[Causes and managements of acetabular fracture during primary total hip arthroplasty].

OBJECTIVE

To investigate the causes and managements of acetabular fracture during primary total hip arthroplasty (THA).

METHODS

Between May 2005 and July 2008, 9 patients (9 hips) suffered from acetabular fractures during primary THA. There were 1 male and 8 females with an average age of 63.3 years (range, 41-73 years), including 4 cases of developmental dysplasia of the hip, 2 cases of rheumatoid arthritis, 1 case of old femoral neck fracture, 1 case of avascular necrosis of femoral head, and 1 case of ankylosing spondylitis. Three left hips and 6 right hips were involved. The preoperative Harris score was 40.4 +/- 2.9. All the patients underwent cementless THA. Among nine acetabular fractures, 8 fractures were stable (2 anterior wall fractures and 6 posterior wall fractures), which were fixed by additional augmentation screws in 7 cases and accepted no special treatment in 1 case; 1 fracture was unstable (posterior wall fracture with posterior column incomplete fracture), which was treated by bone grafting and additional screws.

RESULTS

The postoperative X-ray films showed that the position of the prosthesis were favorable. All incisions healed by first intention without early complication. Nine patients were followed up 1-4 years (mean, 2 years and 7 months). The Harris score was 87.8 +/- 3.9 at last follow-up, showing significant difference when compared with the preoperative score (t = 44.904, P = 0.000). The X-ray films showed fracture healing at 8 weeks. No loosening occurred.

CONCLUSION

When primary THA is performed, the preoperative X-ray film should be studied and measured carefully, operation should be accurate and violence should be avoided. The diameter of the acetabular component should be equal to the diameter of a drill or not larger than 2 mm. In patients with severe osteoporosis, the diameter of the acetabular components should be the same diameter as a drill and additional screws are used to fix, or cemented cup is used. Once an acetabular fracture occurs during the primary THA, additional screw or bone grafting with additional screws should be chosen according to the fracture type and stability, and good clinical results can be expected.