In short-term outcomes ( 5 years or less , with follow-up of 0–5 years ) , the best implant of choice that has lowest risk of revision and dislocation after THA is DMTHA follow by BTHA .
Abstract Postoperative dislocation is a challenging complication after  total hip arthroplasty ( THA ) that affects patient outcome worldwide .
Instability is one of the main complications with rates exceeding 20 % in some series .
Currently , alternative acetabular components are available with dual mobility ( DMTHA ) bearing surfaces and larger femoral head size that may reduce the risk of dislocation , yet provide the functional benefit of st and ard single mobility ( STHA ) bearing surface THA .
However , whether STHA , big femoral head ( BTHA ) and DMTHA should be used is still controversial .
This systematic review and meta- analysis aim to compare postoperative dislocation and revision ( aseptic loosening and infection ) of BTHA , STHA and DMTHA in primary or revision THA .
These clinical outcomes consist of postoperative dislocation and revision ( aseptic loosening and infection ) .
A constrained liner cemented into a secure cementless acetabular shell.
BACKGROUND Constrained acetabular components have been used to treat hips with recurrent instability following total hip arthroplasty and hips that demonstrate instability during revision surgery . In such hips , when a secure cementless acetabular shell is present , the surgeon can cement a constrained liner into the existing shell . The purpose of this study was to evaluate the clinical and radiographic outcome of this technique with use of a tripolar constrained liner that was cemented into a well-fixed cementless acetabular shell . METHODS Between 1988 and 2000 , constrained liners were cemented into thirty-one well-fixed cementless acetabular shells  at three centers . The average age of the patients at the time of the index surgery was 72.1 years , and the indications for the procedure were recurrent hip instability in sixteen hips and intraoperative instability in fifteen hips . The patients were evaluated with respect to the clinical outcome and radiographic evidence of shell loosening and osteolysis . RESULTS At an average duration of follow-up of 3.9 years , twenty-nine liners ( 94 % ) were securely fixed in the cementless shells and two constrained liners had failed . One liner failed because it separated from the cement , and one failed because of fracture of the capturing mechanism . Both hips were successfully revised with another cemented tripolar constrained liner . No acetabular component demonstrated radiographic evidence of progressive loosening or osteolysis . CONCLUSIONS A constrained tripolar liner cemented into a secure , well-positioned cementless acetabular shell provides stability and durability at short-term follow-up . Careful attention to the preparation of the liner , the sizing of the component , and the cementing technique are likely to reduce the failure of this construct , which can be used for difficult cases of total hip instability
In short-term outcomes ( 5 years or less , with follow-up of 0–5 years ) , the best implant of choice that has lowest risk of revision and dislocation after THA is DMTHA follow by BTHA .
Abstract Postoperative dislocation is a challenging complication after  total hip arthroplasty ( THA ) that affects patient outcome worldwide .
Instability is one of the main complications with rates exceeding 20 % in some series .
Currently , alternative acetabular components are available with dual mobility ( DMTHA ) bearing surfaces and larger femoral head size that may reduce the risk of dislocation , yet provide the functional benefit of st and ard single mobility ( STHA ) bearing surface THA .
However , whether STHA , big femoral head ( BTHA ) and DMTHA should be used is still controversial .
This systematic review and meta- analysis aim to compare postoperative dislocation and revision ( aseptic loosening and infection ) of BTHA , STHA and DMTHA in primary or revision THA .
These clinical outcomes consist of postoperative dislocation and revision ( aseptic loosening and infection ) .