[99m]tc-ubiquicidin [29-41], a promising radiopharmaceutical to differentiate orthopedic implant infections from sterile inflammation

Ubiquicidin [UBI] [29-41] is a synthetic cationic antimicrobial peptide that preferentially binds to bacterial cell membrane at the site of infection. We aimed to assess diagnostic value of [99m]Tc-UBI [29-41] as a radiopharmaceutical in differentiation of bacterial infection from sterile inflammation in suspected orthopedic implants. Nine patients suspected for orthopedic implant infection, all males with the mean age of 41.6 +/- 20.9 years, were studied. A dose of 10 MBq/Kg [range: 555-740 MBq] [99m]Tc-UBI [29-41] was injected intravenously. A dynamic study followed by static whole body imaging at 30, 60 and 120 min post-radiotracer injection was acquired. Periprosthetic tissue culture was considered the closest test to a gold standard for diagnosing infections and scintigraphic scans were categorized as true- or false-positive and true- or false-negative, considering the bacterial culture as the gold standard. No adverse reaction was observed during or after the radiotracer injection days. There were five true positive, four true negative and no false positive and false negative scans. Sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] were all calculated as 100%. We found a high diagnostic accuracy for [99m]Tc-UBI [29-41] scintigraphy in differentiation of bacterial infection from sterile inflammation in suspected orthopedic implants. Therefore, [99m]Tc-UBI [29-41] scintigraphy might be potentially recommended as a safe and promising imaging modality in these settings. However, further studies on a larger number of patients and different pathologies are still needed

[Knee stability evaluation following double-bundle versus single-bundle anterior cruciate ligament reconstruction]

Anterior cruciate ligament [ACL] reconstruction is a first choice treatment for ACL-deficient knees, and arthroscopic single-bundle reconstruction has been widely accepted around the world in this regard. Although, such single-bundle reconstructions result in sufficient knee stability in most cases, but some patients have not been satisfied with postsurgical results in both short-term and long term clinical studies. One of the reasons for these unsatisfactory results could be related to the fact that normal function of the native ACL has not been restored by the traditional ACL reconstruction which uses only a single-bundle graft. The natural ACL consists of a 3-dimensional structure with multibundle fascicles, which can be anatomically divided into 2 main bundles, the anteromedial [AM] and the posterolateral [PL] bundles named for the orientation of their tibial insertions. The purpose of the present study was to compare double-bundle and single-bundle ACL reconstruction. Twenty-two patients with anterior cruciate ligament tear who were candidates for ACL reconstruction were enrolled in the study undertaken in Shariati Hospital from 2009 to 2010. Fourteen patients underwent single-bundle and 8 patients double-bundle ACL reconstruction. The patients were evaluated by arthrometer and physical examination in postoperation follow up visit at least 9 months after the operations. Four out of 14 patients with single-bundle reconstruction had knee joint translation greater than 5 mm but nobody had knee translation more than 5 mm in the double-bundle reconstruction group. Double-bundle ACL reconstruction seems to be more stable than single-bundle ACL reconstruction