Purpose of Review Over the past decade, our understanding of the biomechanics of the reverse total shoulder arthroplasty (RTSA) has advanced, resulting in design adjustments, improved outcomes, and expanding indications. The purpose of this review is to summarize recent literature regarding the biomechanics of RTSA and the evolving indications for its use. Recent Findings While Grammont's principles of RTSA biomechanics remain pillars of contemporary designs, a number of modifications have been proposed and trialed in later generations to address complications such as impingement and glenoid failure. Clinical and biomechanical literature suggest that less medialized, more inferior glenospheres result in less impingement and notching. On the humerus, a more vertical neck cut is associated with less impingement. Indications for RTSA continue to expand beyond the classic indication of cuff tear arthropathy (CTA). Patients without a functional cuff but no arthritis now have a reliable option in the RTSA. RTSA has also replaced hemiarthroplasty as the implant of choice for displaced three-and four-part proximal humerus fractures in the elderly. Finally, updated design options and modular components now allow for treatment of glenoid bone loss, failed arthroplasty, and proximal humerus tumors with RTSA implants. Summary Reverse total shoulder arthroplasty design has been modernized on both the glenoid and humerus to address biomechanical challenges of early implants. As outcomes improve with these modifications, RTSA indications are growing to address complex bony pathologies such as tumor and bone loss. Longitudinal follow-up of patients with updated designs and novel indications is essential to judicious application of RTSA technology.

Background: Many youth athletes focus on 1 sport to gain a competitive advantage, but early sport specialization may increase risk of overuse injuries and burnout. College athletes have successfully achieved advanced status; therefore, the study of their specialization patterns is a method to assess how specialization affects an athletic career. Purpose: To determine trends in sport specialization by sex, sport, and decade of participation in National Collegiate Athletic Association (NCAA) athletes and assess the effect of specialization on scholarship attainment, injury, and attrition. Study Design: Cohort study; Level of evidence, 3. Methods: An electronic survey was distributed to NCAA athletes who participated from 1960 to 2018. Survey topics included sex, sport, decade of participation, scholarship status, ≥30-day time-loss injuries sustained in college, orthopaedic surgery in college, career length, and age of single-sport specialization. Early specialization was defined as specialization in a single sport before age 15 years. Rates of early specialization were calculated for each sport, sex, individual and team sports, and decade of participation. Rates of scholarship attainment, injury, and attrition were compared between groups. Univariate associations were queried with logistic regression analysis to determine predictors of specialization, scholarship attainment, injury, and early attrition. Results: Of 1550 athletes who participated (17% response rate), 544 (35.1%) were women. Overall, 18.1% of athletes specialized before age 15 years (n = 281). Athletes in gymnastics, tennis, swimming and diving, and soccer were significantly more likely to specialize early, whereas football and baseball athletes were more likely to specialize late ( P < .05 for all groups). Early specialization was more common among women (23.4% vs 15.2%; odds ratio, 1.72; P < .01). There was a trend toward earlier specialization for recent college graduates, with graduates from the last decade more likely to be classified as early specialization than those from previous decades ( P = .036). Scholarship attainment was overall equivalent between groups. Time-loss injuries, lower extremity injuries, and orthopaedic surgery in college were not statistically different between groups. Career lengths were similar, but burnout was more common among early specialization athletes (10.5% vs 7.0%; odds ratio, 3.76; P < .01). Conclusion: Less than one-fifth of NCAA athletes surveyed specialized before age 15 years, and neither scholarship attainment nor time-loss injury rate was affected by early specialization. Early specialization is on the rise but is associated with increased burnout.

This is the first case in which trigeminal neuralgia was treated with a third ventriculostomy and one of only four cases of isolated trigeminal neuralgia associated with a Chiari malformation. Acquired aqueductal stenosis may have caused the hydrocephalus which, in turn, caused the Chiari malformation configuration that caused the trigeminal neuralgia. The rationale for the treatment modality and possible causes of Chiari I-induced trigeminal neuralgia are discussed.

Purpose To evaluate risk factors for conversion of hip arthroscopy to total hip arthroplasty (THA) within 2 years in a closed patient cohort. Methods This study was a case series of consecutive hip arthroscopy procedures from September 2008 to November 2018 in the electronic medical record of Kaiser Permanente Northern California. Patients were included with minimum 2-year follow-up or if they had conversion to THA within 2 years (the primary outcome) regardless of follow-up time. Patient characteristics at the time of the index arthroscopy were extracted; characteristics of patients who experienced the outcome event versus those who did not were compared by use of multivariable logistic regression models and receiver operating characteristic (ROC) curves. Results The mean follow-up time was 4.9 years (median 4.6, range 0.6 to 11.6). The mean age was 37.2 years (range 10 to 88), and 57% were female. During the follow-up period, 82 patients underwent a THA within 2 years of their arthroscopies (5.3%, 95% confidence interval 4.3% to 6.5%) after a median time of 9 months (interquartile range 5.9 to 14.4) after the initial arthroscopy. Increasing age was highly predictive of early THA conversion (area under the ROC curve = 0.78, P < .001). Although other predictors showed significant bivariable associations with early failure, body mass index (BMI), race, sex, and prior arthroscopy did not add meaningful independent predictive information. Conclusions The risk of conversion to THA within 2 years after hip arthroscopy increased substantially with patient age at the time of the procedure. BMI, race, sex, and prior arthroscopy were not important independent predictors of conversion beyond the information contained in patient age. Level of Evidence Level IV, therapeutic case series.

Positron emission tomography (PET) using 18fluoro-2-deoxyglucose (FDG) has become a standard clinical tool for staging and response assessment in aggressive lymphomas. The use of PET scans in clinical trials is still under exploration, however. In this review, we examine current data regarding PET in DLBCL, and its potential applicability to development of a surrogate endpoint to expedite clinical trial conduct. Interim PET scanning in DLBCL shows mixed results, with qualitative assessment variably associated with outcome. Addition of quantitative assessment might improve predictive power of interim scans. Data from multiple retrospective studies support that PET-defined response at end of treatment correlates with outcome in DLBCL. Optimal technical criteria for standardization of acquisition and criteria for interpretation of scans require further study. Prospective studies to define the correlation of PET-defined response and time-dependent outcomes such as progression free survival (PFS) and overall survival (OS), critical for development of PET as a surrogate endpoint for clinical trials, are ongoing. In conclusion, evolving data regarding utility of PET in predictcing outcome of patients with DLBCL show promise to support the use of PET as a surrogate endpoint in clinical trials of DLBCL in the future.