Background: Peri-operative dexamethasone has been shown to effectively reduce post-operative nausea and vomiting and aide in analgesia after total joint arthroplasty (TJA); however, systemic glucocorticoid therapy has many adverse effects. The purpose of this study is to determine the effects of dexamethasone on prosthetic joint infection (PJI) and blood glucose levels in patients undergoing TJA. Methods: A retrospective chart review of all patients receiving primary TJA from 2011 to 2015 (n ¼ 2317) was conducted. Patients were divided into 2 cohorts: dexamethasone (n ¼ 1426) and no dexamethasone (n ¼ 891); these groups were subdivided into diabetic and non-diabetic patients. The primary outcome was PJI; secondary measures included glucose levels and pre-operative hemoglobin A1c (A1c) values. Statistics were carried out using logistic and regression models. Results: Of the 2317 joints, 1.12% developed PJI; this was not affected by dexamethasone (P ¼ .166). Diabetics were found to have higher rate of infection (P < .001); however, diabetics who received dexamethasone were not found to have a significantly higher infection rate that non-diabetics (P ¼ .646). Blood glucose levels were found to increase post-operatively, and dexamethasone did not increase this change (P ¼ .537). Diabetes (P < .001) and increasing hemoglobin A1c (P < .001) were also associated with increased serum glucose levels; however, this was not influenced by dexamethasone (P ¼ .595). Conclusion: Although diabetic patients were found to have a higher infection rate overall, this was not affected by administration of intravenous dexamethasone, nor was the post-operative elevation in serum glucose levels. In this study population, peri-operative intravenous dexamethasone did not increase the rate of PJI and was safe to administer in patients undergoing TJA.

Background: Patella instability and medial patellofemoral ligament (MPFL) injury are frequently encountered in pediatric patients. MPFL reconstruction is often chosen to treat this condition with good results; however, no consensus has been reached about which graft or technique to use. The purpose of this study was to evaluate the differences in graft survivorship, clinical outcomes (assessed with Kujala scores), and cost between autograft and allograft usage in MPFL reconstruction in pediatric patients. Methods: In this retrospective review of patients who underwent MPFL reconstruction between 2012-2015, autograft gracilis tendon was used for Group 1, and allograft gracilis tendon was used for Group 2. Outcomes were graft survivorship, postoperative Kujala scores, operative time, costs, graft size, and tibial tubercle-trochlear groove distance. Results: Fifty-six patients were included in this study, 21 in Group 1 and 35 in Group 2. No differences in age, sex, or chronicity were seen between the groups. Patients in Group 1 had longer operative times (134.5 minutes vs 97.3 minutes, P=0.0002), higher rates of graft failure (28.6% vs 0%, P=0.0037), and lower Kujala scores (80.3 vs 92.1, P=0.0032) compared to Group 2. All graft failures occurred in patients with chronic patella dislocations and occurred an average of 13.8 months postoperatively. Overall, autograft was costlier than allograft because of the cost of reoperation. Conclusion: This study supports the use of allograft for chronic patellar instability because of improved graft survivorship and clinical outcome scores, as well as the lower cost and reoperation rate.

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Background: The role of tear etiology in outcomes after rotator cuff repair is not well understood. Purpose/Hypothesis: The purpose of this study was to determine the difference in outcomes after rotator cuff repair based on tear etiology. We hypothesized that traumatic rotator cuff tears will have greater improvements in functional outcome measures and range of motion (ROM) than atraumatic tears. Study Design: Cohort study; Level of evidence, 3. Methods: We conducted a chart review of 221 consecutive patients who underwent arthroscopic rotator cuff repair; prospectively collected preoperative and minimum 2-year postoperative data were evaluated. Shoulder ROM, strength, and standard shoulder physical examination findings were recorded pre- and postoperatively. Outcome measures included visual analog scale for pain, Subjective Shoulder Value (SSV), 10-item Patient-Reported Outcomes Measurement Information System (PROMIS-10; physical and mental components), and American Shoulder and Elbow Surgeons (ASES) form. Results: Of the 221 patients, 73 had traumatic tears and 148 had atraumatic/degenerative tears. There were no differences in age, body mass index, or Charlson Comorbidity Index between groups. Patients in the atraumatic cohort had significantly longer duration of symptoms before presentation (18 vs 7 months; P < .01). Preoperatively, the traumatic cohort had less motion to forward flexion (mean ± SD; 138° ± 43.7° vs 152° ± 29.8°; P = .02). Postoperatively, both groups experienced significant improvements in visual analog scale and SSV scores ( P < .001 each). However, only the traumatic cohort demonstrated improvements in ASES and PROMIS-10 physical component scores. Patients with traumatic rotator cuff tears had lower preoperative SSV and less motion than those with atraumatic tears, but they had greater improvements in SSV (40.6% ± 39.0% vs 29.2% ± 39.7%; P = .005) and forward flexion (21.6° ± 48.6° vs 2.3° ± 48.2°; P < .001), as well as strength in forward flexion, external rotation, and internal rotation ( P < .001, P = .003, and P = .002, respectively). Conclusion: Patients with traumatic rotator cuff tears have worse preoperative symptoms and more functional deficits but experience greater improvements in ROM, strength, and perceived shoulder function than those with degenerative/atraumatic tears.

Background: The trapezoid is the least commonly fractured carpal bone, comprising 4% of all carpal fractures. To date, few articles have been published on isolated trapezoid fractures. Mechanisms of injury have typically been reported as an axial load, with or without forced wrist flexion/extension, that is transmitted from the second metacarpal indirectly to the trapezoid. Case Reports: Two patients presenting with symptoms of nonspecific wrist pain after acute trauma were initially worked up with plain film x-rays. Physical examinations identified nonspecific wrist pain in both patients. Mechanisms of injury involved direct trauma and an axial force transmitted through the scaphoid region of an extended wrist in each patient. Plain x-rays were negative for trapezoid fracture in both patients. Computed tomography and magnetic resonance imaging revealed the diagnoses. Conservative management consisted of splinting and immobilization, with full recovery reported at 2.5-and 3-month follow-up. Conclusion: Isolated fractures of the trapezoid require a high index of suspicion as they are rare, and localizing signs and symptoms are typically vague and may mimic those of scaphoid fractures. When athletes present with dorsal wrist pain, swelling, and snuffbox tenderness in the setting of negative plain x-rays, the most likely mechanisms of injury are associated with athletic activity. Treatment depends on the degree of displacement and other associated injuries and ranges from activity modification or immobilization to open reduction with internal fixation.

BACKGROUND Hyperglycemia can blunt the cardioprotective effects of isoflurane in the setting of ischemia-reperfusion injury. Previous studies suggest that reactive oxygen species (ROS) and increased mitochondrial fission play a role in cardiomyocyte death during ischemia-reperfusion injury. To investigate, the role of glucose concentration in ROS production and mitochondrial fission during ischemia-reperfusion (with and without anesthetic protection), we used the novel platform of human-induced pluripotent stem-cell-derived cardiomyocytes (iPSC-CMs). METHODS Cardiomyocyte differentiation from iPSC was characterized by the expression of CM-specific markers using immunohistochemistry and by measuring contractility. iPSC-CMs were exposed to varying glucose conditions (5, 11, 25 mM) for 24 hours. Mitochondrial permeability transition pore (mPTP) opening, cell viability, and ROS generation end-points were used to assess the effects of various treatment conditions. Mitochondrial fission was monitored by the visualization of fragmented mitochondria using confocal microscopy. Expression of activated dynamin-related protein 1 (Drp1), a key protein responsible for mictochodrial fission was assessed by western blot. RESULTS Cardiomyocytes were successfully differentiated from iPSC. Elevated glucose conditions (11 and 25 mM) significantly increased ROS generation, while only the 25 mM high glucose condition induced mitochondrial fission and increased the expression of activated Drp1 in iPSC-CMs. Isoflurane delayed mPTP opening and protected iPSC-CMs from oxidative stress in 5 and 11 mM glucose conditions to a similar level as previously observed in various isolated animal cardiomyocytes. Scavenging ROS with Trolox or inhibiting mitochondrial fission with mdivi-1 restored the anesthetic cardioprotective effects in iPSC-CMs in 25 mM glucose conditions. CONCLUSIONS Human iPSC-CM is a useful, relevant model for studying isoflurane cardioprotection, and can be manipulated to recapitulate complex clinical perturbations. We demonstrate that the cardioprotective effects of isoflurane in elevated glucose conditions can be restored by scavenging ROS or inhibiting mitochondrial fission. These findings may contribute to further understanding and guidance for restoring pharmacological cardioprotection in hyperglycemic patients.

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PurposeThis study aimed to evaluate posterolateral tibial plateau impaction fractures and how they contribute to rotatory knee laxity using quantitative pivot shift analysis. It was hypothesised that neither the presence of nor the degree of involvement of the plateau would affect rotatory knee laxity in the ACL‐deficient knee. MethodsA retrospective review of prospectively collected data on 284 patients with complete anterior cruciate ligament (ACL) injuries was conducted. Posterolateral tibial plateau impaction fractures were identified on preoperative MRI. The patients were divided into two cohorts: “fractures” or “no fractures”. The cohort with fractures was further categorised based on fracture morphology: “extra‐articular”, “articular‐impaction”, or “displaced‐articular fragment”. All data were collected during examination under anaesthesia performed immediately prior to ACL reconstruction. This included a standard pivot shift test graded by the examiner and quantitative data including anterior tibial translation (mm) via Rolimeter, quantitative pivot shift (QPS) examination (mm) via PIVOT tablet technology, and acceleration (m/sec2) during the pivot shift test via accelerometer. Quantitative examinations were compared with the contralateral knee. ResultsThere were 112 patients with posterolateral tibial plateau impaction fractures (112/284, 39%). Of these, 71/112 (63%) were “extra‐articular”, 28/112 (25%) “articular‐impaction”, and 13/112 (12%) “displaced‐articular”. Regarding the two groups with or without fractures, there was no difference in subjective pivot shift (2 ± 0 vs 2 ± 0, respectively,  n.s.), QPS (2.4 ± 1.6 mm vs 2.7 ± 2.2 mm, respectively, n.s.), anterior tibial translation measurements (6 ± 3 mm vs 5 ± 3 mm, respectively, n.s.), or acceleration of the knee during the pivot (1.7 ± 2.3 m/s2 vs 1.8 ± 3.1 m/s2, respectively, n.s.). When the fractures were further subdivided, subgroup analysis revealed no significant differences noted in any of the measured examinations between the fracture subtypes. ConclusionThis study showed that the posterolateral tibial plateau impaction fractures are commonly encountered in the setting of ACL tears; however, contrary to previous reports, they do not significantly increase rotatory knee laxity. This suggests that this type of concomitant injury may not need to be addressed at the time of ACL reconstruction. Level of evidenceLevel III.