Abstract
Background
The rotational acetabular osteotomy (RAO), that was developed in Japan, has been used successfully in patients with developmental dysplasia of the hip (DDH) (Figure 1). However there are some patients who are forced to have a total hip arthroplasty (THA) due to the progression of osteoarthritis. It is unknown if a RAO poses technical difficulties or increases the chances of complications if a THA must be performed afterwards becausethere is not much data on patients who underwent a THA after a previous RAO.
Objectives
The purpose of this study was to investigate the mid-term results of a THA after a RAO.
Methods
We compared 22 THAs (2 males and 16 females) that were performed after previous RAOs (group R) with a control group of 28 patients (30 hips) who only underwent THAs (2 males and 27 females, group C). The average age at surgery in Group R and C was 53.6 years and 55.8 years, the average follow-up period was 7.2 years (range, 6–10 years), 7.7 years (range, 6–11 years). The average interval from osteotomy to THA was 12.7 years. Trilogy acetabular components (Zimmer) were used for all patients.
Results
No acetabular or femoral components exhibited loosening or revision in both groups. No osteolysis was seen in both groups and there was no significant difference in terms of the incidence of ectopic ossification. The Harris hip score (HHS) at the most recent follow-up was not compromised (Group R: mean, 93.2, Group C: 94.3), there were no significant differences in intraoperative blood loss and operative times between the two groups (Group R: mean, 136.0 ml; 89.5 mins, Group C: 131.3 ml; 96.3 mins) Group R did not have higher rates of infection, dislocation, intraoperative fracture or deep venous thrombosis compared with group C. Acetabular components in group R were placed more superiorly and laterally than group C (Figure 2, Table 1). On the other hand, the acetabulum after RAO often gets harder than the one that did not undergo a previous osteotomy. The Screw that is used to fix the acetabular component has been found to work well in securing the sclerotic acetabulum, thus screw fixation of a cementless cup is a feasible option for a THA after a RAO.
Conclusions
Patients who underwent aTHA after a successful RAO had mid-term results similar to those of other dysplastic hips. The results of this study found RAOs do not lead to higher revisions rates, compromised HHSs, or shortened survivorships in eventual THAs in DDHs. However there was a tendency of superolateral placement of the acetabular component, therefore a longer follow-up is required to confirm if polyethylene wear increases. The results of this study indicated rotational acetabular osteotomies do not lead to higher revisions rates, compromised HHSs, or shortened survivorships in eventual total hip arthroplasties in developmental dysplasia of the hip.
