Faculty Bibliography

The demand for TKA continues to rise within the United States, while increasing quality measures and cost containment became the basis of reimbursement for hospital systems. Length of stay is a major driver in the cost of TKA. Early mobilization with physical therapy has been shown to increase range of motion and decrease complications, but with mixed results in regards to length of stay. We postulate that initiating physical therapy on post-operative day zero will decrease length of stay in an urban public hospital. Retrospective chart review was performed at a large, urban, public academic medical center to identify patients who have had a primary TKA over the course of a 3-year period. Groups who underwent post-operative day zero therapy were compared with those who initiated physical therapy on post-operative day one. Length of stay was the primary outcome. Patient demographic characteristics and discharge disposition were also collected. There were 98 patients in the post-operative day-one physical therapy cohort and 58 in the post-operative day zero physical therapy group. Hospital length of stay was significantly decreased in the post-operative day zero physical therapy group. (p < 0.01) There was no difference in discharge disposition between the two groups.

BACKGROUND:Total hip arthroplasty is increasingly being performed as a same day procedure. Additionally, greater emphasis is being placed on patient satisfaction surveys such as the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS)® Survey. This study aims to assess if patients who undergo THA through a same day discharge program respond with higher HCAHPS scores. METHODS:Patients undergoing THA through our same day surgery (SDD) program at our institution from January 1, 2015, to September 2016 and completed HCAHPS surveys were compared to a cohort of patients who underwent THA as a standard inpatient and completed the HCAHPS survey during the same period. Electronic medical records were reviewed to obtain demographic data and improvement in validated patient reported outcomes measures. RESULTS:Patientsin our SDD program were significantly more likely to rate the hospital as "top box" on eight of 11 HCAHPS domains. The remaining three domains that did not reach statistical significance all showed a trend toward increased likelihood of rating the hospital in the "top box" level. For willingness to recommend, 91% of SDD patients vs. 77% of non-SDD patients (p = 0.045) rated our hospital as "top box." We had no significant difference between the groups in change from pre- to postoperative EQ-5D score or Hip Disability and Osteoarthritis Outcomes Score (HOOS). CONCLUSION/CONCLUSIONS:A same day surgery program can significantly improve patient satisfaction with THA as measured by the HCAHPS survey.

Total knee arthroplasty (TKA) has been established as the most effective treatment for end-stage, symptomatic osteoarthritis of the knee. However, improper polyethylene size selection has been proposed to predispose patients to postoperative stiffness following TKA. The aim of this study is to evaluate if there is a correlation between the use of the thinnest tibial implant thickness and implant manufacturer with the likelihood of undergoing manipulation under anesthesia (MUA). A retrospective review of unilateral TKAs performed between January 2012 and November 2015 was performed. Each knee implant system was normalized by total tibial component thickness for each individual implant system (metal back plus polyethylene) and reaggregated to assess the difference in MUA rates when comparing the thinnest tibial component thickness against the next two sizes. Subset analysis was performed comparing the thinnest tibial component thickness for each individual implant system versus (1) all other tibial component sizes and (2) tibial components one and two sizes larger. A total of 2,728 patients were retrospectively evaluated, of which 71 (2.60%) underwent MUA. Combined tibial component thickness ranged from 8 to 21 mm. When aggregated together to compare the MUA rate between the thinnest liner and the next two sizes, no statistically significant difference was observed (p = 1). Subset analysis demonstrated inconsistent significant differences in MUA rates. Our results suggest that the polyethylene liner thickness alone is not a predictor of postoperative knee stiffness necessitating MUA. When selecting a polyethylene liner, a proper fit maximizing flexion/extension stability is the most crucial factor.

Background: The SWIFT trial, is a multi-site, prospective trial comparing knee physical function outcomes in patients with severe obesity who undergo bariatric surgery prior to TKA versus TKA only. This preliminary report compares knee outcomes in patients that completed bariatric surgery only vs. patients that had TKA without bariatric surgery.
Method(s): Knee outcomes for this analysis included Visual Analog Scale for knee pain, Timed Up and Go, 30-second Chair Stand, and 40-meter fast paced walk. The percent with >10% improvement in knee outcomes were compared between groups using logistic regression (adjusting for age and baseline BMI).
Result(s): This report includes 17 TKA eligible patients that completed 6-month follow-up after bariatric surgery and another 17 patients that completed 6-month follow-up after TKA only. The groups had a similar sex distribution (18% males in the bariatric group and 12% in TKA group, p=0.999) but the bariatric group was younger (53 vs 60, p=0.0056) and had a higher baseline BMI (47.1 vs 40.7, p=0.0020). Although the percent with >10% improvement was consistently higher in the TKA group, these differences were not significant for Visual Analog Pain Scale (48% vs 41%, p=0.762), Timed Up and Go (65% vs 59%, p=0.750), 30-second Chair Stand (77% vs 41%, p=0.091), or the 40-meter fast paced walk (76% vs 44%, p=0.147).
Conclusion(s): Bariatric surgery Results in modest improvements in knee outcomes in patients that are eligible for TKA and demonstrates potential to diminish the short term needs for knee replacement.
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BACKGROUND:The Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) score is a nationally standardized measure of a patient's hospital experience. This study aims to assess whether HCAHPS scores vary by demographic or surgical factors in patients undergoing primary total hip arthroplasty. METHODS:Patients who completed an HCAHPS survey after a primary total hip arthroplasty between October 2011 and November 2016 were included in this study. Patient demographics and surgical factors were evaluated for correlations with individual HCAHPS questions. RESULTS:increase (β = 0.0020 ± 0.0010; P < .05). For each day increase in length of stay, HCAHPS top-box response rates decrease by 3.41% (β = -0.0341 ± 0.0051; P < .0001). Race, marital status, smoking status, insurance type, and discharge disposition were not found to be significantly correlated with HCAHPS top-box response rate (P > .05). CONCLUSION/CONCLUSIONS:The HCAHPS quality measurement metric affects physician reimbursement and may be biased by a number of variables including sex, length of stay, and BMI, rather than a true reflection of the quality of their hospital experience. Further research is warranted to determine whether HCAHPS scores are an appropriate measure of the quality of care received.

BACKGROUND:No study has yet assessed the efficacy of virtual reality (VR) simulation for teaching orthopedic surgery residents. In this blinded, randomized, and controlled trial, we asked if the use of VR simulation improved postgraduate year (PGY)-1 orthopedic residents' performance in cadaver total hip arthroplasty and if the use of VR simulation had a preferentially beneficial effect on specific aspects of surgical skills or knowledge. METHODS:Fourteen PGY-1 orthopedic residents completed a written pretest and a single cadaver total hip arthroplasty (THA) to establish baseline levels of knowledge and surgical ability before 7 were randomized to VR-THA simulation. All participants then completed a second cadaver THA and retook the test to assess for score improvements. The primary outcomes were improvement in test and cadaver THA scores. RESULTS:There was no significant difference in the improvement in test scores between the VR and control groups (P = .078). In multivariate regression analysis, the VR cohort demonstrated a significant improvement in overall cadaver THA scores (P = .048). The VR cohort demonstrated greater improvement in each specific score category compared with the control group, but this trend was only statistically significant for technical performance (P = .009). CONCLUSIONS:VR-simulation improves PGY-1 resident surgical skills but has no significant effect on medical knowledge. The most significant improvement was seen in technical skills. We anticipate that VR simulation will become an indispensable part of orthopedic surgical education, but further study is needed to determine how best to use VR simulation within a comprehensive curriculum. LEVEL OF EVIDENCE/METHODS:Level 1.

Interprosthetic femur fractures are a rare but serious complication following total hip and knee arthroplasty. Classification systems have focused not only on diagnosis but also on treatment algorithm. Critical to the evaluation of patients with these fractures are an assessment of fracture location, bone quality, and the presence of stemmed implants. The gold standard for fracture fixation is locked plating with bicortical and unicortical screws, supplemented with wires or cables as needed. For patients with compromised bone stock or insufficient bony area for fixation, allograft augmentation with struts or interprosthetic sleeves may be used. For fractures with severe bone loss, conversion to a megaprosthesis or total femur replacement may be warranted.

Background/UNASSIGNED:The most common indications for revision total hip arthroplasty are instability/dislocation and mechanical loosening. Efforts to address this have included the use of dual mobility (DM) articulations. The aim of this study is to report on the use of cemented DM cups in complex acetabular revision total hip arthroplasty cases with a high risk of recurrent instability. Methods/UNASSIGNED:A multicenter, retrospective study was conducted. Patients who received a novel acetabular construct consisting of a monoblock DM cup cemented into a fully porous metal shell were included. Outcome data included 90-day complications and readmissions, revision for any reason, and Harris Hip Scores. Results/UNASSIGNED:< .001). One (2.6%) patient experienced a dislocation on postoperative day 1, and was closed reduced with no further complications. There was 1 (2.6%) reoperation for periprosthetic joint infection treated with a 2-stage exchange. Conclusions/UNASSIGNED:In this complex series of patients, cementation of a monoblock DM cup into a newly implanted fully porous revision shell reliably provided solid fixation with a low risk of dislocation at short-term follow-up. Although longer term follow-up is needed, utilization of this novel construct should be considered in patients at high risk for instability.

Background:In Canada, health care is covered by provincial health insurance programs; patients do not directly participate in paying for their acute care expenses. The aim of this study is to assess the willingness of Canadian patients to contribute to the costs of novel total joint arthroplasty implants. Methods:We administered a questionnaire to patients attending an outpatient arthroplasty clinic in Ontario. In the questionnaire, the longevity and risk of complications of a “standard” implant were described. We asked if participants would be willing to contribute to the cost of 3 novel implants that had differing longevities and risks of complications compared with the standard implant. Results:One hundred and fifteen patients completed our questionnaire. Up to 62% of patients were willing to contribute a copayment to get an implant with greater longevity. Willingness to pay decreased to 40% for an implant with greater longevity but an increased risk of complications. Forty percent of participants were willing to pay for an implant with the same longevity as the standard implant but a decreased risk of complications. Participants with a higher income were more willing than other participants to contribute to the cost of a novel implant with greater longevity or lower complication rates. Conclusion:This study demonstrated that up to 62% of our sample of patients in Ontario were willing to share the costs of a novel total joint replacement implant. Willingness to pay was associated with the proposed benefits of the implant and certain patient characteristics. Our study shows that a high proportion of Canadian patients may be willing to copay to have access to new technologies.

Aseptic loosening and infection are two of the leading causes of revision in total knee arthroplasty. While several patient-related factors can play a role in the development of these complications, there are certain modifiable surgeon factors that can help mitigate the risk. Intraoperatively, this can begin with the curing process of bone cement which is broken down into four different stages: mixing, waiting, working, and setting. Understanding each stage of the process is beneficial in obtaining successful long-term outcomes. Developing optimal bone-cement penetration is of utmost importance in establishing a strong interface. Proper penetration of cement is dependent on multiple factors including the cement's properties along with its application to the prosthesis and bone surfaces. Combinations of different cement application techniques have yielded results with varying bone-cement interface strength. While a proper cementation technique is critical to the long-term success of a total knee replacement, other factors, such as antibiotic-loaded bone cement (ALBC), can help prevent and treat complications (such as infection). Although ALBC was not approved in North America by the Food and Drug Administration (FDA) until 2003, it was first described in 1970 and has been routinely used in revision total knee arthroplasty with reliable antibiotic elution properties and an acceptable safety profile.