Sex differences in guideline-consistent diagnostic testing for acute pulmonary embolism among adult emergency department patients aged 18-49.

BACKGROUND: Pulmonary embolism (PE) is a frequent diagnostic consideration in emergency department (ED) patients, yet diagnosis is challenging because symptoms of PE are nonspecific. Guidelines recommend the use of clinical decision tools to increase efficiency and avoid harms from overtesting, including D-dimer screening in patients not at high risk for PE. Women undergo testing for PE more often than men yet have a lower yield from testing. Our study objective was to determine whether patient sex influenced the odds of received guideline-consistent care. METHODS: We performed a retrospective cohort study at two large U.S. academic EDs from January 1, 2016, to December 31, 2018. Nonpregnant patients aged 18-49 years were included if they presented with chest pain, shortness of breath, hemoptysis, or syncope and underwent testing for PE with D-dimer or imaging. Demographic and clinical data were exported from the electronic medical record (EMR). Pretest risk scores were calculated using manually abstracted EMR data. Diagnostic testing was then compared with recommended testing based on pretest risk. The primary outcome was receipt of guideline-consistent care, which required an elevated screening D-dimer prior to imaging in all non-high-risk patients. RESULTS: We studied 1991 discrete patient encounters; 37% (735) of patients were male and 63% (1256) were female. Baseline characteristics, including revised Geneva scores, were similar between sexes. Female patients were more likely to receive guideline-consistent care (70% [874/1256] female vs. 63% [463/735] male, p < 0.01) and less likely to be diagnosed with PE (3.1% [39/1256] female vs. 5.3% [39/735] male, p < 0.05). The most common guideline deviation in both sexes was obtaining imaging without a screening D-dimer in a non-high-risk patient (75% [287/382] female vs. 75% [205/272] male). CONCLUSIONS: In this cohort, females were more likely than males to receive care consistent with current guidelines and less likely to be diagnosed with PE.

Motion and Strength Analysis of 2-Tine Staple and K-Wire Fixation in Scapholunate Ligament Stabilization in a Cadaver Model.

Purpose: Previous studies have demonstrated the benefits of 2- and 4-tine staple fixation in scapholunate interosseous ligament (SLIL) reconstruction, including improved rotational control and avoidance of the articular surface. This study compared scaphoid and lunate kinematics after SLIL fixation with traditional Kirschner wire (K-wire) fixation or 2-tine staple fixation. Methods: Eight fresh frozen cadaver arms with normal scapholunate (SL) intervals were included. Infrared motion capture was used to assess kinematics between the scaphoid and lunate as the wrists were moved through a simulated dart-throw motion. Kinematic data were recorded for each wrist in 4 states: SLIL intact, SLIL sectioned, K-wire fixation across SL interval and scaphocapitate joint, and 2-tine Nitinol staple fixation across SL interval. Strength of the SL staple fixation was evaluated using an axial load machine to assess load to failure of the staple construct. Results: Range of motion of the scaphoid and lunate with SLIL intact and SLIL sectioned were similar. K-wire fixation across the SL interval significantly decreased the overall wrist range of motion as well as scaphoid and lunate motion in all planes except for scaphoid flexion. Conversely, scaphoid and lunate motion after staple fixation was similar to that in normal wrists, except for a significant decrease in scaphoid extension. Under axial load simulating a ground-level fall, 3 of 8 arms demonstrated no failure, and none of the failures was due to direct failure of the 2-tine staple. Conclusions: This study demonstrates 2-tine staple fixation across the SL interval is effective in providing initial stability and maintaining physiologic motion of the scaphoid and lunate compared with K-wire fixation after SLIL injury. Clinical relevance: This study demonstrates an alternate technique for the stabilization of the SL interval in repair of acute SLIL injuries using 2-tine staple fixation, which maintains near physiologic motion of the scaphoid and lunate after SLIL injury.

Analysis and Modeling of Rat Gait Biomechanical Deficits in Response to Volumetric Muscle Loss Injury.

There is currently a substantial volume of research underway to develop more effective approaches for the regeneration of functional muscle tissue as treatment for volumetric muscle loss (VML) injury, but few studies have evaluated the relationship between injury and the biomechanics required for normal function. To address this knowledge gap, the goal of this study was to develop a novel method to quantify the changes in gait of rats with tibialis anterior (TA) VML injuries. This method should be sensitive enough to identify biomechanical and kinematic changes in response to injury as well as during recovery. Control rats and rats with surgically-created VML injuries were affixed with motion capture markers on the bony landmarks of the back and hindlimb and were recorded walking on a treadmill both prior to and post-surgery. Data collected from the motion capture system was exported for post-hoc analysis in OpenSim and Matlab. In vivo force testing indicated that the VML injury was associated with a significant deficit in force generation ability. Analysis of joint kinematics showed significant differences at all three post-surgical timepoints and gait cycle phase shifting, indicating augmented gait biomechanics in response to VML injury. In conclusion, this method identifies and quantifies key differences in the gait biomechanics and joint kinematics of rats with VML injuries and allows for analysis of the response to injury and recovery. The comprehensive nature of this method opens the door for future studies into dynamics and musculoskeletal control of injured gait that can inform the development of regenerative technologies focused on the functional metrics that are most relevant to recovery from VML injury.

The effects of knee support on the sagittal lower-body joint kinematics and kinetics of deep squats.

Little work has been done to examine the deep squat position (>130° sagittal knee flexion). In baseball and softball, catchers perform this squat an average of 146 times per nine-inning game. To alleviate some of the stress on their knees caused by this repetitive loading, some catchers wear foam knee supports. OBJECTIVES: This work quantifies the effects of knee support on lower-body joint kinematics and kinetics in the deep squat position. METHODS: Subjects in this study performed the deep squat with no support, foam support, and instrumented support. In order to measure the force through the knee support, instrumented knee supports were designed and fabricated. We then developed an inverse dynamic model to incorporate the support loads. From the model, joint angles and moments were calculated for the three conditions. RESULTS: With support there is a significant reduction in the sagittal moment at the knee of 43% on the dominant side and 63% on the non-dominant side compared to without support. These reductions are a result of the foam supports carrying approximately 20% of body weight on each side. CONCLUSION: Knee support reduces the moment necessary to generate the deep squat position common to baseball catchers. Given the short moment arm of the patella femoral tendon, even small changes in moment can have a large effect in the tibial-femoral contact forces, particularly at deep squat angles. Reducing knee forces may be effective in decreasing incidence of osteochondritis dissecans.