 3.65 vs. 3.22, p < 0.001) compared to the cementless group. On univariate analysis, the cemented cohort had decreased odds of periprosthetic fracture at 30 days postoperatively (OR: 0.556, 95%-CI 0.424-0.729, p < 0.0001), but higher odds of hip dislocation, periprosthetic joint infection, aseptic loosening, wound dehiscence, readmission, medical complications, and death at all timepoints. On multivariate analysis, the cemented fixation cohort demonstrated reduced odds of periprosthetic fracture at all postoperative timepoints: 30 (OR: 0.350, 95%-CI 0.233-0.506, p < 0.0001), 90 (OR: 0.544, 95%-CI 0.400-0.725, p < 0.0001), and 180 days (OR: 0.573, 95%-CI 0.396-0.803, p = 0.002). Cemented femoral fixation was associated with significantly fewer short-term periprosthetic fractures, but more unplanned readmissions, deaths, and postoperative complications compared to cementless femoral fixation in patients undergoing elective THA.

Postoperative Complication and Reoperation Rates Following Resection of Soft Tissue vs. Bone Malignancies Based on Anatomic Location in the Inpatient Setting.

Introduction: Surgical excisions of upper and lower extremity malignancies are increasing annually, due in part to the rising incidence of sarcomas. The purpose of this study is to compare readmissions, reoperation rate, and complications following surgical excision of soft/connective tissue vs bone malignancies of the upper and lower extremities. Methods: The Nationwide Readmissions Database (NRD) was queried from 2016-2017 to conduct a retrospective analysis of 16,435 patients diagnosed with malignant neoplasms of the long bone (ULLB, n = 1,433) and soft tissue (ULST, n = 2,049) of the upper limb and malignant neoplasms of the long bone (LLLB, n = 5,422) and soft tissue (LLST, n = 7,531) of the lower limb. Patients who underwent surgical excision of their neoplasms were included. Binomial multivariate logistic regression was used to compare complications, nonelective readmission rates, and reoperation rates between the two groups at 30 and 90 days. Results: Average age of the ULST group was 61.88, with 36% female. Average age of the ULLB group was 44.97, with 41.90% female. Average age of the LLST group was 60.96, with 46.90% female. Average age of the LLLB group was 43.09, with 42.60% female. The ULST group had lower odds of readmission within 30 days (p=0.263), which became significant within 90 days of surgery (p=0.045). The LLST group had significantly higher odds of infection, reoperation within 30 to 90 days of the index surgery compared to the LLLB group (p < 0.0001). The LLST group had significantly lower odds of readmission within 30 (p=0.04) and 90 days (p=0.015) of the index surgery. Conclusion: Patients in the ULST group had significantly lower odds of 90-day readmission compared to the ULLB group. There were also significantly lower odds of 30- and 90-day readmission in the LLST group compared to the LLLB group. However, the LLST group had significantly higher odds of infection and reoperation within 30 and 90 days compared to the LLLB group.

Tumor lysis syndrome following ifosfamide monotherapy in metastatic osteosarcoma: a case report and review of the literature.

BACKGROUND: Tumor lysis syndrome is an oncologic emergency that involves multiple metabolic abnormalities and clinical symptoms such as acute renal failure, cardiac arrhythmias, seizures, and multiorgan failure, and may be fatal if not promptly recognized. Tumor lysis syndrome occurs most often in patients with hematologic malignancies, and relatively few cases have been described in patients with sarcoma. CASE PRESENTATION: A 64-year-old male of Asian heritage presented to his primary care physician with a right lower-extremity mass and was ultimately diagnosed with widely metastatic osteosarcoma. He was treated with one cycle of cisplatin and doxorubicin that was complicated by hypervolemia and hypoxic respiratory failure. Given concerns for volume overload, therapy was changed to single-agent, dose-reduced ifosfamide. After receiving one dose of ifosfamide 1 g/m2 (1.8 g total) intravenously over 1 hour, the patient developed renal failure, hyperuricemia, hyperkalemia, hyperphosphatemia, and lactic acidosis. The patient ultimately died from severe electrolyte abnormalities associated with tumor lysis syndrome. CONCLUSION: This is the first instance of tumor lysis syndrome described in a patient with osteosarcoma undergoing ifosfamide monotherapy. Clinicians must be vigilant in identifying tumor lysis syndrome regardless of the malignancy type or chemotherapy regimen in order to prevent potentially fatal complications.

Interobserver and Intraobserver Reliability of the Sirveaux Classification of Scapular Notching After Reverse Total Shoulder Arthroplasty.

The Sirveaux classification characterizes the severity of scapular notching after reverse total shoulder arthroplasty (rTSA). However, its reliability has not been validated. The goal of the current study was to determine the interobserver and intraobserver reliability of the Sirveaux classification. An online survey was sent to the American Shoulder and Elbow Surgeons (ASES), containing 10 radiographs showing a range of scapular notching. Members were asked to grade the degree of scapular notching with the Sirveaux classification system. Then ASES members from our institution regraded the images a second time after a minimum of 6 weeks. Fleiss' and Cohen kappa coefficients were calculated to determine the degree of interobserver and intraobserver reliability, respectively. A total of 50 ASES members graded the radiographs and 3 regraded images after more than 6 weeks. Fleiss' kappa coefficient was 0.2437, indicating fair interobserver agreement. Surgeons who perform more than 20 rTSA procedures per year (n=34) had a Fleiss' kappa of 0.2864. The mean Cohen kappa coefficient was 0.4763, indicating moderate intraobserver reliability. The Sirveaux classification system has fair interobserver and moderate intraobserver reliability. Surgeons should use additional means to describe the severity of notching, particularly when communicating with other physicians or publishing research. [Orthopedics. 2022;45(4):239-243.].