Patellofemoral Arthroplasty.

Patellofemoral arthroplasty (PFA) as a treatment option for isolated patellofemoral disease continues to evolve. Enhancement in patient selection, surgical technique, implant design, and technology has led to improved short-term and midterm outcomes. Furthermore, in the setting of a younger patient with isolated patellofemoral arthritis, PFA represents an option for improved function with faster recovery times, bone preservation, maintenance of ligamentous proprioception, and the ability to delay total knee arthroplasty (TKA). The most common reason for revising PFA to a TKA is progression of tibiofemoral arthritis. In general, conversion of PFA to TKA leads to successful outcomes with minimal bone loss and the ability to use primary TKA implants and instrumentation. PFA seems to be a cost-effective alternative to TKA in appropriately selected patients with 5-, 10-PFA survivorships of 91.7% and 83.3%, respectively, and an annual revision rate of 2.18%; however, more long-term clinical studies are needed to determine how new designs and technologies affect patient outcomes and implant performance.

Does Individualization of Cup Position Affect Prosthetic or Bone Impingement Following Total Hip Arthroplasty?

BACKGROUND: Spinopelvic (SP) mobility patterns during postural changes affect three-dimensional acetabular component position, the incidence of prosthetic impingement, and total hip arthroplasty (THA) instability. Surgeons have commonly placed the acetabular component in a similar "safe zone" for most patients. Our purpose was to determine the incidence of bone and prosthetic impingement with various cup orientations and determine if a preoperative SP analysis with individualized cup orientation lessens impingement. METHODS: A preoperative SP evaluation of 78 THA subjects was performed. Data were analyzed using a software program to determine the prevalence of prosthetic and bone impingement with a patient individualized cup orientation versus 6 commonly selected cup orientations. Impingement was correlated with known SP risk factors for dislocation. RESULTS: Prosthetic impingement was least with the individualized choice of cup position (9%) versus preselected cup positions (18%-61%). The presence of bone impingement (33%) was similar in all groups and not affected by cup position. Factors associated with impingement in flexion were age, lumbar flexion, pelvic tilt (stand to flexed seated), and functional femoral stem anteversion. Risk factors in extension included standing pelvic tilt, standing SP tilt, lumbar flexion, pelvic rotation (supine to stand and stand to flexed seated), and functional femoral stem anteversion. CONCLUSION: Prosthetic impingement is reduced with individualized cup positioning based on SP mobility patterns. Bone impingement occurred in one-third of patients and is a noteworthy consideration in preoperative THA planning. Known SP risk factors for THA instability correlated with the presence of prosthetic impingement in both flexion and extension.

Screening and Management of Malnutrition in Total Joint Arthroplasty.

Malnutrition is an increasingly prevalent problem in patients undergoing total joint arthroplasty (TJA). Increased risks associated with TJA in the setting of malnourishment have been well documented. Standardized scoring systems in addition to laboratory parameters such as albumin, prealbumin, transferrin, and total lymphocyte count have been developed to identify and evaluate malnourished patients. Despite an abundance of recent literature, there is no consensus on the best approach for screening TJA patients from a nutritional standpoint. Although there are a variety of treatment options, including nutritional supplements, nonsurgical weight loss therapies, bariatric surgery, and the involvement of dieticians and nutritionists, the effect of these interventions on TJA outcomes has not been well characterized. This overview of the most current literature aims to provide a clinical framework for approaching nutrition status in arthroplasty patients. A comprehensive understanding of the tools available for managing malnourishment will facilitate improved arthroplasty care.

Routine Laboratory Tests are not Necessary After Primary Total Joint Arthroplasty: A Prospective Study Utilizing a Selective Algorithmic Approach.

BACKGROUND: Laboratory tests are obtained following total joint arthroplasty (TJA) despite a lack of supporting evidence. No prior study has prospectively analyzed the effect of discontinuing routine laboratory tests. This study aimed to determine whether discontinuing routine laboratory tests in TJA patients resulted in a difference in 90-day complications. METHODS: This was a prospective protocol change study at a high-volume center. Prior to protocol change, patients underwent routine laboratory tests following primary unilateral TJA (control group). After the change, an algorithmic approach was used to selectively order laboratory tests (protocol group). Patients with bleeding disorders, chronic obstructive pulmonary disease, arrhythmia, coronary artery disease, congestive heart failure, chronic renal failure, dementia, abnormal preoperative sodium, potassium, or hemoglobin <10 g/dL were excluded. In-hospital and 90-day data were collected. Student's t-test was used to analyze continuous variables and chi-squared test was used for categorical variables. A pre-hoc analysis examining the primary outcome required 607 patients per group to achieve 80% power. RESULTS: The protocol group included 937 patients, whereas the control group included 891 patients. The protocol group had fewer females and total hip arthroplasties. There were no differences in age, body mass index, American Society of Anesthesiologists classification, tranexamic acid administration, or estimated blood loss between the protocol and control groups. There were also no differences in transfusions, electrolyte corrections, unplanned consults, length of stay, or transfers. The protocol cohort had more fluid boluses and home discharges. There was no difference in 90-day complications between the 2 groups. CONCLUSIONS: This study utilizing an algorithmic approach to laboratory collection demonstrates that discontinuing routine laboratory tests following TJA is safe and effective. We believe this protocol can be implemented for most patients undergoing primary unilateral TJA.

The PROMIS Upper Extremity Computer Adaptive Test Correlates With Previously Validated Metrics in Patients With Carpal Tunnel Syndrome.

Background: The Patient-Reported Outcomes Measurement Information System Upper Extremity (PROMIS UE) computer adaptive test was developed to improve precision and reduce question burden. We hypothesized that in patients with carpal tunnel syndrome (CTS): (1) PROMIS UE would correlate with established patient-reported outcome measures (PROs); (2) the time and number of questions required would be lower than current metrics; (3) there would be no floor or ceiling effects; and (4) PROMIS UE would not correlate with disease severity. Methods: Patients undergoing electrodiagnostic evaluation found to have a primary diagnosis of unilateral CTS prospectively completed PROMIS UE, Quick Disabilities of the Arm, Shoulder and Hand (qDASH), and Boston Carpal Tunnel Syndrome Questionnaire (BCTQ). Electrophysiologic and clinical severity was recorded. The relationships among PROs were described with Spearman coefficients. A floor or ceiling effect was confirmed if >15% of patients achieved the lowest or highest possible score, respectively. Results: Fifty-one patients (average, 53.9 years) were enrolled. An excellent correlation was identified between PROMIS UE and qDASH (R = -0.76, P < .001). There was a good correlation between PROMIS UE and BCTQ (R = -0.58, P < 0.001). The PROMIS UE required less time and fewer questions than qDASH and BCTQ (P = .02 and P < .001). There were no floor or ceiling effects. Neither neurophysiologic nor clinical severity correlated with PROMIS UE (R = 0.24, P > .05 and R = -0.18, P > .05). Conclusions: The PROMIS UE has an excellent correlation with qDASH and a good correlation with BCTQ in patients with CTS. Furthermore, PROMIS UE required less time and fewer questions than established PROs. Used as a single PRO, PROMIS UE represents a practical alternative to current metrics in patients with CTS.

A Nurse Navigator Program Is Effective in Reducing Episode-of-Care Costs Following Primary Hip and Knee Arthroplasty.

BACKGROUND: Alternative payment models for total hip arthroplasty (THA) and total knee arthroplasty (TKA) have incentivized providers to deliver higher quality care at a lower cost, prompting some institutions to develop formal nurse navigation programs (NNPs). The purpose of this study was to determine whether a NNP for primary THA and TKA resulted in decreased episode-of-care (EOC) costs. METHODS: We reviewed a consecutive series of primary THA and TKA patients from 2015-2016 using claims data from the Centers for Medicare and Medicaid Services and Medicare Advantage patients from a private insurer. Three nurse navigators were hired to guide discharge disposition and home needs. Ninety-day EOC costs were collected before and after implementation of the NNP. To control for confounding variables, we performed a multivariate regression analysis to determine the independent effect of the NNP on EOC costs. RESULTS: During the study period, 5275 patients underwent primary TKA or THA. When compared with patients in the prenavigator group, the NNP group had reduced 90-day EOC costs ($19,116 vs $20,418 for Medicare and $35,378 vs $36,961 for private payer, P < .001 and P < .012, respectively). Controlling for confounding variables in the multivariate analysis, the NNP resulted in a $1575 per Medicare patient (P < .001) and a $1819 per private payer patient cost reduction (P = .005). This translates to a cost savings of at least $5,556,600 per year. CONCLUSION: The implementation of a NNP resulted in a marked reduction in EOC costs following primary THA and TKA. The cost savings significantly outweighs the added expense of the program. Providers participating in alternative payment models should consider using a NNP to provide quality arthroplasty care at a reduced cost.

Bundled Payments Are Effective in Reducing Costs Following Bilateral Total Joint Arthroplasty.

BACKGROUND: Alternative payment models such the Centers for Medicare and Medicaid Services Bundled Payments for Care Improvement (BPCI) initiative have been effective in reducing costs following unilateral total hip (THA) and knee arthroplasty (TKA), but few studies exist on bilateral arthroplasty. This study aimed to determine whether the BPCI program for bilateral THA and TKA reduced episode-of-care costs. METHODS: We retrospectively reviewed a consecutive series of patients who underwent simultaneous bilateral primary THA and TKA between 2015 and 2016. We recorded demographic variables, comorbidities, readmissions, and calculated 90-day episode-of-care costs based on Centers for Medicare and Medicaid Services claims data. We compared data from patients before and after the start of our BPCI program, and performed a multivariate analysis to identify independent risk factors for increased costs. RESULTS: Of 319 patients, 38 underwent bilateral THA (12%) while 287 underwent bilateral TKA (88%). There were 239 patients (74%) in the bundled payment group. Although there was no change in readmission rate (9% vs 8%), the post-BPCI group demonstrated reduced hospital costs ($21,251 vs $18,783), post-acute care costs ($15,488 vs $12,439), and overall 90-day episode-of-care costs ($39,733 vs $34,305). When controlling for demographics, procedure, and comorbidities, our BPCI model demonstrated a per-patient reduction of $5811 in overall claims costs. Additional risk factors for increased episode-of-care costs included age ($516/y increase) and cardiac disease ($5916). CONCLUSION: Our bundled payment program for bilateral THA and TKA was successful with reduction in 90-day episode-of-care costs without placing the patient at higher risk of readmission. Older Medicare beneficiaries and those with cardiac disease should likely not undergo a simultaneous bilateral procedure due to concerns about increased costs.

How Much Does a Readmission Cost the Bundle Following Primary Hip and Knee Arthroplasty?

BACKGROUND: As alternative payment models increase in popularity for total joint arthroplasty (TJA), providers and hospitals now share the financial risk associated with unexpected readmissions. While studies have identified postacute care as a driver for costs in a bundle, the fiscal burden associated with specific causes of readmission is unclear. The purpose of this study is to quantify the additional costs associated with each of the causes of readmission following primary TJA. METHODS: We reviewed a consecutive series of primary TJA patients at our institution from 2015 to 2016 using claims data from the Centers for Medicare and Medicaid Services and Medicare Advantage patients from a single private insurer. We collected demographic data, medical comorbidities, 90-day episode-of-care costs, and readmissions for all patients. Medical records for each readmission were reviewed and classified into 1 of 11 categories. We then compared the mean facility readmission costs, postacute care costs, and overall 90-day episode-of-care costs between the reasons for readmission. RESULTS: Of the 4704 patients, there were 325 readmissions in 286 patients (6.1%), with 50% being readmitted to a different facility than their index surgery hospital. The mean additional cost was $8588 per readmission. Medical reasons accounted for the majority of readmissions (n = 257, 79.1%). However, patients readmitted for revision surgery (n = 68, 20.9%) had the highest mean readmission cost ($15,356, P < .001). Furthermore, readmissions for revision surgery had the highest mean postacute care ($37,207, P = .002) and overall episode-of-care costs ($52,162, P = .003). Risk factors for readmission included age >75 years (odds ratio [OR], 1.85; P < .001), body mass index >35 kg/m2 (OR, 1.63; P = .004), history of congestive heart failure (OR, 2.47; P = .002), diabetes mellitus (OR, 2.0; P < .001), and renal disease (OR, 2.28; P = .005). CONCLUSION: Providers participating in alternative payment models should be cognizant of the increased bundle costs attributed to readmissions, especially due to revision surgery. Improved communication with patients and close postoperative monitoring may help minimize the large percentage of readmissions at different facilities.

Evaluation of the PROMIS Upper Extremity Computer Adaptive Test Against Validated Patient-Reported Outcomes in Patients With Basilar Thumb Arthritis.

PURPOSE: The Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE) computer adaptive test was developed to reduce test burden and improve precision. We hypothesized that, in patients with thumb basilar joint arthritis (BJA), (1) PROMIS UE would correlate with established patient-outcomes (PROs), (2) PROMIS UE would require less time and fewer questions than current metrics, (3) there would be no floor or ceiling effects, and (4) PROMIS UE would not correlate with radiographic disease severity. METHODS: Patients presenting with a primary diagnosis of thumb BJA completed the Quick Disabilities of the Arm Shoulder and Hand (QuickDASH), Thumb Disability Examination (TDX), Patient-Rated Wrist Hand Evaluation (PRWHE), and PROMIS UE. Radiographic disease severity as described by the Eaton scoring system was recorded. The relationships among PROs were described with Spearman correlation coefficients. The presence of a floor or ceiling effect was confirmed if greater than 15% of patients achieved the lowest or the highest possible score, respectively. RESULTS: One hundred patients with thumb BJA formed the sample for this study. A good to excellent correlation was identified between PROMIS UE and QuickDASH. There were good correlations between PROMIS UE and TDX as well as PRWHE. The PROMIS UE was significantly less time consuming (average: 58.5 seconds vs QuickDASH, 92.2; TDX, 62.6; and PRWHE, 144.7), and required fewer questions than current metrics (average: 4.9 questions vs QuickDASH, 11; TDX, 20; and, 15). In addition, there were no appreciable floor or ceiling effects. Radiographic disease severity did not correlate with PROMIS UE. CONCLUSIONS: The PROMIS UE has a good to excellent correlation with QuickDASH and good correlations with PRWHE and TDX. In addition, PROMIS UE required less time and fewer questions than established PROs. There were no floor or ceiling effects. Used as a single PRO, PROMIS UE may be a practical alternative to legacy scales in patients with thumb BJA. CLINICAL RELEVANCE: The PROMIS UE PRO instrument may be a valuable addition in the assessment of patients with basilar thumb arthritis.

No Difference in Total Episode-of-Care Cost Between Staged and Simultaneous Bilateral Total Joint Arthroplasty.

BACKGROUND: Due to concerns about higher complication rates, surgeons debate whether to perform simultaneous bilateral total joint arthroplasty (BTJA), particularly in the higher-risk Medicare population. Advances in pain management and rehabilitation protocols have called into question older studies that found an overall cost benefit for simultaneous procedures. The purpose of this study was to compare 90-day episode-of-care costs between staged and simultaneous BTJA among Medicare beneficiaries. METHODS: We retrospectively reviewed a consecutive series of 319 simultaneous primary TJAs and 168 staged TJAs (336 procedures) at our institution between 2015 and 2016. We recorded demographics, comorbidities, readmission rates, and 90-day episode-of-care costs based upon Centers for Medicare and Medicaid Services claims data. To control for confounding variables, we performed a multivariate regression analysis to identify independent risk factors for increased costs. RESULTS: Simultaneous patients had decreased inpatient facility costs ($19,402 vs $23,025, P < .001), increased post-acute care costs ($13,203 vs $10,115, P < .001), and no difference in total episode-of-care costs ($35,666 vs $37,238, P = .541). Although there was no difference in readmissions (8% vs 9%, P = .961), simultaneous bilateral patients were more likely to experience a thromboembolic event (2% vs 0%, P = .003). When controlling for demographics, procedure, and comorbidities, a simultaneous surgery was not associated with an increase in episode-of-care costs (P = .544). Independent risk factors for increased episode-of-care costs following BTJA included age ($394 per year increase, P < .001), cardiac disease ($4877, P = .025), history of stroke ($14,295, P = .010), and liver disease ($12,515, P = .016). CONCLUSION: In the Medicare population, there is no difference in 90-day episode-of-care costs between simultaneous and staged BTJA. Surgeons should use caution in performing a simultaneous procedure on older patients or those with a history of stroke, cardiac, or liver disease.

Ischemia/Reperfusion Induces Interferon-Stimulated Gene Expression in Microglia.

Innate immune signaling is important in the pathophysiology of ischemia/reperfusion (stroke)-induced injury and recovery. Several lines of evidence support a central role for microglia in these processes. Recent work has identified Toll-like receptors (TLRs) and type I interferon (IFN) signaling in both ischemia/reperfusion-induced brain injury and ischemic preconditioning-mediated neuroprotection. To determine the effects of "ischemia/reperfusion-like" conditions on microglia, we performed genomic analyses on wild-type (WT) and TLR4-/- cultured microglia after sequential exposure to hypoxia/hypoglycemia and normoxia/normoglycemia (H/H-N/N). We observed increased expression of type 1 IFN-stimulated genes (ISGs) as the predominant transcriptomal feature of H/H-N/N-exposed WT, but not TLR4-/-, microglia. Microarray analysis on ex vivo sorted microglia from ipsilateral male mouse cortex after a transient in vivo ischemic pulse also demonstrated robust expression of ISGs. Type 1 IFNs, including the IFN-αs and IFN-ß, activate the interferon-α/ß receptor (IFNAR) complex. We confirmed both in vitro H/H-N/N- and in vivo ischemia/reperfusion-induced microglial ISG responses by quantitative real-time PCR and demonstrated that both were dependent on IFNAR1. We characterized the effects of hypoxia/hypoglycemia on phosphorylation of signal transducer and activator of transcription 1 (STAT1), release of type 1 IFNs, and surface expression of IFNAR1 in microglia. We demonstrated that IFN-ß induces dose-dependent secretion of ISG chemokines in cultured microglia and robust ISG expression in microglia both in vitro and in vivo Finally, we demonstrated that the microglial ISG chemokine responses to TLR4 agonists were dependent on TLR4 and IFNAR1. Together, these data suggest novel ischemia/reperfusion-induced pathways for both TLR4-dependent and -independent, IFNAR1-dependent, type 1 IFN signaling in microglia.SIGNIFICANCE STATEMENT Stroke is the fifth leading cause of death in the United States and is a leading cause of serious long-term disability worldwide. Innate immune responses are critical in stroke pathophysiology, and microglia are key cellular effectors in the CNS response to ischemia/reperfusion. Using a transcriptional analysis approach, we identified a robust interferon (IFN)-stimulated gene response within microglia exposed to ischemia/reperfusion in both in vitro and in vivo experimental paradigms. Using a number of complementary techniques, we have demonstrated that these responses are dependent on innate immune signaling components including Toll-like receptor-4 and type I IFNs. We have also elucidated several novel ischemia/reperfusion-induced microglial signaling mechanisms.

Somatosensory evoked potential changes in neuroendovascular procedures: incidence and association with clinical outcome in 873 patients.

BACKGROUND: Neurophysiological monitoring is routinely used during neurosurgical procedures. Use of neurophysiological monitoring has extended to neuroendovascular procedures, but evidence of its impact on clinical outcome in this arena is limited. OBJECTIVE: To report the incidence of significant intraoperative somatosensory evoked potential (SSEP) changes during neuroendovascular surgery and to correlate SSEP changes with clinical outcomes. METHODS: Patients who underwent neuroendovascular surgery at our institution between 2011 and 2013 were included in the analysis. Medical charts and imaging studies were reviewed retrospectively for sex, age, lesion type and size, clinical presentation, type of endovascular procedure, duration of SSEP change, reversibility of SSEP change, incidence of intraoperative complications and related mortalities, presence of new infarction within 72 hours of intervention, and discharge outcome. RESULTS: Of 873 consecutive patients, 52 (6%) had clinically significant intraoperative SSEP changes. Twenty-four patients (46%) had SSEP changes that were corrected, and 28 patients (54%) had changes that were not reversed before the end of surgery. Both decreased duration and reversal of SSEP changes were associated with a lower incidence of postoperative infarction and more favorable clinical outcome on discharge. The positive predictive value of an irreversible SSEP change for postoperative infarction in our study was 21%, and the negative predictive value was 83%. CONCLUSION: The approximate incidence of SSEP changes is 6% during neuroendovascular procedures. Rapid reversal of SSEP changes is associated with better outcomes. SSEP monitoring may be a valuable tool for preventing complications after neuroendovascular interventions.