[Dislocation after total hip arthroplasty]

From 1997 to 2002 in the Department of Traumatology there had been performed 488 total hip replacements: 334 in men and 454 in women at the age between 20 and 84 (average 63.6). The procedures were performed by 12 surgeons and postero-lateral approach was used. Dislocation was found in 22 patients (4.51%): 14 women and 8 men. Majority of dislocation occurred during first 8 weeks after an operation and 68% of them happened during first 6 weeks. The surgical treatment was necessary in 10 cases (45% of all dislocation): 3 patients had only a surgical reposition and 7 patients had a revision arthroplasty. There was found that most cases of dislocation took place at the age above 81 years. Dislocation occurred 5 times more frequently in patients operated on for a femoral neck fractures then for coxarthrosis. The prosthesis TT1 most often dislocated possibly due to its shape (low Head Neck Ratio). Based on our own experience we find dislocation is a multifactorial complication and precise description of causes is usually very difficult.