Abstract
Background and Objective
Total hip arthroplasty (THA) has been applied to treat pain and disability in patients with post-traumatic arthritis after acetabular fracture for many years. However, the midterm and long-term results of THA for this unique population are still controversial. According to previous studies, we found that uncemented acetabular reconstructions were usually performed in patients who were most likely to have the best results and an abnormal acetabular structure was usually the reason for THA failure. In this study, we evaluated the midterm results of using uncement acetabular components to treat posttraumatic arthritis after acetabular fracture. In addition, we investigated the effects of different acetabular fracture treatments and fracture patterns on THA.
Materials and Methods
Between January 2000 to December 2003, 34 uncemented acetabular reconstructions were performed in 34 patients for posttraumatic arthritis after acetabular fractures. Among them, 31 patients underwent complete clinical and radiographic follow-up for an average of 6.3 years (range, 3.1–8.4 years). There were 22 men and 9 women. The patients' average age was 51 ± 12 years (range, 27–74 years) at the time of arthroplasty. The average interval from fracture to THA was 5.58 ± 4.42 years (range, 0.75–17.5 years). Of the 31 patients, 19 had undergone ORIF (open-reduction group) and 12 had received conservative treatment for the acetabular fractures (conservative-treatment group). Then, 14 had simple pattern fractures (simple group) and 17 had complex pattern fractures (complex group). After midterm follow-up, the radiographic and clinic results of the different groups were compared.
Results
During 6.3 years' follow up, no infection occurred and no revision was needed in the 31 patients. In the open-reduction and conservative-treatment groups, the respective averages for duration of surgery, intraoperative blood loss, and amount of blood transfused were 138 ± 29 minutes and 98 ± 16 minutes (P < .001), 726 ± 288 mL and 525 ± 101 mL (P = .01), and 1,130 ± 437 mL and 1,016 ± 422 mL (P = .62). In the complex group and the simple group, the respective averages for duration of surgery, intraoperative blood loss, and amount of blood transfused were 132 ± 28 minutes and 109 ± 31 minutes (P = .042), 741 ± 221 mL and 536 ± 248 mL (P = .02), and 1,100 ± 414 mL and 1,075 ± 456 mL (P = .91). The average Harris Hip Score increased from 49 ± 15 before surgery to 89 ± 5 in the latest follow up, and 29 patients (94%) had either excellent or good results. The average Harris Hip Score for the open-reduction group and the conservative-treatment group increased to 87 ± 6 and 91 ± 3 (P = .07), respectively, after surgery; for the complex group and the simple group, it increased to 88 ± 6 and 90 ± 4 (P = .25), respectively. There was no significant difference between the open-reduction group and the conservative-treatment group or between the complex group and the simple group regarding the number of hips with excellent and good results. Of our 31 patients, none had a change in acetabular component abduction of >4°. The average horizontal migration of cup was 1.48 ± 0.46 mm (range, 0.7–2.33 mm), and the average vertical migration was 1.41 ± 0.54 mm (range, 0.5–2.51 mm). The average rate of polyethylene liner wear was 0.25 ± 0.11 mm/y (range, 0.03–0.41 mm/y). Average wear rates were 0.25 ± 0.12 mm/y and 0.24 ± 0.11 mm/y for the open-reduction group and the conservative-treatment group (P = .72), respectively, and 0.24 ± 0.13 mm/y and 0.26 ± 0.10 mm/y in the complex group and the simple group (P = .67), respectively. The average rate of polyethylene wear for all patients was positively related to BMI (r = .36; P = .047). After THA, all 31 patients had a reconstructed hip center within 20 mm of vertical and horizontal symmetry compared with the contralateral hip, including 27 patients (87%) with anatomic restoration and 4 patients with reconstructed hip center between 10–20 mm of vertical and horizontal symmetry. Anatomic restoration was positively related to fracture treatment (r = .48; P = .006), but it had no relation to fracture pattern (r = .16; P = .40).
Conclusion
Uncement acetabular reconstruction following acetabular fracture had favorable midterm results. Fracture treatments and patterns are associated with increased operative time and hemorrhage amount. Open reduction and internal fixation of fracture favours anatomic restoration of hip rotational center.
