METHODS: Twenty-one patients had a history of nursemaid\'s elbow and had a successful reduction before enrollment in this study. A high-frequency linear array 6 to 24 MHz hockey stick transducer was used to detect small morphologic changes in the peripheral rim of the radial head epiphysis and the posterior synovial fringe during rotation of the capitellum-radial joint.
RESULTS: In complete pronation, the anterior edge of the posterior synovial fringe contacts the beveled articular surface of the radial head peripheral rim in all 21 patients. In neutral and complete supination, the anterior edge of the posterior synovial fringe contacts the convexly nonarticular surface of the radial head peripheral rim and extends deep into the foveal radius. The posterior synovial fringe and the capsule-aponeurotic membrane were tightened in passive pronation in all 21 cases. The posterior synovial fringe and the capsule-aponeurosis membrane were all loose in the neutral and supination positions.
CONCLUSIONS: The anterior edge of the posterior synovial fringe touches the beveled peripheral rim of the radial head epiphysis during complete pronation, and the tension of the lateral collateral ligament complex during pronation may further cause unstable conditions of the anterior edge of the posterior synovial fringe. We hypothesized that the beveled peripheral rim of the radial epiphysis and its relationship with the anterior edge of the posterior synovial fringe could be the reason why nursemaid\'s elbow only occurs while the elbow is in the pronator position.
方法:21例患者有护士肘部病史,在纳入本研究前成功复位。使用6至24MHz的高频线性阵列曲棍球棒换能器来检测the头-the关节旋转过程中the头的外围边缘和后部滑膜边缘的微小形态变化。
结果:在完整内旋中,在所有21例患者中,后滑膜边缘的前缘与radial头外周边缘的倾斜关节面接触。在中性和完全旋后,后滑膜边缘的前边缘接触radial头外周边缘的凸状非关节表面,并延伸到中央凹radius骨深处。在所有21例中,后滑膜边缘和囊膜膜膜均在被动内旋中收紧。后滑膜边缘和囊膜膜在中性和旋后位置均松散。
结论:在完全内旋期间,后滑膜边缘的前边缘接触radial骨and骨的倾斜周缘,内旋期间外侧副韧带复合体的张力可能进一步导致后滑膜边缘前缘的不稳定状况。我们假设radial骨的倾斜周缘及其与后滑膜边缘的前边缘的关系可能是保姆肘部仅在肘部处于旋前位置时才发生的原因。