Diagnosis of a full-thickness tear can be learned to a high degree of accuracy. Despite the radiologist's level of experience and knowledge of the arthroscopic findings, the sensitivity for diagnosis of partial tears is poor.

Background Falls and fall-related injuries are a major public health concern. HIV-infected adults have been shown to have a high incidence of falls. Identification of major risk factors for falls that are unique to HIV or similar to the general population will inform development of future interventions for fall prevention. Methods HIV-infected and uninfected men and women participating in a Hearing and Balance Sub-study of the Multicenter AIDS Cohort Study and Women’s Interagency HIV Study were asked about balance symptoms and falls during the prior 12 months. Falls were categorized as 0, 1, or ≥ 2; proportional odds logistic regression models were used to investigate relationships between falls and demographic and clinical variables and multivariable models were created. Results 24% of 303 HIV-infected participants reported ≥1 fall compared to 18% of 233 HIV-uninfected participants (p=0.27). HIV-infected participants were demographically different from HIV-uninfected participants, and were more likely to report clinical imbalance symptoms (p≤0.035). In univariate analyses, more falls were associated with hepatitis C, female sex, obesity, smoking, and clinical imbalance symptoms, but not age, HIV serostatus, or other comorbidities. In multivariable analyses, female sex and imbalance symptoms were independently associated with more falls. Among HIV-infected participants, smoking, number of medications, and imbalance symptoms remained independent fall predictors while current protease inhibitor use was protective. Discussion Similar rates of falls among HIV-infected and uninfected participants were largely explained by a high prevalence of imbalance symptoms. Routine assessment of falls and dizziness/imbalance symptoms should be considered, with interventions targeted at reducing symptomatology.

Popliteus muscle and tendon injuries are not uncommon. They usually occur in conjunction with other significant injuries of the knee and can be characterized with MR imaging.

Evidence has been presented to support the idea that iodine plays an important role in autoimmune thyroiditis. Excessive amounts induce thyroiditis in genetically susceptible animal strains, while intrathyroidal depletion of iodine prevents disease in strains susceptible to severe thyroiditis. While the mechanisms by which iodine promotes thyroiditis is unknown, several hypotheses have been proposed. (1) T and/or B cells may react specifically to iodinated portions of thyroglobulin (Tg) so that severe iodine depletion renders Tg non-immunogenic. (2) A defect in the iodine processing machinery in thyroid epithelial cells of a susceptible person or animal may, in the presence of iodine, result in elevated levels of oxygen or iodine radicals, which could damage membrane lipids or proteins. (3) Defective iodine processing may result in the iodination of lipid or proteins (other than Tg) which could act either as immunogens or polyclonal activators.

Experiments were performed to analyze one mechanism by which elevated levels of dietary iodine may induce thyroglobulin (Tg) autoantibodies. We tested the hypothesis that highly iodinated Tg synthesized by animals fed a high iodine diet is significantly more immunogenic than Tg containing fewer iodine atoms. Cornell strain (CS) chickens, genetically susceptible to iodide-induced thyroiditis, were fed either a high or a low iodine diet. They were killed, and their thyroidal Tg was analyzed for iodine; the high iodine Tg (HI-Tg) had at least 60 and the low iodine Tg (LI-Tg) had less than 13 atoms/molecule of Tg. To determine if the degree of Tg iodination affected its immunogenicity, these Tg preparations were administered iv to normal chickens without adjuvants. Their sera were tested for antibodies by direct binding radioassays and RIAs. HI-Tg stimulated the synthesis of antibodies that reacted well with HI-Tg and the thyroid hormones T3 and T4, but only weakly with LI-Tg. The birds immunized with LI-Tg produced very little antibody to LI-Tg, T3, or T4, but a modest amount to HI-Tg. In other experiments, Tg autoantibodies found in chickens maintained on a high iodine diet similarly demonstrated enhanced binding to HI-Tg. The present studies show that HI-Tg is more immunogenic than LI-Tg and supports the hypothesis that a high iodine diet induces Tg autoantibodies by increasing the immunogenicity of the Tg molecule. In marked contrast with iodide-induced Tg antibodies, the Tg antibodies accompanying the severe and early-onset thyroiditis of obese strain chickens are to a large degree independent of dietary iodine intake.