Abstract:

Objective To evaluate the feasibility and clinical significance of the three-dimensional acetabular oval fossa-guided positioning technique in acetabular prosthesis placement during total hip arthroplasty （THA）. Methods Sixty patients with femoral neck fractures who underwent primary THA were randomly divided into two groups （n = 30 per group）. The observation group received acetabular component placement guided by a three-dimensional positioning technique based on preoperative acetabular angle measurements and pelvic model reconstruction using CT data. During surgery， placement was performed according to the preoperative plan， using anatomical landmarks including the acetabular fossa， transverse acetabular incision， and transverse acetabular ligament. The control group underwent conventional freehand acetabular component placement. The two groups were compared in terms of surgical parameters （operation time， intraoperative fluoroscopy frequency， blood loss）， postoperative deviations in acetabular component angles （abduction and anteversion angles）， Harris hip score （HHS）， visual analog scale （VAS） for pain， and dislocation rate. Results Baseline characteristics were comparable between groups. The observation group exhibited a slightly longer operation time and significantly greater blood loss compared to the control group， with no significant difference in fluoroscopy frequency. Postoperative radiographic measurements showed that deviations in both the abduction and anteversion angles of the acetabular component were significantly smaller in the observation group than in the control group. At one month postoperatively， the HHS was significantly higher and the VAS score was significantly lower in the observation group. However， no significant differences in functional or pain scores were found between the two groups at three and six months postoperatively. No dislocations were observed in the observation group， whereas one dislocation occurred in the control group. Conclusions The three-dimensional acetabulum oval fossa-guided positioning technique， which integrates anatomical landmarks with individualized preoperative planning， enables precise quantitative measurement and significantly enhances the accuracy of acetabular component placement angles in THA. This improvement contributes to faster postoperative functional recovery and leads to favorable clinical outcomes， demonstrating strong practical application value.

Key words: acetabulum oval fossa, three-dimensional positioning, preoperative planning, total hip arthroplasty （THA）, acetabular prosthesis, precision placement