Ulnar Nerve Translocation Following a Routine Distal Radius Fracture.

A 35-year-old right hand dominant male sustained a high energy closed right distal radius fracture with associated generalized paresthesias. Following closed reduction, the patient was found to have an atypical low ulnar nerve palsy upon outpatient follow-up. After continued symptoms and an equivocal wrist MRI the patient underwent surgical exploration. Intraoperatively, the ulnar nerve as well as the ring and small finger flexor digitorum superficialis tendons were found to be translocated around the ulnar head. The nerve and tendons were reduced, the median nerve was decompressed, and the fracture was addressed with volar plating. Post-operatively, the patient continued to have sensory deficits and stiffness of the ring and small fingers. After one year, he reported substantial improvements as demonstrated by full sensation (4.0 mm two-point discrimination) and fixed flexion contractures at the proximal and distal interphalangeal joints of the small finger. The patient returned to work without functional limitations. This case highlights a unique case of ulnar nerve and flexor tendon entrapment following a distal radius fracture. History, physical examination, and a high index of clinical suspicion is essential for proper management of this rare injury. Level of Evidence: V.

Evaluating trunnionosis in modular anatomic shoulder arthroplasties: a retrieval study.

BACKGROUND: Shoulder arthroplasty procedures are widely indicated, and the number of shoulder arthroplasty procedures has drastically increased over the years. Rapid expansion of the utilization of reverse total shoulder arthroplasty has outpaced the more modest growth of anatomic total shoulder arthroplasty (aTSA) while shoulder hemiarthroplasty (HA) has trended down. Recently, shoulder prostheses have transitioned to increasingly modular systems offering more individualized options with the potential for decreased pain and increased range of motion. However, increased primary procedures has resulted in increased revision surgeries, with one potential cause being fretting and corrosion damage within these modular systems. METHODS: Following institutional review board approval, 130 retrieved aTSA and 135 HA explants were identified through database query. Humeral stem and head components were included in all 265 explants, whereas 108 included polyethylene glenoid liner components. All explanted components were macroscopically evaluated for standard damage modes, and taper junctions were microscopically examined for fretting/corrosion using a modified Goldberg-Cusick classification system that was 4-quadrant graded for both the male and female component. Medical records were reviewed for patient demographics and surgical information. RESULTS: In this series, 158 of explants were from female patients (male = 107), and 162 explants were from the right shoulder. Average age at implantation was 61 years (range: 24-83), average age at explanation was 66 years (range, 32-90), and average duration of implantation was 61.4 months (range, 0.5-240). Scratching, edge deformation, and burnishing were the most commonly observed standard damage modes. Of the 265 explants, 146 had a male stem component vs. 118 with a female stem component. Average summed fretting grades on male and female stem components were 8.3 and 5.9, respectively (P < .001). Average summed corrosion grades for male and female stem components were 8.2 and 6.2, respectively (P < .001). Wider male tapers (>11 mm) showed significantly less fretting and corrosion (P < .001). Lastly, mismatched metal compositions between the head and stem components showed greater fretting and corrosion damage (P = .002). CONCLUSION: In this series of 265 aTSA and HA explants, there was substantial damage present on the explanted components. All components demonstrated macroscopic damage. In this retrieval study, small-tapered male stems with small, thin female heads and mismatched metal composition between components were risk factors for increased implant wear. As shoulder arthroplasty volume increases, optimizing design is paramount for long-term success. Additional work could determine the clinical significance of these findings.

Suture Fixation of Subacute Pediatric Seymour Fractures.

Seymour fractures are common injuries in the pediatric population. High rates of deep infection have been reported due to delayed presentation and subsequent treatment. This report describes the case of a 13-year-old male wrestler who presented 1 month after a finger injury that was later diagnosed as a subacute Seymour fracture with osteomyelitis. The patient underwent irrigation and debridement and fracture reduction stabilized with nonabsorbable suture fixation. After 6 weeks of intravenous antibiotics, the patient was recovering well, with radiographic evidence of fracture healing and clearance of infection. This case highlights the use of a single suture as a treatment option for fixation of unstable Seymour fractures with delayed presentation. The management of acute open distal phalangeal physeal fractures is well described in the literature; however, further investigations are warranted into the optimal management of chronically infected digits with unstable Seymour fractures.

Effect of local retropharyngeal steroids on fusion rate after anterior cervical discectomy and fusion.

BACKGROUND CONTEXT: Anterior cervical discectomy and fusion (ACDF) is considered the gold standard surgical intervention for cervical myelopathy and radiculopathy. Obtaining a solid fusion is an important goal of ACDF, and doing so has correlated with favorable clinical outcomes. A common complication after surgery is postoperative dysphagia. Multiple techniques have been utilized in attempt to prevent and treat dysphagia, including use of retropharygeal steroids. PURPOSE: To examine the effects of retropharyngeal steroids on fusion rate in ACDF. STUDY DESIGN: Case control METHODS: Forty-two patients who received local retropharyngeal steroids during ACDF surgery were the sample patient population. The control group consisted of matched cases based on number of spinal levels treated and age at approximately 1:2 case to control ratio. Data were collected on demographic variables, as well as operative and postoperative courses. Radiographic data were collected and fusion determined by <2 mm motion on flexion/extension views and bridging bone. Data were compared between case and control populations. Continuous variables were compared using Student's t test and nominal/ordinal values were compared using Z-test. Fusion status was assessed using Pearson chi-squared test. RESULTS: A total of 121 patients were reviewed based on matching status and sufficient follow-up. The case and control groups were successfully matched based on age, spinal levels treated, and smoking status. The case group had an overall fusion rate of 64.7%, whereas the control group had a fusion rate of 91%. When analyzed at each level of attempted fusion, the case group had a fusion rate of 81% compared to 93% in the control group. There was a single patient in the case group that developed esophageal rupture and retropharygeal abscess requiring surgical intervention with irrigation, debridement and repair at 8 months after index operation. CONCLUSIONS: The use of retropharyngeal steroids to mitigate postoperative dysphagia is associated with a decreased rate of radiographic fusion in ACDF surgery.

Development of a periprosthetic joint infection by Abiotrophia defectiva years after total knee arthroplasty.

A 74-year-old male presented with acute right knee pain and inability to ambulate. The patient had a total knee arthroplasty, previously complicated by a periprosthetic femur fracture requiring surgical fixation and subsequent methicillin-resistant Staphylococcus epidermidis periprosthetic joint infection treated via two-stage revision. Cultures from knee fluid aspiration were positive for Abiotrophia defectiva. Identification was confirmed using matrix-assisted laser desorption ionization-time of flight mass spectrometry. The patient underwent a two-stage revision. Between stages, the patient received intravenous ceftriaxone for six weeks with subsequent normalization of inflammatory markers. Diagnosis of periprosthetic joint infection with identification of the organism is important to guide appropriate treatment.

A Biomechanical and Structural Comparison of Articular Cartilage and Subchondral Bone of the Glenoid and Humeral Head.

BACKGROUND: The underlying cause of glenohumeral arthritis is poorly understood. Glenohumeral arthrosis patterns have been classified and described, and differential contact stresses within the joint have been implicated as a cause of joint degeneration, but the intrinsic cause of degeneration patterns in the glenohumeral joint (GHJ) remains largely unknown. PURPOSE/HYPOTHESIS: The purpose of this study was to assess morphological and mechanical differences in articular cartilage (AC) and subchondral bone (SCB) of the glenoid and humeral head in matched cadaveric specimens. We hypothesized that there would be significant zone-dependent differences between the intrinsic characteristics (AC thickness, SCB thickness, compressive forces) of the glenoid and humeral head. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten human cadaveric GHJs (mean age, 60.2 years) were dissected to expose articular surfaces to facilitate biomechanical testing. A 2-mm and 6-mm osteochondral plug was harvested at 5 zones (central, anterior, posterior, inferior, superior) on the glenoid and humeral head (N = 200 plugs). Each 2-mm core was histologically sectioned and stained with hematoxylin and eosin. AC thickness measurements were taken using light microscopy. The 6-mm plugs were imaged using micro-computed tomography to measure SCB thickness. After imaging, AC specimens were removed from the SCB and tested in confined compression. The compressive aggregate modulus (HA0), compressive stiffening coefficient (ß), and compressive modulus at 16% strain (HA0.16) and at 50% strain (HA0.50) were calculated. RESULTS: The overall AC thickness was significantly greater on the glenoid. The glenoid also had significantly thicker AC at the inferior, posterior, and superior zones as well as significantly higher SCB thickness overall and significantly greater SCB thickness at the anterior and central zones. The glenoid had significantly greater overall HA0.50 and HA0.50 values at the superior zone and had a significantly greater overall compressive stiffening coefficient (ß). CONCLUSION: The glenoid had thicker AC, thicker SCB, and greater compressive stiffness at high strain. CLINICAL RELEVANCE: These intrinsic differences may help better elucidate the cause of differential degeneration patterns between the glenoid and humeral head.

Acute Effect of Intermittent Exercise and Action-Based Video Game Breaks on Math Performance in Preadolescent Children.

PURPOSE: The purpose of this study was to compare the acute effects of video game breaks and intermittent exercise breaks, performed at varying intensities, on math performance in preadolescent children. METHODS: A total of 39 children (18 males and 21 females; aged 7-11 y) completed 4 experimental conditions in random order: 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity exercise breaks or 20 two-minute sedentary computer game breaks. The intensity of exercise breaks for the low-, moderate-, and high-intensity conditions corresponded with 25%, 50%, and 75% of heart rate reserve, respectively. Math performance was assessed 3 times throughout each condition day using a 90-second math test consisting of 40 single-digit addition and subtraction questions. RESULTS: There were no significant differences in percent change in math scores (correct answers out of attempted) by condition [low: -1.3 (0.8), moderate: 0.1 (1.3), high: -1.8 (0.7), and computer: -2.5 (0.8); P > .05]. There were significant differences in percent change in math scores over the course of the condition days with lower math scores reported at end-of-day test compared with midday test [-2.4 (0.5) vs -0.4 (0.3); P = .01]. There were no significant condition × time, time × age, condition × age, or condition × time × age interactions (all Ps > .05). CONCLUSION: Action-based video game and exercise breaks elicit the same level of math performance in children; however, time of day may impact this relationship. These findings may have important implications for instructional time in elementary classrooms.

Acute Compensatory Responses to Interrupting Prolonged Sitting With Intermittent Activity in Preadolescent Children.

PURPOSE: The purpose of this study was to compare the effects of intermittent activity performed at varying intensities and of prolonged sitting on physical activity compensation. METHODS: A total of 33 children (14 boys and 19 girls; age 7-11 y; 24% overweight/obese; 61% nonwhite) completed 4 experimental conditions in random order: 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary computer game breaks. Physical activity energy expenditure (PAEE) was assessed via accelerometry to establish baseline PAEE and throughout each condition day (8-h in-lab PAEE, out-of-lab PAEE, and 3-d postcondition). RESULTS: Compared with baseline PAEE, total daily PAEE was significantly higher during the high-intensity condition day (153 ± 43 kcal, P = .03), unchanged during the low-intensity (-40 ± 23 kcal, P > .05) and moderate-intensity condition days (-11 ± 18 kcal, P > .05), and decreased in response to prolonged sitting (-79 ± 22 kcal, P = .03). There were no significant differences in PAEE 3-day postcondition across conditions (P > .05). CONCLUSION: Despite the varying levels of PAEE accumulated during the 8-hour laboratory conditions, out-of-lab PAEE during each condition day and 3-day postcondition did not change from the baseline. These findings provide preliminary evidence that spontaneous physical activity in children does not change in response to intermittent activity or prolonged sitting.

Affective Responses to Intermittent Physical Activity in Healthy Weight and Overweight/Obese Elementary School-Age Children.

BACKGROUND: The purpose of this study was to examine the acute effects of intermittent physical activity (2-min bouts of varying intensities) on psychological mood and enjoyment in elementary school-age children and to examine the effect of weight status on these psychological outcomes. METHODS: A total of 39 children (healthy weight, n = 26; overweight/obese, n = 13) completed 4 experimental conditions in random order, which consisted of 8 hours of sitting interrupted with 20 two-minute low--, moderate-, or high-intensity activity breaks or 20 two-minute screen-time breaks. Mood was assessed using the Feeling Scale immediately following each break. Enjoyment was assessed using the Physical Activity Enjoyment Scale immediately following 10 and 20 breaks. RESULTS: Mood was significantly higher during the sedentary versus active conditions (P < .01). Overweight/obese children reported lower mood scores compared with healthy weight children at the initiation of the low- (P < .05) and high-intensity conditions (P < .001) but experienced improvements in mood throughout the day in all 3 active conditions (P = .02). Enjoyment was significantly higher after completing the active versus sedentary conditions (P = .02). CONCLUSION: These findings suggest that both healthy weight and overweight/obese children felt better immediately after engaging in screen-time breaks but subsequently rated the activity breaks as more enjoyable compared with screen-time breaks.

Thrombolytic-Enhanced Extracorporeal Cardiopulmonary Resuscitation After Prolonged Cardiac Arrest.

OBJECTIVE: To investigate the effects of the combination of extracorporeal cardiopulmonary resuscitation and thrombolytic therapy on the recovery of vital organ function after prolonged cardiac arrest. DESIGN: Laboratory investigation. SETTING: University laboratory. SUBJECTS: Pigs. INTERVENTIONS: Animals underwent 30-minute untreated ventricular fibrillation cardiac arrest followed by extracorporeal cardiopulmonary resuscitation for 6 hours. Animals were allocated into two experimental groups: t-extracorporeal cardiopulmonary resuscitation (t-ECPR) group, which received streptokinase 1 million units, and control extracorporeal cardiopulmonary resuscitation (c-ECPR), which did not receive streptokinase. In both groups, the resuscitation protocol included the following physiologic targets: mean arterial pressure greater than 70 mm Hg, cerebral perfusion pressure greater than 50 mm Hg, PaO2 150 ± 50 torr (20 ± 7 kPa), PaCO2 40 ± 5 torr (5 ± 1 kPa), and core temperature 33°C ± 1°C. Defibrillation was attempted after 30 minutes of extracorporeal cardiopulmonary resuscitation. MEASUREMENTS AND MAIN RESULTS: A cardiac resuscitability score was assessed on the basis of success of defibrillation, return of spontaneous heart beat, weanability from extracorporeal cardiopulmonary resuscitation, and left ventricular systolic function after weaning. The addition of thrombolytic to extracorporeal cardiopulmonary resuscitation significantly improved cardiac resuscitability (3.7 ± 1.6 in t-ECPR vs 1.0 ± 1.5 in c-ECPR). Arterial lactate clearance was higher in t-ECPR than in c-ECPR (40% ± 15% vs 18% ± 21%). At the end of the experiment, the intracranial pressure was significantly higher in c-ECPR than in t-ECPR. Recovery of brain electrical activity, as assessed by quantitative analysis of electroencephalogram signal, and ischemic neuronal injury on histopathologic examination did not differ between groups. Animals in t-ECPR group did not have increased bleeding complications, including intracerebral hemorrhages. CONCLUSIONS: In a porcine model of prolonged cardiac arrest, t-ECPR improved cardiac resuscitability and reduced brain edema, without increasing bleeding complications. However, early electroencephalogram recovery and ischemic neuronal injury were not improved.