Faculty Bibliography

BACKGROUND: Alternative payment models aim to improve quality and decrease costs associated with total joint replacement. Postoperative readmissions within 90 days are of interest to clinicians and administrators as there is no additional reimbursement beyond the episode bundled payment target price. The aim of this study is to improve the understanding of the patterns of readmission which would better guide perioperative patient management affecting readmissions. We hypothesize that readmissions have different timing, location, and patient health profile patterns based on whether the readmission is related to a medical or surgical diagnosis. METHODS: A retrospective cohort of 80 readmissions out of 1412 total joint replacement patients reimbursed through a bundled payment plan was analyzed. Patients were grouped by readmission diagnosis (surgical or medical) and the main variables analyzed were time to readmission, location of readmission, and baseline Perioperative Orthopaedic Surgical Home and American Society of Anesthesiologists scores capturing pre-existing state of health. Nonparametric tests and multivariable regressions were used to test associations. RESULTS: Surgical readmissions occurred earlier than medical readmissions (mean 18 vs 33 days, P = .011), and were more likely to occur at the hospital where the surgery was performed (P = .035). Perioperative Orthopaedic Surgical Home and American Society of Anesthesiologists scores did not predict medical vs surgical readmissions (P = .466 and .879) after adjusting for confounding variables. CONCLUSION: Readmissions appear to follow different patterns depending on whether they are surgical or medical. Surgical readmissions occur earlier than medical readmissions, and more often at the hospital where the surgery was performed. The results of this study suggest that these 2 types of readmissions have different patterns with different implications toward perioperative care and follow-up after total joint replacement.

BACKGROUND: To curb the unsustainable rise in health care expenses, health care payers are developing programs to incentivize hospitals and physicians to improve the value of care delivered to patients. Payers are utilizing various metrics, such as length of stay (LOS) and unplanned readmissions, to track progression of quality metrics. Relevant to orthopedic surgeons, the Centers for Medicare and Medicaid Services announced in 2015 the Comprehensive Care for Joint Replacement Payment Model-a program aimed at improving the quality of health care delivered to patients by shifting more of the financial risk of patient care onto providers. METHODS: We analyzed the medical records of 1329 consecutive lower extremity total joint patients enrolled in Centers for Medicare and Medicaid Services' Bundled Program for Care Improvement treated over a 21-month period. The goal of this study was to ascertain if hospital LOS is associated with unplanned readmissions within 90 days of admission for a total hip or knee arthroplasty. RESULTS: After controlling for multiple demographic variables including sex, age, comorbidities and discharge location, we found that hospital LOS greater than 4 days is a significant risk factor for unplanned readmission within 90 days (odd ratio = 1.928, P = .010). Total knee arthroplasty (TKA) and discharge to a location other than home are also independent risk factors for 90-day readmission. CONCLUSION: Our results demonstrate that increased LOS is a significant risk factor for readmission within 90 days of admission for a hip or knee arthroplasty in the Medicare population.

BACKGROUND: The incidence of hip fractures is growing with the increasing elderly population. Typically, hip fractures are treated with open reduction internal fixation, hemiarthroplasty, or total hip arthroplasty (THA). Failed hip fracture fixation is often salvaged by conversion THA. The total number of conversion THA procedures is also supplemented by its use in treating different failed surgical hip treatments such as acetabular fracture fixation, Perthes disease, slipped capital femoral epiphysis, and developmental dysplasia of the hip. As the incidence of conversion THA rises, it is important to understand the perioperative characteristics of conversion THA. Some studies have demonstrated higher complication rates in conversion THAs than primary THAs, but research distinguishing the 2 groups is still limited. METHODS: Perioperative data for 119 conversion THAs and 251 primary THAs were collected at 2 centers. Multivariable linear regression was performed for continuous variables, multivariable logistic regression for dichotomous variables, and chi-square test for categorical variables. RESULTS: Outcomes for conversion THAs were significantly different (P < .05) compared to primary THA and had longer hospital length of stay (average 3.8 days for conversion THA, average 2.8 days for primary THA), longer operative time (168 minutes conversion THA, 129 minutes primary THA), greater likelihood of requiring metaphysis/diaphysis fixation, and greater likelihood of requiring revision type implant components. CONCLUSION: Our findings suggest that conversion THAs require more resources than primary THAs, as well as advanced revision type components. Based on these findings, conversion THAs should be reclassified to reflect the greater burden borne by treatment centers.

PURPOSE: The objective of this study was to quantify the amount of ensuing internal rotation of the tibial component when positioned along the medial border of the tibial tubercle, thus establishing a reproducible intraoperative reference for tibial component rotational alignment during total knee arthroplasty (TKA). METHODS: The angle formed from the tibial geometric centre to the intersection of both lines from the middle of the tibial tuberosity and its medial border was measured in 50 patients. The geometric centre was determined on an axial CT slice at 10 mm below the lateral tibial plateau and transposed to a slice at the level of the most prominent part of the tibial tuberosity. Similar measurements were taken in 25 patients after TKA, in order to simulate the intraoperative appearance of the tibia after making its proximal resection. RESULTS: This angle was found to be similar (n.s.) in normal and post-TKA tibiae [median 20.4 degrees (range 15 degrees -24 degrees ) vs. 20.7 degrees (range 16 degrees -25 degrees ), respectively]. In 89.3 % of the patients, the angle ranged from 17 degrees to 24 degrees . No statistical difference (p n.s.) was found between women and men in both normal [median -20.7 degrees (range 16 degrees -25 degrees ) vs. 19.9 degrees (range 15 degrees -24 degrees )] and post-TKA tibiae [median 21.4 degrees (range 19 degrees -24 degrees ) vs. 20 degrees (range 16 degrees -25 degrees )]. CONCLUSION: This study found that in 90 % of the patients, the medial border of the tibial tuberosity is internally rotated 17 degrees -24 degrees in relation to the line connecting the middle of the tuberosity to the tibial geometric centre. Since this anatomical landmark may be more easily identifiable intraoperatively than the commonly used "medial 1/3", it can provide a better quantitative reference point and help surgeons achieve a more accurate tibial implant rotational position. LEVEL OF EVIDENCE: Cohort and case control studies, Level III.

BACKGROUND: Previously, our group successfully established one of the nation's first Perioperative Surgical Homes (PSHs) aimed at coordinating services to patients undergoing primary total hip arthroplasty (THA) and primary total knee arthroplasty (TKA). As we now focus on extending the PSH to other service lines within the hospital, the long-term sustainability of this practice model is an important factor to consider moving forward. METHODS: We prospectively collected data from all patients who underwent elective primary TKA and THA at our institution between October 1, 2012, and September 30, 2014. Prospectively collected data included length of stay (LOS), 30-day readmission rate, postoperative pain scores, and complications. RESULTS: During the 2-year period, there were 328 primary joint arthroplasty patients. Overall, the median LOS was significantly shorter in the second year of the PSH initiative (P = 0.03). Stratified by procedure, the median LOS for patients undergoing THA was significantly shorter in the second year (P = 0.02), whereas the median LOS for patients undergoing TKA did not differ between the 2 time periods. In the second year of the PSH initiative, significantly more patients were discharged home than to a skilled nursing facility compared with year 1 of the PSH initiative (P = 0.02). Readmission rates within 30 days after surgery to our institution were 0.9% (0.0-4.4) in the first year of the PSH initiative and 3.3% (confidence interval, 1.3%-7.2%) in the second year of the PSH initiative (P = not significant). Pain scores did not change significantly from year 1 to year 2 (P = not significant). CONCLUSIONS: Data for the second year of implementation demonstrate similarly positive results in LOS, pain control, discharge destination, readmission, transfusion rates, and complications.

Patient-reported outcomes (PROs) are essential to assessing the effectiveness of care, and many general-health and disease-specific PROs have been developed. Until recently, data were collected predominantly with pen-and-paper questionnaires. Now, though, there is a potential role for electronic medical records in data collection. In this study, patients were randomly assigned to complete either tablet or paper questionnaires. They were surveyed on patient demographics, patterns of electronic device use, general-health and disease-specific PROs, and satisfaction. The primary outcome measure was survey completion rate. Secondary outcome measures were total time for completion, number of questions left unanswered on incomplete surveys, patient satisfaction, and survey preferences. The study included 483 patients (258 in tablet group, 225 in paper group), and the overall completion rate was 84.4%. There was no significant difference in PRO completion between the tablet and paper groups. Time to completion did not differ between the groups, but their satisfaction rates were similar. However, more paper group patients reported a preference for a tablet survey. Advantages of digital data collection include simple and reliable data storage, ability to improve completion rates by requiring patients to answer all questions, and development of interface adaptations to accommodate patients with handicaps. Given our data and these theoretical benefits, we recommend using tablet data collection systems for PROs.

OBJECTIVES: Acute pain in the postoperative period after total joint arthroplasty (TJA) has a significant effect on early rehabilitation, hospital length of stay, and the development of chronic pain. Consequently, efforts have been made to predict the occurrence of postoperative pain using preoperative and intraoperative factors. In this study, we tested the usefulness of preoperative pressure pain threshold (PPT) values in the prediction of three outcomes for patients who underwent TJA: visual analog scale pain scores, hospital length of stay, and opioid consumption. MATERIALS AND METHODS: Using a digital pressure algometer, we measured the preoperative PPT in 41 patients expected to undergo TJA at three different body sites: the first web space of the hand, the operative joint, and the contralateral joint. We correlated each PPT separately with postoperative visual analog scale pain scores, hospital length of stay, and opioid consumption. RESULTS: No significant correlation was found between preoperative PPT and the three postoperative outcomes. This finding held true when patients were subdivided by surgery type (total knee arthroplasty vs. total hip arthroplasty). There was no significant difference in PPT between the three body testing sites. DISCUSSION: This study failed to prove the usefulness of PPT in the prediction of acute postoperative pain, pain medication consumption, and length of stay. The pressure algometer has previously found a place in the assessment of pain in a variety of clinical settings, but its utility has not yet been demonstrated in patients undergoing TJA.

The stability of a total knee arthroplasty is determined by the ability of the prosthesis components in concert with supportive bone and soft tissue structures to sufficiently resist deforming forces transmitted across the knee joint. Constrained prostheses are used in unstable knees due to their ability to resist varus and valgus transformative forces across the knee. Constraint requires inherent rigidity, which can facilitate early implant failure. The purpose of this study was to describe the comparative indications for surgery and postoperative outcomes of varus valgus constrained knee (VVK) and rotating-hinge knee (RHK) total knee arthroplasty prostheses. Seven retrospective observational studies describing 544 VVK and 254 RHK patients with an average follow-up of 66 months (range, 7-197 months) were evaluated. Patients in both groups experienced similar failure rates (P=.74), ranges of motion (P=.81), and Knee Society function scores (P=.29). Average Knee Society knee scores were 4.2 points higher in VVK patients compared with RHK patients, indicating minimal mid-term clinical differences may exist (P<.0001). Absent collateral ligament support is an almost universal indication for RHK implantation vs VVK. Constrained device implantation is routinely guided by inherent stability of the knee, and, when performed, similar postoperative outcomes can be achieved with VVK and RHK prostheses.

BACKGROUND: A Perioperative Surgical Home (PSH) care model applies a standardized multidisciplinary approach to patient care using evidence-based medicine to modify and improve protocols. Analysis of patient outcome measures, such as postoperative nausea and vomiting (PONV), allows for refinement of existing protocols to improve patient care. We aim to compare the incidence of PONV in patients who underwent primary total joint arthroplasty before and after modification of our PSH pain protocol. METHODS: All total joint replacement PSH (TJR-PSH) patients who underwent primary THA (n=149) or TKA (n=212) in the study period were included. The modified protocol added a single dose of intravenous (IV) ketorolac given in the operating room and oxycodone immediate release orally instead of IV Hydromorphone in the Post Anesthesia Care Unit (PACU). The outcomes were (1) incidence of PONV and (2) average pain score in the PACU. We also examined the effect of primary anesthetic (spinal vs. GA) on these outcomes. The groups were compared using chi-square tests of proportions. RESULTS: The incidence of post-operative nausea in the PACU decreased significantly with the modified protocol (27.4% vs. 38.1%, p=0.0442). There was no difference in PONV based on choice of anesthetic or procedure. Average PACU pain scores did not differ significantly between the two protocols. CONCLUSION: Simple modifications to TJR-PSH multimodal pain management protocol, with decrease in IV narcotic use, resulted in a lower incidence of postoperative nausea, without compromising average PACU pain scores. This report demonstrates the need for continuous monitoring of PSH pathways and implementation of revisions as needed.