Incidence, Causes, and Timing of 30-Day Readmission Following Total Knee Arthroplasty.

BACKGROUND: It is important to study the incidence and causes of readmissions in order to understand why they occur and how to reduce them. This study looks at a national sample of patients following total knee arthroplasty (TKA) to identify incidences, trends, causes, and timing of 30-day readmissions. METHODS: Patients undergoing primary TKA from 2012 to 2016 in the American College of Surgeons National Surgical Quality Improvement Program database were identified (n = 197,192). Patients with fractures (n = 177), nonelective surgery (n = 2234), bilateral TKA (n = 5483), and cases with unknown readmission status (n = 1047) were excluded, leaving a total of 188,251 cases. Linear regression analysis was used to determine trends over time. RESULTS: The incidence of overall 30-day readmission following primary TKA from 2012 to 2016 was 3.19% (6014/188,251), with significant decreases in readmission rates during this time (ß = -0.001, P < .001). The top 5 causes of readmission included superficial surgical site infection (SSI; 9.7%), non-SSI infection (9.5%), cardiovascular complications (CV; 9.3%), gastrointestinal complications (8.8%), and venous thromboembolisms (8.8%). The most common cause of readmission during postoperative week 1 was CV complications (12.2%), week 2 was superficial SSI (11.6%), week 3 was deep SSI (11.4%), and week 4 was deep SSI (12.4%). CONCLUSION: Overall, 30-day readmissions following TKA were found to significantly decline from 2012 to 2016. The most common causes of overall readmission included superficial SSI, non-SSI infection, CV complications, gastrointestinal complications, and venous thromboembolisms. However, the most common causes of readmission changed from week to week postoperatively. This data may help institutions develop policies to prevent unplanned readmissions following TKA.

Reliability of International Classification of Diseases, Ninth Edition, Codes to Detect Morbid Obesity in Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: Although the impact of coding errors, with respect to obesity, has been previously reported, it is unclear whether morbid obesity is prone to similar coding inaccuracies. Therefore, the purpose of this study was to evaluate the reliability of coding for morbid obesity in patients who underwent total hip arthroplasty (THA). METHODS: A total of 10,475 primary THAs performed at a single institution from 2004 to 2014 were identified. The presence of International Classification of Diseases, ninth edition diagnosis codes denoting any grade of obesity or morbid obesity during the admission was noted. The sensitivity of coding was evaluated along with the effect of morbid obesity (defined by body mass index or coding) on complications within 90 days of THA. RESULTS: The sensitivity of obesity coding was 28.3%, while that of morbid obesity was 27.9% (area under the curve: 0.63 vs 0.63, P = .765). Among the 882 surgeries performed in morbidly obese patients, a code for any obesity was present in 467 (53%) surgeries, but only 53% (246) of these patients had a code specific for morbid obesity, while 47% (221) had a code for obesity not specifying morbid obesity. Nevertheless, the effects of morbid obesity on complications were similar regardless of how it was defined (coding or body mass index). CONCLUSION: Although morbidly obese patients are likely to be easily identified as obese using codes, these patients may not be receiving a specific code. Researchers and clinicians should be aware that coding errors are prevalent even among higher grades of obesity in patients undergoing THA which may lead to suboptimal reimbursements and affect the results of studies using codes.

Utility of Serological Markers for Detecting Persistent Infection in Two-Stage Revision Arthroplasty in Patients With Inflammatory Arthritis.

BACKGROUND: Serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are commonly used for the diagnosis of persistence of infection after the first stage of 2-stage revision arthroplasty for periprosthetic joint infection (PJI). As both ESR and CRP are markers of systemic inflammation, the utility of these tests to monitor infection clearance in patients with inflammatory arthritis is unclear. METHODS: From 2001 to 2016, 44 two-stage revision total hip or knee arthroplasties in patients with an inflammatory arthritis diagnosed by a rheumatologist were identified. Persistence of infection at the time of planned second stage was defined as satisfying the Musculoskeletal Infection Society criteria for PJI (14 infected, 30 noninfected). ESR and CRP values were compared between the stages using nonparametric tests. Receiver operating characteristic analysis was performed to obtain the diagnostic parameters. RESULTS: ESR and CRP decreased between the stages in the noninfected group (ESR: mean decrease = 31.6 mm/h [19.2-44.0], P < .001; CRP: mean decrease = 5.2 mg/dL [2.1-8.2], P < .001), but remained elevated in the infected group (ESR: mean decrease = 7.7 [-23.1 to 36.6], P = .572; CRP: mean decrease = 1.5 [-2.2 to 5.1], P = .258). Optimal thresholds for persistent infection were 29.5 mm/h and 2.8 mg/dL, respectively, for ESR and CRP. The sensitivity and specificity at the optimal thresholds were 64% and 77% for ESR, and 64% and 90% for CRP. CONCLUSION: ESR and CRP responded to the treatment of PJI in patients with inflammatory arthritis and had reasonably high specificities with moderate sensitivities. ESR and CRP appear to be useful tools in diagnosing persistent infection even in patients with inflammatory arthritis.

Diagnostic Utility of Histological Analysis for Detecting Ongoing Infection During Two-Stage Revision Arthroplasty in Patients With Inflammatory Arthritis.

BACKGROUND: Surgeons often rely on intra-operative histology (frozen sections [FS]) to determine the next step in surgical management during the second stage (re-implantation surgery) of 2-stage revision arthroplasty. The purpose of the study is to assess the accuracy of permanent sections (PS) and FS in the diagnosis of persistent infection during re-implantation in patients with an inflammatory arthritis. METHODS: From 2001 to 2016, 47 planned second-stage revision total hip arthroplasty and total knee arthroplasty in patients with inflammatory arthritis were identified. Revisions were classified as having persistent infection if they were Musculoskeletal Infection Society positive at the time of second stage. PS or FS was considered to be positive for infection when at least one of the specimens demonstrated an acute inflammation. Receiver operating characteristic analysis was performed to obtain the diagnostic parameters. RESULTS: There were 9 (19%) persistent infections. Both PS and FS had very high specificity (PS = FS = 94.7%). Sensitivity of PS was higher than FS, although not statistically significant (PS = 88.9%, FS = 55.6%, P = .083). Overall, PS had a better diagnostic utility than FS (area under the curve: PS vs FS = 0.92 vs 0.75, P = .045). Four specimens had discrepancies between PS and FS histology. In all 4 instances, the specimens were read as positive (infected) by PS, but negative by FS. CONCLUSION: Histological analysis is recommended at the time of re-implantation surgery even in patients with inflammatory arthritis. PS had a better diagnostic utility than FS suggesting that areas of acute inflammation may be scattered and may not always be captured in the specimens taken for FS.

Reduction of Particles in the Operating Room Using Ultraviolet Air Disinfection and Recirculation Units.

BACKGROUND: Airborne bacteria are a major source for wound contamination during total joint arthroplasty. Crystalline ultraviolet C (C-UVC) filter units were designed to disinfect and recirculate air in the operating room (OR). This preliminary study assessed the particle reducing capacity of C-UVC units in a highly controlled OR setting. METHODS: A particle counter was deployed in a positive-pressure OR to measure total and viable particle counts (TPC/VPC). Thirty 23-minute experiments were performed. At 4 designated times a person would walk through the door to mimic OR traffic. Ten experiments were performed as controls, 10 experiments used a C-UVC unit 4 meters (m) from the door, and 10 cases with the C-UVC unit at 8 m. Outcomes included overall, change (Δ), and maximum TPC/VPC. Mann-Whitney U-tests determined statistical differences in TPC/VPC. RESULTS: Compared to controls, the cases with the C-UVC unit at 4 m had significantly lower particle levels. Overall TPC/VPC, changes in TPC/VCP, and maximum TPC/VPC were all significantly lower (P < .05) in the C-UVC unit (4 m) group compared to the controls. The C-UVC at 8 m significantly reduced TPC in all 3 outcomes (P < .05) compared to controls; however, it did not significantly reduce changes in VPC (P = .107) and maximum VPC (P = .052). There were no significant differences in any outcomes between the 4 m and 8 m group. CONCLUSION: C-UVC units have shown to be capable of significantly reducing TPC and VPC in a highly controlled OR setting. Reducing airborne particles using C-UVC units may reduce infection rates following total joint arthroplasty.

Cryotherapy Treatment After Unicompartmental and Total Knee Arthroplasty: A Review.

BACKGROUND: Cryotherapy is widely utilized to enhance recovery after knee surgeries. However, the outcome parameters often vary between studies. Therefore, the purpose of this review is to compare (1) no cryotherapy vs cryotherapy; (2) cold pack cryotherapy vs continuous flow device cryotherapy; (3) various protocols of application of these cryotherapy methods; and (4) cost-benefit analysis in patients who had unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA). METHODS: A search for "knee" and "cryotherapy" using PubMed, EBSCO Host, and SCOPUS was performed, yielding 187 initial reports. After selecting for RCTs relevant to our study, 16 studies were included. RESULTS: Of the 8 studies that compared the immediate postoperative outcomes between patients who did and did not receive cryotherapy, 5 studies favored cryotherapy (2 cold packs and 3 continuous cold flow devices). Of the 6 studies comparing the use of cold packs and continuous cold flow devices in patients who underwent UKA or TKA, 3 favor the use of continuous flow devices. There was no difference in pain, postoperative opioid consumption, or drain output between 2 different temperature settings of continuous cold flow device. CONCLUSION: The optimal device to use may be one that offers continuous circulating cold flow, as there were more studies demonstrating better outcomes. In addition, the pain relieving effects of cryotherapy may help minimize pain medication use, such as with opioids, which are associated with numerous potential side effects as well as dependence and addiction. Meta-analysis on the most recent RCTs should be performed next.

Cryotherapy Treatment After Arthroscopic Knee Debridement and ACL Reconstruction: A Review.

Pain, swelling, and inflammation of the knee joint and its surrounding soft-tissue structures are common during the postoperative period after arthroscopic knee debridement and anterior cruciate ligament reconstruction. These challenges can make patient recovery difficult immediately after surgery. Several options exist, however, to help patients overcome these challenges. Cryotherapy has been noted to decrease pain, swelling, and inflammation. However, while a number of studies exist characterizing the use of cryotherapy after knee surgery, no definitive cryotherapy devices and modalities have been identified. Therefore, the purpose of this review was to evaluate randomized controlled trials to assess the use of cryotherapy after: 1) arthroscopic debridement; and 2) anterior cruciate ligament reconstruction.

A Comparison of Relative Value Units in Primary versus Revision Total Ankle Arthroplasty.

INTRODUCTION: To determine the effort required to provide a service, the United States Medicare uses Relative Value Units (RVUs). Consequently, higher RVUs are assigned to the procedures or services that require more effort, which ultimately means the physician will be properly compensated for the additional effort required. In total ankle arthroplasty (TAA), revision cases usually are more technically challenging and require more effort than primary TAA. Therefore, the purpose of this study was to compare the: 1) RVUs; 2) length-of-surgery; 3) RVU per unit of time between primary and revision total ankle arthroplasty; and 4) the individualized idealized surgeon annual cost difference analysis. MATERIALS AND METHODS: We utilized the American College of Surgeons, National Surgical Quality Improvement Program database from 2008 to 2015 to identify patients who underwent either a primary Current Procedural Terminology [CPT]: 27702) or revision (CPT: 27703) TAA. There were a total of 653 patients, 586 of which underwent a primary, and 67 who underwent a revision, TAA. The mean RVUs, length of surgery (in minutes), and RVU per minute, were calculated. Dollar amount per minute, per case, per day, and per year, to find an individualized idealized surgeon annual cost difference, were also calculated. An analysis of variance was used to compare variables between primary and revision TAA. A p-value of less than 0.05 was used to determine statistical significance. RESULTS: The mean RVU was significantly higher in revision versus primary TAA (16.93 vs. 14.41, p=0.001). However, there was no significant difference in the mean lengths of surgery between primary and revision TAA (160 vs. 157 minutes, p=0.613). Additionally, the mean RVU per minute was significantly higher in revision versus primary TAA (0.13 vs. 0.10, p=0.001). CONCLUSION: Based on the results of this study, it appears that revision TAA cases are appropriately assigned a higher RVU per minute for performing them as they require more effort and are more challenging compared to the primary TAA. Furthermore, not only did the revision cases have lower mean lengths of surgery, but they also maintained a higher RVU per minute. Therefore, orthopaedists can use this information to further help them yield the best potential practice design.

Sequential occurrence of thrombotic thrombocytopenic purpura, essential thrombocythemia, and idiopathic thrombocytopenic purpura in a 42-year-old African-American woman: a case report and review of the literature.

INTRODUCTION: Thrombotic thrombocytopenic purpura and idiopathic thrombocytopenic purpura are two well recognized syndromes that are characterized by low platelet counts. In contrast, essential thrombocythemia is a myeloproliferative disease characterized by abnormally high platelet numbers.The coexistence of thrombotic thrombocytopenic purpura and idiopathic thrombocytopenic purpura in a single patient has been reported in the literature on a few occasions. However, having essential thrombocythemia complicating the picture has never been reported before. CASE PRESENTATION: We present a case where thrombotic thrombocytopenic purpura, essential thrombocythemia, and idiopathic thrombocytopenic purpura were diagnosed in a 42-year-old African-American woman in the space of a few years; we are reporting this case with the aim of drawing attention to this undocumented occurrence, which remains under investigation. CONCLUSIONS: As the three conditions have different natural histories and require different treatment modalities, it is important to recognize that these diseases may be seen sequentially. This case emphasizes the importance of reviewing peripheral blood smears for evaluation of thrombocytopenia and bone marrow aspirations for diagnosis of thrombocythemia in order to reach an accurate diagnosis and tailor therapy accordingly. Moreover, this case demonstrates the variability and complexity of platelet disorders. This occurrence of three different types of platelet disorders in one patient remains a pure observation on our part; regardless, this does raise the possibility of a common underlying, as yet undiscovered, pathophysiology that could explain the phenomenon.