The purpose of this study was to assess mid-term survivorship following primary total knee arthroplasty (TKA) with Optetrak Logic components and identify the most common revision indications at a single institution. We identified a retrospective cohort of 7,941 Optetrak primary TKAs performed from January 2010 to December 2018. We reviewed the intraoperative findings of 369 TKAs that required revision TKA from January 2010 to December 2021 and the details of the revision implants used. Kaplan-Meier analysis was used to determine survivorship. Cox regression analysis was used to examine the impact of patient variables and year of implantation on survival time.Aims
Methods
Many patients undergoing total knee arthroplasty (TKA) have severe osteoarthritis (OA) in both knees and may consider either simultaneous or staged bilateral TKA. The implications of simultaneous versus staged bilateral TKA for return to work are not well understood. We hypothesized that employed patients who underwent simultaneous bilateral TKA would have significantly fewer days missed from work compared with the sum of days missed from each operation for patients who underwent staged bilateral TKA. The prospective arthroplasty registry at the Hospital for Special Surgery was used. Baseline characteristics and patient-reported outcome scores were evaluated. We used a linear regression model, adjusting for potential confounding variables including age, sex, preoperative BMI, and type of work (sedentary, moderate, high activity, or strenuous), to analyze time lost from work after simultaneous compared with staged bilateral TKA.Aims
Methods
A large proportion of patients undergoing total knee arthroplasty (TKA) have severe osteoarthritis in both knees and may consider either simultaneous or staged bilateral TKA. The implications of staged versus simultaneously bilateral TKA for return to work are not well understood. We hypothesized that employed patients who underwent simultaneous bilateral TKA would have significantly fewer days missed from work compared to the sum of days missed from each surgery for patients who underwent staged bilateral TKA. The prospective arthroplasty registry at Hospital for Special Surgery was utilized. We identified 61 employed patients who had undergone staged bilateral TKA and 152 employed patients who had undergone simultaneous bilateral TKA and had completed the registry's return to work questionnaire. Baseline characteristics and patient reported outcome scores were evaluated. We used a linear regression model, adjusting for potential confounders including age, sex, pre-op BMI, and work type (sedentary, moderate, high activity, or strenuous), to analyze workdays lost after staged versus simultaneous bilateral TKA.Introduction
Methods
Primary total knee arthroplasties (TKA) performed in younger patients raise concerns regarding the potential for accelerated polyethylene wear, aseptic loosening, and thus revision TKA at a younger age. The purpose of this study was to determine the long-term implant survivorship, functional outcomes, and pain relief of primary TKA performed in patients under 35 years of age. A retrospective review of our institutional registry identified 185 TKAs performed in 119 patients under the age of 35 between 1985 and 2010. Medical records and radiographs were reviewed. Patients were contacted for two serial questionnaires in 2011–2012 and again in 2018. Implant survivorship was calculated using Kaplan-Meier survivorship curves and Cox proportional hazard model. The median age was 26.1 (21.5–30.1) years, with a BMI of 23.5 (20.4–26.6) kg/m2. Median follow-up was 13.9 (8.5–19.8) years.Introduction
Methods
Total knee arthroplasty (TKA) is a successful treatment for degenerative end stage knee arthritis. Younger patients who undergo TKA may face multiple revisions during their lifetime due to aseptic loosening, infection, and instability. The purpose of this study was to compare the early complication rates and revision free survivorship between age groups undergoing TKA in a nationwide database. The PearlDiver national insurance database was queried from 2007–2015 for all patients who underwent primary TKA. Kaplan-Meier Curve survival analysis and log rank test were performed to evaluate revision rates between age groups (<40, 40–49, 50–59, 60–69, 70–79, 80–89, and ≥90 years). Complication rates were compared to rates in the age 60–79 group using multiple logistic regressions controlling for baseline demographics and comorbidities.Introduction
Methods
Conventional, extramedullary (EM) tibial alignment guides are only 65%–88% accurate in creating a tibial resection within 2° of perpendicular to the tibial mechanical axis in total knee arthroplasty (TKA). The purpose of this study was to compare the overall, tibial component alignment, and the surgeon's ability to achieve a specific, intraoperative goal for alignment between a portable, navigation system (KneeAlign™) and conventional, EM alignment guides. One hundred patients were enrolled in a prospective, randomized controlled study. Fifty patients received a TKA using the KneeAlign™ to perform the tibial resection, and 50 patients an EM alignment guide. Standing AP hip-to-ankle radiographs and lateral knee-to-ankle radiographs were obtained at the first, postoperative visit.Background:
Methods:
Implant designs for hip and knee arthroplasty have undergone a continual improvement process, but development of implants for total elbow arthroplasty (TEA) have lagged behind despite the marked mechanical burden placed on these implants. TEA is not as durable with failure rates approaching thirty percent at five years. The Coonrad-Morrey (Zimmer, Warsaw, IN), a linked design, remains the standard-bearer, employing polyethylene bushings through which a metal axle passes. A common failure mode is bushing wear and deformation, causing decreased joint function as the bushing-axle constraint decreases and osteolysis secondary to release of large volumes of wear debris. Improving upon this poor performance requires determining which factors most influence failure, so that failure can be avoided through design improvements. The approach integrates clinical observations of failed TEAs with implant retrieval analysis, followed by measurements of loads across the elbow for use in stress analyses to assess the performance of previous designs, and, finally, new design approaches to improve performance. Examination of the clinical failures of more than seventy Coonrad-Morrey TEAs revealed patterns of decreased constraint and stem loosening. Implant retrieval analysis from more than thirty of these cases showed excessive bushing deformation and wear and burnishing of the fixation stems consistent with varus moments across the joint. To determine loads across the elbow, motion analysis data were collected from eight TEA patients performing various activities of daily living. The kinematic data were input into a computational model to calculate contact forces on the total elbow replacement. The motion that produced the maximum contact force was a feeding motion with the humerus in 90° of abduction. For this motion, the joint reaction forces and moments at the point of maximum contact were determined from a computational model. We applied these loads to numerical models of the articulating bushings and axle of the Coonrad-Morrey to examine polyethylene strains as measures of damage and wear. Strain patterns in response to the large varus moment applied to the elbow during feeding activities showed extensive plastic deformation in the locations at which deformation and wear damage were observed in our retrieved implants (Fig. 1). Finally, we examined a new semi-constrained design concept intended to meet two goals: transfer contact loads away from the center of the joint, thus allowing contact to provide a larger internal moment to resist the large external varus moment; and reduce polyethylene strains by utilizing curved contacting surfaces on both the axle and the bushings (Fig. 2). After a sensitivity analysis to determine optimal dimensional choices (e.g., bushing and axle radii), we compared the resulting polyethylene strains between the Coonrad-Morrey and new design at locations that experienced the largest strains (Fig. 3). Substantial decreases were achieved, suggesting far less deformation and wear, which should relate to marked improvements in performance. Currently, we are incorporating this new design concept, along with alterations in stem design achieved from examination of load transfer at the fixation interfaces based on the same loading conditions, to achieve an implant system intended to improve the performance of TEA.
Blood loss during total knee replacement (TKR)
remains a significant concern. In this study, 114 patients underwent TKR,
and were divided into two groups based on whether they received
a new generation fibrin sealant intra-operatively, or a local infiltration
containing adrenaline. Groups were then compared for mean calculated
total blood volume (TBV) loss, transfusion rates, and knee range
of movement. Mean TBV loss was similar between groups: fibrin sealant
mean was 705 ml (281 to 1744), local adrenaline mean was 712 ml
(261 to 2308) (p = 0.929). Overall, significantly fewer units of
blood were transfused in the fibrin sealant group (seven units)
compared with the local adrenaline group (15 units) (p = 0.0479).
Per patient transfused, significantly fewer units of blood were transfused
in the fibrin sealant group (1.0 units) compared with the local
adrenaline group (1.67 units) (p = 0.027), suggesting that the fibrin
sealant may reduce the need for multiple unit transfusions. Knee
range of movement was similar between groups. From our results,
it appears that application of this newer fibrin sealant results
in blood loss and transfusion rates that are low and similar to
previously applied fibrin sealants. Cite this article:
