A new mini-navigation tool allows accurate component placement during anterior total hip arthroplasty.

Introduction: Computer-assisted navigation systems have been explored in total hip arthroplasty (THA) to improve component positioning. While these systems traditionally rely on anterior pelvic plane registration, variances in soft tissue thickness overlying anatomical landmarks can lead to registration error, and the supine coronal plane has instead been proposed. The purpose of this study was to evaluate the accuracy of a novel navigation tool, using registration of the anterior pelvic plane or supine coronal plane during simulated anterior THA. Methods: Measurements regarding the acetabular component position, and changes in leg length and offset were recorded. Benchtop phantoms and target measurement values commonly seen in surgery were used for analysis. Measurements for anteversion and inclination, and changes in leg length and offset were recorded by the navigation tool and compared with the known target value of the simulation. Pearson\u27s Results: The device accurately measured cup position and leg length measurements to within 1° and 1 mm of the known target values, respectively. Across all simulations, there was a strong, positive relationship between values obtained by the device and the known target values ( Conclusion: The preliminary findings of this study suggest that the novel navigation tool tested is a potentially viable tool to improve the accuracy of component placement during THA using the anterior approach

The impact of patellar resurfacing in two-stage revision of the infected total knee arthroplasty.

Evidence for optimal management of the patellofemoral joint in revision surgery for the infected TKA is limited. We reviewed 69 infected TKAs undergoing two-stage revision. Fifty four patellae were resurfaced, 11 had patelloplasty performed, two were augmented with trabecular metal, one had impaction grafting, and one knee underwent patellectomy. Average follow-up was 4.5years. The patients that received patellar resurfacing at re-implantation experienced statistically significant improvements in KSS pain score, functional KSS, and patellar score (

Think Twice before Prescribing Antibiotics for That Swollen Knee: The Influence of Antibiotics on the Diagnosis of Periprosthetic Joint Infection.

Periprosthetic joint infection (PJI) is a rare but devastating complication after total joint arthroplasty. An estimated 7-12% of patients have negative cultures despite clear clinical evidence of infection. One oft-cited reason for this occurrence is the administration of antibiotics in the weeks prior to obtaining cultures. This article reviews the influence of antibiotics on the diagnosis of PJI. Specifically, we examine the effect of prophylactic and therapeutic antibiotic administration on the diagnostic accuracy of microbiological cultures as well as serum and synovial biomarkers. We also explore the potential of molecular techniques in overcoming these limitations in patients who have received antibiotics before specimen collection and propose areas for future research

Periprosthetic Knee Infection: Ten Strategies That Work.

Periprosthetic joint infection (PJI) is one of the most serious complications following total knee arthroplasty (TKA). The demand for TKA is rapidly increasing, resulting in a subsequent increase in infections involving knee prosthesis. Despite the existence of common management practices, the best approach for several aspects in the management of periprosthetic knee infection remains controversial. This review examines the current understanding in the management of the following aspects of PJI: preoperative risk stratification, preoperative antibiotics, preoperative skin preparation, outpatient diagnosis, assessing for infection in revision cases, improving culture utility, irrigation and debridement, one and two-stage revision, and patient prognostic information. Moreover, ten strategies for the management of periprosthetic knee infection based on available literature, and experience of the authors were reviewed

Definition of Periprosthetic Joint Infection

Diagnosis of periprosthetic joint infection (PJI) remains challenging as no “gold standard” for diagnosis exists [3]. The challenge is then what test(s) or criterion (ia) can be used to define PJI. In an effort to standardize the definition of PJI, Musculoskeletal Infection Society (MSIS) convened a workgroup in 2011 to issue diagnostic criteria for PJI [1]. The MSIS definition of PJI consists of two major criteria, when the presence of either criterion would indicate PJI, and six minor criteria, when the presence of four or more would indicate PJI

A prospective analysis of glove perforation in primary and revision total hip and total knee arthroplasty.

Literature in regard to glove perforation rates in revision total joint arthroplasty (TJA) is scarce. Our purpose was to determine the incidence of perforation in revision TJA. Gloves from all scrubbed personnel were tested based on the American Society for Testing and Materials. A total of 3863 gloves were collected from 58 primary and 36 revision arthroplasty cases. Surgeons had a 3.7% outer-glove perforation rate in primary TJA compared with 8.9% in revision TJA. When both gloves were perforated, the outer-glove perforation was recognized intraoperatively 100% of the time, and the inner-glove perforation was noted only 19% of the time. The surgeon has the highest rate of glove perforation. Outer-glove perforations should prompt careful inspection of the inner glove

Conversion Total Knee Arthroplasty Needs Its Own Diagnosis Related Group Facility Reimbursement Code

Introduction: Conversion from a prior surgery to a total knee arthroplasty (TKA) is a more technically difficult procedure than primary TKA and is associated with worse short-term outcomes and increased complication and readmission rates, despite being undifferentiated under the current bundled payment model. The aim of this study was to determine differences in facility costs between primary TKA and conversion TKA, which we hypothesize are significant, to ensure providers are not penalized for treatment and high-risk patients have the same access to care. Methods: We retrospectively reviewed a consecutive series of patients undergoing primary TKA at two hospitals within Rothman Orthopaedic Institute from 2015-2017, comparing itemized facility costs between primary and conversion TKA patients. Secondary endpoints included length of stay, discharge disposition, and additional implants used. A multivariate regression analysis was performed to identify independent risk factors for increased facility costs, the need for additional implants, length of stay, and discharge disposition. Results: Of 2447 primary TKA procedures, 678 (27.7%) underwent conversion to TKA, which was associated with greater implant costs ($3424.25 vs. 3272.29, P\u3c0.0001), preoperative personnel costs ($1269.89 vs. $1217.72, p\u3c0.0001), and total costs ($6859.16 vs. $6703.55, p=0.0015). Presence of prior surgical hardware was a risk factor for increased implant costs ($501.1 increase, p=0.0024) and total cost ($501.4 increase, p=0.0024). Discussion: Conversion TKA is associated with significantly greater facility costs than primary TKA, thus confirming our hypothesis, and should be adjusted for in alternative payment models to ensure these patients do not encounter difficulties in accessing quality orthopaedic care

Nanotechnology: current concepts in orthopaedic surgery and future directions.

Nanotechnology is the study, production and controlled manipulation of materials with a grain size \u3c 100 nm. At this level, the laws of classical mechanics fall away and those of quantum mechanics take over, resulting in unique behaviour of matter in terms of melting point, conductivity and reactivity. Additionally, and likely more significant, as grain size decreases, the ratio of surface area to volume drastically increases, allowing for greater interaction between implants and the surrounding cellular environment. This favourable increase in surface area plays an important role in mesenchymal cell differentiation and ultimately bone-implant interactions. Basic science and translational research have revealed important potential applications for nanotechnology in orthopaedic surgery, particularly with regard to improving the interaction between implants and host bone. Nanophase materials more closely match the architecture of native trabecular bone, thereby greatly improving the osseo-integration of orthopaedic implants. Nanophase-coated prostheses can also reduce bacterial adhesion more than conventionally surfaced prostheses. Nanophase selenium has shown great promise when used for tumour reconstructions, as has nanophase silver in the management of traumatic wounds. Nanophase silver may significantly improve healing of peripheral nerve injuries, and nanophase gold has powerful anti-inflammatory effects on tendon inflammation. Considerable advances must be made in our understanding of the potential health risks of production, implantation and wear patterns of nanophase devices before they are approved for clinical use. Their potential, however, is considerable, and is likely to benefit us all in the future. Cite this article: Bone Joint J 2014; 96-B: 569-73

Red Cell Distribution Width: an Unacknowledged Predictor of Mortality and Length of Stay following Revision Arthroplasty

Introduction Red blood cell distribution width (RDW), a measure of variability in size of circulating erythrocytes, is routinely reported in complete blood cell analysis, and together with mean cell volume (MCV) has conventionally been used to distinguish the cause of anemia. It is calculated by (Standard deviation of MCV÷ mean MCV) x 100, with normal range being 11.5%-14.5%. Several recent publications have described RDW as an independent predictor of adverse outcome and mortality in patients with different underlying medical conditions such as acute and chronic heart failure, peripheral artery disease, chronic pulmonary disease and acute kidney injury1. The purposes of this study were 1) to investigate possible relationship between RDW levels and length of stay (LOS) and mortality following revision total joint arthroplasty (TJA), and if that correlation existed, 2) to develop predictive models for LOS and mortality based on preoperative patient-related factors including RDW values

The Use of Cementless Components Does Not Significantly Increase Procedural Costs in Total Knee Arthroplasty

Introduction: Modern cementless total knee arthroplasty (TKA) designs have shown promising early clinical success; however, concerns exist regarding the higher cost of the cementless implants. The purpose of this study is to evaluate the total facility cost of cementless vs traditional cemented TKA along with the effect of cementless fixation on short-term outcomes. Methods: We reviewed a consecutive series of patients between 2015 and 2017 who underwent either cementless or cemented primary TKA. Itemized facility costs were calculated for every procedure using a time-driven activity-based costing algorithm. Controlling for demographic variables and medical comorbidities, we performed a multivariate analysis to identify independent risk factors for facility costs following TKA. Short-term outcome metrics including complications, readmissions, and patient-reported outcomes were compared between groups. Results: Among the 2426 primary TKA patients in this study, 119 (4.91%) were performed using cementless implants. When compared to cemented TKA, cementless TKA patients had higher implant costs, but lower supply costs and lower operating room personnel costs. When controlling for confounding variables, cementless fixation did not have a significant effect on total facility cost or outcomes. Discussion: The use of cementless TKA implants did not significantly increase total procedural costs when compared to traditional cemented TKA components at our institution. Our data suggest that the increased cost of a cementless implant is recouped through savings in cost of cement and supplies, as well as shorter operative times. The authors encourage investigators at other institutions to use the authors\u27 methodology to evaluate (preferably in a prospective manner) whether the findings from this study can be corroborated