We have designed and constructed an atmospheric pressure laser desorption/chemical ionization (AP-LD/CI) source that utilizes a laser pulse to desorb intact neutral molecules, followed by chemical ionization via reagent ions produced by a corona discharge. This source employs a heated capillary atmospheric pressure inlet coupled to a quadrupole ion trap mass spectrometer and allows sampling under normal ambient air conditions. Preliminary results demonstrate that this technique provides approximately 150-fold increase in analyte ions compared to the ion population generated by atmospheric pressure infrared matrix-assisted laser desorption/ionization (AP-IR-MALDI).

Recurrent or persistent infection after two-stage exchange arthroplasty for previously infected total knee replacement is a challenging clinical situation. We asked whether a second two-stage procedure could eradicate the infection and preserve knee function. We evaluated 18 selected patients with failed two-stage total knee arthroplasty implantation treated with a second two-stage reimplantation between 1999 and 2005. Failure of treatment was defined as recurrence or persistence of infection. The minimum followup was 24 months (mean, 40 months; range, 24-83 months). Recurrent or persistent infection was diagnosed in four of 18 patients, two of whom were successfully treated with a third two-stage exchange arthroplasty. Knee Society score questionnaires administered at the last followup showed an average Knee Society knee score of 73 points (range, 24-100 points) and an average functional score of 49 points (range, 20-90 points). The data suggest repeat two-stage exchange arthroplasty is a reasonable option for eradicating periprosthetic infection, relieving pain, and achieving a satisfactory level of function for some patients.

Background:At the annual National Football League (NFL) Scouting Combine, the medical staff of each NFL franchise performs a comprehensive medical evaluation of all athletes potentially entering the NFL. Currently, little is known regarding the overall epidemiology of injuries identified at the combine and their impact on NFL performance.Purpose:To determine the epidemiology of injuries identified at the combine and their impact on initial NFL performance.Study Design:Cohort study; Level of evidence, 3.Methods:All previous musculoskeletal injuries identified at the NFL Combine from 2009 to 2015 were retrospectively reviewed. Medical records and imaging reports were examined. Game statistics for the first 2 seasons of NFL play were obtained for all players from 2009 to 2013. Analysis of injury prevalence and overall impact on the draft status and position-specific performance metrics of each injury was performed and compared with a position-matched control group with no history of injury or surgery.Results:A total of 2203 athletes over 7 years were evaluated, including 1490 (67.6%) drafted athletes and 1040 (47.2%) who ultimately played at least 2 years in the NFL. The most common sites of injury were the ankle (1160, 52.7%), shoulder (1143, 51.9%), knee (1128, 51.2%), spine (785, 35.6%), and hand (739, 33.5%). Odds ratios (ORs) demonstrated that quarterbacks were most at risk of shoulder injury (OR, 2.78; P = .001), while running backs most commonly sustained ankle (OR, 1.39; P = .040) and shoulder injuries (OR, 1.55; P = .020) when compared with all other players. Ultimately, defensive players demonstrated a greater negative impact due to injury than offensive players, with multiple performance metrics significantly affected for each defensive position analyzed, whereas skilled offensive players (eg, quarterbacks, running backs) demonstrated only 1 metric significantly affected at each position.Conclusion:The most common sites of injury identified at the combine were (1) ankle, (2) shoulder, (3) knee, (4) spine, and (5) hand. Overall, performance in the NFL tended to worsen with injury history, with a direct correlation found between injury at a certain anatomic location and position of play. Defensive players tended to perform worse compared with offensive players if injury history was present.

Ankle impingement is a syndrome that encompasses a wide range of anterior and posterior joint pathology involving both osseous and soft tissue abnormalities. In this review, the etiology, pathoanatomy, diagnostic workup, and treatment options for both anterior and posterior ankle impingement syndromes are discussed.

The neutral products eliminated upon the collisionally activated dissociation (CAD) of C :; ions ( z = 1-4) are post-ionized to cations or anions and collected in neutral fragment-reionization (+N,R+v -) mass spectra. These spectra provide conclusive evidence that the decompositions Cl; + C,+' + C,, (where x > 30 and 2n < 30) proceed by cleavage of whole C,, clusters, not consecutive losses of nC, . As the charge of the fullerene precursor ion increases, the largest detectable neutral loss decreases, from CZ8 for z = 1 to C,, for = 4. Post-ionization of C,, to cations preferentially produces odd-carbon cluster ions (e.g., Cs+, C, +, C:,, C:s) whereas post-ionization to anions yields abundant even-carbon cluster ions (C, -, C8-).

Objectives: Tarsometatarsal (Lisfranc) joint injuries commonly occur in American professional football competition; however, the career impact of these injuries is unknown. This study aims to define the time to return to competition for professional football players who sustained Lisfranc injuries and to quantify their effect on athletic performance. Methods: Data on National Football League (NFL) players who sustained a Lisfranc injury during a ten-year time period (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) were collected for analysis. Recorded demographic variables included age, experience, position, and operative vs. non-operative management. Outcomes data collected for offensive players (running backs, wide receivers, tight ends) included time to return to competition and yearly total yards and touchdowns. Outcomes data collected for defensive players (defensive linemen, linebackers, defensive backs) included time to return to competition and yearly total tackles, sacks, and interceptions. Offensive power ratings (OPR=total yards/10 + total touchdowns x6) and defensive power ratings (DPR=total tackles + total sacks x2 + total interceptions x2) were calculated for the injury season and for 3 seasons before and after the injury season. Offensive and defensive control groups consisted of all players of similar positions without an identified Lisfranc injury that competed in the 2005 season. Results: Lisfranc injuries were identified in 28 NFL athletes in the study period, including 11 offensive players and 17 defensive players. While 2 of 28 (7.1%) players never returned to the NFL, the remaining 26 (92.9%) athletes returned to competition at a median 11.1 (interquartile range: 10.3-12.5) months from time of injury and missed a median 8.5 (6.3-13.0) NFL regular season games. Players treated non-operatively were noted to have an earlier return to play with a median absence from play of 6.2 (1.9-10.7) months and 7.0 (4.5-8.0) games compared to those treated operatively who returned after a median 11.6 (10.7-12.6) months (p=0.02) and 10.0 (7.0-13.3) games missed (p=0.09). Analysis of pre-and post-injury athletic performance revealed no statistically significant changes following return to sport after Lisfranc injury. The magnitude of change in median OPR for 3 seasons prior to index season compared to 3 seasons after index season observed in the Lisfranc-injured offensive study group, -34.8 (-64.4-1.4), was greater than that observed in the offensive control group, -18.8 (-52.9-31.5); however, these differences did not reach statistical significance (p=0.33). Similarly, the magnitude of change observed in the Lisfranc-injured defensive study group, -13.5 (-30.9-4.3), was greater than that observed in the defensive control group, -5.0 (-22.0-14.0); however, these differences also did not reach statistical significance (p=0.21). Conclusion: Greater than 90% of NFL athletes who sustained Lisfranc injuries returned to play in the NFL at a median 11.1 months from time of injury. Operative treatm...

Objectives:Tarsometatarsal (Lisfranc) joint injuries commonly occur in American professional football competition; however, the career impact of these injuries is unknown. This study aims to define the time to return to competition for professional football players who sustained Lisfranc injuries and to quantify their effect on athletic performance.Methods:Data on National Football League (NFL) players who sustained a Lisfranc injury during a ten-year time period (2000-2010) were collected for analysis. Recorded demographic variables included age, experience, position, and operative vs. non-operative management. Outcomes data collected for offensive players (running backs, wide receivers, tight ends) included time to return to competition and yearly total yards and touchdowns. Outcomes data collected for defensive players (defensive linemen, linebackers, defensive backs) included time to return to competition and yearly total tackles, sacks, and interceptions. Offensive power ratings (OPR=total yards/10 + total touchdowns x6) and defensive power ratings (DPR=total tackles + total sacks x2 + total interceptions x2) were calculated for the injury season and for 3 seasons before and after the injury season. Offensive and defensive control groups consisted of all players of similar positions without an identified Lisfranc injury that competed in the 2005 season.Results:Lisfranc injuries were identified in 28 NFL athletes in the study period, including 11 offensive players and 17 defensive players. While 2 of 28 (7.1%) players never returned to the NFL, the remaining 26 (92.9%) athletes returned to competition at a median 11.1 (interquartile range: 10.3-12.5) months from time of injury and missed a median 8.5 (6.3-13.0) NFL regular season games. Players treated non-operatively were noted to have an earlier return to play with a median absence from play of 6.2 (1.9-10.7) months and 7.0 (4.5-8.0) games compared to those treated operatively who returned after a median 11.6 (10.7-12.6) months (p=0.02) and 10.0 (7.0-13.3) games missed (p=0.09). Analysis of pre- and post-injury athletic performance revealed no statistically significant changes following return to sport after Lisfranc injury. The magnitude of change in median OPR for 3 seasons prior to index season compared to 3 seasons after index season observed in the Lisfranc-injured offensive study group, -34.8 (-64.4-1.4), was greater than that observed in the offensive control group, -18.8 (-52.9-31.5); however, these differences did not reach statistical significance (p=0.33). Similarly, the magnitude of change observed in the Lisfranc-injured defensive study group, -13.5 (-30.9-4.3), was greater than that observed in the defensive control group, -5.0 (-22.0-14.0); however, these differences also did not reach statistical significance (p=0.21).Conclusion:Greater than 90% of NFL athletes who sustained Lisfranc injuries returned to play in the NFL at a median 11.1 months from time of injury. Operative treatment was associated with a longer time to return; however, this...

Anterior glenohumeral instability is a common clinical entity, particularly among young athletic patient populations. Nonoperative management and arthroscopic treatment of glenohumeral instability have been associated with high rates of recurrence, particularly in the setting of glenohumeral osseous defects. Coracoid transfer, particularly the Latarjet procedure, has become the treatment of choice for recurrent anterior glenohumeral instability in the setting of osseous deficiencies greater than 20% to 30% of the glenoid surface area and may also be considered for the primary treatment of recurrent instability in the high-risk contact athlete, even in the setting of limited osseous deficiency. The following Technical Note provides a diagnostic approach for suspected glenohumeral instability, as well as a detailed description of the congruent-arc Latarjet procedure, performed with a deltoid split, with its postoperative management.