Faculty Bibliography

Introduction/objectives: In this study, we evaluate the application of preoperative PRO scores, such as the Hip dysfunction and Osteoarthritis Outcomes Score (HOOS) and EuroQol-5Dimension (EQ-5D), as potential predictive modelling tools to anticipate adverse in-hospital outcomes. Methods: Patients between the ages of 18 to 95 undergoing a primary THA between January 2015 and January 2017 at this institution were chart reviewed for inclusion in this study. 40% of our patient population completed preoperative PRO scores within 1 year of surgery and were included in this study. Nursing documentation was reviewed for patient demographics and in-hospital course metrics, such as visual analogue scale (VAS) for pain and morphine equivalence usages. EQ-5D was noted to be binomially distributed and subsequently transformed into a categorical variable with patients scoring >50% placed into a "high EQ-5D" group, and those scoring below into a "low EQ-5D" group. Results: In total, 349 patients including 157 males and 192 females were recruited for this study. The average age and body mass index (BMI) was 62.4+/-11.0 years and 28.6+/-5.61 kg/m2, respectively. The median American Society of Anesthesiology (ASA) Score within our patient cohort was 2. Of the pre-operative scores, age, BMI, EQ-5D, and HOOS section scores were compared with average daily pain, all but age were significantly correlated. However, these values had low r2 values <0.1, indicating poor predictive strength. Conclusion: Our study demonstrates that baseline PRO scores, such as the HOOS and EQ-5D, contain a small predictive component for in-hospital pain scores and average daily morphine. Furthermore, PRO tools can potentially be used to develop systematic, predictive risk stratification models

Introduction/objectives: Computer-assisted hip navigation offers the potential for more accurate placement of hip components, which is important in avoiding dislocation, impingement, and edge-loading. The purpose of this study was to determine if the use of computer-assisted hip navigation reduced the rate of dislocation in patients undergoing revision THA. Methods: We retrospectively reviewed 72 patients who underwent computer-navigated revision THA between January 2015 and December 2016. Demographic variables, indication for revision, type of procedure, and postoperative complications were collected for all patients. Clinical follow-up was performed at 3 months, 1 year, and 2 years. Results: All 72 patients (48% female; 52% male) were included in the final analysis. Mean age of patients undergoing revision THA was 70.4, mean BMI was 26.4 +/- 5.2 kg/m2. The most common indications for revision THA were instability (31%), aseptic loosening (29%), osteolysis/ eccentric wear (18%), infection (11%), and miscellaneous (11%). During revision procedure, polyethylene component was most commonly changed (46%), followed by femoral head (39%), and acetabular component (15%). At final follow-up, there were no dislocations among all study patients (0%). Compared to preoperative dislocation values, there was a significant reduction in the rate of dislocation with the use of computer- assisted hip navigation (31% vs. 0%; p<0.05). Conclusion: Our study demonstrates a significant reduction in the rate of dislocation following revision THA with the use of computer navigation. Although the cause of postoperative dislocation is often multifactorial, the use of computer- assisted surgery may help to curtail femoral and acetabular malalignment in revision THA

Introduction/objectives: As the chronically infected HCV population ages, the demand for total hip arthroplasty (THA) will increase. Previous reports demonstrate that HCV infection may predispose patients to inferior postoperative outcomes following THA. No study to date has evaluated surgical outcomes in THA recipients that have been successfully treated for HCV. The purpose of the current study was to assess surgical outcomes following THA in patients that have been successfully treated for their HCV infection compared to patients that did not receive treatment. Methods: A retrospective review of all patients diagnosed with HCV that underwent primary unilateral and bilateral THA between January 2006 and April 2017 was conducted. Patients were divided into two cohorts: (1) patients that received treatment for HCV (HCV-T) and (2) patients that did not receive treatment for HCV (HCV-NT). All patient variables including demographics, HCV infection characteristics, operative details, in-hospital complications, clinical follow-up, and revisions were carefully studied. Results: 26 patients (32 hips) were in the HCV-T cohort, and 32 patients (38 hips) were in the HCV-UT cohort. Mean age at surgery was 59.5+/-7.3 and 60.0+/-10.2 years in the HCV-T and HCV-UT cohorts, respectively. Mean follow-up time was 26.3+/-23.4 and 31.7+/-28.3 months in the HCV-T and HCV-UT cohorts, respectively. There were significantly more in- hospital complications (p<0.01) and more patients required THA (p=0.04) in the HCV-UT cohort compared to the HCV-T cohort, respectively. Conclusion: Treatment of HCV prior to primary THA can reduce the incidence of in-hospital complications and need for revision THA. HCV treatment regimens should be a part of patient optimization prior to THA

Introduction/objectives: Nonmodular and modular femoral stems have been associated with complications following revision total hip arthroplasty (rTHA). This study aims to report outcomes of modular and nonmodular femoral components in rTHA. Methods: From January 1st, 2013 to September 30th, 2017, all rTHAs using modular or nonmodular femoral stems were identified. Demographic data including age, gender, American Anesthesiology Society (ASA) score. Surgical details including operative time, length of implant, and implant cost were collected. Clinical outcomes including length of stay (LOS), dislocation, infection, fracture, femoral implant re-revision, reoperation, and mortality were also collected. Simple linear regression analysis and sub-analysis using multivariable logistic regression were performed. Results: Of 247 rTHA cases identified, 136 (55.1%) cases utilized modular stems while 111 (44.9%) cases utilized nonmodular components. The average follow-up was 15.5 months (range 0.5-59 months). Nonmodular stems had a significantly lower cost when compared to modular implants (54.3% of modular cost; p<0.001). There were no differences appreciated in cohort demographics including age (p=0.831), gender (p=0.459), and ASA (p=0.053). In addition, there were no differences observed in the surgical details or clinical outcomes assessed, including operative time (p=0.386), LOS (p=0.638), and rates of re-revision of the femoral implant (p=0.327), re-operation (p=0.410), and post-op complications including, infection (p=0.322), dislocation (p=0.687), fracture (p=0.528), and mortality (p=0.446). Conclusion: The use of distal fixation, tapered-fluted, titanium nonmodular components may offer a more costeffective approach to rTHA compared to their modular counterparts

Introduction/objectives: Surgical correction of instability after total hip arthroplasty (THA) remains a complex challenge to the hip arthroplasty surgeon. At our institution, we have developed a stepwise evaluation and surgical correction strategy for patients presenting with THA instability. Methods: 37 patients presenting to a single surgeon for evaluation of THA instability underwent a standardized pre- operative protocol to determine causative factors leading to instability. Radiographic images were reviewed for leg length, offset, cup inclination and anteversion, and dynamic changes in pelvic tilt from supine to standing, and standing to sitting. Findings were confirmed intraoperatively, and instability was addressed surgically through the stepwise algorithm. Results: 37 consecutive patients have been prospectively revised for THA instability. Average pre-operative acetabular abduction was 47.8 degrees and anteversion was 13.4 degrees. Average pelvic incidence was 38 degrees. The acetabular component alone was revised in 22 patients, and the stem alone in 2 patients. Both acetabular and femoral components were revised in 4 patients. There were 9 cases where the head and liner were exchanged to a larger size. No isolated head or isolated liner exchanges were performed. Dual mobility heads were used in 20 patients (54%), with 40mm heads used in 11 patients and 36mm heads used in 6 patients. Post-operative acetabular abduction was 39.2 degrees (range 37-43) and post-operative anteversion was 27.3 degrees (range 22-34), p<0.003 for both. Conclusion: Using this stepwise evaluation as a tool to guide surgical correction of instability, our study demonstrates a significant and promising decrease in the risk of recurrent instability in this high-risk population

Introduction/objectives: Here we report on the shortterm outcomes of a novel monolithic, tapered, fluted, gritblasted, forged titanium stem. Methods: A multicenter, retrospective study was conducted using institutional databases. Patients were included for this study if they underwent primary or revision THA surgery using this particular monolithic, tapered, fluted, grit-blasted, forged titanium stem. Demographic data was collected including gender, age, race, body mass index (BMI), number of prior hip surgeries, and Charlson Comorbidity Index. Surgical data included reason for revision, femoral bone stock as determined by the Paprosky classification, use of trochanteric osteotomies, and length of stay (LOS). Outcomes data included 30- and 90- day complications and readmissions, revision for any reason, femoral revision free interval, and post-operative implant subsidence assessed on serial radiographs. Results: Sixty-three THAs in 62 patients were included in this study. Mean total subsidence from baseline was 1.615 mm at 2 weeks postoperatively (20/62 hips), 1.595 mm at 6 weeks (21/62 hips), 1.267 mm at 3 months (18 hips), 1.430 mm at 6 months (10/62 hips), and 2.167 mm at 9 months (3/62 hips). Three patients underwent subsequent femoral head and liner exchange within 1 year of surgery: 1 for recurrent dislocation, 2 for early periprosthetic joint infection. Conclusion: In total, only 4 patients in our multicenter case series had progressive subsidence within the first three months postoperatively, while the remaining 34 hips with radiographic data had either no subsidence or clinically insignificant subsidence (<5mm). However, the available data suggests that this monolithic, tapered, fluted, grit-blasted, forged-titanium stem achieves early stable femoral fixation

BACKGROUND:Hospital length of stay is a major driver of cost in the total hip arthroplasty (THA) episode of care, and as a result, significant efforts are being made to minimize it. This study aims to assess the utility of the Outpatient Arthroplasty Risk Assessment (OARA) screening tool in accurately identifying patients for safe and early discharge after THA. METHODS:A retrospective review was conducted on 332 consecutive patients who underwent primary THA at a single tertiary academic center. Patients were evaluated using the OARA score, a tool that has been proposed to identify patients who can safely undergo early discharge after THA. The validity of these claims was assessed by analyzing the OARA score's positive and negative predictive values for high vs low OARA scores between patients enrolled in our (1) same-day discharge (SDD) and 2) next-day discharge (NDD) pathways. RESULTS:When comparing the utility of the OARA score in accurately predicting length of stay, the OARA score demonstrated a (1) higher, but constant, positive predictive value for discharge on postoperative day (POD) 0 for SDD (86.1%) than POD1 for NDD (35.5%) and (2) lower negative predictive value for discharge on POD0 (23.1%) for SDD than POD1 for NDD (86.1%). CONCLUSION/CONCLUSIONS:The OARA score was developed to risk-stratify patients who can safely undergo SDD or NDD after THA. In this study, the OARA score was a highly predictive tool in identifying NDD patients at risk for failure of discharge by POD1.

Background/UNASSIGNED:Hip and knee replacements for osteoarthritis are established procedures for improving joint pain and function, yet their safety in patients with multiple sclerosis (MS) is unknown. Patients with MS face unique surgical challenges due to underlying neurologic dysfunction. Current literature on arthroplasty in MS is limited to case reports focusing on adverse events. Methods/UNASSIGNED:Of 40 identified patients who underwent hip or knee replacement, 30 had sufficient data for inclusion. We reviewed their medical records and recorded reasons for surgery, age at surgery, MS characteristics, surgical complications, and ambulatory aid status before and after surgery. We supplemented medical record review with questionnaires regarding preoperative and postoperative pain and satisfaction with surgical outcomes. Results/UNASSIGNED:Median follow-up was 26 months. Complications of surgery were reported in ten patients (33%), mostly mild and self-limited, although four patients (13%) required repeated operation. Six patients (20%) reported improvements in ambulatory aid use compared with presurgery baseline, ten (33%) worsened, and 14 (47%) were unchanged. In 20 patients who completed the questionnaire, mean ± SD joint pain scores (on 0-10 scale) decreased from 8.6 ± 2.0 preoperatively to 2.9 ± 2.4 postoperatively (P < .001). Five patients (25%) were free of joint pain at last follow-up. Conclusions/UNASSIGNED:These results suggest that pain reduction is a realistic outcome of total knee or hip arthroplasty in people with MS and that improved functional gait outcomes are possible in some patients. Prospective, multicenter, collaborative studies are needed to optimize selection and improve outcomes in people with MS considering arthroplasty.

BACKGROUND:For Medicare beneficiaries, hospital reimbursement for nonrevision hip arthroplasty is anchored to either diagnosis-related group code 469 or 470. Under alternative payment models, reimbursement for care episodes is not further risk-adjusted. This study's purpose was to compare outcomes of primary total hip arthroplasty (THA) vs conversion THA to explore the rationale for risk adjustment for conversion procedures. METHODS:All primary and conversion THAs from 2007 to 2014, excluding acute hip fractures and cancer patients, were identified in the National Surgical Quality Improvement Program database. Conversion and primary THA patients were matched 1:1 using propensity scores, based on preoperative covariates. Multivariable logistic regressions evaluated associations between conversion THA and 30-day outcomes. RESULTS:A total of 2018 conversions were matched to 2018 primaries. There were no differences in preoperative covariates. Conversions had longer operative times (148 vs 95 minutes, P < .001), more transfusions (37% vs 17%, P < .001), and longer length of stay (4.4 vs 3.1 days, P < .001). Conversion THA had increased odds of complications (odds ratio [OR] 1.75; 95% confidence interval [CI] 1.37-2.24), deep infection (OR 4.21; 95% CI 1.72-10.28), discharge to inpatient care (OR 1.52; 95% CI 1.34-1.72), and death (OR 2.39; 95% CI 1.04-5.47). Readmission odds were similar. CONCLUSION/CONCLUSIONS:Compared with primary THA, conversion THA is associated with more complications, longer length of stay, and increased discharge to continued inpatient care, implying greater resource utilization for conversion patients. As reimbursement models shift toward bundled payment paradigms, conversion THA appears to be a procedure for which risk adjustment is appropriate.

BACKGROUND:Periprosthetic joint infection following total knee arthroplasty (TKA) is a serious complication often related to obesity which leads to poor patient outcomes and increased resource utilization. A periarticular soft tissue index (PASTI) may help predict postoperative wound complications than BMI alone. METHODS:Three hundred seventy-six TKA patients with a preoperative, lateral knee X-ray radiograph and 1 year of follow up were analyzed. We used 2 pairs of soft tissue and bony measurements, one referencing the femur and the other the tibia. A high PASTI was defined as a ratio >3.0. Minor complications involved clinical interventions related to the surgical wound. Major complications involved return to the operating room. RESULTS:More minor complications occurred in high PASTI for both tibial (20.9% vs 6.4%; odds ratio 3.89, 95% confidence interval 1.94-7.79, P < .001) and femoral measurements (15.3% vs 7.2%; odds ratio 2.09, 95% confidence interval 1.06-4.15, P = .013). Major complications were also more frequent in high PASTI, though not statistically significant. The proportion of obesity (BMI > 30) in both minor (12.4% vs 7.7%, P = .140) and major complications (2.8% vs 3.3%, P = .788) was not statistically different. CONCLUSION/CONCLUSIONS:More wound complications occurred in patients with high PASTI, while no difference was seen using BMI. BMI has traditionally approximated patient size, but does not describe variations in body habitus. PASTI is a more reliable and direct way to assess the periarticular soft tissue envelope size, which is associated with postoperative wound complications in the knee.