Faculty Bibliography

BACKGROUND:The purpose of this study is to determine if the number and types of patient-reported drug allergies are associated with prosthetic joint infection (PJI) and functional outcomes following total joint arthroplasty (TJA). METHODS:This is a retrospective review of all patients who underwent a primary, elective total hip (THA) or knee arthroplasty (TKA) over a 10-year period at a single academic institution. Demographic, clinical information, and number and type of patient-reported drug allergy was collected. Univariate and multivariate logistic regressions were performed to identify risk factors for PJI and risk of PJI based on number of allergies. Univariate analysis was also performed to identify if the number of patient-reported allergies affected functional outcome scores. RESULTS:Of 31,109 patients analyzed, there were 941 (3%) revisions for infection (491 knees and 450 hips). At least one allergy was reported by 16,435 (52.8%) patients, with a mean of 1.2 ± 1.9. Those who underwent revision for infection had a significantly higher number of reported allergies (1.68 ± 1.9 vs 1.23 ± 1.9, P < .0005, 95% confidence interval -0.58 to 0.33). On univariate regression the number of allergies independently predicted revision TJA for infection (P < .0001) as did age, gender, body mass index, and smoking status. On multivariate regression for each additional patient-reported allergy, risk of PJI increased by 1.11 times (95% confidence interval 1.07-1.14, P < .0001). Number of patient-reported allergies did not predict 3-month or 1-year functional outcome scores. CONCLUSION/CONCLUSIONS:Patients with a higher number of reported allergies may be at increased risk of PJI following TJA. LEVEL OF EVIDENCE/METHODS:Prognostic Level II.

BACKGROUND:The use of technology such as navigation and robotic systems may improve the accuracy of component positioning in total hip arthroplasty (THA), but its impact on patient-reported outcome measures (PROMs) remains unclear. This study aims to elucidate the association between the use of intraoperative technology and PROMs in patients who underwent primary THA. METHODS:We retrospectively reviewed a consecutive series of patients who underwent primary THA between 2016 and 2020 and answered PROM questionnaires. Patients were separated into 3 groups depending on intraoperative technology utilization: computer-assisted navigation, robotic-assisted, or no technology (conventional) THA. Forgotten Joint Score-12 and Hip disability and Osteoarthritis Outcome Score, Joint Replacemen scores were collected at various time points. Demographic differences were assessed with chi-square and analysis of variance. Mean scores between groups were compared using univariate analysis of covariance, controlling for all significant demographic differences. RESULTS:Of the 1960 cases identified, 896 used navigation, 135 used robotics, and 929 used no technology. There were significant statistical differences in one-year Hip disability and Osteoarthritis Outcome Score, Joint Replacement scores (85.23 vs 85.95 vs 86.76, respectively; P = .014) and two-year Forgotten Joint Score-12 scores (64.72 vs 73.35 vs 74.63, respectively; P = .004) between the 3 groups. However, these differences did not exceed the mean clinically important differences. Length of stay was statistically longest for patients who underwent conventionally performed THA versus navigation and robotics (2.22 vs 1.46 vs 1.91, respectively; P < .001). Surgical time was significantly longer for cases performed using robotics versus navigation and conventionally (119.61 vs 90.35 vs 95.35, respectively; P < .001). CONCLUSION/CONCLUSIONS:Statistical differences observed between all modalities are not likely to be clinically meaningful with regard to early patient-reported outcomes. Although intraoperative use of technology may improve the accuracy of implant placement, these modalities have not yet translated into improved early reported functional outcomes. LEVEL III EVIDENCE/UNASSIGNED:Retrospective cohort.

BACKGROUND:Venous thromboembolism (VTE), defined as pulmonary embolism or deep venous thrombosis, is a rare but serious complication following revision total hip arthroplasty (RTHA) and revision total knee arthroplasty (RTKA). Previous studies show that obesity may be associated with an increased risk for pulmonary embolism, wound complications, and infection. With no current universal standard of care for VTE prophylaxis, we sought to determine whether aspirin prescribed (ASA) is safe and effective in obese patients undergoing RTHA/RTKA. METHODS:). RESULTS:The cohort comprised of 335 patients with a normal BMI, 511 were overweight, 408 obese, 232 severely obese, and 92 morbidly obese. Total VTE rates were statistically similar between BMI groups (0.90% vs 0.78% vs 0.74% vs 0.43% vs 0%, P = .89). There were no differences in bleeding rates (0.90% vs 0% vs 0% vs 0.43% vs 0%, P = .08), wound complications (0.30% vs 0.20% vs 0.25% vs 0% vs 0%, P = .93), infection (1.49% vs 1.57% vs 0.98% vs 1.29% vs 1.09%, P = .66), or mortality (0% vs 0.20% vs 0% vs 0% vs 0%, P = .72). CONCLUSION/CONCLUSIONS:ASA is safe and effective for VTE prevention in obese patients with similar complication rates to nonobese patients undergoing RTHA/RTKA.

As perioperative protocols have improved, there has been a reduction in the rates of key complications after hip and knee arthroplasty. Likewise, as we have been able to make patients more comfortable postoperatively, hospital length of stay has decreased and in some centers, hip and knee arthroplasty is now routinely performed as an outpatient. While the number of surgeons offering this option and patients choosing to have procedures performed as an outpatient grows, many questions revolve around this movement. This article will review the data supporting outpatient arthroplasty, the business and legal aspects involved, if surgeons can align with their hospital to offer these services, and how tightly knit and highly organized teams are key to the success of safely offering hip and knee arthroplasty on an outpatient basis.

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: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:As the Center for Medicare and Medicaid (CMS) moves toward bundled payment plans for total joint arthroplasty (TJA), it becomes necessary to reduce factors that increase cost for an episode of care such as readmissions. The goal of this study is to evaluate the payment for observation stay versus readmission for patients who present to the emergency department. METHODS:A retrospective review from 2014-2019 was conducted identifying all Medicare patients who had a primary, elective TJA and visited the ED within 90 days postoperatively. If a readmission was one midnight or less or had an equivalent diagnosis to an observation stay patient, it was characterized as a readmission that could have qualified as an observation stay. Using our institution's average payment for Medicare readmissions and observations, actual and potential savings were calculated. RESULTS:Sixty-nine out of 523 (13.2%) patients were placed under observation, while 454 (86.8%) patients were readmitted. Eighty-six out of 523 (18.9%) patients qualified for observation status. There was an actual savings of 11.8% by placing patients on observation status and readmission rate was decreased by 13.2%. Savings could have increased by a total of 27.7% and readmissions decreased by a total of 29.6% if all patients who qualified had been placed on observation status. CONCLUSION/CONCLUSIONS:At our institution, the implementation of observation stay has led to a savings of 11.8% and a potential total savings of 27.7%. The rate of readmissions was decreased by 13.2% and had the potential to decrease by a total of 29.6%.

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.].

Limb alignment is a critically important factor to consider in the management of the patient with knee arthritis. Abnormal alignment is associated with the accelerated progression of osteoarthritis and, if not addressed at the time of surgery, may contribute to early failure of knee replacement implants. The contribution of the hindfoot to overall limb alignment has received limited attention in the context of deformity correction in total knee arthroplasty (TKA). In this review, we present evidence supporting the inclusion of the hindfoot in the consideration of overall limb alignment for TKA and propose a management algorithm.

A critical component in the evaluation of a patient with a periprosthetic hip fracture is determination of stem stability. Failure to critically evaluate preoperative radiographs and subsequently intraoperative stem position may result in an incorrect treatment algorithm and early catastrophic failure of the implant construct. In 2018, this is becoming a larger issue as demand for revision total hip arthroplasty increases. Several factors contribute to the type of implant used in these fractures and depend on age, activity level, comorbidities, and available bone stock. The purpose of this article is to review the evaluation of periprosthetic hip fractures around a loose stem and provide tips and tricks for their management to allow for a successful, long-lasting outcome.