Faculty Bibliography

AIMS:Revision total knee arthroplasty (rTKA) accounts for approximately 5% to 10% of all TKAs. Although the complexity of these procedures is well recognized, few investigators have evaluated the cost and value-added with the implementation of a dedicated revision arthroplasty service. The aim of the present study is to compare and contrast surgeon productivity in several differing models of activity. MATERIALS AND METHODS:rTKA with a single OT; and 3) primary TKA with two OTs versus rTKA with a single OT. RESULTS:In total, 4570 procedures were performed: 4128 primary TKAs, 51 TKA liner exchanges, and 391 full rTKAs. Surgical time was significantly different between the primary TKA, liner exchange, and rTKA cohorts (100.6, 97.1, and 141.7 minutes, respectively; p < 0.001). Primary TKA yielded a mean of 7.1% more RVU/min per procedure than rTKA. Our one-OT model demonstrated that primary TKA (n = 4) had a 1.9% RVU/day advantage over rTKA (n = 3). If two OTs are used for primary TKA (n = 6), the outcome strongly favours primary TKA by an added 34.6% RVUs/day. CONCLUSION:Our results suggest that a dedicated rTKA service would lead to lower surgeon remuneration based on the current RVU paradigm. Revision arthroplasty specialists may need additional or alternative incentives to promote the development of a dedicated revision service. Through such an approach, healthcare organizations could enhance the quality of care provided, but surgeon productivity measures would need to be adjusted to reflect the burden of these cases. Cite this article: Bone Joint J 2019;101-B:675-681.

AIMS/OBJECTIVE:non-anterior (NA) surgical approaches on prosthetic joint infection (PJI), and examined the impact of new perioperative protocols on PJI rates following all surgical approaches at a single institution. PATIENTS AND METHODS/METHODS:(13.3 to 57.6, sd 6.1), respectively. Infection rates were calculated yearly for the DA and NA approach groups. Covariates were assessed and used in multivariate analysis to calculate adjusted odds ratios (ORs) for risk of development of PJI with DA compared with NA approaches. In order to determine the effect of adopting a set of infection prevention protocols on PJI, we calculated ORs for PJI comparing patients undergoing THA for two distinct time periods: 2013 to 2014 and 2015 to 2016. These periods corresponded to before and after we implemented a set of perioperative infection protocols. RESULTS:There were 1985 patients in the DA group and 4101 patients in the NA group. The overall rate of PJI at our institution during the study period was 0.82% (50/6086) and decreased from 0.96% (12/1245) in 2013 to 0.53% (10/1870) in 2016. There were 24 deep PJIs in the DA group (1.22%) and 26 deep PJIs in the NA group (0.63%; p = 0.023). After multivariate analysis, the DA approach was 2.2 times more likely to result in PJI than the NA approach (OR 2.2 (95% confidence interval 1.1 to 3.9); p = 0.006) for the overall study period. CONCLUSION/CONCLUSIONS:2019;101-B(6 Supple B):2-8.

AIMS/OBJECTIVE:Studying the indications for revision total hip arthroplasty (THA) may enable surgeons to change their practice during the initial procedure, thereby reducing the need for revision surgery. The aim of this study was to identify and describe the potentially avoidable indications for revision THA within five years of the initial procedure. PATIENTS AND METHODS/METHODS:A retrospective review of 117 patients (73 women, 44 men; mean age 61.5 years (27 to 88)) who met the inclusion criteria was conducted. Three adult reconstruction surgeons independently reviewed the radiographs and medical records, and they classified the revision THAs into two categories: potentially avoidable and unavoidable. Baseline demographics, perioperative details, and quality outcomes up to the last follow-up were recorded. RESULTS:A total of 60 revision THAs (51.3%) were deemed potentially avoidable and 57 (48.7%) were deemed unavoidable. The following were identified as avoidable factors: suboptimal positioning of the acetabular component (29; 48%), intraoperative fracture or a fracture missed on an intraoperative radiograph (20; 33%), early (less than two weeks) aseptic loosening (seven; 11.7%), and symptomatic leg length discrepancy of > 1 cm (four; 6.7%). CONCLUSION/CONCLUSIONS:2019;101-B(6 Supple B):97-103.

BACKGROUND:Short-stem (SS) hip prostheses for total hip arthroplasty (THA) have gained popularity as surgeons strive to reproduce physiological stress distributions at the proximal femur. Additionally, as THA indications continue to target younger populations, preservation of femoral bone stock for potential revision surgeries is particularly appealing. However, little is known regarding the short-term complications of each variety of short stem during the learning curve period. The purpose of this study is to evaluate the short-term complications among the THA recipients with the use of a novel SS hip prosthesis. METHODS:A retrospective chart review was performed of all patients undergoing primary THA utilizing an Echo Bi-Metric Microplasty hip stem. Patient demographics, surgical factors, complications and quality outcomes were collected utilizing our institution's data warehouse and verified by chart review. RESULTS:In total, 182 SSs were implanted in 168 patients undergoing primary THA. Of these, 5 (2.9%) patients sustained a periprosthetic fracture. Two fractures occurred during the index hospital admission, and 3 occurred in the post-discharge period. Subset analysis demonstrated that 4 (80%) fractures had occurred during the initial learning curve period, within the first 30 surgical cases with a SS. CONCLUSION/CONCLUSIONS:Short-stem hip prostheses are a safe alternative for THA. The results of the present study demonstrate a fracture incidence of 2.9% among patients. However, surgeons should remain cautious when utilizing new implant system and expect a learning curve. In this study, 80% of periprosthetic fractures following SS THA occurred within the first 30 cases for experienced arthroplasty-trained surgeons.

BACKGROUND:As the clinical and financial environments of total joint arthroplasty (TJA) have evolved over the last several decades so has the role of the surgeon in providing this care to patients. Our objective was to examine current practices and influential factors among fellowship-trained arthroplasty surgeons. METHODS:An electronic survey was sent to all surgeons who had completed one of the three high-volume adult reconstruction fellowships from the years 2007-2016. The survey consisted of 34 questions regarding current practice characteristics, case volumes for primary and revision total hip arthroplasty (THA) and total knee arthroplasty (TKA), use of advanced technologies, choice of surgical approach and implant design, factors influencing their choices, and their involvement in implant selection and contract negotiations. RESULTS:Questionnaires were sent to 53 surgeons; 52 were completed. Sixty percent of respondents performed at least 100 TKAs and 84% performed at least 50 THAs annually. Ninety-four percent use a single company's implant for more than 90% of primary TKA and THA. Fellowship or residency experience was the most significant influence on TKA and THA implant selection for 62% and 45% of surgeons, respectively, while contracts of their current institution were the primary influence for 17% and 12%, respectively. Fifty-five percent of surgeons used some advanced technology of which 16% said this influenced their implant choice. Eighty-six percent perform the majority of cases at centers performing at least 200 TJAs per year, and 39% participate in implant contract negotiations. CONCLUSION/CONCLUSIONS:Despite changes in the economic environment of TJA, this study demonstrates that experience with a specific implant during training, particularly fellowship, is the most influential factor for implant selection among fellowship-trained arthroplasty surgeons.

BACKGROUND:Patients with developmental dysplasia of the hip (DDH) require special surgical considerations for total hip arthroplasty (THA). Despite the difficulties posed by the population's anatomical abnormalities, few large evaluations of postoperative outcomes exist. This study seeks to characterize outcomes following primary THA among patients diagnosed with DDH. METHODS:A retrospective review was conducted at a tertiary care center on all THA patients between June 2011 and March 2018. Inclusion criteria for this study included any patient diagnosed with DDH undergoing primary THA. Baseline information, operative reports, and postoperative outcomes were pulled from the medical record. RESULTS:. Most patients were female (82%). The majority of hips (89%, n = 344) were Crowe type 1, followed by 2 (6.9%, n = 26), 3 (2.6%, n = 10), and 4 (1.3%, n = 5). Most hips were Hartofilakidis Class A (83%, n = 320), followed by Class B (15%, n = 59), then C (1.6%, n = 6). Mean follow-up was 24.8 months. Revision THA was required in 19 (4.9%) cases, with the most common indications being infection (2.1%) and periprosthetic fracture (1.0%). Readmission rates were 1.8% (7 hips) and 2.9% (11 hips) at 30-day and 90-day, respectively. The 30-day and 90-day ED visit rates were 1.3% (5 hips) and 2.1% (8 hips), respectively. No complications were seen following 344 (87%) THAs. CONCLUSION/CONCLUSIONS:Despite their surgical complexity, DDH patients on average have notably low rates of revision and dislocation. Longer follow-up is needed to better assess outcomes after THA in this complex patient population.

Hip dislocation remains a major concern following total hip arthroplasty due to its high frequency and economic burden. This article evaluates the cost-effectiveness regarding dual mobility as an alternative to standard implant designs. A review of literature analyzing the PubMed Central database was undertaken using the following terms in the primary query: dual mobility, cost-effectiveness, cost-analysis, or economic analysis. Dual mobility systems may be a cost-effective alternative when the price of the implant does not exceed the traditional system by $1023. Dual mobility cups may be an essential component for the future success of value-based total hip arthroplasty.

Proper ligament tension in knee flexion within cruciate-retaining (CR) total knee arthroplasty has long been associated with clinical success; however, traditional balancing principles have assumed that the distal femoral joint line (DFJL) affects only extension. The purpose of this study was to determine the effect DFJL may have on ligament strains and tibiofemoral kinematics of CR knee designs in flexion. A computational analysis was performed using a musculoskeletal modeling system for two different knee implants, the high-flex CR (HFCR) and guided-motion CR (GMCR). Tibiofemoral kinematics and ligament strain were measured at 90-degree knee flexion while the implants' DFJL was incrementally shifted proximally. Femoral implant position and kinematics were used to determine the femur's anteroposterior position relative to the tibia. The change in the femoral medial condyle position relative to the tibia was 0.33 mm and 0.53 mm more anterior per each 1-mm elevation of the DFJL for HFCR and GMCR, respectively. The change in the lateral condyle position was 0.20 mm more anterior and 0.06 mm more posterior for HFCR and GMCR, respectively. The strain in the lateral and medial collateral ligaments changed minimally with elevation of the DFJL. In both implants, strain increased in the anterior lateral and posterior medial bundles of the posterior collateral ligament with elevation of the DFJL, whereas strain decreased in the iliotibial band and iliotibial patellar band. Our findings suggest that DFJL affects ligament tension at 90-degree knee flexion and therefore flexion balance for CR implants. Elevating the DFJL to address tight extension space in a CR knee while flexion space is well balanced could result in increased flexion tension especially when the flexion-extension mismatch is large. To achieve balanced flexion and extension, the amount of DFJL elevation may need to be reduced.

BACKGROUND:Advancements in the management of human immunodeficiency virus (HIV) now permit HIV-positive patients to have longer life spans, increasing their cumulative risk of developing an advanced degenerative joint disease, necessitating total hip arthroplasty (THA). The purpose of this study was to provide an extended follow-up on a previously published study on a cohort of HIV-positive THA recipients in an effort to confirm the safety and longevity of THA in this population. METHODS:This study is a follow-up on a previous study comprised of 41 hips in 31 HIV-positive THA recipients. At this follow-up, 5 patients from the original cohort required contralateral THA. Postoperative complications were recorded up to the patient's last follow-up date. A survivorship analysis was performed using the Kaplan-Meier method with revision THA as the end point. RESULTS:Since the last report, 2 additional hips were revised (one for aseptic loosening and one for a periprosthetic fracture), and 5 patients underwent contralateral THA. This resulted in a total of 5 (13.8%) hips requiring revision THA at the latest follow-up. The mean follow-up interval for the original cohort and for the contralateral 5 hips was 78.9 ± 50.2 months and 54.6 ± 45.3 months, respectively. Kaplan-Meier survivorship analysis with revision THA for any reason as the end point demonstrated survivorship of 93% (2 years), 90% (5 years), and 81% (10 and 14 years) after primary THA, respectively. CONCLUSION/CONCLUSIONS:Our study suggests that it is possible to achieve a low incidence of postoperative infection in HIV-positive THA recipients. In addition, our study demonstrates that non-hemophiliac HIV-positive patients have comparable revision rates to previously published reports on HIV-negative patients of similar age, underscoring the clinical efficacy of highly active antiretroviral therapy.

BACKGROUND:Although preoperative risk assessment tools have been effective in predicting discharge disposition after total joint arthroplasty (TJA), studies reporting on discharge planning in extended length of stay (ELOS), >3 days, patients are lacking. The purpose of this study was to describe the predictive utility of the Risk Assessment and Prediction Tool (RAPT) for discharge disposition in ELOS patients. METHODS:Our study included 260 patients with LOS >3 days who underwent primary TJA between 2014 and 2016. Patients were separated into 3 cohorts, based on their RAPT score: low risk (9-12), medium risk (6-9), and high risk for discharge to a facility (1-6). Scores were compared among cohorts and correlated with discharge disposition for patients who stayed beyond 3 days. RESULTS:In ELOS, RAPT had a higher utility in predicting discharge disposition in the low-risk (76.5% to home) and high-risk (62.9% to facility) patient cohorts, while medium-risk patients (56.5% to home) were the least accurate. Responses that significantly correlated with discharge home included male gender (odds ratio [OR], 1.81; P < .05), ambulation without walking aids (OR, 2.94; P < .01) or a single-point cane (OR, 2.95; P < .0001), <1 community support visit per week preoperatively (OR, 1.86; P < .05), and having support from someone at home (OR, 3.43; P < .0001). CONCLUSION/CONCLUSIONS:The RAPT score in ELOS patients is better correlated with the low-risk and high-risk cohorts than in medium-risk patients. Conversely, medium-risk ELOS patients constituted 56.8% of our sample size, but only predicted 56.5% of discharge dispositions correctly. Future discharge disposition risk assessment tools are needed to stratify medium-risk patients.