Are periprosthetic hip fractures more severe than native hip fractures? A systematic review of outcomes and resource utilization.

BACKGROUND: There is a paucity of data comparing periprosthetic hip fracture (PPHFx) outcomes and resource utilization to native fractures. Many surgeons consider periprosthetic hip fractures to be more severe injuries than native fractures. The aim of this systematic review is to characterize the outcomes of PPHFx and assess their severity relative to native hip fractures (NHFx). METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analysis systematic review was conducted using Medline, Biosis, and Cinahl. Primary outcomes were time to surgery, length of stay (LOS), cost of management, disposition, complication rates, readmission rates, and mortality. RESULTS: 14 articles (13,489 patients) from 2010 to 2018 were included in the study. Study quality was generally low. Patient follow-up ranged from 1 month to 3.2 years. LOS ranged from 5.2 to 38 days. US cost of management was best estimated at $53,669 ± 19,817. Discharge to skilled nursing facilities ranged from 64.5 to 74.5%. Time to surgery ranged from 1.9 to 5.7 days. Readmission rates ranged from 12 to 32%. Per Clavien-Dindo classification, 33.9% suffered minor complications; 14.3% suffered major complications. 1 month and 1 year mortality ranged from 2.9% to 10% and 9.7% to 45%, respectively. CONCLUSION: Time to surgery and LOS were longer for PPHFx relative to NHFx. Complications' rates were higher for PPHFx compared to NHFx. There is no evidence for differences in LOS, cost, discharge, readmission rates, or mortality between PPHFx and NHFx. These results may serve as a baseline in future evaluation of PPHFx management.

Comparable Outcomes Between Native and Periprosthetic Fractures of the Distal Femur.

Despite the rising prevalence of arthroplasty and aging population, limited data exist regarding differences in periprosthetic fracture clinical outcomes compared with native counterparts. This study compares differences in hospital treatment, morbidity, and mortality associated with periprosthetic distal femur fractures at an urban level 1 trauma center. We retrospectively reviewed all adult AO/OTA type 33 fractures (526) that presented to our institution between 2009 and 2018. In total, 54 native and 54 periprosthetic fractures were matched by age and gender. We recorded demographics, operative measures, length of stay (LOS), discharge disposition, and mortality. We used McNemar's and paired t-tests for analysis where appropriate (p < 0.05) (IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY; IBM Corp.). The average age at injury was 74 years ± 12 (native) compared with 73 years ± 12 (periprosthetic). After 1:1 matching, the groups had similar body mass index (31.01 vs. 32.98, p = 0.966 for native and periprosthetic, respectively) and mechanisms of injury with 38 native and 44 periprosthetic (p = 0.198) fractures from low-energy falls. Both groups had 51/54 fractures managed with open reduction internal fixation with a locking plate. The remaining were managed via amputation or intramedullary nail fixation. Mean operative time (144 minutes (±64) vs. 132 minutes (±62), p = 0.96) and estimated blood loss (319 mL (±362) vs. 289 mL (±231), p = 0.44) were comparable between the native and periprosthetic groups, respectively. LOS: 9 days ± 7 (native) versus 7 days ± 5 (periprosthetic, p = 0.31); discharge disposition (to skilled nursing facility/rehab): n = 47 (native) versus n = 43 (periprosthetic, p = 0.61); and mortality: n = 6 (native) versus n = 8 (periprosthetic, p = 0.55). No significant differences were observed. We found no statistical differences in morbidity and mortality in periprosthetic distal femur fractures treated over 10 years at a level 1 trauma center. Native and periprosthetic AO/OTA type 33 distal femur fractures are serious injuries with similar outcomes at a level 1 trauma center.

Unicompartmental Knee Arthroplasty in Octogenarians versus Younger Patients: A Comparison of 30-Day Outcomes.

As the United States' octogenarian population (persons 80-89 years of age) continues to grow, understanding the risk profile of surgical procedures in elderly patients becomes increasingly important. The purpose of this study was to compare 30-day outcomes following unicompartmental knee arthroplasty (UKA) in octogenarians with those in younger patients. The American College of Surgeons National Surgical Quality Improvement Program database was queried. All patients, aged 60 to 89 years, who underwent UKA from 2005 to 2016 were included. Patients were stratified by age: 60 to 69 (Group 1), 70 to 79 (Group 2), and 80 to 89 years (Group 3). Multivariate regression models were estimated for the outcomes of hospital length of stay (LOS), nonhome discharge, morbidity, reoperation, and readmission within 30 days following UKA. A total of 5,352 patients met inclusion criteria. Group 1 status was associated with a 0.41-day shorter average adjusted LOS (99.5% confidence interval [CI]: 0.67-0.16 days shorter, p < 0.001) relative to Group 3. Group 2 status was not associated with a significantly shorter LOS compared with Group 3. Both Group 1 (odds ratio [OR] = 0.15, 99.5% CI: 0.10-0.23) and Group 2 (OR = 0.33, 99.5% CI: 0.22-0.49) demonstrated significantly lower adjusted odds of nonhome discharge following UKA compared with Group 3. There was no significant difference in adjusted odds of 30-day morbidity, readmission, or reoperation when comparing Group 3 patients with Group 1 or Group 2. While differences in LOS and nonhome discharge were seen, octogenarian status was not associated with increased adjusted odds of 30-day morbidity, readmission, or reoperation. Factors other than age may better predict postoperative complications following UKA.

Orthopedic Implant-Associated and Central Venous Catheter-Associated Infections Caused by Microbacterium spp. in the Veterans Affairs Healthcare System from 2000 to 2020.

Background: A 72-year-old male developed a late-onset infection of an internal fixation device caused by Microbacterium oxydans. Although often considered contaminants, bacteria from the genus Microbacterium may also be pathogens. We also summarize cases from the Veteran Health Administration (VHA) from which Microbacterium isolates were recovered and review the relevant literature. Patients and Methods: Using the national VHA database, we identified patients with cultures that grew Microbacterium spp. We also review published clinical reports describing Microbacterium spp. as a cause of infections. Results: Between January 2000 and September 2020, 18 cases had Microbacterium spp. Of those, Microbacterium isolates were regarded as pathogens for seven cases; all involved prosthetic material that was consequently removed. Two patients had internal fixation devices whereas the remaining five were patients with a central venous catheter. Conclusions: For patients with prosthetic material, recovery of Microbacterium spp. from device-related clinical cultures should prompt consideration of device removal when possible.

Are Readmissions After Total Knee Arthroplasty Preventable?

Readmission within 90 days following total joint arthroplasty has become a central quality measure of reimbursement initiatives; however, the validity of readmission rates as a measure of hospital care quality and the proportion of readmissions that are preventable are unknown. The purpose of this study is to determine if readmissions within 30 and 90 days after total knee arthroplasty (TKA) were related to orthopaedic or medical etiology and identify if these readmissions were preventable. We retrospectively reviewed 1,625 elective TKAs performed between 2011 and 2014 at our institution. Readmissions within 30 and 90 days were categorized into orthopaedic and medical etiologies and an expert research panel determined if readmissions were potentially preventable based on objective criteria from national or peer-reviewed consensus guidelines. Out of the 1,625 TKAs performed during the study period, there were a total of 79 (4.8%) readmissions within 90 days of surgery, of which 17 (22%) were of orthopaedic etiology and 62 (78%) were of medical etiology. Fifty-two (66%) of the 79 readmissions occurred within 30 days, with 11 (21%) of orthopaedic and 41 (80%) of medical etiology. Only 2 of 79 (3%) readmissions within 90 days were deemed potentially preventable, and neither of them were orthopaedic in nature. Hospital readmissions after total joint arthroplasty are inevitable; however, only a small percentage (3%) of readmissions to our health care system was potentially preventable. Orthopaedic readmissions constituted a minority of the proportion of readmissions at 30 or 90 days, and none were deemed preventable.

Appropriate Use Criteria for the Nonarthroplasty Treatment of Knee Osteoarthritis in Veterans.

While patients without knee instability use more nonarthroplasty treatments over a longer period prior to total knee arthroplasty, patients with less severe knee osteoarthritis are at risk of receiving interventions judged to be rarely appropriate.

Preoperative Hyponatremia Is Associated with Reoperation and Prolonged Length of Hospital Stay following Total Knee Arthroplasty.

Hyponatremia is a risk factor for adverse surgical outcomes, but limited information is available on the prognosis of hyponatremic patients who undergo total knee arthroplasty (TKA). The purpose of this investigation was to compare the incidence of major morbidity (MM), 30-day readmission, 30-day reoperation, and length of hospital stay (LOS) between normonatremic and hypontremic TKA patients.The American College of Surgeons National Surgical Quality Improvement Program database was used to identify all primary TKA procedures. Hyponatremia was defined as <135 mEq/L and normonatremia as 135 to 145 mEq/L; hypernatremic patients (>145 mEq/L) were excluded. Multivariable logistic regression was used to determine the association between hyponatremia and outcomes after adjusting for demographics and comorbidities. An α level of 0.002 was used and calculated using the Bonferroni correction. Our final analysis included 88,103 patients of which 3,763 were hyponatremic and 84,340 were normonatremic preoperatively. In our multivariable models, hyponatremic patients did not have significantly higher odds of experiencing an MM (odds ratio [OR]: 1.05; 99% confidence interval [CI] 0.93-1.19) or readmission (OR: 1.12; 99% CI: 1-1.24). However, patients with hyponatremia did experience significantly greater odds for reoperation (OR: 1.24; 99% CI: 1.05-1.46) and longer hospital stay (OR: 1.15; 99% CI: 1.09-1.21). We found that hyponatremic patients undergoing TKA had increased odds of reoperation and prolonged hospital stay. Preoperative hyponatremia may be a modifiable risk factor for adverse outcomes in patients undergoing TKA, and additional prospective studies are warranted to determine whether preoperative correction of hyponatremia can prevent complications.

Predicting Discharge Disposition After Shoulder Arthroplasty in the United States.

INTRODUCTION: Postdischarge management for shoulder replacement continues to be performed on a case-by-case basis, with no uniform guidelines dictating management. The goal of this study was to develop a nomogram to preoperatively predict a patient's discharge disposition after elective shoulder arthroplasty. METHODS: Patients who underwent elective shoulder arthroplasty between 2012 and 2015 were identified in the National Surgical Quality Improvement Program database. A multivariable logistic regression model was used to identify risk factors for discharge to a postacute care facility, and these results were used to create a predictive nomogram. RESULTS: From 2012 to 2015, 8,363 procedures were identified. In our cohort, 962 patients (11.5%) were discharged to a postacute care facility, and 7,492 patients (88.5%) were discharged home. Preoperative functional status, followed by American Society of Anesthesiologists Class and age, had the strongest predictive value for discharge disposition after shoulder arthroplasty. DISCUSSION: Discharge disposition can be predicted using a nomogram with commonly identified preoperative and intraoperative variables. LEVEL OF EVIDENCE: Level III, retrospective cohort design, observational study.

The Evidence Behind Peroxide in Orthopedic Surgery.

Peroxide is a strong oxidizing agent and disinfectant frequently used in orthopedic surgery. The authors conducted a systematic literature review of peroxide in orthopedic surgery, evaluating use, complications, efficacy, and appropriate concentrations. One hundred seventy-five reports were identified, with 24 being eligible for analysis. Orthopedic surgeons used peroxide for irrigation and bacterial reduction in various procedures. Complications included cytotoxicity, allergic reactions, suture damage, and inflammation. Use of the standard concentration of 3% peroxide and standard time in situ are without evidence. Laboratory studies suggest that diluted concentrations retain the benefit of bacterial decolonization without increasing the risk for complications. [Orthopedics. 2018; 41(6):e756-e764.].

Trends in the Orthopaedic Surgery Fellowship Match 2013 to 2017.

INTRODUCTION: This study describes trends in the postgraduate orthopaedic surgery fellowship match from 2013 to 2017. METHODS: We determined the numbers of applicants and positions in Adult Reconstruction/Oncology, Foot and Ankle, Pediatrics, Shoulder and Elbow, Spine, Sports Medicine, and Trauma. We also defined the odds of matching in each subspecialty. We determined the applicant's odds of matching in their first or second choice by year and specialty. We also determined the number of applications made by applicants in each subspecialty. Data were obtained from the San Francisco Match. RESULTS: In 2017, Adult Reconstruction/Oncology was the most selective, with a 68% match rate in 2017, whereas Pediatric Orthopaedic Surgery had a 93% chance of matching. The odds of matching in one's first (14% to 41%) or second (8% to 16%) choice was low in the study period. The average range of applications made by applicants varied from 18 to 28 applications, depending on year and specialty. Sports applicants made significantly more mean number of applications than all specialties (range +5 to 9.8 applications; P < 7.59 × 10-7 to 0.011). DISCUSSION: The numbers of positions and odds of matching in postgraduate orthopaedic surgery fellowships are variable by year and subspecialty. Applicants need to consider their entire match list carefully due to low odds of matching in their first or second choice. These trends are valuable to applicants and training programs when selecting the numbers of applications and interviews for a successful match.

National Incidence of Patient Safety Indicators in the Total Hip Arthroplasty Population.

BACKGROUND: The Centers for Medicare & Medicaid Services use the incidence of patient safety indicators (PSIs) to determine health care value and hospital reimbursement. The national incidence of PSI has not been quantified in the total hip arthroplasty (THA) population, and it is unknown if patient insurance status is associated with PSI incidence after THA. METHODS: All patients in the Nationwide Inpatient Sample (NIS) who underwent THA in 2013 were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. The incidence of PSI was determined using the International Classification of Diseases, Ninth Revision, diagnosis code algorithms published by the Centers for Medicare & Medicaid Services and the Agency for Healthcare Research and Quality. The association of insurance status and the incidence of PSI during the inpatient episode was determined by comparing privately insured and Medicare patients with Medicaid/self-pay patients using a logistic regression model that controlled for patient demographics, patient comorbidities, and hospital characteristics. RESULTS: In 2013, the NIS included 68,644 hospitalizations with primary THA performed during the inpatient episode. During this period, 429 surgically relevant PSI were recorded in the NIS. The estimated national incidence rate of PSI after primary THA was 0.63%. In our secondary analysis, the privately insured cohort had significantly lower odds of experiencing one or more PSIs relative to the Medicaid/self-pay cohort (odds ratio, 0.47; 95% confidence interval, 0.29-0.76). CONCLUSION: The national incidence of PSI among THA patients is relatively low. However, primary insurance status is associated with the incidence of one or more PSIs after THA. As value-based payment becomes more widely adopted in the United States, quality benchmarks and penalty thresholds need to account for these differences in risk-adjustment models to promote and maintain access to care in the underinsured population.

Microfluidic processing of synovial fluid for cytological analysis.

Cytological analysis of synovial fluid is widely used in the clinic to assess joint health and disease. However, in general practice, only the total number of white blood cells (WBCs) are available for cytologic evaluation of the joint. Moreover, sufficient volume of synovial aspirates is critical to run conventional analyses, despite limited volume of aspiration that can normally be obtained from a joint. Therefore, there is a lack of consistent and standardized synovial fluid cytological tests in the clinic. To address these shortcomings, we developed a microfluidic platform (Synovial Chip), for the first time in the literature, to achieve repeatable, cost- and time-efficient, and standardized synovial fluid cytological analysis based on specific cell surface markers. Microfluidic channels functionalized with antibodies against specific cell surface antigens are connected in series to capture WBC subpopulations, including CD4+, CD8+, and CD66b+ cells, simultaneously from miniscule volumes (100 µL) of synovial fluid aspirates. Cell capture specificity was evaluated by fluorescent labeling of isolated cells in microchannels and was around 90% for all three WBC subpopulations. Furthermore, we investigated the effect of synovial fluid viscosity on capture efficiency in the microfluidic channels and utilized hyaluronidase enzyme treatment to reduce viscosity and to improve cell capture efficiency (>60%) from synovial fluid samples. Synovial Chip allows efficient and standardized point-of-care isolation and analysis of WBC subpopulations in miniscule volumes of patient synovial fluid samples in the clinic.

An Anatomic Investigation Into the Relationship Between Posterior Condylar Offset and Posterior Tibial Slope of One Thousand One Hundred Thirty-Eight Cadaveric Knees.

BACKGROUND: Posterior condylar offset (PCO) and posterior tibial slope (PTS) have critical consequences in total knee arthroplasty, especially with regards to sagittal plane balancing. However, there has only been limited investigation into the functional consequences of each, and there have only been anecdotal observations regarding any associations between PCO and PTS. METHODS: In a large osteological study of 1138 knees, standardized measurements of PCO and PTS were taken using previously described techniques on specimens of different age, race, and gender. Multiple linear regression was performed to determine the independent predictors of medial and lateral PTS. RESULTS: Mean standardized medial PCO was greater than lateral PCO (1.22 ± 0.16 vs 1.15 ± 0.19 mm, P < .001) and medial PTS was greater than lateral PTS (7.3 ± 3.8° vs 5.7 ± 3.7°, P < .001). Decreasing PCO, female gender, and African-American race were associated with both increased medial and lateral PTS. Neither age nor femoral length correlated with medial or lateral PTS. CONCLUSION: These data are the first to quantify that an inverse correlation between PCO and PTS exists. This relationship represents an important area for future biomechanical and clinical studies.

Are Readmissions After THA Preventable?

BACKGROUND: Readmissions after total joint arthroplasty have become a key quality measure in elective surgery in the United States. The Affordable Care Act includes the Hospital Readmission Reduction Program, which calls for reduced payments to hospitals with excessive readmissions. This policy uses a method to determine excess readmission ratios and calculate readmission payment adjustments to hospitals, however, it is unclear whether readmission rates are an effective quality metric. The reasons or conditions associated with readmission after elective THA have been well established but the extent to which readmissions can be prevented after THA remains unclear. QUESTIONS/PURPOSES: (1) Are unplanned readmissions after THA associated with orthopaedic or medical causes? (2) Are these readmissions preventable? (3) When during the course of aftercare are orthopaedic versus medical readmissions more likely to occur? METHODS: We retrospectively evaluated all 1096 elective THAs for osteoarthritis performed between January 1, 2011 and June 30, 2014 at a major academic medical center. Of those, 69 patients (6%) who met inclusion criteria were readmitted in our healthcare system within 90 days of discharge after the index procedure during the study period. Fifty patients were readmitted within 30 days of discharge after the index procedure (5%). We defined a readmission as any unplanned inpatient or observation status admission to the hospital spanning at least one midnight. A panel of physicians not involved in the care of these patients used available criteria and existing consensus guidelines to evaluate the medical records, radiographs, and operative reports to identify whether the underlying reason for readmission was orthopaedic versus medical. They subsequently were classified as either nonpreventable or potentially preventable readmissions, based on any care that may have occurred during the index hospitalization. To make such determinations, consensus specialty society guidelines were used whenever possible for each readmission diagnosis. RESULTS: A total of 50 of 1096 patients (5% of those who underwent THA during the period in question) were readmitted within 30 days and 69 of 1096 (6%) were readmitted within 90 days of their index procedures. Thirty-one patients were readmitted for orthopaedic reasons (31/69; 45%) and 38 of 69 were readmitted for medical reasons (55%). Three readmissions (three of 69; 4%) were identified as potentially preventable. Of these potentially preventable readmissions, one was orthopaedic (hip dislocation) and two were medical. Thirty-day readmissions were more likely to be orthopaedic than 90-day readmissions (odds ratio, 4.06; 95% CI, 1.18-13.96; p = 0.026). CONCLUSIONS: Using a panel of expert reviewers, available existing criteria, and consensus methodology, it appears only a small percentage of readmissions after THA are potentially preventable. Orthopaedic readmissions occur earlier during the postoperative course. Currently, existing policies and readmission penalties may not serve as valuable external quality metrics. The readmission rates in our study may represent the threshold for expected readmission rates after THA. Future studies should enroll larger numbers of patients and have independent review panels in efforts to refine criteria for what constitutes preventable readmissions. LEVEL OF EVIDENCE: Level III, therapeutic study.