[Kinematics of the pelvis. Grading and pathomechanical classification of injuries of the pelvic joints and kinematic and clinical consequences of surgical management].

The concept of kinematics as an idea basic to the operative and non-operative treatment of pelvic trauma, whether a fractures or a pelvic joint dislocation, is gaining ground in thinking and in technical management. The human pelvic ring may be interpreted by kinematic aspects as a three-bar linkage moving with three bony links (sacrum and both ossa coxae), (n = 3), in three real joints (symphysis pubis and both sacroiliac joints, (g = 3), as a transformer of great forces into small movements, and as a halter under periodic oscillating femoral impulses. The closed kinematic chain of the symmetric pelvic girdle possesses eight degrees of freedom (sigma g f = 8) subject to two external parameters of influence (F = 2), the gravity exerted by the trunk acting on the sacrum as a driving link caudally and ventrally, jointly creating a ring tension inside the pelvis. The guided linkage allows synthesis of a kinematic number and a positive movement equation in accordance with the spatial kinematic rule: F = 6(n-1)-6g + sigma g f = 2. This formula is applied to the investigation of all possible of pelvic joint dislocations types and fractures, and different forms of surgical treatment are described.(ABSTRACT TRUNCATED AT 250 WORDS)