Beneficial Effect of Calcium Treatment for Hyperkalemia Is Not Due to "Membrane Stabilization".

Objectives: Hyperkalemia is a common life-threatening condition causing severe electrophysiologic derangements and arrhythmias. The beneficial effects of calcium (Ca 2+ ) treatment for hyperkalemia have been attributed to "membrane stabilization," by restoration of resting membrane potential (RMP). However, the underlying mechanisms remain poorly understood.

Beneficial Effect of Calcium Treatment for Hyperkalemia Is Not Due to "Membrane Stabilization".

Objectives: Hyperkalemia is a common life-threatening condition causing severe electrophysiologic derangements and arrhythmias. The beneficial effects of calcium (Ca 2+ ) treatment for hyperkalemia have been attributed to "membrane stabilization," by restoration of resting membrane potential (RMP). However, the underlying mechanisms remain poorly understood.

Intersurgeon Consistency of Ulnar Collateral Ligament Repair With Internal Brace: A Biomechanical Analysis.

Background: Injury to the ulnar collateral ligament (UCL) of the medial elbow has been treated successfully with ligament repair augmented with internal brace. Previous work has shown that this procedure does not overconstrain the ulnohumeral joint; however, the procedures were conducted by a single surgeon, which controlled for anchor placement and graft tensioning.

Purpose/hypothesis: Our purpose was to evaluate the reproducibility of contact mechanics and joint torque after UCL repair with internal brace as performed by different surgeons compared with repair by a single surgeon.

Performance and return to sport after injury in professional mixed martial arts.

Background: Mixed Martial Arts (MMA) is an increasingly popular combat sport incorporating striking and grappling that results in a high incidence of injuries.

Objectives: The purpose of this study was to analyze the impact of injuries on the return to sport and post-injury performance of professional MMA athletes. We hypothesize that increased age is associated with lower probability of return to sport and diminished post-injury performance.

Total Hip Arthroplasty for Femoral Neck Fracture in the Setting of Challenging Extraction of an Intramedullary Femoral Nail: A Case Report.

Introduction: Performing total hip arthroplasty (THA) for femoral neck fracture in the setting of a pre-existing intramedullary nail can be technically challenging, particularly if nail extraction is not feasible.

Case Report: A 76-year-old male presented with a with a displaced femoral neck fracture in the setting of a previously placed antegrade intramedullary nail with a healed femoral shaft fracture. After failed nail extraction, a novel technique was used to remove the proximal portion of the nail to allow for hybrid THA with implantation of a cemented femoral stem.

Effect of Amiodarone and Hypothermia on Arrhythmia Substrates During Resuscitation.

Background Amiodarone is administered during resuscitation, but its antiarrhythmic effects during targeted temperature management are unknown. The purpose of this study was to determine the effect of both therapeutic hypothermia and amiodarone on arrhythmia substrates during resuscitation from cardiac arrest. Methods and Results We utilized 2 complementary models: (1) In vitro no-flow global ischemia canine left ventricular transmural wedge preparation.

The Evolution of Arthroscopy A Historical Perspective.

The Hospital for Joint Disease was constructed in 1924, ushering in a new generation of orthopedic leaders in research and clinical care. One such surgeon, Michael S. Burman, helped pioneer the early advancement and development of arthroscopy in North America.

Excision of Prominent Bony Mass due to Skeletal Fluorosis: A Case Report.

Case: A 72-year-old man presented for evaluation of bony prominences over extremities. Radiographic imaging demonstrated masses of varying sizes extending from the cortical surfaces without medullary continuity. The patient had a history of Freon inhalation abuse and was diagnosed with skeletal fluorosis due to elevated serum fluoride levels.

Clinical Outcomes of Hip Arthroscopy in Patients With Systemic Inflammatory Diseases Compared With Matched Controls at a Minimum of 2-Year Follow-Up.

Purpose: To evaluate postoperative outcomes and preoperative risk factors for patients with underlying systemic inflammatory disorders after hip arthroscopy.

Methods: A retrospective analysis of patients who had undergone hip arthroscopy, with a history of systemic inflammatory disease, was performed. This included patients with a diagnosis of lupus, a positive antinuclear antibody test, rheumatoid arthritis, psoriatic arthritis, sarcoidosis, inflammatory bowel disease, Reiter syndrome, and mixed connective tissue disease.

Effect of Shoulder Stabilization on Career Length and Performance in National Basketball Association Athletes.

Purpose: Untreated episodes of shoulder instability can have major consequences on athletic careers. Operative shoulder stabilization reduces the rate of recurrent instability and allows for high rates of return to sport (RTS). Basketball players who experience an episode of instability have high rates of recurrence, though little is known about postoperative player performance.

Robot-Assisted Medial Compartment Arthroplasty Following Remote Patellectomy: A Case Report.

Introduction: Total patellectomies are uncommon procedures that are reserved as salvage treatment for severely comminuted fractures of the patella. Due to the alteration of normal joint mechanics, these patients present later on in life with degenerative cartilage damage to the femorotibial joint and altered extensor mechanism. There are very few reports of unicondylar knee arthroplasties following previous patellectomy and none that specifically address robot-assisted unicompartmental knee arthroplasty.

Rotating hinge prosthesis for complex revision total knee arthroplasty: A review of the literature.

Introduction: The rotating hinge prosthesis was originally used and designed as a primary total knee arthroplasty implant, but was hampered due to poor outcomes and catastrophic failures. Newer rotating hinge implants can be utilized in complex revision total knee arthroplasties when appropriately indicated, but their outcome data is very difficult to interpret due to the strict and varied indications for use and subsequently small number of procedures performed. The goal of this review is to evaluate the current evidence on large cohort, rotating hinge knee prostheses used in the revision setting, in order to provide a clearer understanding of the indications, outcomes and complications.

Skilled Nursing Facility Partnerships May Decrease 90-Day Costs in a Total Joint Arthroplasty Episode Under the Bundled Payments for Care Improvement Initiative.

Background: The Bundled Payments for Care Improvement initiative was developed to reduce costs associated with total joint arthroplasty through a single payment for all patient care from index admission through a 90-day post-discharge period, including care at skilled nursing facilities (SNFs). The aim of this study is to investigate whether forming partnerships between hospitals and SNFs could lower the post-discharge costs. We hypothesize that institutionally aligned SNFs have lower post-discharge costs than non-aligned SNFs.

Interobserver Agreement in the Classification of Partial-Thickness Rotator Cuff Tears Using the Snyder Classification System.

Background: At present, there is no widely accepted classification system for partial-thickness rotator cuff tears, and as a result, optimal treatment remains controversial.

Purpose: To examine the interobserver reliability and accuracy of classifying partial rotator cuff tears using the Snyder classification system. We hypothesized that the Snyder classification would be reproducible with high reliability and accuracy.

Accuracy of palpation-directed intra-articular glenohumeral injection confirmed by magnetic resonance arthrography.

Purpose: The aim of this study was to determine the accuracy of anatomic palpation-directed injections in the office setting.

Methods: Two hundred twenty-six shoulders in 208 patients were studied using a 0.2-Tesla extremity scanner after the injection of gadolinium-diethylene triamine pentaacetic acid-saline.

Sensitivity of magnetic resonance imaging in the diagnosis of mobile and nonmobile L4-L5 degenerative spondylolisthesis.

Background Context: Lumbar degenerative spondylolisthesis (LDS) is often diagnosed by conventional supine magnetic resonance imaging (MRI). Numerous studies have shown, however, that the degree of spondylolisthesis can be reduced or disappears when the patient is supine as compared with standing lateral and flexion-extension (SLFE) radiographs.

Purpose: To compare the sensitivity of supine MRI with SLFE radiographs in patients with L4-L5 LDS.

Analysis of Low-Field MRI Scanners for Evaluation of Shoulder Pathology Based on Arthroscopy.

Background: Many studies have compared the diagnostic capabilities of low-field magnetic resonance imaging (MRI) scanners to high-field MRI scanners; however, few have evaluated the low-field MRI diagnoses compared with intraoperative findings.

Purpose: To determine the accuracy and sensitivity of low-field MRI scanners in diagnosing lesions of the rotator cuff and glenoid labrum.

Study Design: Cohort study (diagnosis); Level of evidence, 3.

Complication of the use of a radiofrequency device in arthroscopic shoulder surgery: second-degree burn of the shoulder girdle.

Radiofrequency ablation (RF) energy devices are increasingly being used in arthroscopic surgery. This is a case report of a 53-year-old man who had second-degree burns of the shoulder and chest wall as a result of fluid overheating due to RF. During an extensive arthroscopic bursal dissection of the left shoulder, the suction device on the RF wand and the valve was left open, allowing fluid to drip onto the chest and arm of the patient.