Acetabular component malpositioning in total hip arthroplasty increases the risk of dislocations, impingement, and long-term component wear. The purpose of this Sawbones study was to define the efficacy of a novel acetabular imprinting device (AID) with 3D preoperative planning in accurately placing the acetabular component. Four surgeons performed the study on osteoarthritic and dysplastic Sawbone models using 3 different methods for placing the acetabular component (total n = 24). The 3 methods included (1) standard preoperative planning and instrumentation (i.e., standard method), (2) 3D computed tomographic (CT) scan planning and standard instrumentation (i.e., 3D planning method), and (3) 3D CT scan planning combined with an acetabular imprinting device (i.e., AID method). In the AID method, 3D planning software was used to virtually place the acetabular component at 40° of inclination and 22° of anteversion and create a parallel guide pin trajectory. A patient-specific surrogate bone model with a built-in guide pin trajectory was then manufactured as a stereoltihography device (Fig. 1A). The surgeon molded bone cement into the acetabulum imprinting the acetabular features while maintaining the guide pin trajectory (Fig. 1B). Afterward, the AID was removed from the surrogate bone model and placed onto the Sawbone, ensuring a secure fit (Fig. 1C). A guide pin was drilled into the Sawbone along the prescribed trajectory. With the guide pin in place, the surgeon could ream the acetabulum and impact the acetabular component using the guide pin as a visual aid (Fig. 1D). Postoperatively, a CT scan was used to define and compare the actual implant location with the preoperative plan. Statistical analysis was performed as 3 group comparisons using the chi-squared test for categorical data and analysis of variance (ANOVA) for continuous measurements.Background:
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Primary total knee arthroplasty (TKA) is associated with perioperative bleeding, and some patients will require allogenic blood transfusion during their inpatient admission. While blood safety has improved in the last several decades, blood transfusion still carries significant complications and costs. Transfusion indications and alternative methods of blood conservation are being explored. However, there is limited nationally representative data on allogenic blood product utilization among TKA patients, and its associated outcomes and financial burden. The purpose of this study was to use a national administrative database to investigate the trends in utilization and outcomes (i.e. in-hospital mortality, length of stay, admission costs, acute complications) of allogenic blood transfusion in primary TKA patients. The Nationwide Inpatient Sample (NIS), the largest all-payer inpatient care database representing a 20% stratified sample of United States hospitals, was utilized. Primary TKA (ICD-9-CM 81.54) cases from 2000 to 2009 were retrospectively queried (n = 4,544,999; weighted national frequency). A total of 67,841 admissions were excluded (Figure 1). The remaining 4,477,158 cases were separated into two study cohorts: (1) patients transfused with allogenic blood products (red blood cells, platelets, serum) (n = 540,270) and (2) patients not transfused (n = 3,936,888). Multivariable regression and generalized estimating equations were used to examine the effect of transfusion on outcomes, adjusting for patient/hospital characteristics and comorbidity.Introduction:
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