[Secondary total hip arthroplasty for osteonecrosis of femoral head after failed internal fixation of femoral neck fracture].

OBJECTIVE

To compare the efficiency of secondary total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH) after failed internal fixation of femoral neck fracture and the primary THA for non-traumatic ONFH and to evaluate if the two groups have significant difference.

METHODS

From June 2004 to July 2007, 203 cases of ONFH were treated by THA. In group A, 83 patients (83 hips) with ONFH after failed internal fixation included 56 males (56 hips) and 27 females (27 hips) with an average age of 58.3 years (range 45-75 years). According to Ficat classification, there were 61 cases at stage III and 22 cases at stage IV. The Harris score was 37.6 +/- 2.0. The disease course was 1-6 years with an average of 2.6 years. In group B, 120 patients (167 hips) with non-traumatic ONFH included 67 males (94 hips) and 53 females (73 hips) with an average age of 52.6 years (range 41-67 years). According to Ficat classification, there were 56 cases (83 hips) at stage III and 64 cases (84 hips) at stage IV. The Harris score was 38.2 +/- 1.0. The disease course was 1.5-5.0 years with an average of 2.6 years. There were no significant differences in general data between two groups (P > 0.05).

RESULTS

All 203 cases were followed up for 2 to 5 years (average 3.4 years). There were no significant differences in the operation time of single-hip, the blood loss, the blood transfusion between two groups (P > 0.05). Intraoperative fractures occurred in 4 hips (4.8%) of group A and 2 hips (1.2%) of group B, showing significant difference (P < 0.05). There were no significant differences (P > 0.05) in the incidence of dislocation [3 hips (3.6%) in group A and 1 hip (0.6%) in group B], continuous femoral pain [2 hips (2.4%) in group A and 1 hip (0.6%) in group B] and infection [1 hip (0.6%) in group B] between two groups. There were no significant differences (P > 0.05) in acetabular abduction, anteversion, femoral anteversion, and combined anteversion angles as well as the recovery rate of acetabular rotational center between two groups. The Harris scores of groups A and B after 2 years were 79.4 +/- 2.1 and 84.2 +/- 3.5. There was no significant difference between two groups (P > 0.05). The Harris score postoperation had significant differences compared with preoperation (P < 0.05).

CONCLUSION

Compared to the primary THA to non-traumatic ONFH, secondary THA to ONFH after failed internal fixation has no significant increase in operative difficulty, the postoperative hip function is good, but the incidence of intraoperative fracture is higher.