Adverse Local Tissue Reaction Secondary to Corrosion at Multiple Junctions in a Modular, Segmental, Distal Femoral Replacement.

While adverse local tissue reactions are well described in the total hip arthroplasty literature, there have only been case reports and case series in the total knee arthroplasty literature. There have been no cases described in the setting of a distal femoral replacement. In this case, we describe a 69-year-old female with a complex history of left knee revision arthroplasty with a distal femoral and proximal tibial replacement who presented with left knee pain and was found to have extensive adverse local tissue reaction with corrosion at the femoral stem-extension piece junction and the extension piece-distal femoral component junction. The femoral taper was then manually cleaned and modular components replaced. Corrosion at the stem-distal femoral component junction can result in adverse local tissue reaction in patients with distal femoral replacements. It is important to consider this diagnosis when evaluating patients with knee pain following distal femoral replacement.

Irrigation and Debridement for Early Periprosthetic Knee Infection: Is It Effective?

BACKGROUND: Irrigation and debridement (I&D) is performed for early management of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). Symptom reporting is a subjective measure and may miss direct management of PJI. Utilizing an objective time interval from index procedure to I&D may better inform treatment decisions. METHODS: From 2009 to 2017, retrospective review was performed of 55 knee PJI cases at our institution. All patients underwent polyethylene liner exchange and I&D for PJI. Patients were stratified by time from index procedure to I&D (≤2 weeks, >2 weeks). Success was defined as eradication of infection and resolution of presenting symptoms. Failed cases required subsequent procedures due to infection. RESULTS: Average follow-up time after index TKA was 2.5 years. Among patients with I&D within 2 weeks of index TXA, 14 patients (82%) were successfully treated while 3 (18%) had infection recurrence. These outcomes were significantly improved compared to patients with I&D after 2 weeks: 19 (50%) successes and 19 (50%) failures (P = .024). Staphylococcal species were the most frequent pathogen in patients treated before and after 2 weeks of index TKA (39% and 50%, respectively). Outcomes were pathogen-independent in PJIs treated before or after 2 weeks of index TKA (P = .206 and .594, respectively). CONCLUSION: Our results demonstrate that patients with early PJI managed with I&D and liner exchange within 2 weeks of index TKA had higher rates of treatment success when compared to those with I&D beyond 2 weeks. These findings suggest that time from index TKA to I&D is an objective and reliable indicator of treatment success when considering I&D in acute onset knee PJI.

Has Health Care Reform Legislation Reduced the Economic Burden of Hospital Readmissions Following Primary Total Joint Arthroplasty?

BACKGROUND: The purpose of this study was to determine whether the cost of readmissions after primary total hip and knee arthroplasty (THA and TKA) has decreased since the introduction of health care reform legislation and what patient, clinical, and hospital factors drive such costs. METHODS: The 100% Medicare inpatient dataset was used to identify 1,654,602 primary THA and TKA procedures between 2010 and 2014. The per-patient cost of readmissions was evaluated in general linear models in which the year of surgery and patient, clinical, and hospital factors were treated as covariates in separate models for THA and TKA. RESULTS: The year-to-year risk of 90-day readmission was reduced by 2% and 4% (P < .001) for THA and TKA, respectively. By contrast, the cost of readmissions did not change significantly over time. The 5 most important variables associated with the cost of 90-day THA readmissions (in rank order) were the nature of the readmission (ie, due to medical or procedure-related reasons), the length of stay, hospital's teaching status, discharge disposition, and hospital's overall total joint arthroplasty volume. The top 5 factors associated with the cost of 90-day TKA readmissions were (in rank order) the length of stay, hospital's teaching status, discharge disposition, patient's gender, and age. CONCLUSION: Although readmission rates declined slightly, the results of this study do not support the hypothesis that readmission costs have decreased since the introduction of health care reform legislation. Instead, we found that clinical and hospital factors were among the most important cost drivers.

Which Clinical and Patient Factors Influence the National Economic Burden of Hospital Readmissions After Total Joint Arthroplasty?

BACKGROUND: The Affordable Care Act of 2010 advanced the economic model of bundled payments for total joint arthroplasty (TJA), in which hospitals will be financially responsible for readmissions, typically at 90 days after surgery. However, little is known about the financial burden of readmissions and what patient, clinical, and hospital factors drive readmission costs. QUESTIONS/PURPOSES: (1) What is the incidence, payer mix, and demographics of THA and TKA readmissions in the United States? (2) What patient, clinical, and hospital factors are associated with the cost of 30- and 90-day readmissions after primary THA and TKA? (3) Are there any differences in the economic burden of THA and TKA readmissions between payers? (4) What types of THA and TKA readmissions are most costly to the US hospital system? METHODS: The recently developed Nationwide Readmissions Database from the Healthcare Cost and Utilization Project (2006 hospitals from 21 states) was used to identify 719,394 primary TJAs and 62,493 90-day readmissions in the first 9 months of 2013 based on International Classification of Diseases, 9th Revision, Clinical Modification codes. We classified the reasons for readmissions as either procedure- or medical-related. Cost-to-charge ratios supplied with the Nationwide Readmissions Database were used to compute the individual per-patient cost of 90-day readmissions as a continuous variable in separate general linear models for THA and TKA. Payer, patient, clinical, and hospital factors were treated as covariates. We estimated the national burden of readmissions by payer and by the reason for readmission. RESULTS: The national rates of 30- and 90-day readmissions after THA were 4% (95% confidence interval [CI], 4.2%-4.5%) and 8% (95% CI, 7.5%-8.1%), respectively. The national rates of 30- and 90-day readmissions after primary TKA were 4% (95% CI, 3.8%-4.0%) and 7% (95% CI, 6.8%-7.2%), respectively. The five most important variables responsible for the cost of 90-day THA readmissions (in rank order, based on the Type III F-statistic, p < 0.001) were length of stay (LOS), all patient-refined diagnosis-related group (APR DRG) severity, type of readmission (that is, medical- versus procedure-related), hospital ownership, and age. Likewise, the five most important variables responsible for the cost of 90-day TKA readmissions were LOS, APR DRG severity, gender, hospital procedure volume, and hospital ownership. After adjusting for covariates, mean 90-day readmission costs reimbursed by private insurance were, on average, USD 1324 and USD 1372 greater than Medicare (p < 0.001) for THA and TKA, respectively. In the 90 days after TJA, two-thirds of the total annual readmission costs were covered by Medicare. In 90 days after THA, more readmissions were still associated with procedure-related complications, including infections, dislocations, and periprosthetic fractures, which in aggregate account for 59% (95% CI, 59.1%-59.6%) of the total readmission costs to the US healthcare system. For TKA, 49% of the total readmission cost (95% CI, 48.8%-49.6%) in 90 days for the United States was associated with procedure issues, most notably including infections. CONCLUSIONS: Hospital readmissions up to 90 days after TJA represent a massive economic burden on the US healthcare system. Approximately half of the total annual economic burden for readmissions in the United States is medical and unrelated to the joint replacement procedure and half is related to procedural complications. CLINICAL RELEVANCE: This national study underscores LOS during readmission as a primary cost driver, suggesting that hospitals and doctors further optimize, to the extent possible, the clinical pathways for the hospitalization of readmitted patients. Because patients readmitted as a result of infection, dislocation, and periprosthetic fractures are the most costly types of readmissions, efforts to reduce the LOS for these types of readmissions will have the greatest impact on their economic burden. Additional clinical research is needed to determine the extent to which, if any, the LOS during readmissions can be reduced without sacrificing quality or access of care.

Which Hospital and Clinical Factors Drive 30- and 90-Day Readmission After TKA?

BACKGROUND: The purpose of this study was to analyze the hospital, clinical, and patient factors associated with inpatient readmission after total knee arthroplasty (TKA) in the Medicare population and to understand the primary reasons for readmission. METHODS: The Medicare 100% national hospital claims database was used to identify 952,593 older patients (65+) with a primary TKA in 3848 hospitals between 2010 and 2013. A multilevel logistic regression analysis with a clustered data structure was used to investigate the risk of all-cause 30- and 90-day readmission, incorporating hospital, clinical, and patient factors. RESULTS: At 30 days, readmission ranged from 0% to 22% (median, 4.9%), whereas at 90 days, readmission ranged from 0% to 32% (median, 8.6%). Geographic census region, hospital procedure volume, rural hospital location, and nonprofit ownership were the only significant hospital factors among those we studied. Evaluation of clinical factors showed use of a perioperative transfusion was associated with 13% greater risk; patients discharged to home had 25% lower risk; and surgeon volume and length of stay were also significant. These effect sizes were at least comparable to patient factors, such as age, gender, comorbidities, and socioeconomic status. The top 5 most frequently reported primary reasons for 30- or 90-day readmission in TKA were surgery and medical related: wound infection, deep infection, atrial fibrillation, cellulitis and abscess of leg, or pulmonary embolism. CONCLUSION: The results of this study support further optimization of anti-infection measures, both intraoperative and postoperative, to reduce the broad variation in hospital readmissions.

Hospital, Patient, and Clinical Factors Influence 30- and 90-Day Readmission After Primary Total Hip Arthroplasty.

BACKGROUND: The purpose of this study was to analyze the hospital, clinical, and patient factors associated with inpatient readmission after total hip arthroplasty (THA) in the Medicare population and to understand the primary reasons for readmission. METHODS: The Medicare 100% national hospital claims database was used to identify 442,333 older patients (65+) with a primary THA in 3730 hospitals between 2010 and 2013. A multilevel logistic regression analysis with a clustered data structure was used to investigate the risk of all-cause 30- and 90-day readmission, incorporating hospital, clinical, and patient factors. RESULTS: At 30 days, 5.8% (median) of the patients were readmitted, whereas at 90 days, 10.5% (median) were readmitted. Geographic census region, hospital procedure volume, and nonprofit ownership were the only significant hospital factors among those we studied. Overall, clinical factors explained more of the variation in readmission rates than general hospital factors. Use of a perioperative transfusion was associated with 14% greater risk, patients discharged to home had 28% lower risk, and surgeon volume and length of stay were also significant risk factors. The top 5 most frequently reported primary reasons for 30-day readmission in THA were procedure related: dislocation (5.9%), deep infection (5.1%), wound infection (4.8%), periprosthetic fracture (4.4%), or hematoma (3.4%). CONCLUSION: These findings support further optimization of the delivery of care-both intraoperative and postoperative-to reduce the broad variation in hospital readmissions.

Survivorship and Complications of Revision Total Hip Arthroplasty with a Mid-Modular Femoral Stem.

We retrospectively reviewed 161 revision THAs with diaphyseal fitting, mid-modular femoral components performed by ten surgeons at two academic medical centers. The average follow-up was 6.1 years. At final follow-up, 4 patients required re-revision for failure of the femoral component; 3 (2%) for aseptic loosening and 1 for mechanical failure of stem in setting of periprosthetic fracture. There were a total of 24 (14.9%) revisions for any reason, with the most common reason being septic failure (10 of 24). To our knowledge, this is the largest reported series of mid-term survivorship and complications of revision THA with mid-modular femoral components. Our results show that these stems have a low rate of aseptic loosening, subsidence, and mechanical failure.

Constrained acetabular liners cemented into cages during total hip revision arthroplasty.

The combination of acetabular bone loss and hip instability is challenging. Sixteen patients underwent revision total hip arthroplasty using constrained acetabular liners cemented into cages. The average follow-up was 28 months (range, 24-60 months). Clinical evaluation was obtained using the Harris hip score along with radiographic data. At latest follow-up, 13 patients were available for evaluation. Although the average postoperative Harris hip score was 62 points, which was better than the preoperative score of 27 points, the overall radiographic failure rate was 23%. The combination of poor acetabular bone stock and altered stresses from the increased constraint likely led to the poor outcome. We would only recommend use of a cemented, constrained acetabular liner in combination with a protrusio cage as a bail out or salvage procedure.

Obturator dislocation of total hip arthroplasty--a case report.

This study consists of a single case report of a patient who had an irreducible obturator dislocation of a total hip arthroplasty after a motor vehicle accident, not previously described in the English literature. In particular, the focus will be on offering an educated opinion on the risk factors for dislocation and difficulties encountered with this type of dislocation. The aim is to offer valuable insight based on the operative experience with this patient and to supplement the literature with the management of such a complication following total hip arthroplasty.

Granulomatous inflammation after Hylan G-F 20 viscosupplementation of the knee : a report of six cases.

BACKGROUND: Recently, intra-articular viscosupplementation with hyaluronate-derived products has gained popularity as a palliative modality for the treatment of osteoarthritis of the knee. Mild pain or swelling at the site of injection may occur in up to 20% of patients, although severe local inflammation, warmth, and joint effusion are rare. We present a series of six cases in which granulomatous inflammation of the synovium was observed after hyaluronate viscosupplementation of the knee. METHODS: Six knees (five patients) treated with intra-articular Hylan G-F 20 viscosupplementation underwent a surgical procedure because of persistent symptoms. Routine histopathological evaluation, supplemented by alcian-blue staining and hyaluronidase digestion, was performed in each case. RESULTS: Chronically inflamed synovium with areas of histiocytic and foreign-body giant-cell reaction was observed surrounding acellular, amorphous material. The material stained with alcian blue, a stain for hyaluronate, which disappeared after hyaluronidase digestion. CONCLUSIONS: We believe that the injected hyaluronate (Hylan G-F 20) may have been responsible for the synovitis in our patients and thus may be a pathological cause of recalcitrant symptoms after such injection. It is not known whether the responsible pathological agent was the hyaluronate derivative, a contaminant of the purification process, or a component of the carrier substance. Importantly, it appears that the findings in these patients most likely represent a previously unreported pathological response to a viscosupplementation product. This report should raise clinical awareness about this potential complication.