Radiographic Assessment of Total Knee Arthroplasty Alignment With and Without Accelerometer-Based Navigation at a Resident Training Institution.

Malalignment and lack of surgeon experience are cited as risk factors for prosthetic failure and the need for subsequent revision surgery in total knee arthroplasty (TKA). Various conventional (CON) and computer-assisted surgical (CAS) methods have been developed to try and prevent malalignment and limit outliers. One of these methods is through an accelerometer-based CAS (aCAS), which intraoperatively helps determine the angulation and amount of resection necessary to restore alignment in TKA.

Operative Efficiency in Military Total Joint Arthroplasty Is Superior at an External Resource Sharing Agreement Facility as Compared to a Military Treatment Facility.

Introduction: Surgeries within the Military Health System (MHS) are often performed by military physicians at External Resource Sharing Agreement (ERSA) hospitals to offload the operative demand at Military Treatment Facilities (MTFs). These agreements allow physicians flexibility in selecting where to treat military service members and other TRICARE beneficiaries. However, there is a paucity of military orthopedic literature comparing ERSA hospitals and MTFs.

Stress Radiograph Confirmation of Translational Instability After Cruciate-Retaining Total Knee Arthroplasty.

Introduction: Late rupture of the posterior cruciate ligament (PCL) in cruciate-retaining total knee arthroplasty (TKA) can lead to increased AP instability. This results in increased stress on the medial hamstrings resulting in hamstring-based pain. We looked to identify patients with late PCL failure using a lateral stress radiograph.

Biomechanics and Outcomes of Modern Tibial Polyethylene Inserts.

Purpose Of Review: There have been many attempts to use variations in tibial polyethylene design to better recreate normal knee kinematics in the total knee arthroplasty. The goal of this review is to provide an overview of the various types of tibial inserts that exist and review the theoretical mechanics versus what was demonstrated in vivo.

Recent Findings: Many polyethylene inserts have been attempted to re-create normal knee kinematics, but none have been able to successfully do so.

Bioburden Increases Heterotopic Ossification Formation in an Established Rat Model.

Background: Heterotopic ossification (HO) develops in a majority of combat-related amputations wherein early bacterial colonization has been considered a potential early risk factor. Our group has recently developed a small animal model of trauma-induced HO that incorporates many of the multifaceted injury patterns of combat trauma in the absence of bacterial contamination and subsequent wound colonization.

Questions/purposes: We sought to determine if (1) the presence of bioburden (Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus [MRSA]) increases the magnitude of ectopic bone formation in traumatized muscle after amputation; and (2) what persistent effects bacterial contamination has on late microbial flora within the amputation site.

Early Characterization of Blast-related Heterotopic Ossification in a Rat Model.

Background: Heterotopic ossification (HO) affects the majority of combat-related lower extremity wounds involving severe fracture and amputation. Defining the timing of early osteogenic-related genes may help identify candidate prophylactic agents and guide the timing of prophylactic therapy after blast and other combat-related extremity injuries.

Questions/purposes: Using a recently developed animal model of combat-related HO, we sought to determine (1) the timing of early chondrogenesis, cartilage formation, and radiographic ectopic bone development; and (2) the early cartilage and bone-related gene and protein patterns in traumatized soft tissue.