Dact gene expression profiles suggest a role for this gene family in integrating Wnt and TGF-ß signaling pathways during chicken limb development.

BACKGROUND: Dact gene family encodes multifunctional proteins that are important modulators of Wnt and TGF-ß signaling pathways. Given that these pathways coordinate multiple steps of limb development, we investigated the expression pattern of the two chicken Dact genes (Dact1 and Dact2) from early limb bud up to stages when several tissues are differentiating. RESULTS: During early limb development (HH24-HH30) Dact1 and Dact2 were mainly expressed in the cartilaginous rudiments of the appendicular skeleton and perichondrium, presenting expression profiles related, but distinct. At later stages of development (HH31-HH35), the main sites of Dact1 and Dact2 expression were the developing synovial joints. In this context, Dact1 expression was shown to co-localize with regions enriched in the nuclear ß-catenin protein, such as developing joint capsule and interzone. In contrast, Dact2 expression was restricted to the interzone surrounding the domains of bmpR-1b expression, a TGF-ß receptor with crucial roles during digit morphogenesis. Additional sites of Dact expression were the developing tendons and digit blastemas. CONCLUSIONS: Our data indicate that Dact genes are good candidates to modulate and, possibly, integrate Wnt and TGF-ß signaling during limb development, bringing new and interesting perspectives about the roles of Dact molecules in limb birth defects and human diseases.

Morphophysiopathology of synovial plica from knee joint: a literature review

Synovial plicae around the knees are a relatively common occurrence. They have been the object of many clinical and anatomical researches, not only because of their intra-articular existence, but also for their painful symptomatology caused on knee joint. These plicae are excessive folds of synovial membrane and are remnants from embryonic septum, which were not properly absorbed during fetal development. These synovial plicae are divided anatomically, as location and existence, and are classified into suprapatellar, infrapatellar, medial patellar and lateral patellar plicae; being still each of these subdivided according to their appearance and juxtaposition. Material and methods: A retrospective literature review selected articles in PubMed and MEDLINE databases; papers were searched using the keywords: synovial plicae, knee, embryology, anatomy, histology and treatment. Results: In this literature review was verified the incidence about the types, shape, location, symptoms, pathophysiology, and the main methods of study for the verification of synovial plica and treatments. Conclusion: In summary, asymptomatic plica can become symptomatic due to a bucket‑handle tear following a twisting injury and lateral traction to the knee, when carefully diagnosed; a synovial plica represents a potential cause of pain in patients. After careful examination, arthroscopic resection of the bucket‑handle portion of the plica is sufficient for the improvement of the symptoms if conservative treatment of pathological plica fail.

Treatment of pathological synovial plicae of the knee.

OBJECTIVE: To analyze the incidence, clinical significance, and clinical manifestations of pathological synovial plicae of the knee. MATERIAL AND METHODS: Between 2002 and 2006, 63 patients with pathological synovial plicae of the knee were studied. Of those 63 patients, 21 had the diagnosis confirmed by previously performed magnetic resonance imaging. All of the patients initially underwent conservative treatment for 90 days that involved strengthening and improving the flexibility of the muscles surrounding the knee as well as modification of their sports activities. RESULTS: A total of 55 patients improved after conservative treatment. Six of these patients eventually experienced a recurrence of symptoms, but the symptoms were not incapacitating in any of these patients. The other eight patients underwent arthroscopic removal of the synovial plica. Of these eight patients, six returned to their pretreatment physical activities, and two had persistent symptoms during physical activity. CONCLUSION: The presence of a synovial plica of the knee should be considered as a potential diagnosis in patients with knee pain, especially those who practice sports inappropriately. Conservative treatment is effective in most cases, and surgical treatment should be reserved for exceptional cases that do not improve with conservative treatment.

Treatment of pathological synovial plicae of the knee

OBJECTIVE: To analyze the incidence, clinical significance, and clinical manifestations of pathological synovial plicae of the knee. MATERIAL AND METHODS: Between 2002 and 2006, 63 patients with pathological synovial plicae of the knee were studied. Of those 63 patients, 21 had the diagnosis confirmed by previously performed magnetic resonance imaging. All of the patients initially underwent conservative treatment for 90 days that involved strengthening and improving the flexibility of the muscles surrounding the knee as well as modification of their sports activities. RESULTS: A total of 55 patients improved after conservative treatment. Six of these patients eventually experienced a recurrence of symptoms, but the symptoms were not incapacitating in any of these patients. The other eight patients underwent arthroscopic removal of the synovial plica. Of these eight patients, six returned to their pretreatment physical activities, and two had persistent symptoms during physical activity. CONCLUSION: The presence of a synovial plica of the knee should be considered as a potential diagnosis in patients with knee pain, especially those who practice sports inappropriately. Conservative treatment is effective in most cases, and surgical treatment should be reserved for exceptional cases that do not improve with conservative treatment.