Background: As the popularity of total ankle arthroplasty (TAA) increases and indications expand, surgeons require a better understanding of which patient factors are associated with implant failure. In this study, we aimed to use a large total ankle database to identify independent risk factors for implant failure at mid- to long-term follow-up. Methods: A prospectively collected database was used to identify all patients who underwent primary TAA with a minimum 5 years’ follow-up. The primary outcome was revision, defined as removal of one or both metal components; failures due to infection were excluded. Patient and clinical factors analyzed included age, sex, body mass index (BMI), smoking status, presence of diabetes, indication for TAA, implant, tourniquet time, and presence of ipsilateral hindfoot fusion. Preoperative coronal deformity and sagittal talar translation were assessed, as were postoperative coronal and sagittal tibial component alignment. Univariable and multivariable analyses were performed to identify predictors of implant failure. After excluding 5 ankles that failed because of deep infection, 533 ankles with a mean 7 (range, 5-11) years of follow-up met the inclusion criteria. Four implants were used: INBONE I, INBONE II, STAR, and Salto-Talaris. Results: Thirty-four ankles (6.4%) were revised or removed a mean 4 (range, 1-9) years postoperatively. The only independent predictors of failure were the INBONE I prosthesis and ipsilateral hindfoot fusion ( P = .006 and P = .023, respectively). Conclusions: This is among the largest studies to analyze the relationship between TAA failure rates and multiple different patient, operative, and radiographic factors. Of note, age, BMI, and amount of deformity were not associated with higher failure rates. Only patients with ipsilateral hindfoot fusion or who received the INBONE I prosthesis were at significantly higher risk of implant failure. Level of Evidence: Level III, retrospective cohort study.

BackgroundObesity-related diseases, including type 2 diabetes and cardiovascular disease, have reached epidemic proportions in industrialized nations, and dietary interventions for their prevention are therefore important. Resistant starches (RS) improve insulin sensitivity in clinical trials, but the mechanisms underlying this health benefit remain poorly understood. Because RS fermentation by the gut microbiota results in the formation of physiologically active metabolites, we chose to specifically determine the role of the gut microbiota in mediating the metabolic benefits of RS. To achieve this goal, we determined the effects of RS when added to a Western diet on host metabolism in mice with and without a microbiota.ResultsRS feeding of conventionalized mice improved insulin sensitivity and redressed some of the Western diet-induced changes in microbiome composition. However, parallel experiments in germ-free littermates revealed that RS-mediated improvements in insulin levels also occurred in the absence of a microbiota. RS reduced gene expression of adipose tissue macrophage markers and altered cecal concentrations of several bile acids in both germ-free and conventionalized mice; these effects were strongly correlated with the metabolic benefits, providing a potential microbiota-independent mechanism to explain the physiological effects of RS.ConclusionsThis study demonstrated that some metabolic benefits exerted by dietary RS, especially improvements in insulin levels, occur independently of the microbiota and could involve alterations in the bile acid cycle and adipose tissue immune modulation. This work also sets a precedent for future mechanistic studies aimed at establishing the causative role of the gut microbiota in mediating the benefits of bioactive compounds and functional foods.Electronic supplementary materialThe online version of this article (doi:10.1186/s40168-017-0230-5) contains supplementary material, which is available to authorized users.

No abstract

Level III, case-control study.

Level II, cross sectional study.

Level II, cross-sectional study.

Background: Despite the importance of shoe wear to patients with hallux valgus (HV), few studies have investigated changes in foot width following surgery in this population. The purpose of our study was to determine if the modified Lapidus procedure would effectively decrease foot width in patients with HV. Methods: Thirty-one feet (19 left, 12 right) in 30 patients (29 females, 1 male) who underwent a modified Lapidus procedure in combination with a modified McBride and Akin osteotomy for treatment of HV were included in the study. All patients had preoperative and at least 5-month postoperative imaging, consisting of both weightbearing radiographs and computed tomography (WBCT) scans, which were used to measure bony and soft tissue foot widths pre- and postoperatively by 2 independent observers. Results: Intraclass correlation coefficients (ICCs) demonstrated high interobserver reliability (all ICCs >0.90). Bony foot width decreased significantly, by a mean of 8.9 mm (9.1%) on radiographs and 7.9 mm (8.4%) on WBCT scans ( P < .001). The soft tissue foot width also decreased significantly, by a mean of 6.9 mm (6.3%) on radiographs and 6.7 mm (6.4%) on WBCT scans ( P < .001). Changes in the hallux valgus angle and intermetatarsal angle correlated with changes in bony foot width on WBCTs (both r > 0.4, P < .02). Conclusions: The modified Lapidus procedure in combination with a modified McBride and Akin osteotomy resulted in statistically significant changes in both bony and soft tissue foot width. Patients should be counseled that foot width decreases, on average, by 0.5 to 1 cm. Level of Evidence: Level III, comparative series.

Background: To date, no study has assessed fulfillment of patients’ expectations after foot and ankle surgery. This study aimed to validate a method of assessing expectation fulfillment in foot/ankle patients postoperatively. Methods: Preoperatively, patients completed the expectations survey, consisting of 23 questions for domains including pain, ambulation, daily function, exercise, and shoe wear. At 2 years postoperatively, patients answered how much improvement they received for each item cited preoperatively. A fulfillment proportion (FP) was calculated as the amount of improvement received versus the amount of improvement expected. The FP ranges from 0 (no expectations fulfilled), to between 0 and 1 (expectations partially fulfilled), to 1 (expectations met), to greater than 1 (expectations surpassed). Receiver operating characteristic (ROC) curves and areas under the curve (AUCs) with 95% confidence intervals (CIs) were used to compare the expectations survey to other outcome surveys, including Foot and Ankle Outcome Score, improvement, overall fulfillment, Delighted-Terrible scale, and satisfaction. Results: Of the 271 patients (mean age 55.4 years, mean BMI 27.5, 65% female), 34% had expectations surpassed (FP >1), 4% had expectations met, 58% had expectations partially fulfilled (FP between 0 and 1), and 5% had no expectations met. The mean FP was 0.84 ± 0.41 (range 0-3.13), indicating partially fulfilled expectations. FP correlated significantly with all outcome measures ( P ≤ .007). FP was associated most closely with satisfaction ( r = 0.66 [95% CI 0.57-0.75]; AUC = 0.92 [95% CI 0.88-0.96]; P < .001) and improvement ( r = 0.73 [95% CI 0.64-0.81]; AUC = 0.94 [95% CI 0.91-0.96]; P < .001). Based on the associations with satisfaction and improvement outcomes, a clinically important proportion of expectations fulfilled is 0.68, with sensitivity 0.85-0.90 and specificity 0.84-0.86. Conclusion: The proportion of expectations fulfilled is a novel patient-centered outcome that correlated with validated outcome measures. The expectations survey may be used by surgeons to counsel patients preoperatively and also to assess patients’ results postoperatively. Level of Evidence: Level II, prospective comparative series.