Faculty Bibliography

AIMS/OBJECTIVE:Liposomal bupivacaine (LB) as part of a periarticular injection protocol continues to be a highly debated topic in total knee arthroplasty (TKA). We evaluated the effect of discontinuing the use of LB in a periarticular protocol on immediate postoperative pain scores, opioid consumption, and objective functional outcomes. METHODS:On 1 July 2019, we discontinued the use of intraoperative LB as part of a periarticular injection protocol. A consecutive group of patients who received LB as part of the protocol (Protocol 1) and a subsequent group who did not (Protocol 2) were compared. All patients received the same opioid-sparing protocol. Verbal rating scale (VRS) pain scores were collected from our electronic data warehouse and averaged per patient per 12-hour interval. Events relating to the opiate administration were derived as morphine milligram equivalences (MMEs) per patient per 24-hour interval. The Activity Measure for Post-Acute Care (AM-PAC) tool was used to assess the immediate postoperative function. RESULTS:A total of 888 patients received Protocol 1 and while 789 received Protocol 2. The mean age of the patients was significantly higher in those who did not receive LB (66.80 vs 65.57 years, p = 0.006). The sex, BMI, American Society of Anesthesiologists physical status score, race, smoking status, marital status, operating time, length of stay, and discharge disposition were similar in the two groups. Compared with the LB group, discontinuing LB showed no significant difference in postoperative VRS pain scores up to 72 hours (p > 0.05), opioid administration up to 96 hours (p > 0.05), or AM-PAC scores within the first 24 hours (p > 0.05). CONCLUSION/CONCLUSIONS: 2021;103-B(6 Supple A):102-107.

BACKGROUND:To measure functional outcome, patient reported outcome measures (PROMs) are most often used but biomechanical tests can provide valuable supplementary data. The objective of this study was to investigate instrumented insoles for measuring ground-to-foot forces during basic activities. METHODS:Three groups were evaluated: normal controls, preoperative, and postoperative total knees. The Knee Society Scoring System (KSS) Short Form was used, and with foot pressure sensor insoles, a timed-up-and-go (TUG) test and a sit-to-stand (STS) test was used. RESULTS:Comparing preoperative to postoperative and control groups, there were significant differences in most parameters. There were no significant differences between controls and postoperative knees. Of the 33 correlation coefficients between three PROM parameters and six biomechanical parameters for the three groups, only five coefficients were greater than 0.5. CONCLUSIONS:The biomechanical data was substantially independent of the PROM data and provided additional functional evaluation. The most useful parameters were the left-right force ratios during sit-to stand (STS) and the timed-up-and-go (TUG) time.

The purpose of this study was to investigate whether preoperative opioid use had any effect on clinical outcomes and patient-reported outcome measures (PROMs) before and after primary, elective total hip arthroplasty (THA). The authors retrospectively reviewed 793 patients who underwent primary THA from November 2018 to March 2020 with available PROMs. Patients were stratified into two groups based on whether or not they were taking opioids preoperatively. Demographics, clinical data, and PROMs (Forgotten Joint Score-12 [FJS-12], Hip disability and Osteoarthritis Outcome Score for Joint Replacement [HOOS, JR], and Veterans RAND 12 [VR-12] Physical Component Score [PCS] and Mental Component Score [MCS]) were collected at various time periods. Demographic differences were assessed with chi-square and independent sample t tests. Clinical data and PROMs were compared using multilinear regressions. Seventy-five (10%) patients were preoperative opioid users and 718 (90%) were not. Preoperative opioid users had a longer stay (1.37 vs 1.07 days; P=.030), a longer surgical time (102.44 vs 90.20 minutes; P=.001), and higher all-cause postoperative emergency department visits (6.7% vs 2.1%; P=.033) compared with patients not taking opioids preoperatively. Preoperative HOOS, JR (46.63 vs 51.26; P=.009), VR-12 PCS (27.79 vs 31.53; P<.001), and VR-12 MCS (46.24 vs 49.33; P=.044) were significantly lower for preoperative opioid users, but 3-month and 1-year postoperative scores were not statistically different. At 3 months and 1 year, FJS-12 scores did not differ significantly. Mean improvement preoperatively to 1 year in HOOS, JR values exceeded the minimal clinically important difference, with preoperative opioid users experiencing a greater improvement (36.50 vs 33.11; P=.008). Preoperative opioid users had a longer stay, a longer surgical time, and higher all-cause emergency department visits compared with preoperatively opioid naïve patients. Although preoperative opioid users reported significantly lower preoperative PROMs, they did not statistically differ postoperatively, which indicates a larger delta improvement and similar benefits following THA. [Orthopedics. 2021;44(2):77-84.].

»/UNASSIGNED:The potential benefits of computer-assisted surgical (CAS) navigation and robotic total knee arthroplasty (TKA) systems, such as increased reliability of restoring the mechanical axis, fewer outliers, more rapid hospital discharge, less physical therapy requirements, decreased blood loss, and decreased revision rates, have led to their application not only in primary cases but also in complex cases such as preoperative deformity and revision. »/UNASSIGNED:Early evidence demonstrates that CAS navigation may help to improve alignment in complex cases of femoral and tibial deformity and in cases of femoral bowing. »/UNASSIGNED:Data regarding deformity correction with robotic systems are similar to CAS navigation with regard to alignment, but are more limited. There are also scant data regarding revision cases and cases of previous intramedullary canal instrumentation. »/UNASSIGNED:Concerns remain regarding cost, learning curves, and operative times. There are potential long-term cost savings associated with a decrease in revisions and readmissions that require additional investigation. »/UNASSIGNED:Early evidence for the use of these emerging technologies for deformity correction and revision cases is promising, but their impact on long-term functional outcomes remains to be demonstrated. Additional well-designed comparative studies are warranted.

BACKGROUND:Patellar maltracking is a potential surgical complication following total knee arthroplasty (TKA) and can result in anterior knee pain, recurrent patellar dislocation, and damage to the medial patellar soft tissue stabilizers. Data remain unclear as to whether the patellar button should be revised during a revision TKA (rTKA) if changing the component implant system. Our study examines whether retaining the original patellar button during an rTKA using a different implant system affects patellar tracking. METHODS:A retrospective cohort study of rTKA patients between August 2011 and June 2019 was performed at an urban, tertiary referral center. Patients were divided into 2 cohorts depending on whether their retained patella from their primary TKA was of the same (SIM) or different implant manufacturer (DIM) as the revision system used. Radiographic measurements were performed on preoperative and postoperative knee radiographs and differences were compared between the 2 groups. Baseline demographic data were also collected. RESULTS:Of the 293 consecutive, aseptic rTKA cases identified, 122 underwent revision in the SIM cohort and 171 in the DIM cohort. There were no demographic differences between the groups. No statistical significance was calculated for differences in preoperative and postoperative patellar tilt or Insall-Salvati ratio between the groups. The DIM group was found to have more lateral patellar translation (-0.01 ± 6.09 vs 2.68 ± 7.61 mm, P = .001). However, when calculating differences in the magnitude of the translation (thereby removing differences due to laterality), no difference was observed (0.06 ± 3.69 vs 0.52 ± 4.95 mm, P = .394). CONCLUSION/CONCLUSIONS:No clinically significant differences in patellar tracking were observed when the original patellar component was retained and a different revision implant system was used. Given the inherent risks of bone loss and fracture with patellar component revision, surgeons performing rTKA may retain the primary patella if it is well fixed and can still expect appropriate patellar tracking regardless of the revision implant system used. LEVEL OF EVIDENCE/METHODS:III, Retrospective cohort study.

BACKGROUND:Range of motion (ROM) after revision total knee arthroplasty (RTKA) is an important clinical outcome, as decreased ROM can lead to patient dissatisfaction and diminished mobility. This study sought to determine the effect of type of revision, implant constraint level, and reason for revision has on RTKA ROM. METHODS:A retrospective review of 832 RTKA cases from 2011 to 2019 was conducted at a single, urban academic institution. Patients who underwent aseptic RTKA and had preoperative and 1-year postoperative ROM in their chart were included. The ΔROM was calculated by subtracting the preoperative ROM from the 1-year postoperative ROM. ROM was compared between tibial polyethylene liner-only revisions (liner) and all other revision types (component) and based on reason for revision. Subanalysis was performed within the liner and component revision cohorts to determine the effect of reason for revision and implant constraint level on ROM. RESULTS:In total, 290 patients qualified. Forty-two patients had liner revisions (14.5%) and 248 had component revisions (85.5%). The ΔROM for component revision cases was significantly higher than liner exchange only (10° ± 24° vs.1° ± 19°; P = .03). ΔROM was not significant when comparing the level of implant constraint nor was it when separating and comparing by type of revision. Component revisions due to instability were found to significantly decrease ΔROM. CONCLUSION/CONCLUSIONS:Component revision cases have significantly improved ΔROM when compared with liner-only revision. Constraint level is not significantly associated with changes in ROM in either liner or component revisions. Component revisions due to instability significantly reduce ΔROM.

BACKGROUND:Dual mobility (DM) total hip arthroplasty (THA) implants have been advocated for patients at risk for impingement due to abnormal spinopelvic mobility. Impingement against cobalt-chromium acetabular bearings, however, can result in notching of titanium femoral stems. This study investigated the incidence of femoral stem notching associated with DM implants and sought to identify risk factors. METHODS:A multicenter retrospective study reviewed 256 modular and 32 monoblock DM components with minimum 1-year clinical and radiographic follow-up, including 112 revisions, 4 conversion THAs, and 172 primary THAs. Radiographs were inspected for evidence of femoral notching and to calculate acetabular inclination and anteversion. Revisions and dislocations were recorded. RESULTS:Ten cases of femoral notching were discovered (3.5%), all associated with modular cylindrospheric cobalt-chromium DM implants (P = .049). Notches were first observed radiographically at mean 1.3 years after surgery (range 0.5-2.7 years). Notch location was anterior (20%), superior (60%), or posterior (20%) on the prosthetic femoral neck. Notch depth ranged from 1.7% to 20% of the prosthetic neck diameter. Eight cases with notching had lumbar pathology that can affect spinopelvic mobility. None of these notches resulted in stem fracture, at mean 2.7-year follow-up (range 1-7.6 years). There were no dislocations or revisions in patients with notching. CONCLUSION/CONCLUSIONS:Femoral notching was identified in 3.5% of DM cases, slightly surpassing the dislocation rate in a cohort selected for risk of impingement and instability. Although these cases of notching have not resulted in catastrophic failures thus far, further study of clinical sequelae is warranted. Component position, spinopelvic mobility, and implant design may influence risk.

BACKGROUND:As orthopaedic physician fees continue to come under scrutiny by the U.S. Centers for Medicare & Medicaid Services (CMS), there is a continued need to evaluate trends in reimbursement rates across contemporary time intervals. Although substantially lower work relative value units (RVUs) have been previously demonstrated for septic revision total knee arthroplasty (TKA) compared with aseptic revisions, to our knowledge, there has been no corresponding analysis comparing total physician fees. Therefore, the purpose of our study was to analyze temporal trends in Medicare physician fees for septic and aseptic revision TKAs. METHODS:Current Procedural Terminology (CPT) codes related to septic 1-stage and 2-stage revision TKAs and aseptic revision TKAs were categorized. From 2002 to 2019, the facility rates of physician fees associated with each CPT code were obtained from the CMS Physician Fee Schedule Look-Up Tool. Monetary data from Medicare Administrative Contractors at 85 locations were used to calculate nationally representative means. All total physician fee values were adjusted for inflation and were translated to 2019 U.S. dollars using Consumer Price Index data from the U.S. Bureau of Labor Statistics. Cumulative annual percentage changes and compound annual growth rates (CAGRs) were computed utilizing adjusted physician fee data. RESULTS:After adjusting for inflation, the total mean Medicare reimbursement (and standard deviation) for aseptic revision TKA decreased 24.83% ± 3.65% for 2-component revision and 24.21% ± 3.68% for 1-component revision. The mean septic revision TKA total Medicare reimbursement declined 23.29% ± 3.73% for explantation and 33.47% ± 3.24% for reimplantation. Both the dollar amount (p < 0.0001) and the percentage (p < 0.0001) of the total Medicare reimbursement decline for septic revision TKA were significantly greater than the decline for aseptic revision TKA. CONCLUSIONS:Septic revision TKAs have been devalued at a rate greater than their aseptic counterparts over the past 2 decades. Coupled with our findings, the increased resource utilization of septic revision TKAs may result in financial barriers for physicians and subsequently may reduce access to care for patients with periprosthetic joint infections. CLINICAL RELEVANCE/CONCLUSIONS:The devaluation of revision TKAs may result in reduced patient access to infection management at facilities unable to bear the financial burden of these procedures.

BACKGROUND:Tranexamic acid (TXA) is increasingly used to minimize blood loss during total joint arthroplasty (TJA). Although TXA has been shown to be highly effective in reducing operative blood loss, many surgeons believe that it places patients with coronary artery disease (CAD) or a history of coronary stents at an increased risk for myocardial infarction. The purpose of this study was to determine if TXA is safe to use in patients with a history of CAD or coronary stents. METHODS:We performed a retrospective analysis at a single, tertiary academic medical center identifying consecutive total hip and knee arthroplasty cases over an 8-year period. From this cohort who received TXA intraoperatively, we identified patients with a history of CAD or coronary stents and determined the total myocardial infarction and venous thromboembolism (VTE) rates within a 90-day postoperative period. Chi-square analyses were used to identify differences in VTE rates between cohorts. A post hoc power analysis was also performed to determine whether our results were powered to detect a difference in VTE rates. RESULTS:In the 26,808 identified at-risk patients, there were no postoperative myocardial infarctions. No significant differences were observed for VTE rates compared with the control cohort using either topical or intravenous TXA, with regard to CAD (0.29% compared with 0.76%; p = 0.09) or coronary stents (0% compared with 0.76%; p = 0.14). Moreover, there was no significant difference observed in VTE rates when administration was subcategorized into intravenous and topical methods with regard to CAD (0.13% compared with 0.72%; p = 0.12) or coronary stents (0% compared with 0%; p = 1.0). CONCLUSIONS:In our series, topical and intravenous TXA were equally safe when used in patients with a history of CAD and coronary stents in comparison with the control cohort. With equal efficacy and risk of adverse events, we recommend intravenous TXA, which may enable easier institutional implementation. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:Vancomycin is often used as antimicrobial prophylaxis in patients undergoing total hip or knee arthroplasty. Vancomycin requires longer infusion times to avoid associated side effects. We hypothesized that vancomycin infusion is often started too late and that delayed infusion may predispose patients to increased rates of surgical site infections and prosthetic joint infections. METHODS:We reviewed clinical data for all primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients at our institution between 2013 and 2020 who received intravenous vancomycin as primary perioperative gram-positive antibiotic prophylaxis. We calculated duration of infusion before incision or tourniquet inflation, with a cutoff of 30 minutes defining adequate administration. Patients were divided into two groups: 1) appropriate administration and 2) incomplete administration. Surgical factors and quality outcomes were compared between groups. RESULTS:We reviewed 1047 primary THA and TKA patients (524 THAs and 523 TKAs). The indication for intravenous vancomycin usage was allergy (61%), methicillin-resistant staphylococcus aureus colonization (17%), both allergy and colonization (14%), and other (8%). 50.4% of patients began infusion >30 minutes preoperatively (group A), and 49.6% began infusion <30 minutes preoperatively (group B). Group B had significantly higher rates of readmissions for infectious causes (3.6 vs 1.3%, P = .017). This included a statistically significant increase in confirmed prosthetic joint infections (2.2% vs 0.6%, P = .023). Regression analysis confirmed <30 minutes of vancomycin infusion as an independent risk factor for PJI when controlling for comorbidities (OR 5.22, P = .012). CONCLUSION/CONCLUSIONS:Late infusion of vancomycin is common and associated with increased rates of infectious causes for readmission and PJI. Preoperative protocols should be created to ensure appropriate vancomycin administration when indicated.