The Pavlik harness in the treatment of developmentally dislocated hips: results of Japanese multicenter studies in 1994 and 2008

AbstractBackgroundIt has already been more than 50years since the Pavlik harness was introduced in Japan, and today the Pavlik harness is widely recognized as the standard initial treatment modality for developmental dysplasia of the hip. We performed a multicenter nationwide questionnaire study concerning the results of Pavlik harness treatment twice in 1994 and 2008.MethodsIn 1994 and in 2008, we sent questionnaires to 12 institutes in Japan specializing mainly in pediatric orthopedics. We compare the results of these two studies and discuss differences in reduction rates, incidence of avascular necrosis in the femoral epiphysis and the percentage of joints with acceptable morphology (Severin grade I+II/total) at skeletal maturity. We statistically assessed these results to see whether there were changes in the treatment outcomes over this 14-year period.ResultsReduction of the dislocated hips was obtained by the Pavlik harness in 80.2% (1990/2481 hips; 1994) and 81.9% (1248/1523 hips; 2008). The incidences of avascular necrosis of the proximal femoral epiphysis in the dysplastic hips were 14.3% (119/835 hips; 1994) and 11.5% (76/663 hips; 2008). The type of avascular necrosis in hips from the 2008 study was determined according to the classification of Kalamchi and MacEwen: 24/69 hips (34.8%) were classified as group I; 20/69 hips (29.0%) as group II; 11/69 hips (15.9%) as group Ill; 14/69 hips (20.3%) as group IV. The percentages of hips with acceptable outcomes at skeletal maturity discerned from Severin X-ray changes (grade I+II/total) were 72.3% (604/835 hips; 1994) and 77.7% (488/628 hips; 2008).ConclusionReduction rates and the incidence of avascular necrosis in 2008 were statistically similar to the results in 1994. The rate of acceptable outcome (Severin grade I+II/total) in 2008 was statistically higher than that of 1994

マウスの胸腺と脾臓におけるIgE転写の比較

1週齢から5週齢BALB/cマウスの抗体遺伝子の転写を,胸腺と脾臓で比較した。調べた抗体のクラスのなかで,IgEの転写量に関しては,胸腺と脾臓で明瞭な差異が認められた。胸腺では,雌雄ともに,IgEは1週齢から転写されていた。脾臓では3週齢までは検出できなかった。雌では,3週齢から4週齢の間で,脾臓でもIgEの転写が検出され始めた。雄では,5週齢まででは,脾臓でIgEの転写は検出できなかった。IgEの転写に関して胸腺と脾臓で明瞭な差異が認められることから,胸腺で抗体遺伝子を転写している細胞は,胸腺内の血管内のBリンパ球ではなく,また,脾臓で分化したBリンパ球が流入したものでもなく,発生段階で流入した幹細胞から胸腺内で分化したリンパ球であると考えられる。Immunoglobulin heavy chain gene transcription was investigated by reverse transcription PCR both in the thymus and in the spleen of BALB/c mice of age 1 to 5 weeks old. A definitive difference in IgE transcriptions was found between in the thymus and in the spleen. IgE transcriptions were demonstrated clearly in the thymus of all mice, while, in the spleen, not detected in 1 to 3 weeks old. Therefore, the cells transcribing antibody genes in the thymus of mouse are neither B lymphocytes in blood vessels, nor invaded B lymphocytes after proliferation and development in the spleen. Those will be specific cells which proliferate and develop in the thymus from stem cells which immigrated at embryonic stage