A Possible Case of COVID-19 Booster Vaccine-Associated Rhabdomyolysis and Acute Kidney Injury.

Background: Nearly 10 billion doses of the various messenger ribonucleic acid (mRNA) and viral vector vaccines against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have been administered worldwide. Adverse drug reactions (ADRs) have been overwhelmingly mild to moderate in nature. Rare side effects have included myocarditis/pericarditis, thrombosis with thrombocytopenia syndrome (TTS), Guillain-Barré Syndrome (GBS), and death. However, vaccine-related ADR data are still being collected using a variety of reporting systems. Purpose: We will describe a case of suspected mRNA coronavirus disease 2019 (COVID-19) booster-related rhabdomyolysis in a woman who developed signs and symptoms 10 days after administration of the vaccine dose. With a Naranjo ADR probability score of 4, the vaccine was deemed to be a possible cause of our patient's rhabdomyolysis. Methods: A search of the VAERS (Vaccine Adverse Event Reporting System) mined in November 2021 revealed 386 reported cases of COVID-19 vaccine-related rhabdomyolysis. However, system limitations make the utility of the information problematic. Conclusions: It is vitally important that clinicians, scientists, and patients are aware of rhabdomyolysis as a potential side effect of vaccination. Suspected vaccine-related ADRs should be promptly and accurately reported via VAERS or other surveillance systems to support the ongoing effort to ensure vaccine safety.

Extreme oceanographic forcing and coastal response due to the 2015-2016 El Niño.

The El Niño-Southern Oscillation is the dominant mode of interannual climate variability across the Pacific Ocean basin, with influence on the global climate. The two end members of the cycle, El Niño and La Niña, force anomalous oceanographic conditions and coastal response along the Pacific margin, exposing many heavily populated regions to increased coastal flooding and erosion hazards. However, a quantitative record of coastal impacts is spatially limited and temporally restricted to only the most recent events. Here we report on the oceanographic forcing and coastal response of the 2015-2016 El Niño, one of the strongest of the last 145 years. We show that winter wave energy equalled or exceeded measured historical maxima across the US West Coast, corresponding to anomalously large beach erosion across the region. Shorelines in many areas retreated beyond previously measured landward extremes, particularly along the sediment-starved California coast.

Kinematic analysis of a posterior cruciate retaining mobile-bearing total knee arthroplasty.

Using video fluoroscopy, 10 subjects having a mobile-bearing posterior cruciate-retaining total knee arthroplasty were analyzed to determine their in vivo kinematic patterns. Under weight-bearing conditions, while in extension, the average contact position was posterior to the mid-tibia sagittal plane with posterior translation of both condyles to 60 degrees of flexion, followed by anterior translation to 120 degrees of flexion. Under non-weight-bearing conditions, the average condylar contact positions were significantly more anterior from full extension to 90 degrees of knee flexion (P=.01). The average range of motion was 129 degrees under non-weight-bearing conditions and 119 degrees during weight-bearing. Although subjects in this study exhibited variable motion patterns, they are accommodated by the unconstrained optimized articulation of this highly conforming mobile-bearing implant.

In vivo determination of posterior femoral rollback for subjects having a NexGen posterior cruciate-retaining total knee arthroplasty.

This study determines the in vivo kinematics during a deep-knee bend activity for subjects implanted with a posterior cruciate-retaining total knee arthroplasty having asymmetric geometries. Of 20 subjects, 19 experienced posterior femoral rollback (PFR) of the lateral condyle (average -3.9 mm), and 13 subjects experienced PFR of the medial condyle (average -3.1 mm). As a result of the lateral condyle rolling further posterior than the medial condyle, on average, subjects experienced 1.4 degrees of normal axial rotation. Of 20 subjects, 10 experienced normal axial rotation, whereas 10 experienced an opposite rotation pattern. Condylar lift-off occurred predominantly with the lateral condyle. Contrary to previous in vivo studies, the subjects in this study experienced consistent PFR of the posterior cruciate-retaining total knee arthroplasty. It can be hypothesized that having asymmetric femoral condyles may lead to PFR with increasing knee flexion.

In vivo determination of knee kinematics for subjects implanted with a unicompartmental arthroplasty.

Femorotibial contact positions for 20 subjects implanted with a unicompartmental knee arthroplasty (UKA) were analyzed using videofluoroscopy. Femorotibial contact paths were determined using a computer-automated model-fitting technique. Subjects having a medial UKA experienced on average -0.8 mm of posterior femoral rollback, whereas subjects having a lateral UKA experienced -2.5 mm of posterior femoral rollback. Twelve of 17 subjects having a medial UKA and 2 of 3 subjects having a lateral UKA experienced normal axial rotation (average, 3.3 degrees and 11.2 degrees ). The results for some subjects suggest that the anterior cruciate ligament was unable to thrust the femur anteriorly at full extension. These results support the findings that the anterior cruciate ligament plays a significant role in knee kinematics, which may contribute to UKA longevity.

In vivo kinematics for subjects with and without an anterior cruciate ligament.

The objective of the current study was to compare kinematic patterns of anterior cruciate retaining total knee arthroplasty and posterior stabilized total knee arthroplasty. Fifteen patients received an anterior cruciate retaining total knee arthroplasty and 15 received a posterior stabilized total knee arthroplasty. All total knee arthroplasties were clinically successful (Hospital for Special Surgery score > 90). Each patient was examined during level walking using fluoroscopy. Femorotibial contact paths for the medial and lateral condyles were determined using a computer automated model-fitting technique. Ten of 15 (67%) patients receiving an anterior cruciate retaining total knee arthroplasty and 12 of 15 patients (80%) receiving a posterior stabilized total knee arthroplasty experienced anterior contact at some phase of the gait cycle. Anterior contact in anterior cruciate retaining total knee arthroplasty can be attributed to the presence of the anterior cruciate ligament, resisting the anterior tibial shear forces during gait. The reason for anterior contact observed in posterior stabilized total knee arthroplasty is unclear, possibly related to the sagittal topography (dwell-point position) of the tibial component. Increased axial rotation was seen in anterior cruciate retaining total knee arthroplasty possibly because of the preservation of the four-bar linkage within the knee. Patients receiving an anterior cruciate retaining total knee arthroplasty experienced kinematic patterns more similar to the normal knee.

Correlation between condylar lift-off and femoral component alignment.

The current study analyzed subjects having a total knee arthroplasty to determine the incidence of condylar lift-off and correlate lift-off with the alignment of the femoral component with respect to the transepicondylar axis. Twenty-five subjects, implanted with a posterior stabilized total knee prosthesis, were asked to do weightbearing deep knee bends while under fluoroscopic surveillance. The two-dimensional fluoroscopic images were converted into three-dimensional images using a fully automated computer model-fitting technique. Each subject then was assessed for the incidence of condylar lift-off. The five subjects having the maximum amount of lift-off were reanalyzed for comparison using computed tomography. Using digitization, the angle between the posterior femoral condylar line and the transepicondylar axis was measured and correlated with the presence of femoral condylar lift-off. The incidence of condylar lift-off was significantly less for subjects in this study compared with subjects reported in previous fluoroscopic studies. Forty percent (10 of 25) of the subjects experienced condylar lift-off. The maximum amount of lift-off was 2.3 mm and the average for subjects experiencing lift-off was 1.4 mm. There also was a distinct correlation between femoral component alignment and condylar lift-off. Using computed tomography, it was determined that 69.2% of the subjects had a correlation between condylar lift-off and malalignment of the femoral component relative to the epicondylar axis. Placement of the femoral component parallel to the transepicondylar axis seems to lessen the incidence of femoral condylar lift-off and may reduce polyethylene wear by reducing eccentric edge loading.

Kinematic comparison of posterior cruciate sacrifice versus substitution in a mobile bearing total knee arthroplasty.

Interest in mobile bearing total knee arthroplasty (TKA) has increased significantly. The objective of this in vivo study was to analyze 2 different mobile bearing TKAs during gait and during a knee bend from 0 degrees to 90 degrees flexion. Femorotibial contact positions for 10 subjects, implanted by a single surgeon, were analyzed using videofluoroscopy. Five subjects were implanted with a posterior-stabilized mobile bearing TKA (PS), and 5 subjects were implanted with a posterior cruciate-sacrificing mobile bearing TKA (PCS). Each subject, while under fluoroscopic surveillance, performed 2 weight-bearing activities: i) normal gait and ii) deep-knee bend. This study showed that the kinematic patterns for subjects having either a PS or PCS mobile bearing TKA were similar during gait but different during a deep-knee bend. Subjects having a PS TKA experienced more posterior femoral rollback of the lateral condyle during the deep-knee bend. Findings of kinematic similarities in gait and differences in a deep-knee bend between these 2 mobile bearing designs are similar to previously published findings of fixed bearing posterior cruciate-retaining and PS TKA.

In vivo comparison of femorotibial contact positions for press-fit posterior stabilized and posterior cruciate-retaining total knee arthroplasties.

The objective of this study was to determine the in vivo medial and lateral femorotibial condyle contact positions for 20 subjects having either a posterior cruciate-retaining (PCR) or posterior-stabilized (PS) total knee arthroplasty (TKA) while sitting and kneeling. The two-dimensional radiographic images were converted into three-dimensional images using an iterative computer model-fitting technique. Anteroposterior contact positions, axial rotation, and condylar lift-off were assessed for each subject. In a seated position, the femorotibial contact points were, on average, posterior for both TKA groups (PCR: medial = -2.4 mm, lateral = -3.4 mm; PS: medial = -5.1 mm, lateral = -8.9 mm; medial, P=.21; lateral, P=.08). In a kneeling position, the contact position shifted anteriorly for the PCR TKA group (medial = 0.9 mm, lateral = -0.8 mm), whereas the contact positions in the PS TKA group remained posterior (medial = -5.6 mm, lateral = -8.3 mm; medial, P=.002; lateral, P=.0004). It is hypothesized that while in a kneeling position, the posterior cruciate ligament has less resistance to the anterior thrust of the femur relative to the tibia than in a PS TKA, in which this force is absorbed in the cam-and-post mechanism.

Motion of a mobile bearing knee allowing translation and rotation.

The kinematics of a mobile bearing knee, which allowed +/-20 degrees of rotation and 4.5 mm of anteroposterior translation, was measured for ascending and descending a step, deep-knee bend, normal walking, and twisting. A fluoroscopic technique was used, analyzed by 2 different methods. The rotations and displacements during the activities were similar to those of moderate-to-high constrained fixed bearing knees. The motion patterns were variable among test subjects and in general did not reproduce normal knee motion. Because of the freedom of anteroposterior translation and rotation in the design, however, each knee could determine its own neutral position and its own axis of internal-external rotation, depending on the activity.