Sequential Sectioning of the Ulnar Collateral Ligament of the Elbow in Cadaveric Arms with Ulnohumeral Laxity Assessed by Dynamic Ultrasonography

Objectives: Injury of the ulnar collateral ligament (UCL), whether acute or chronic, is potentially career-threatening for elite overhead throwing athletes. Dynamic ultrasound (DUS) allows for rapid, cost-effective, non-invasive, and non-radiating evaluation of the UCL and elbow joint both at rest and with applied stress. The purpose of this study was to determine the amount of cadaveric elbow valgus laxity with sequential UCL sectioning using DUS. Our objective was to quantify which portions of the UCL must be injured to cause the varying levels of laxity seen clinically on DUS testing. No prior study has used DUS to quantify valgus joint laxity with sequential cadaveric UCL sectioning. It was hypothesized that the change in laxity due to release of the anterior band of the UCL would be greater than that seen when the posterior and transverse bands were cut. Methods: Twelve cadaveric elbows were dissected free of skin and subcutaneous tissue by an experienced orthopaedic surgeon. Baseline DUS at rest and with applied valgus stress was then performed by an experienced ultrasonographer. Sequential sectioning of the medial elbow soft-tissue stabilizing structures was then carried out with valgus stress applied to the joint at each sectioning interval utilizing a standardized device (Telos, Marburg, Germany). First the transverse band of the UCL was released, followed by the posterior band, then the anterior bundle of the anterior band, the remaining posterior bundle of the anterior band, and finally the complete flexor pronator mass. Results: Mean ulnohumeral laxity in millimeters with 95% CIs was calculated for each step of the sequence. The deltas between each step of the dissection were also calculated with means and 95% CIs. Mean baseline laxity of the unstressed ulnohumeral joint at rest was 3.2 mm (CI, 2.2-4.2); with the addition of valgus stress, mean laxity was 4.7 mm (CI, 3.5-6.0). When the transverse band was cut, ulnohumeral laxity increased to a mean of 5.5 mm (CI, 4.0-7.0). With release of the posterior band, mean laxity was 6.4 mm (CI, 4.3-8.5). When the anterior bundle of the anterior band of the UCL was cut, mean ulnohumeral laxity was 8.4 mm (CI, 5.7-11.0) and when the entire anterior band was released, mean laxity was 10.9 mm (CI, 7.8-14.0). Complete release of the flexor pronator muscle mass resulted in mean ulnohumeral laxity of 15.5 mm (CI, 12.9-18.1). The largest deltas were observed with release of the anterior bundle of the anterior band (2.0 mm; CI, 1.0-3.0), the entire anterior band (2.6 mm; CI, 1.3-3.8), and flexor pronator mass (4.6 mm; CI, 1.3-3.8). Release of the transverse and posterior bands of the UCL resulted in deltas of 0.74 mm (CI, 0.1-1.3) and 0.9 mm (CI, 0.3-1.5) respectively. Conclusion: DUS allows for rapid, cost-effective, non-invasive, non-radiating evaluation of the elbow joint and UCL both at rest and with applied valgus stress. Previous studies have indicated that DUS can identify abnormalities of the UCL associated with chronic degeneration and ligamentous injury including thickening of the anterior band of the UCL as well as hypoechoic foci/calcifications. The results of the current cadaveric study suggest that different changes in clinical laxity are seen on DUS with injury of particular bands of the UCL. Early identification and localization of injury to a particular band of the UCL may allow more appropriate selection of patients who will benefit from operative treatment. © The Author(s) 2013

Management of Elbow Dislocations in the National Football League.

Background: Although much literature exists regarding the treatment and management of elbow dislocations in the general population, little information is available regarding management in the athletic population. Furthermore, no literature is available regarding the postinjury treatment and timing of return to play in the contact or professional athlete. Purpose: To review the clinical course of elbow dislocations in professional football players and determine the timing of return to full participation. Study Design: Case series; Level of evidence, 4. Methods: All National Football League (NFL) athletes with elbow dislocations from 2000 through 2011 who returned to play during the season were identified from the NFL Injury Surveillance System (NFL ISS). Roster position, player activity, use of external bracing, and clinical course were reviewed. Mean number of days lost until full return to play was determined for players with elbow dislocations who returned in the same season. Results: From 2000 to 2011, a total of 62 elbow dislocations out of 35,324 injuries were recorded (0.17%); 40 (64.5%) dislocations occurred in defensive players, 12 (19.4%) were in offensive players; and 10 (16.1%) were during special teams play. Over half of the injuries (33/62, 53.2%) were sustained while tackling, and 4 (6.5%) patients required surgery. A total of 47 (75.8%) players who sustained this injury were able to return in the same season. For this group, the mean number of days lost in players treated conservatively (45/47) was 25.1 days (median, 23.0 days; range, 0.0-118 days), while that for players treated operatively (2/47) was 46.5 days (median, 46.5 days; range, 29-64 days). Mean return to play based on player position was 25.8 days for defensive players (n = 28; median, 21.5 days; range, 3.0-118 days), 24.1 days for offensive players (n = 11; median, 19 days; range, 2.0-59 days), and 25.6 days for special teams players (n = 8; median, 25.5 days; range, 0-44 days). Conclusion: Elbow dislocations comprise less than a half of a percent of all injuries sustained in the NFL. Most injuries occur during the act of tackling, with the majority of injured athletes playing a defensive position. Players treated nonoperatively missed a mean of 25.1 days, whereas those managed operatively missed a mean of 46.5 days

Anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft versus allograft in young patients

Objectives: Traditionally, bone-patella tendon-bone (BTB) autograft has been the gold standard graft choice for younger, athletic patients requiring ACL reconstruction. However, donor site morbidity, post-operative patella fracture, and increased operative time have led many surgeons to choose BTB allograft for their reconstructions. Opponents of allografts feel that slower healing time, higher rate of graft failure, and potential for disease transmission makes them undesirable graft choices in athletic patients. The purpose of this study is to evaluate the clinical outcomes, both subjective and objective, of young patients that who have undergone either BTB autograft or allograft reconstructions with a minimum of 2-year follow-up. Methods: One hundred and twenty patients (60 autograft, 60 allograft), age 25 and below at time of surgery, were contacted after being retrospectively identified as patients having an ACL reconstruction with either a BTB allograft or autograft by one senior surgeon. Patients were administered the Lysholm Knee Scoring Scale and IKDC Subjective Knee Evaluation questionnaires. Fifty (25 BTB autograft and 25 BTB allograft) of the 120 returned for physical examination as well as completion of a single leg hop test and laxity evaluation using a KT-1000 arthrometer evaluation. Of the 120 patients contacted, there were a total of 7 failures (5.8%) requiring revision, 6 in the allograft group (86%) and 1 in the autograft group (14%). Results: The average Lysholm scores were 89.0 and 89.56 and the average IKDC scores were 90.8 and 92.1 in the autograft and allograft groups respectively. The differences in the Lysholm scores and the IKDC scores were not significant. The single leg hop and KT-1000 scores were also not significantly different. One autograft patient had a minor motion deficit. Three allograft patients had a grade 1 Lachman and pivot glide. One autograft patient and two allograft patients had mild patellafemoral crepitus. There was no significant difference in anterior knee pain between the two groups Conclusion: There is no significant difference in patient-rated outcome between ACL reconstructions using BTB autografts versus allografts. However, the overall study group did reveal an increased failure rate requiring revision in the allograft group. © The Author(s) 2015

Kerlan-Jobe Orthopaedic Clinic overhead athlete scores in asymptomatic professional baseball pitchers.

BACKGROUND: The Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow score is a subjective questionnaire that has been validated and been shown to be more specific in overhead athletes than the American Shoulder and Elbow Surgeons scale. The purpose of this study was to determine a mean KJOC score and reasonable range of KJOC scores within which a healthy asymptomatic professional baseball pitcher will fall. It was hypothesized that healthy professional baseball pitchers would have very high KJOC scores. MATERIALS AND METHODS: KJOC questionnaires were given to all healthy pitchers before the start of the season at all levels in 1 professional Minor League system. Pitchers were asked to complete the questionnaire upon reporting to their AAA, AA, or A affiliate team. Any pitcher starting the season on the disabled list was excluded from the study. RESULTS: KJOC scores were returned by 44 pitchers. The mean score for all pitchers was 94.82 (95% confidence interval, 92.94-96.70). The mean score for each question was greater than 9 of 10. The mean score for the AAA affiliate was significantly higher than that for the AA affiliate (P = .015). No other significant differences in scores were found between class levels or groups based on professional playing experience. CONCLUSION: Only 7 of 44 healthy asymptomatic pitchers (16%) had a KJOC score below 90. Therefore, we believe that the KJOC score is an accurate assessment for overhead athletes and normal values should be greater than 90. Anything below this value could be a potential cause for concern for team physicians. LEVEL OF EVIDENCE: Basic Science, Survey Study, Healthy Subjects

Triceps Tendon Ruptures Requiring Surgical Repair in National Football League Players.

BACKGROUND: Complete triceps tendon ruptures are relatively rare in the general population but slightly more prevalent in professional football. One prior study found 11 complete ruptures over a 6-season period. HYPOTHESIS: Triceps ruptures occur more commonly in football linemen due to forced elbow flexion during an eccentric contraction and may occur more commonly with the increasing size and speed of professional players. Surgical repair allows full return to sports, but with a lengthy recovery time. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A search of the National Football League Injury Surveillance System (NFLISS) found a total of 37 triceps tendon ruptures requiring surgical repair from the years 2000 to 2009. Data were obtained for setting of injury, player position, activity causing injury, play type, time of game when injury occurred, height, weight, body mass index (BMI), and number of days lost from football. RESULTS: There were 37 players requiring surgical repair for triceps tendon ruptures over the 10-season period. The average height, weight, and BMI of the players were 75 inches, 292 pounds, and 36.5 kg/m(2), respectively. The majority of players were linemen (86%): 16 defensive, 15 offensive, and 1 tight end. The injury took place while blocking or being blocked in 29 players (78%) and while tackling or being tackled in 5 players (14%). Players missed an average of 165 days (range, 49-318 days) from football as a result of their injury and surgery. CONCLUSION: Triceps tendon tears requiring surgical repair are more common in professional football players than in the general population and are occurring more commonly than previously reported. Surgical repair allows return to play. CLINICAL RELEVANCE: Our study identifies the rate of triceps tendon tears requiring repair in the NFL according to position, identifying which players may be most at risk for this injury

The malaria parasite egress protease SUB1 is a calcium-dependent redox switch subtilisin.

Malaria is caused by a protozoan parasite that replicates within an intraerythrocytic parasitophorous vacuole. Release (egress) of malaria merozoites from the host erythrocyte is a highly regulated and calcium-dependent event that is critical for disease progression. Minutes before egress, an essential parasite serine protease called SUB1 is discharged into the parasitophorous vacuole, where it proteolytically processes a subset of parasite proteins that play indispensable roles in egress and invasion. Here we report the first crystallographic structure of Plasmodium falciparum SUB1 at 2.25 Å, in complex with its cognate prodomain. The structure highlights the basis of the calcium dependence of SUB1, as well as its unusual requirement for interactions with substrate residues on both prime and non-prime sides of the scissile bond. Importantly, the structure also reveals the presence of a solvent-exposed redox-sensitive disulphide bridge, unique among the subtilisin family, that likely acts as a regulator of protease activity in the parasite

Combinatorial small-molecule therapy prevents uropathogenic Escherichia coli catheter-associated urinary tract infections in mice

Catheter-associated urinary tract infections (CAUTIs) constitute the majority of nosocomial urinary tract infections (UTIs) and pose significant clinical challenges. These infections are polymicrobial in nature and are often associated with multidrug-resistant pathogens, including uropathogenic Escherichia coli (UPEC). Urinary catheterization elicits major histological and immunological alterations in the bladder that can favor microbial colonization and dissemination in the urinary tract. We report that these biological perturbations impact UPEC pathogenesis and that bacterial reservoirs established during a previous UPEC infection, in which bacteriuria had resolved, can serve as a nidus for subsequent urinary catheter colonization. Mannosides, small molecule inhibitors of the type 1 pilus adhesin, FimH, provided significant protection against UPEC CAUTI by preventing bacterial invasion and shifting the UPEC niche primarily to the extracellular milieu and on the foreign body. By doing so, mannosides potentiated the action of trimethoprim-sulfamethoxazole in the prevention and treatment of CAUTI. In this study, we provide novel insights into UPEC pathogenesis in the context of urinary catheterization, and demonstrate the efficacy of novel therapies that target critical mechanisms for this infection. Thus, we establish a proof-of-principle for the development of mannosides to prevent and eventually treat these infections in the face of rising antibiotic-resistant uropathogens

Effect of Sleep Apnea and Continuous Positive Airway Pressure on Cardiac Structure and Recurrence of Atrial Fibrillation

Background: Sleep apnea (SA) is associated with an increased risk of atrial fibrillation (AF). We sought to determine the effect of SA on cardiac structure in patients with AF, whether therapy for SA was associated with beneficial cardiac structural remodelling, and whether beneficial cardiac structural remodelling translated into a reduced risk of recurrence of AF after pulmonary venous isolation (PVI). Methods and Results: A consecutive group of 720 patients underwent a cardiac magnetic resonance study before PVI. Patients with SA (n=142, 20%) were more likely to be male, diabetic, and hypertensive and have an increased pulmonary artery pressure, right ventricular volume, atrial dimensions, and left ventricular mass. Treated SA was defined as duration of continuous positive airway pressure therapy of >4 hours per night. Treated SA patients (n=71, 50%) were more likely to have paroxysmal AF, a lower blood pressure, lower ventricular mass, and smaller left atrium. During a follow‐up of 42 months, AF recurred in 245 patients. The cumulative incidence of AF recurrence was 51% in patients with SA, 30% in patients without SA, 68% in patients with untreated SA, and 35% in patients with treated SA. In a multivariable model, the presence of SA (hazard ratio 2.79, CI 1.97 to 3.94, P<0.0001) and untreated SA (hazard ratio 1.61, CI 1.35 to 1.92, P<0.0001) were highly associated with AF recurrence. Conclusions: Patients with SA have an increased blood pressure, pulmonary artery pressure, right ventricular volume, left atrial size, and left ventricular mass. Therapy with continuous positive airway pressure is associated with lower blood pressure, atrial size, and ventricular mass, and a lower risk of AF recurrence after PVI

Ring-fused 2-pyridones effective against multidrug-resistant Gram-positive pathogens and synergistic with standard-of-care antibiotics

The alarming rise of multidrug-resistant Gram-positive bacteria has precipitated a healthcare crisis, necessitating the development of new antimicrobial therapies. Here we describe a new class of antibiotics based on a ring-fused 2-pyridone backbone, which are active against vancomycin-resistant enterococci (VRE), a serious threat as classified by the Centers for Disease Control and Prevention, and other multidrug-resistant Gram-positive bacteria. Ring-fused 2-pyridone antibiotics have bacteriostatic activity against actively dividing exponential phase enterococcal cells and bactericidal activity against nondividing stationary phase enterococcal cells. The molecular mechanism of drug-induced killing of stationary phase cells mimics aspects of fratricide observed in enterococcal biofilms, where both are mediated by the Atn autolysin and the GelE protease. In addition, combinations of sublethal concentrations of ring-fused 2-pyridones and standard-of-care antibiotics, such as vancomycin, were found to synergize to kill clinical strains of VRE. Furthermore, a broad range of antibiotic resistant Gram-positive pathogens, including those responsible for the increasing incidence of antibiotic resistant healthcare-associated infections, are susceptible to this new class of 2-pyridone antibiotics. Given the broad antibacterial activities of ring-fused 2-pyridone compounds against Gram-positive (GmP) bacteria we term these compounds GmPcides, which hold promise in combating the rising tide of antibiotic resistant Gram-positive pathogens

Return to School After Anterior Cruciate Ligament Reconstruction: A Prospective Study of Adolescents and Young Adults.

Background: The ability to return to school after orthopaedic surgery is an important consideration for young patients, as there is substantial literature indicating that school attendance is correlated strongly with academic performance. Purpose: To evaluate the time to return to school, the barriers that students encounter when returning to school, and the academic effect of anterior cruciate ligament reconstruction (ACLR) in high school (HS) and college students. Study design: Cohort study; Level of evidence, 2. Methods: Full-time HS and college/graduate school (C/GS) students who underwent ACLR during the 2017 to 2018 and 2018 to 2019 academic periods were included in the study. Patients were contacted 2 weeks postoperatively to complete a questionnaire that assessed their time to return to school and barriers that interfered with their ability to return, and they completed a second questionnaire at 6 weeks postoperatively that assessed academic performance and challenges faced upon returning to school. Results: Included were 36 (52.2%) full-time HS students and 33 (47.8%) full-time C/GS students. HS students reported a longer time to return to school compared with C/GS students (8.51 vs 5.89 days; P = .008). In addition, HS students missed more scheduled school days than C/GS students (5.39 vs 2.90 days; P \u3c .001). The majority of HS (73.5%) and C/GS (65.5%) students cited pain as a barrier to return, and more than half of HS (70.6%) and C/GS (55.2%) students also cited restricted mobility as a barrier to return. HS students were more likely to miss an examination in the early postoperative period compared with their C/GS counterparts (65.7% vs 39.3%; P = .037). Many students in both cohorts received a grade less than expected in the early postoperative period; this was not significantly different between the 2 groups (HS, 50.0%; C/GS, 42.9%; P = .489). Conclusion: ACLR can have a negative effect on school attendance and academic performance among HS and C/GS students. Orthopaedic surgeons should counsel all students and their families adequately about the potential academic effect of orthopaedic surgery in order to maximize clinical results, academic performance, and satisfaction in their patients