If the traumas treated at Ishiuchi Clinic of Showa University during the past 31 years from 1957 to 1988 are classified by topical site and type, the traumas in the knee and ankle joints are seen in many cases, occupying totally 53% of the total traumas. Compared with these, the traumas in the hip joint are relatively rare, and particularly, the cases of traumatic dislocation of the hip joint are extremely rare articular traumas. The subject cases were 6 males and 5 females.
The traumatic mechanisms have been elucidated, and concurrently, super selective angiography was performed on the medial circumflex arteries in 8 cases to determine angiographically the time when loading began.
There are many cases whose posterior dislocations were presumably caused by a mechanism that, while the tibia is fixed by skiing boots in a position including forward in angles slightly wider than 90°, flexion and rotary strengths applied to the hip joint are much strong at the skier's position with extended knee joint because the safety binding does not come loose at the fall of the body forward.
The superior retinacular arteries are said to be very important remification of the medial circumflex femoral artery which supplies 2/3-3/4 of blood stream to the outside of the loaded epiphysial region. What are presumed as the causes for the ineffective and defective angiograms are (1) compression by hematoma, (2) extended SRA and (3) rupture of SRA. The time of loading to begin was found as 2 months in the case with favorable angiograms of SRA and 4 months in the cases with ineffective or defective angiogram.
