Conditioned responding to drug-predictive discrete cues can be strongly modulated by drug-associated contexts. We tested the hypothesis that differential recruitment of the nucleus accumbens core and shell mediates responding to drug cues in a drug versus non-drug context. Rats were trained to discriminate between two, 10-sec auditory stimuli: one stimulus (CS+) was paired with ethanol (10% v/v; 0.2ml; oral) while the other (CS−) was not. Training occurred in operant conditioning chambers distinguished by contextual stimuli, and resulted in increased entries into the ethanol delivery port during the CS+ compared to the CS−. In Experiment 1, port-entries were then extinguished in a second context by withholding ethanol, after which context-induced renewal of ethanol-seeking was tested by presenting both stimuli without ethanol in the prior training context. This manipulation stimulated strong responding to the CS+ in rats pretreated with saline in the core (n=9) or shell (n=10), which was attenuated by pharmacologically inactivating (muscimol/baclofen; 0.1/1.0 mM; 0.3μl/side) either subregion pretest. In Experiment 2, following discrimination training rats were habituated to a different context where ethanol and both stimuli were withheld. Cue-induced ethanol-seeking was then elicited by presenting the CS+ and CS− without ethanol in the different context. Saline pretreated rats responded more to the CS+ than the CS− (core n=8; shell n=9), and inactivating the core but not shell attenuated this effect. These data highlight an important role for the core in cue-induced ethanol-seeking, and suggest that the shell is required to mediate the influence of contexts on conditioned ethanol-seeking.

Background Total knee arthroplasty (TKA) and related interventions such as revision TKA and the treatment of infected TKAs are commonly performed procedures. Hospital readmission rates are used to measure hospital performance, but risk factors (both medical and surgical) for readmission after TKA, revision TKA, and treatment for the infected TKA have not been well characterized. Questions/purposes We measured (1) the unplanned hospital readmission rate in primary TKA and revision TKA, including antibiotic-spacer staged revision TKA to treat infection. We also evaluated (2) the medical and surgical causes of readmission and (3) risk factors associated with unplanned hospital readmission. Methods This retrospective cohort study included a total of 1408 patients (1032 primary TKAs, 262 revision TKAs, 113 revision of infected TKAs) from one institution. All hospital readmissions within 90 days of discharge were evaluated for timing and cause. Diagnoses at readmission were categorized as surgical or medical. Readmission risk was assessed using a Cox proportional hazards model that incorporated patient demographics and medical comorbidities. Results The unplanned readmission rate for the entire cohort was 4% at 30 days and 8% at 90 days. At 90 days postoperatively, revision of an infected TKA had the highest readmission rate, followed by revision TKA, with primary TKA having the lowest rate. Approximately threefourths of readmissions were the result of surgical causes, mostly infection, arthrofibrosis, and cellulitis, whereas the remainder of readmissions were the result of medical causes. Procedure type (primary TKA versus revision TKA or staged treatment for infected TKA), hospital stay more than 5 days, discharge destination, and a fluid/electrolyte abnormality were each associated with risk of unplanned readmission.

Objectives:Purpose: Overuse injuries to the elbow in the throwing athlete are common. Ulnar collateral ligament reconstruction (UCLR), commonly known as Tommy John surgery, is performed on both recreational and high-level athletes. There is no current literature regarding the incidence and demographic distribution of this surgical procedure in relation to age, location within the Unites States (U.S.), and gender. The purpose of this study is to determine the current demographic distribution of UCLR within the U.S.Methods:Methods: A retrospective analysis of private payer database using the PearlDiver Supercomputer (Warsaw, IN) was performed to identify UCLR procedures performed between the years of 2007-2011. The Current Procedural Code (CPT) 24346 (reconstruction of the ulnar collateral ligament of the elbow with the use of a tendinous graft) was used. Statistical analysis was performed as appropriate using STATA (Version 12.1; Statacorp; College Station, TX, USA).Results:Results: Between 2007-2011, 790 patients underwent UCLR. The overall average annual incidence was 2.16+/- 0.27 per 100,000 patients, but was 31.9 +/-3.9 for patients aged 15-19. The average annual growth was 5.72%. There were 695 males and 95 females. Fifteen to 19 year olds accounted for significantly more procedures than any other age group 56.8% (p<0.001), followed by 20 to 24 year olds 23.4%. The incidence of UCLR in the 15-19 year old group increased at an average rate of 6% per year (incidence rate ratio = 1.06, p=0.025). The south region performed significantly more UCLR than any other region p<0.001. The number of procedures significantly increased over time (p=0.039).Conclusion:Conclusion: UCLR was performed significantly more in patients aged 15-19 than any other age group. The average annual incidence of UCLR per 100,000 people for patients aged 15-19 is 31.9. The number of UCLR is increasing over time. Further work should address risk-reduction efforts in this at-risk population.

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Background Total hip arthroplasty (THA) is a beneficial and cost-effective procedure for patients with osteoarthritis. Recent initiatives to improve hospital quality of care include assessing unplanned hospital readmission rates. Patients presenting for THA have different indications and medical comorbidities that may impact rates of readmission. Questions/purposes This study measured (1) the unplanned hospital readmission rate in primary THA, revision THA, and antibiotic-spacer staged revision THA to treat infection. Additionally, we determined (2) the medical and surgical causes of readmission; and (3) the risk factors associated with unplanned readmission. Methods A total of 1415 patients (988 primary THA, 344 revision THA, 82 antibiotic-spacer staged revision THA to treat infection) from a single institution were included. All hospital readmissions within 90 days of discharge were reviewed. Patient demographics and medical comorbidities were included in a Cox proportional hazards model to assess risk of readmission. Results The overall unplanned readmission rate was 4% at 30 days and 7% at 90 days. At 90 days, primary THA (5%) had a lower unplanned readmission rate than revision THA (10%, p \ 0.001) and antibiotic-spacer staged revision THA (18%, p \ 0.001). Medical diagnoses were responsible for almost one-fourth of unplanned readmissions, whereas over half of surgical readmissions were the result of dislocation, surgical site infection, and postoperative hematoma. Type of procedure, hospital stay greater than 5 days, cardiac valvular disease, diabetes with endorgan complications, and substance abuse were each associated with increased risk of unplanned readmission. Conclusions Higher rates of unplanned hospital readmissions in revision THA rather than primary THA suggest that healthcare quality measures that incorporate readmission rates as a proxy for quality of care should distinguish between primary and revision procedures. Failure to do so may negatively impact tertiary referral hospitals that often care for patients requiring complex revision procedures. Level of Evidence Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Background: Recent studies have shown that intra-articular injections ≤3 months before total knee arthroplasty increase the risk of periprosthetic joint infection. We are aware of no previous study that has differentiated the risk of periprosthetic joint infection on the basis of the type of medication injected. In addition, we are aware of no prior study that has evaluated whether hyaluronic acid injections increase the risk of infection after total knee arthroplasty. In this study, we utilized pharmaceutical data to compare patients who received preoperative corticosteroid or hyaluronic acid injections and to determine whether a specific injection type increased the risk of periprosthetic joint infection. Methods: Patients undergoing unilateral primary total knee arthroplasty were selected from a nationwide private insurer database. Ipsilateral preoperative injections were identified and were grouped by medication codes for corticosteroid or hyaluronic acid. Patients who had received both types of injections ≤1 year before total knee arthroplasty were excluded. The outcome of interest was periprosthetic joint infection that occurred ≤6 months following the total knee arthroplasty. The risk of periprosthetic joint infection was compared between groups (no injection, corticosteroid, hyaluronic acid) and between patients who received single or multiple injections. Statistical comparisons were performed using logistic regression controlling for age, sex, and comorbidities. Results: A total of 58,337 patients underwent total knee arthroplasty during the study period; 3,249 patients (5.6%) received hyaluronic acid and 16,656 patients (28.6%) received corticosteroid ≤1 year before total knee arthroplasty. The overall infection rate was 2.74% in the no-injection group. Multivariable logistic regression showed independent periprosthetic joint infection risk for both corticosteroid (odds ratio [OR], 1.21; p = 0.014) and hyaluronic acid (OR, 1.55; p = 0.029) given ≤3 months before total knee arthroplasty. There was no increased risk with injections >3 months prior to total knee arthroplasty. Direct comparison of corticosteroid and hyaluronic acid showed no significant difference (p > 0.05) between medications or between single and multiple injections. Conclusions: Preoperative corticosteroid or hyaluronic acid injection ≤3 months before total knee arthroplasty increased the risk of periprosthetic joint infection. There was no difference in infection risk between medications or between multiple and single injections. On the basis of these data, we recommend avoiding both injection types in the 3 months prior to total knee arthroplasty. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The CEA literature in sports medicine is good; however, there is a paucity of studies, and the available evidence is focused on a few procedures. More work needs to be conducted to quantify the cost-effectiveness of different techniques and procedures within sports medicine. The QHES tool may be useful for the evaluation of future CEAs.

At least half of patients treated with hip arthroscopy for FAI achieve MCID and SCB within the first 6 months after the procedure. However, clinically significant outcome improvement continues to be attained until 2 years postoperatively. Female patients, younger individuals, and those without chondral defects achieve faster clinical outcome improvement. These findings can be helpful for establishing shared decision-making aids and follow-up guidelines for arthroscopic treatment of FAI.