Robertsson O, Wingstrand H, Kesteris U, Jonsson K, Onnerfält R
Department of Orthopedics, University Hospital, Lund, Sweden.
Acta Orthop Scand. 1997 Jun;68(3):231-4. doi: 10.3109/17453679708996690.
We measured the intracapsular pressure preoperatively in 18 hips (17 patients) before revision of a total hip arthroplasty because of aseptic loosening. Distension of the joint capsule was measured with sonography in 13 cases. In extension, the mean intracapsular pressure was 26 (0-60) mmHg, in extension and inward rotation it was 159 (24-280) mmHg, in extension and outward rotation it was 30 (3-67) mmHg and in 45 degrees of flexion it was 12 (0-28) mmHg. A mean of 6 (0.5-20) mL of joint fluid was aspirated after the pressure measurements. Sonography showed increased joint fluid/synovial edema and/or increased capsular thickness, as compared to 34 unrevised, radiographically not loose prosthetic hips, and that the capsular distension correlated to intracapsular pressure during extension and inward rotation. We conclude that the intracapsular pressure usually is elevated in a hip joint with loose prosthetic components, that the intracapsular pressure varies with the position of the hip and that capsular distension reflects increased intracapsular pressure. The increased and often very high pressure, varying during gait, may pump debris away from the joint along the interfaces and even by itself cause osteolysis and loosening.
我们在18例（17名患者）因无菌性松动而行全髋关节置换翻修术前测量了关节囊内压力。其中13例通过超声测量关节囊扩张情况。伸直位时，平均关节囊内压力为26（0 - 60）mmHg，伸直位并内旋时为159（24 - 280）mmHg，伸直位并外旋时为30（3 - 67）mmHg，屈曲45度时为12（0 - 28）mmHg。压力测量后平均吸出6（0.5 - 20）mL关节液。与34例未翻修、影像学检查假体未松动的髋关节相比，超声显示关节液/滑膜水肿增加和/或关节囊厚度增加，且关节囊扩张与伸直位并内旋时的关节囊内压力相关。我们得出结论，假体部件松动的髋关节中关节囊内压力通常升高，关节囊内压力随髋关节位置变化，且关节囊扩张反映关节囊内压力升高。这种升高且常非常高的压力在步态中变化，可能会将碎屑沿界面从关节泵出，甚至自身导致骨质溶解和松动。
