Perilunate Dislocations: Cadaveric Model K-Wire Versus Compression Staple Fixation.

Purpose: Repair of perilunate dislocations requires stabilization of the carpal bones, although there is limited research on the preferred method(s) of stabilization. We compared the biomechanical characteristics of K-wire versus staple fixation of scapholunate (SL) and lunotriquetral (LT) intervals in the wrist. Methods: After creating a grade IV instability model, 20 cadaver wrists were randomized into 2 stabilization model groups using K-wires or surgical staples across the SL and LT intervals. For each ligament, two K-wires or one surgical staple was used to stabilize the proximal carpal row. Each wrist was loaded with 15 N of force and cycled 5,000 times at an angular velocity of 10 rpm. Displacement between bones was measured at different cycles (10, 100, 500, 1,000, 2,000, 3,000, 4,000, and 5,000). A t test was used for comparisons. Results: For the LT K-wire group, the average displacement at 10 cycles was 0.08 mm, and at 5,000 cycles, 0.163 mm. For the SL K-wire group, the average displacement at 10 cycles was 0.025 mm, and at 5,000 cycles, 0.129 mm. For the LT and SL staple fixation models, the average shifts at 10 cycles were 0.029 and 0.063 mm, and at 5,000 cycles, 0.098 and 0.176 mm, respectively. No significant difference between the fixation models was found at any interval. Notably, in each group, a similar number of small outliers with higher amounts of displacement was observed. Conclusions: Either K-wire or surgical staple stabilization is suitable for perilunate dislocations. The surgical method should be selected based on patient-specific circumstances and the provider's judgment. Type of study/level of evidence: Therapeutic III.

Distal Upper Extremity Arterial Calcification as a Predictor for Subclinical Coronary Artery Disease by Coronary Artery Calcium Scoring.

Several studies have linked calcification of the thoracic and lower extremity arterial trunks to an increased risk of developing coronary artery disease (CAD). Calcifications of the radial and/or ulnar artery are regularly identified in hand/wrist x-rays; however, the clinical relevance of these findings as related to identifying subclinical CAD is not well understood. Associations between CAD and upper extremity calcifications have been reported, but the timeline is unclear. The purpose of this study was to evaluate the association between upper extremity arterial calcifications on hand radiographs with CAD by coronary artery calcification (CAC) scoring in patients with no known history of CAD. This is a pilot single-center, prospective, matched cohort study. We included patients with no known history of CAD, related symptoms, or major risk factors. We recruited five patients with calcifications (cal+) and five patients matched by age, race, sex, and medical history but without calcifications (cal-). CAC scores were determined from computed tomography scanning, and lipid profile was evaluated. In the cal+ group, the mean CAC total score was 244.1; in the control (cal-) group, it was 85.2. The mean total cholesterol levels were 220.8 mg per dL and 167 mg per dL in the cal+ and cal- groups, respectively. Two cal+ patients with CAC scores of 937 and 669 died shortly after being enrolled in our study. Preliminary findings suggest that calcifications in the radial or ulnar artery in otherwise asymptomatic patients with no history of CAD may be an independent sign of CAD.

Antibiotic Prophylaxis in the Management of Distal Fingertip Amputation and Crush Injury.

Purpose: We sought to investigate the role of prophylactic antibiotics for distal fingertip crush injury or transphalangeal amputation treated outside of an operating room and better understand the factors that contribute to antibiotic-prescribing decisions. We hypothesized that prophylactic antibiotics do not meaningfully reduce the incidence of infection and that antibiotics are prescribed in a predictable way. Methods: This is a retrospective review of all patients treated in a MedStar-affiliated emergency department or urgent care for nonsurgical distal fingertip trauma in 2019. Patient demographics, comorbidities, injury characteristics, interventions, and follow-up details were recorded. Exclusion criteria included signs of infection at the time of presentation, minor injuries not requiring intervention, bite wounds, one-time intravenous antibiotic administration without oral course, and surgical intervention. Outcomes included infection and interventions at follow-up. Chi-square analysis was performed, comparing antibiotic and no-antibiotic groups. A stepwise binomial regression was used to evaluate for variables predictive of antibiotic prescription. Results: We identified eight infections in 323 patients included in the study (2.5% incidence of infection). There was no statistically significant difference in the incidence of infection between patients treated with antibiotics (2.7%) and those who did not receive antibiotics (2.2%). However, due to the low incidence of infections, we were likely underpowered for this analysis. We also created a model to predict antibiotic prescribing, which achieved an area under the receiver operating characteristic curve of 0.86 (P < .0001) based on age, bleeding disorders, depressive disorders, open wound status, amputation, fractures, and encounter type. Conclusions: The low incidence of infection (2.5%) and lack of a meaningful difference between the groups call into question prophylactic antibiotic prescribing after these distal fingertip injuries. Our model does predict provider prescribing habits, identifying areas for potential practice pattern change. Type of study/level of evidence: Therapeutic III.

Performance of Near-Infrared Spectroscopy in Detecting Acute Tourniquet-Induced Upper-Extremity Ischemia Across Different Skin Phenotypes.

PURPOSE: Diagnosing acute tissue ischemia is challenging, particularly in patients with higher skin melanin content. We investigated whether near-infrared spectroscopy (NIRS) is effective and consistent in detecting upper extremity ischemia across various skin phenotypes. METHODS: Volunteers underwent tourniquet-induced upper extremity ischemia. Skin color was evaluated by the Fitzpatrick scale (FP, range: I-VI) and the Von Luschan scale (vL, range: 1-36). A NIRS probe was placed on one finger. The tourniquet was inflated to 250 mmHg and perfusion was restricted for 7 minutes, followed by a 10-minute monitored reperfusion period. The percent tissue oxygenation (StO2) was recorded. RESULTS: A total of 55 volunteers were enrolled (22 self-identified as Caucasian, 21 African American, 7 Asian, 2 Latinx, and 2 Biracial). Average starting and ending StO2 for the cohort was 72.2% and 45.9%, respectively. However, there was variability based on skin melanin content. Increasing vL correlated with lower starting StO2, smaller StO2 decrease, and shorter time to reach ischemic steady state. High skin melanin (FP scale IV-VI) was associated with significantly lower starting StO2 (-7.1%) and shorter time to reach ischemic steady state (-0.3 mins). African Americans had lower starting StO2 (-8.6%) and 7.8% lesser total StO2 decrease than other groups. CONCLUSIONS: NIRS can rapidly detect acute onset tissue ischemia in the upper extremity. However, given the lower starting StO2 and smaller total StO2 decrease after tourniquet-induced ischemia for patients with higher skin melanin, using NIRS for clinical detection of acute ischemia may be more challenging in these patients. These inconsistencies may limit use of NIRS clinically for spot identification of ischemia. CLINICAL RELEVANCE: Although NIRS has utility in tracking tissue oxygenation, variable performance with different skin melanin content raises concerns as to whether different cutoff/threshold levels are needed for different groups, and whether NIRS is reliable for spot checks in acute events.