Abstract
Introduction
We perform PAO via a modified Smith-Petersen approach. The purpose of this study was to investigate the result of PAO via a modified Smith-Petersen approach at a minimum 10-years' follow-up.
Methods
We retrospectively reviewed 209 hips in 179 patients with acetabular dysplasia who underwent PAO with a modified Smith-Petersen approach from August 1995 to April 2010. Exclusion criteria were as follows: under 10 year follow-up, incomplete clinical or radiographic data. Harris hip score (HHS) was investigated preoperatively, at the time of most improvement and at the final follow-up for clinical evaluation. Tönnis classification was investigated preoperatively and at the final follow-up for evaluation of osteoarthritis. Center edge (CE) angle and acetabular roof obliquity (ARO) were investigated preoperatively, postoperatively and at the final-follow up for radiographic evaluation. Tönnis classification and radiographic parameters were investigated on anterior-posterior radiographs. Patients of conversion of PAO to total hip arthroplasty (THA) were investigated for preparing Kaplan Myer survival analysis. The Wilcoxon signed-rank test was used to compare changes in HHS and radiographic parameters between the preoperative and the postoperative values. Statistical significance was defined a priori as p < 0.05.
Results
Eighty-seven hips in 79 patients (44.1%) were included in this study. 100 patients were excluded from this study. The average age of the patients at the time of surgery was 39 years (rang, 15 to 65 years) and the mean follow-up period was 12 years and 2 months (range, 10 years to 18 years and 3 months). The mean HHS improved from 74 points (range, 38 to 98 points) preoperatively to 95 points (range, 62 to 100 points) at the time of most improvement (p < 0.01) and decrease slightly to 89 points (range, 32 to 100 points) at final follow-up. Tönnis classification was as follows: grade 0 was 4 hips preoperatively and 2 hips at the final follow-up, grade 1 was 55 hips preoperatively and 50 hips at the final follow-up, grade 2 was 25 hips preoperatively and 24 hips at the final follow-up, grade 3 was 3 hips preoperatively and 11 hips at the final follow-up. The mean CE angle improved from 5° (range, −19 to 24°) preoperatively to 30° (range, 2 to 56°) postoperatively (p < 0.01) and increased 38° (range, 12 to 68°) at final follow-up. The mean ARO improved from 24° (range, 6° to 45°) preoperatively to 6° (range, −14° to 48°) postoperatively (p < 0.01) and increased to 12° (range, −24 to 45°) at final follow-up. THA was performed on 5 hips in 5 patients (5.7%) after PAO. The mean duration between PAO and THA was 9 years and 6 months (range, 1 year and 4 months to 15 years 4 months). Ten-year survival rate was 97 % with conversion THA as the end point.
Discussion & Conclusion
Clinical data and radiographic parameter were improved in patients who underwent PAO satisfactory. PAO was instrumental as time-saving surgical treatment of symptomatic acetabular dysplasia or slightly osteoarthritis because of 97% survival rate at 10 years.
