Faculty Bibliography

BACKGROUND:Periprosthetic joint infection (PJI) and subsequent revision surgeries may affect patients' social and physical health, ability to complete daily activities, and disability status. This study sought to determine how PJI affects patients' quality of life through patient-reported outcome measures with minimum 1-year follow-up. METHODS:Patients who suffered PJI following primary total joint arthroplasty (TJA) from 2012 to 2021 were retrospectively reviewed. Patients met Musculoskeletal Infection Society criteria for acute or chronic PJI, underwent revision TJA surgery, and had at least 1 year of follow-up. Patients were surveyed regarding how PJI affected their work and disability status, as well as their mental and physical health. Outcome measures were compared between acute and chronic PJIs. In total, 318 patients (48.4% total knee arthroplasty and 51.6% total hip arthroplasty) met inclusion criteria. RESULTS:Following surgical treatment for knee and hip PJI, a substantial proportion of patients reported that they were unable to negotiate stairs (20.5%), had worse physical health (39.6%), and suffered worse mental health (25.2%). A high proportion of patients reported worse quality of life (38.5%) and social satisfaction (35.3%) following PJI. Worse reported patient-reported outcome measures including patients' ability to complete daily physical activities were found among patients undergoing treatment for chronic PJI, and also, 23% of patients regretted their initial decision to pursue primary TJA. CONCLUSIONS:A PJI negatively affects patients' ability to carry out everyday activities. This patient population is prone to report challenges overcoming disability and returning to work. Patients should be adequately educated regarding the risk of PJI to decrease later potential regrets. LEVEL OF EVIDENCE/METHODS:Case series (IV).

INTRODUCTION/BACKGROUND:Preoperative planning of total hip arthroplasty (THA) using two-dimensional low-dose (2DLD) full-body imaging has gained popularity in recent years. The low-dose imaging system is said to produce a calibrated image with constant 1:1 magnification. However, the planning software used in conjunction with those images may introduce variations in the degree of magnification in 2DLD imaging, and this has not yet been investigated. The purpose of the present study was to quantify any variation in 2DLD image to assess the need for image calibration when using conventional planning software. METHODS:Postoperative 2DLD images from 137 patients were retrospectively evaluated. Only patients who underwent THA for primary osteoarthritis were included in the study cohort. The femoral head diameter was measured by two independent observers using both Orthoview™ and TraumaCad™ planning software programs. Actual sizes of the femoral head implants were extracted from surgical reports to calculate image magnification. Magnification measurement reliability was calculated with the intra-class correlation coefficient (ICC) index. RESULTS:Image magnification varied among cases (mean 133%, range 129-135%). There was no statistical difference in mean image magnification among the various implant sizes (p = 0.8). Mean observer and inter-observer reliability was rated excellent. CONCLUSION/CONCLUSIONS:THA planning with 2DLD imaging is subject to variation in magnification as analyzed with conventional planning software in this series. This finding is of paramount importance for surgeons using 2DLD imaging in preparation for THA since errors in magnification could affect the accuracy of preoperative planning and ultimately the clinical outcome.

BACKGROUND:The lower morbidity and mortality rate associated with increased surgeon and hospital volume may also correlate with improved patient-reported outcome measures. The goal of this study was to determine the relationship between surgeon and hospital volume and patient-reported outcome measures after total knee arthroplasty (TKA) using American Joint Replacement Registry data. METHODS:Using American Joint Replacement Registry data from 2012 to 2020, 8,193 primary, elective TKAs with both preoperative and 1-year postoperative The Knee Injury and Osteoarthritis Outcome Score, Joint Replacement (KOOS-JR) scores were analyzed. This study was powered to detect the minimally clinical important difference (MCID). The main exposure variables were median annual surgeon and hospital volume. Tertiles were formed based on the median annual number of TKAs performed: low-volume surgeons (1 to 52), medium-volume (53 to 114), and high-volume (≥115); low-volume hospitals (1 to 283), medium-volume (284 to 602), and high-volume (≥603). The mean preoperative and 1-year postoperative KOOS-JR were compared. Multivariable logistic regression models were used to determine the effect of surgeon and hospital volume and demographics on achieving the MCID for KOOS-JR. RESULTS:The mean preoperative and 1-year postoperative KOOS-JR score for low-volume surgeons was 47.78 ± 13.50 and 77.75 ± 16.65, respectively, and 47.32 ± 13.73 and 76.86 ± 16.38 for low-volume hospitals. The mean preoperative and 1-year postoperative KOOS-JR score for medium-volume surgeons was 47.20 ± 13.46 and 76.70 ± 16.98, and 48.93 ± 12.50 and 77.15 ± 16.36 for medium-volume hospitals. The mean preoperative and 1-year postoperative KOOS-JR scores for high-volume surgeons were 49.08 ± 13.04 and 78.23 ± 16.72, and 48.11 ± 13.47 and 78.23 ± 17.22 for high-volume hospitals. No notable difference was observed in reaching MCID for KOOS-JR after adjustment for potential confounders. CONCLUSION/CONCLUSIONS:An increased number of TKA cases performed by a given surgeon or at a given hospital did not have an effect on achieving MCID for KOOS-JR outcomes.

BACKGROUND:Chronic prosthetic joint infection (PJI) is most frequently treated with 2-stage revision in conjunction with antibiotic treatment. The aims of this study were 1) to investigate the characteristics of patients who have recurrent infection following 2-stage revision for PJI and 2) to identify risk factors associated with treatment failure. METHODS:A multicenter retrospective review of 90 total knee arthroplasty (TKA) patients who underwent 2-stage revision for treatment of PJI from March 1, 2003 to July 31, 2019, and had recurrent PJI was conducted. The minimum follow-up was 12 months (median follow up of 2.4 years). Microorganisms, subsequent revision, PJI control status, and final joint status were collected. The infection-free survival after initial 2-stage revision was plotted utilizing the Kaplan-Meier method. RESULTS:Mean survival time to reinfection was 21.3 months (range, 0.3 to 160.5). There were 14 recurrent infections that were acute PJIs treated with debridement, antibiotics, and implant retention (DAIR), while 76 were chronic and treated with repeat 2-stage revision. The most common pathogen identified for both index and recurrent PJI was coagulase-negative Staphylococci. Pathogen persistence was observed in 14 (22.2%) of recurrent PJIs. In total, 61 (67.8%) patients possessed a prosthetic reimplantation at their most recent follow-up, and 29 (35.6%) patients required intervention following repeat 2-stage. CONCLUSION/CONCLUSIONS:Overall, 31.1% of the patients obtained infection control after treatment of a failed 2-stage revision due to PJI. The high rate of pathogen persistence and the relatively low survival time to recurrence suggests a need to more closely monitor PJIs cases within 2 years.

BACKGROUND/UNASSIGNED:Many of the current total hip arthroplasty (THA) planning tools only consider sagittal pelvic tilt in the standing and relaxed sitting positions. Considering that the risk of postoperative dislocation is higher when bending forward or in sit-to-stand move, sagittal pelvic tilt in the flexed seated position may be more relevant for preoperative planning. We hypothesized that there was a significant difference in sagittal pelvic tilt between the relaxed sitting and flexed seated positions as measured by the sacral slope in preoperative and postoperative full-body radiographs. METHODS/UNASSIGNED:This was a multicenter retrospective analysis of the preoperative and postoperative simultaneous biplanar full-body radiographs of 93 primary THA patients in standing, relaxed sitting, and flexed seated positions. The sagittal pelvic tilt was measured using the sacral slope relative to the horizontal line. RESULTS/UNASSIGNED:< .0001). This difference was >10° in 51 patients (54.9%) and >30° in 14 patients (15.1%) postoperatively. CONCLUSIONS/UNASSIGNED:There was a significant difference in sagittal pelvic tilt between the relaxed and flexed seated positions. A flexed seated view provides valuable information that might be more relevant for preoperative THA planning in order to prevent postoperative THA instability.

INTRODUCTION/BACKGROUND:The term "spinopelvic mobility" is most often applied to motion within the spinopelvic segment. It has also been used to describe changes in pelvic tilt between various functional positions, which is influenced by motion at the hip, knee, ankle and spinopelvic segment. In the interest of establishing a consistent language for spinopelvic mobility, we sought to clarify and simplify its definition to create consensus, improve communication, and increase consistency with research into the hip-spine relationship. METHODS:A literature search was performed using the Medline (PubMed) library to identify all existing articles pertaining to spinopelvic mobility. We reported on the varying definitions of spinopelvic mobility including how different radiographic imaging techniques are used to define mobility. RESULTS:The search term "spinopelvic mobility" returned a total of 72 articles. The frequency and context for the varying definitions of mobility were reported. 41 papers used standing and upright relaxed-seated radiographs without the use of extreme positioning, and 17 papers discussed the use of extreme positioning to define spinopelvic mobility. DISCUSSION/CONCLUSIONS:Our review suggests that the definitions of spinopelvic mobility is not consistent in the majority of published literature. We suggest descriptions of spinopelvic mobility independently consider spinal motion, hip motion, and pelvic position, while recognizing and describing their interdependence.

AIMS/UNASSIGNED:Revision total knee arthroplasty (rTKA) is a technically challenging and costly procedure. It is well-documented that primary TKA (pTKA) have better survivorship than rTKA; however, we were unable to identify any studies explicitly investigating previous rTKA as a risk factor for failure following rTKA. The purpose of this study is to compare the outcomes following rTKA between patients undergoing index rTKA and those who had been previously revised. METHODS/UNASSIGNED:This retrospective, observational study reviewed patients who underwent unilateral, aseptic rTKA at an academic orthopaedic speciality hospital between June 2011 and April 2020 with > one-year of follow-up. Patients were dichotomized based on whether this was their first revision procedure or not. Patient demographics, surgical factors, postoperative outcomes, and re-revision rates were compared between the groups. RESULTS/UNASSIGNED:= -0.102; p = 0.251). CONCLUSION/UNASSIGNED:Multiply revised TKA had worse outcomes, with higher rates of facility discharge, longer operative times, and greater reoperation and re-revision rates compared to index rTKA.

INTRODUCTION/BACKGROUND:Prior studies have demonstrated an association between time to revision total knee arthroplasty (rTKA) and indication; however, the impact of early versus late revision on post-operative outcomes has not been reported. MATERIALS AND METHODS/METHODS:A retrospective, observational study examined patients who underwent unilateral, aseptic rTKA at an academic orthopedic hospital between 6/2011 and 4/2020 with > 1-year of follow-up. Patients were early revisions if they were revised within 2 years of primary TKA (pTKA) or late revisions if revised after greater than 2 years. Patient demographics, surgical factors, and post-operative outcomes were compared. RESULTS:470 rTKA were included (199 early, 271 late). Early rTKA patients were younger by 2.5 years (p = 0.002). The predominant indications for early rTKA were instability (28.6%) and arthrofibrosis/stiffness (26.6%), and the predominant indications for late rTKA were aseptic loosening (45.8%) and instability (26.2%; p < 0.001). Late rTKA had longer operative times (119.20 ± 51.94 vs. 103.93 ± 44.66 min; p < 0.001). There were no differences in rTKA type, disposition, hospital length of stay, all-cause 90-day emergency department visits and readmissions, reoperations, and number of re-revisions. CONCLUSIONS:Aseptic rTKA performed before 2 years had different indications but demonstrated similar outcomes to those performed later. Early revisions had shorter surgical times, which could be attributed to differences in rTKA indication. LEVEL OF EVIDENCE/METHODS:III, retrospective observational analysis.

INTRODUCTION/BACKGROUND:To improve revision total hip arthroplasty (rTHA) prognosis and postoperative management, a better understanding of how non-elective and elective indications influence clinical outcomes is needed. We sought to compare ambulatory status, complication rates, and implant survival rates in patients who underwent aseptic rTHA for periprosthetic fracture or elective indications. MATERIALS AND METHODS/METHODS:This retrospective study examined all aseptic rTHA patients with a minimum follow-up of two years at a single tertiary referral center. Patients were divided into two groups: fracture rTHA (F-rTHA) if the patient had a periprosthetic femoral or acetabular fracture, and elective rTHA (E-rTHA) if the patient underwent rTHA for other aseptic indications. Multivariate regression was performed for clinical outcomes to adjust for baseline characteristics, and Kaplan-Meier analysis was performed to assess implant survival. RESULTS:A total of 324 patients (F-rTHA: 67, E-rTHA: 257) were included. In the F-rTHA cohort, 57 (85.0%) and 10 (15.0%) had femoral and acetabular periprosthetic fractures, respectively. F-rTHA patients were more likely to be discharged to skilled nursing (40.3% vs. 22.2%, p = 0.049) and acute rehabilitation facilities (19.4% vs. 7.8%, p = 0.004). F-rTHA patients had higher 90-day readmission rates (26.9% vs. 16.0%, p = 0.033). Ambulatory status at three months postoperatively significantly differed (p = 0.004); F-rTHA patients were more likely to use a walker (44.6% vs. 18.8%) and less likely to ambulate independently (19.6% vs. 28.6%) or with a cane (28.6% vs. 41.1%). These differences did not persist at one and two years postoperatively. Freedom from all-cause re-revision (77.6% vs. 74.7%, p = 0.912) and re-revision due to PJI (88.1% vs. 91.9%, p = 0.206) were similar at five-year follow-up. CONCLUSIONS:Compared to rTHA performed for elective aseptic indications, fracture rTHA patients had poorer early functional outcomes, with greater need for ambulatory aids and non-home discharge. However, these differences did not persist long term and did not portend increased infection or re-revision rates.