Role of Dynamic Stabilizers of the Elbow in Radiocapitellar Joint Alignment: A Prospective In Vivo Study.

PURPOSE: To investigate the effect of dynamic stabilizers of the elbow on radiocapitellar joint alignment, before and after the administration of regional anesthesia. METHODS: At a single institution, 14 patients were prospectively enrolled in a study using a within-subjects control design. Before performing a supraclavicular regional block, 10 fluoroscopic images (1 anteroposterior and 9 lateral views) of the elbow were obtained for each patient. The lateral images were obtained with the forearm in maximal supination, neutral rotation, and maximal pronation, and these forearm positions were repeated for 3 elbow positions: (1) full extension; (2) flexion to 90°, with 0° of shoulder internal rotation; and (3) flexion to 90°, with 90° of shoulder internal rotation. After obtaining the 10 initial images, a block was performed to achieve less than 3/5 motor strength of the imaged extremity, followed by obtaining the same 10 images in each patient. Radiocapitellar ratio, defined as the minimal distance between the right bisector of the radial head and the center of the capitellum divided by the diameter of the capitellum, was measured in each image. RESULTS: The 14 patients had a mean age of 47.8 ± 15.7 years, and 10 (71.4%) patients were women. A difference between radiocapitellar ratios measured before and after the regional block administration was observed for all lateral images (-1.0% ± 7.2% to -2.2% ± 8.0%), although this difference was less than the minimum clinically important difference. CONCLUSIONS: Paralysis of the dynamic stabilizers of the elbow produces a difference in the radiocapitellar joint alignment, but this did not reach the minimum clinically important difference. CLINICAL RELEVANCE: Paralysis of the dynamic stabilizers of the elbow via a supraclavicular nerve block produces no clinically relevant effect on the radiocapitellar alignment of uninjured elbows.

Airborne Exposure of Methyl Methacrylate During Simulated Total Hip Arthroplasty and Fabrication of Antibiotic Beads.

As the use of cement remains prevalent in orthopedic surgery, so do concerns over the safety of its active ingredient, methyl methacrylate (MMA). The Occupational Health and Safety Agency (OSHA) limits the airborne exposure to 100 parts per million (ppm) averaged over an 8 hour period. We measured MMA exposure to operating room personnel during simulated total hip arthroplasty (THA), antibiotic bead fabrication and simulated spill of MMA. Cumulative and peak exposures during simulated THA and antibiotic bead fabrication did not exceed OSHA limits of 100ppm. Vacuum mixing and greater distance from the vapor source reduced measured MMA exposure. Spilled MMA led to prolonged and elevated MMA levels. MMA levels returned to a negligible level in all scenarios by 20 minutes after mixing.

Considerations for Hand Surgery in Patients With Scleroderma.

Systemic sclerosis (scleroderma, SSc) is an autoimmune disease that causes significant dysfunction to multiple organ systems, including the musculoskeletal system. It poses significant challenges to the hand surgeon, including calcinosis, ischemic changes, Raynaud phenomenon, tendinopathies, synovitis, and joint contractures. Patients with SSc also suffer from multiorgan dysfunction, which makes them high-risk surgical patients. The hand surgeon must understand the pathophysiology, treatment strategies, and special operative considerations required in this population to avoid complications and help maintain or improve hand function.

Risk Factors for Loss of Reduction After Open Reduction and Internal Fixation of Isolated Olecranon Fractures in Adults.

BACKGROUND: We sought to determine whether any relevant patient, fracture, surgical, or postoperative characteristics are associated with loss of reduction after plate fixation of isolated olecranon fractures in adults. METHODS: Patients who underwent open reduction and internal fixation of an olecranon fracture at our institution over an 11-year period were analyzed. Electronic patient charts and radiographic images were reviewed to gather patient, fracture, surgical, and postoperative data. Statistical analysis to explore the differences between groups was performed. RESULTS: Seven of 96 patients experienced a loss of fracture reduction diagnosed at a median of 19 days after their initial surgery (range: 4-116 days). The radiographic mode of failure of all patients who lost reduction was proximal migration of the proximal fracture fragment with or without implant failure. The group that lost reduction had a significantly smaller proximal fragment (14.2 vs 18.6 mm), a higher incidence of malreduction with a persistent articular step-off greater than 2 mm (6/7 vs 14/89), a greater distance between the most proximal screw and the olecranon tip (19.8 vs 13.5 mm), a higher proportion of constructs with screws placed outside of the primary plate (4/7 vs 14/89), and a higher proportion of patients that were not immobilized postoperatively (3/7 vs 8/89). CONCLUSIONS: Our results suggest anatomical reduction at the articular surface and adequate fixation of the proximal fragment are key factors in maintenance of reduction, with smaller proximal fragments being at higher risk for failure. A period of postoperative immobilization may decrease the risk of loss of reduction.

What is the role of leukopenia in the assessment of septic arthritis?

Background: It is not well-understood how leukopenia affects the synovial white blood cell (WBC) and percent neutrophils (%PMNs) in the setting of septic arthritis. We sought to determine 1. Do synovial WBC and %PMNs differ between patients with culture positive septic arthritis with or without leukopenia? And 2. Are traditional thresholds of synovial fluid studies for accurately diagnosing septic arthritis still applicable in the leukopenic patient population? Methods: A retrospective cohort study was performed at a single institution of 79 non-leukopenic and 11 leukopenic patients diagnosed with culture-positive septic arthritis. Demographic data, serum laboratory values, synovial laboratory values, and culture results were recorded. Significant differences in synovial laboratory values were evaluated using the Wilcoxon-Mann-Whitney test. Results are reported as median, interquartile range, and p values. Results: There was a significant difference in synovial WBC in leukopenic patients compared to non-leukopenic patients with culture positive septic arthritis (p = 0.01). No significant difference was found in the synovial %PMNs between two cohorts (p = 0.33). Conclusion: Leukopenic patients with culture positive septic arthritis have significantly lower synovial WBCs compared to non-leukopenic patients. Traditional thresholds for synovial WBC are not reliable for excluding diagnosis of septic arthritis in leukopenic patients.

Assessment for Septic Arthritis in Immunocompetent and Immunocompromised Patients: A Single-Institution Study.

INTRODUCTION: Prompt diagnosis of septic arthritis is imperative to prevent irreversible joint damage. Immunocompromised patients are at an increased risk of septic arthritis as well as secondary systemic infection. Our aims were to identify features predictive of septic arthritis and to determine whether these features differed between immunocompetent and immunocompromised patients. METHODS: A single institution retrospective cohort study was performed of 173 immunocompetent and 70 immunocompromised patients who underwent aspiration or arthrotomy for suspected septic arthritis from 2010 to 2018. Demographic data, symptoms, laboratory values, and imaging findings were recorded. Multiple variable logistic regression models were used to assess for predictive factors for septic arthritis in both cohorts. Results were reported as odds ratios, 95% confidence intervals, and P values. RESULTS: In the regression analysis, independent predictive factors for septic arthritis in immunocompetent patients were younger age (P = 0.004), presence of radiographic abnormalities (P = 0.006), and C-reactive protein (CRP) (P < 0.001). For immunocompromised patients, only CRP was an independent continuous predictive factor (P = 0.008) for septic arthritis. A risk stratification tool for predicting septic arthritis in immunocompetent patients using age <55 years, CRP >100 mg/dL, and presence of radiographic abnormalities was developed. A similar tool was created using CRP >180 mg/dL and radiographic abnormalities in immunocompromised patients. DISCUSSION: Differences in predictive factors for septic arthritis between immunocompromised and immunocompetent patients suggest dissimilar clinical presentations. The developed risk stratification tools allow one to predict the likelihood of septic arthritis in both groups. This may permit more accurate selection of patients for surgical intervention in the setting of insufficient data from synovial aspiration.

Pyogenic Flexor Tenosynovitis: Evaluation and Management.

Pyogenic flexor tenosynovitis is a closed-space infection that can lead to a devastating loss of finger and hand function. It can spread rapidly into the palm, distal forearm, other digits, and nearby joints. Healthy individuals may present with no signs of systemic illness and often deny any penetrating trauma or inoculation. Early diagnosis and prompt treatment are required to preserve the digit and prevent morbidity and loss of hand function. Many treatment options have been described, although all share 2 common principles: evacuation of the infection and tailored postoperative antibiotic treatment with close monitoring to ensure clinical improvement.

A Comparison of Barbed Suture Versus Traditional Techniques for Muscle Belly Repair.

BACKGROUND: The use of barbed sutures in wound closure and tendon repair has been previously been studied with improved results over traditional suture material. We examine the use of barbed suture in muscle belly repair in a custom configuration, comparing it with traditional configurations and a control. METHODS: Twenty-five matched porcine psoas muscles were assigned to 5 different test groups: Mason-Allen with #1 Ethibond, Figure of Eight Allen with #1 Ethibond, Modified Kessler with #1 Ethibond, Custom Configuration with #2 Barbed PDS, Custom Configuration with #1 Ethibond. Repair was performed on the cut edge of muscle, with the free end of the suture anchored to a fixed base, forming a single-sided repair. An Instron 8874 tensiometer was used to linearly distract the repair to failure at 1 mm/s after 1 N preload. Five samples of each group were run, comparing load to failure and distraction at 10 N. RESULTS: Repair with barbed suture in custom configuration had statistically significantly greater load to failure than all other methods. It also showed statistically significant less displacement at 10 N of force than all other methods of repair except the Mason-Allen repair with #1 Ethibond. Mode of failure for traditional techniques was suture pull-through with tissue loss. Failure with barbed suture was through suture pullout without tissue loss. CONCLUSIONS: Custom configuration with a barbed suture increases the load to failure and decreases displacement of the repair site at 10 N of force. In addition, when the suture does pull out, it does so with minimal tissue loss.