Faculty Bibliography

BACKGROUND: Efforts to mitigate costs while improving surgical care quality have received much scrutiny. This includes the challenging issue of readmission subsequent to hospital discharge. Initiatives attempting to preclude readmission after surgery require planned and unified efforts extending throughout the perioperative continuum. Patient optimization prior to discharge, enhanced disease monitoring, and seamless coordination of care between hospitals and community providers is integral to this process. The perioperative surgical home (PSH) has been proposed as a model to improve the delivery of perioperative healthcare via patient-centered risk stratification strategies that emphasize value and evidence-based processes. RESULTS: This case report seeks to specifically describe implementation of readmission reduction strategies via a PSH paradigm during total joint arthroplasty (TJA) procedures at the University of California Irvine (UCI) Health. An orthopedic surgeon open to collaborate within a PSH paradigm for TJA procedures was recruited to UCI Health in October of 2012. Institution specific data was then prospectively collected for 2 years post implementation of the novel program. A total of 328 unilateral, elective primary TJA (120 hip, 208 knee) procedures were collectively performed. Demographic analysis reveals the following: mean age of 64 +/- 12; BMI of 28.5 +/- 6.2; ASA Score distribution of 0.3 % class 1, 23 % class 2, 72 % class 3, and 4.3 % class 4; and 62.5 % female patients. In all, a 30-day unplanned readmission rate of 2.1 % (95 % CI 0.4-3.8) was observed during the study period. As a limitation of this case report, this reported rate does not reflect readmissions that may have occurred at facilities outside UCI Health. CONCLUSIONS: As healthcare evolves to emphasize value over volume, it is integral to invest efforts in longitudinal patient outcomes including patient disposition subsequent to hospital discharge. As outlined by this case management report, the PSH provides an institution-led means to implement a series of care initiatives that optimize the important metric of readmission following TJA, potentially adding further value to patients, surgical colleagues, and health systems.

INTRODUCTION: Patient-specific implants and instruments (PSI) have been used in both knee and shoulder replacements due to the perceived benefits of improved surgical accuracy and efficiency. The proposed benefits of using a PSI in total hip arthroplasty (THA) are numerous and include reduction of operative time and improved mechanical and anatomical alignment leading to increased implant longevity, increased stability, and clinical outcomes. We describe a novel patient-specific instrumentation and a surgical method that may improve directed resection of acetabular bone and accurate cup placement during THA. MATERIALS AND METHODS: In this cadaveric study, 14 acetabuli were used. Pre-operative CT or MRI scans were obtained as part of the acetabular jigs Bullseye Hip Replacement Instruments(R) (Bullseye Hip Replacement, LLC, Las Vegas, Nevada) protocol. Two senior hip surgeons performed all the operations in accordance to the PSI technique. Post-operative CT scans were obtained and acetabular cup orientation was measured by two independent radiologists. RESULTS: Fourteen acetabuli were implanted using the Bullseye Hip Replacement Instruments(R). Acetabular cup anteversion angle as measured on post-operative CT images averaged, for all 14 acetabuli, 15.50. Acetabular cup abduction/inclination angle as measured on post-operative CT images averaged 35.9 degrees . All implanted components' size/diameter matched the preoperative surgical planned implant size. CONCLUSION: The Bullseye Hip Replacement Instruments(R) show good reproducible acetabular cup placement in both anteversion and abduction angles, and accurate sizing of the acetabular component. .

AIM: To review and report functional outcomes, complications, and survivorship associated with total knee arthroplasty (TKA) in the treatment of post-traumatic arthritis (PTA). METHODS: We conducted a systematic review according to the PRISMA guidelines. We searched PubMed, Cochrane Library, and SCOPUS in December 2015 for English-language clinical research studies, both prospective and retrospective, examining the use of TKA for the treatment of PTA. All relevant articles were accessed in full. The manual search included references of retrieved articles. We extracted data on patients' demographics and clinical outcomes, including preoperative diagnosis and pre- and post-operative functional scores. We summarized the data and reported the results in tables and text. RESULTS: Sixteen studies, four prospective and ten retrospective, examined patients who underwent TKA for PTA due to fractures of the proximal tibia, patella, and/or distal femur. Eleven studies utilized the Knee Society Scores criteria to assess functional outcomes. All studies utilizing these criteria reported an improvement in functional and knee scores of patients following TKA. Further, studies reported an increased range of motion (ROM) and reduction of pain following surgery. The most commonly reported complications with TKA included infection, stiffness, wound complications, intraoperative rupture of tendons, and osteolysis/polyethylene wear. The overwhelming majority of these complications occurred within the first two years following surgery. Six studies examined the survivorship of TKA with subsequent revision for any reason as an endpoint. Compared to patients with osteoarthritis, patients with PTA required more revisions, the majority for polyethylene wear. CONCLUSION: Although associated with higher complication rates, TKA is an effective treatment for PTA, as it improves ROM, pain and functional outcomes.

BACKGROUND: Despite the alleviation of osteoarthritis (OA) symptoms that total knee arthroplasty (TKA) provides for patients with end-stage knee OA, recent studies have suggested that TKA may not increase physical activity levels. In this study, we compare the physical activity levels of patients with OA treated nonoperatively (non-TKA) with both patients who had received TKA (post-TKA) and patients who received TKA within 3 years of data collection (pre-TKA). METHODS: Utilizing the Osteoarthritis Initiative database, accelerometry data were collected from non-TKA, pre-TKA, and post-TKA patients. Accelerometry data were subdivided by physical activity intensity levels, yielding daily minutes of each level of activity. Physical activity levels were then compared between non-TKA and pre-TKA/post-TKA patients. Physical activity levels for each patient were also compared to the Department of Health and Human Services (DHHS) guidelines for physical activity. RESULTS: There was no difference in physical activity between non-TKA and pre-TKA patients, with the exception of non-TKA patients achieving more daily minutes of vigorous activity (P < .001). There was no difference in physical activity between non-TKA and post-TKA patients. Although 11.6% of non-TKA patients met DHHS guidelines, only 4.8% of pre-TKA and 5.3% of post-TKA patients met guidelines. CONCLUSION: Despite the improvements in patient-reported outcome measures following TKA, we found that TKA alone does not improve physical activity levels beyond those seen in the average patient with OA. In our study, the vast majority of patients with OA, treated nonoperatively or operatively, did not meet current DHHS guidelines for physical activity.

AIM: To determine the impact of different characteristics on postoperative outcomes for patients in a joint arthroplasty Perioperative Surgical Home (PSH) program. METHODS: A retrospective review was performed for patients enrolled in a joint arthroplasty PSH program who had undergone primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). Patients were preoperatively stratified based on specific procedure performed, age, gender, body mass index (BMI), American Society of Anesthesiologists Physical Classification System (ASA) score, and Charleston Comorbidity Index (CCI) score. The primary outcome criterion was hospital length of stay (LOS). Secondary criteria including operative room (OR) duration, transfusion rate, Post-Anesthesia Care Unit (PACU) stay, readmission rate, post-operative complications, and discharge disposition. For each outcome, the predictor variables were entered into a generalized linear model with appropriate response and assessed for predictive relationship to the dependent variable. Significance level was set to 0.05. RESULTS: A total of 337 patients, 200 in the TKA cohort and 137 in the THA cohort, were eligible for the study. Nearly two-third of patients were female. Patient age averaged 64 years and preoperative BMI averaged 29 kg/m(2). The majority of patients were ASA score III and CCI score 0. After analysis, ASA score was the only variable predictive for LOS (P = 0.0011) and each increase in ASA score above 2 increased LOS by approximately 0.5 d. ASA score was also the only variable predictive for readmission rate (P = 0.0332). BMI was the only variable predictive for PACU duration (P = 0.0136). Specific procedure performed, age, gender, and CCI score were not predictive for any of the outcome criteria. OR duration, transfusion rate, post-operative complications or discharge disposition were not significantly associated with any of the predictor variables. CONCLUSION: The joint arthroplasty PSH model reduces postoperative outcome variability for patients with different preoperative characteristics and medical comorbidities.

BACKGROUND: Hip arthroplasty is increasingly performed as a treatment for femoral neck fractures (FNFs). However, these cases have higher complication rates than elective total hip arthroplasties (THAs). The Center for Medicare and Medicaid Services has created the Comprehensive Care for Joint Replacement model to increase the value of patient care. This model risk stratifies FNF patients in an attempt to appropriately allocate resources, but the formula has not been disclosed. The goal of this study was to ascertain if patients with FNFs have different readmission rates compared to patients undergoing elective THA so that the resource utilization can be assessed. METHODS: We analyzed all patients undergoing THA at our institution during a 21-month period. Patients classified by a diagnosis-related group of 469 or 470 were included. Multivariate and survival analyses were performed to determine risk of 90-day readmission. RESULTS: Patients admitted for FNFs were older, had higher body mass indices, longer lengths of stay, and were more likely to be discharged to inpatient facilities than patients who underwent elective THA. Increased American Society of Anesthesiologists scores and FNF were also independent risk factors for 90-day readmission, and these patient were more likely to be readmitted during the latter 60 days following admission. CONCLUSION: Results suggest that patients who undergo an arthroplasty following urgent or emergent FNFs have inferior outcomes to those receiving an arthroplasty for a diagnosis of arthritis. Fracture patients should either be risk stratified to allow appropriate resource allocation or be excluded from alternative payment initiatives such as Comprehensive Care for Joint Replacement.

INTRODUCTION: The demand for total knee arthroplasty (TKA) continues to challenge hospital financial resources. Hospitals have countered this economic demand by reducing patient length of stay (LoS), thus requiring a higher utilization of extended care facilities (ECF) and home with home health care (HHC). With an increase in the number of insured low-income families following the Affordable Care Act (ACA), TKA patients' demographics are anticipated to change. Both trends have significant economic implications, and predicting the discharge destinations of TKA patients would help plan for future health expenditures. The purpose of this study was to determine which variables are significant in predicting discharge destinations of patients treated with TKA. METHODS: We utilized the California Hospital Discharge data set of the year 2010. For each hospitalization, the data set includes information about patient demographics (age, gender, race, and ethnicity), insurance type, diagnoses and procedures, and patient disposition. Discharge to home was the reference category. Discharges to a skilled nursing home and discharge to home with home care were the 2 additional alternatives. Independent variables included the Charlson comorbidity index, payer category (private, Medicare, Medical, and other), race, ethnicity, age, and gender. RESULTS: Over 28 611 TKAs were reviewed with 45.9% discharged to HHC, 29.9% going to ECF, and 24.2% going home without home health care. Race, age, insurance, and morbidity proved to be highly significant factors influencing patient discharge destination (P < .001). Medicare coverage relative to private payers was a strong predictor for discharge destination (relative risk ratio (RRR) 1.69, P < .001). The strongest predictors were black and Asian races relative to whites (RRR 1.54, P < .01). Male gender was the only factor that lowered the risk of discharge to a nursing home (RRR 0.43, P < .001). CONCLUSIONS: This study provides insight on which patient characteristics influence discharge destination after TKA. Race, age, insurance, and morbidity were highly significant (P < .001) factors on patient discharge destination.

INTRODUCTION: Proper ligament tension in flexion with posterior cruciate retaining (CR) total knee arthroplasty (TKA) has long been associated with clinical success. The purpose of this study was to determine the effect of varying levels of posterior cruciate ligament (PCL) release on the tibiofemoral kinematics and PCL strain. MATERIALS AND METHODS: A computational analysis was performed and varying levels of PCL release were simulated. Tibiofemoral kinematics was evaluated. The maximum PCL strain was determined for each bundle to evaluate the risk of rupture based on the failure strain. RESULTS: The femoral AP position shifted anteriorly as the PCL stiffness was reduced. PCL strain in both bundles increased as stiffness was reduced. The model predicts that the AL bundle should not rupture for a 75% release. Risk of PM bundle rupture is greater than AL bundle. DISCUSSION: Our findings suggest that a partial PCL release impacts tibiofemoral kinematics and ligament tension and strain. The relationship is dynamic and care should be taken when seeking optimal balance intra-operatively.

The potential for using mobile applications (apps) as an effective tool to monitor patients in an outpatient setting is promising. Past studies have investigated the use of applications in preoperative and postoperative settings as well as in monitoring and treating chronic illnesses such as diabetes, congestive heart failure (CHF), and multiple sclerosis. However, there is limited data on its specific use in the context of total knee arthroplasty. Given the complicated nature and crucial role of patient adherence to protocols during the preparatory and recovery phases of the procedure, the use of an app can serve as a helpful tool in aiding patients throughout this process. We present a pilot study to assess the efficacy of using such an app in order to monitor patient adherence to total knee arthroplasty-specific preoperative and postoperative protocols. Preoperative protocols used in this study included a 5-item medication protocol and multiple activity instructions. Postoperative patient protocols included following instructions on topics such as recording responses to quality-of-life questions, when and how to contact the clinical team if patients had non-emergent concerns or questions, and carrying out daily physical therapy (PT) exercises. Patients received and recorded responses to these preoperative and postoperative instructions using the iGetBetter program application installed on an iPad Mini, provided to the participants. Patient adherence was based on the data gathered from the patient responses inputted on this app. Adherence rates were comparable to those reported in various past studies that also investigated rates of adherence to health management-related instructions communicated through mobile apps.