Conclusion Based on the current data , the use of DM acetabular components are effective in minimising the risk of instability after both primary and revision THA .
This benefit must be balanced against continuing concerns about the additional modularity , and the new mode of failure of intraprosthetic dislocation .
Aims The aim of this systematic review was to report the rate of dislocation following the use of dual mobility ( DM ) acetabular components in primary and revision total hip arthroplasty ( THA ) .
Posterior Soft Tissue Repair After Primary THA is Durable at Mid-term Followup: A Prospective MRI Study
Background The enhanced posterior soft tissue repair has reduced the frequency of dislocation after primary THA performed through the posterolateral approach . However , the long-term integrity of the repair is unknown and could influence surgeon choice regarding surgical technique and THA approach . Questions / Purpose sWe asked : ( 1 ) What is the durability of the enhanced posterior soft tissue repair at a minimum of 49 months using MRI to evaluate soft tissue to bone integrity ? ( 2 ) How does the appearance of the posterior soft tissues change during this time ? ( 3 ) Are there patient characteristics associated with the long-term imaging appearance of the posterior repair ? Methods All patients without a contraindication for MRI who were undergoing unilateral primary uncemented THA through a posterior approach between February and May 2005 were eligible for inclusion . Ninety percent consented to participate ( 36 of 40 patients ) , and 30 patients were followed prospect ively with MRI postoperatively and again at 3 months ; of those , 22 ( 73 % ; 12 men , 10 women ) completed the study by having another MRI study at a minimum of 49 months ( mean , 51 months ; range , 49–59 months ) . Each patient underwent metal-artifact – reduction sequence MRI to evaluate the integrity of the posterior soft tissues , which had been repaired anatomically during primary THA at a minimum of 4 years earlier . The results were compared with those of prior MR images obtained immediately after surgery and at 3 months postoperatively . All patients were given a self-reported modified Harris hip score at the time of the most recent MRI study ( maximum score = 81 ) . Results At latest followup , 21 of 22 ( 96 % ) patients had a posterior capsule in contact with bone , and 21 of 22 ( 96 % ) had an intact quadratus femoris . Twenty-one patients ( 96 % ) had soft tissue or a scar from the piriformis and conjoined tendons in continuity with bone . In these cases , the interface between the piriformis and conjoined tendons and the greater trochanter observed immediately postoperatively and at 3 months postoperatively became filled with hypointense tissue , with signal characteristics similar to tendon . Time from surgery was most associated with changes in native tendon-to-bone distances ( p < 0.001 ) and MRI signal intensity of the repair ( p < 0.001 ) . Conclusions At followup of just more than 4 years , the posterior capsule and quadratus femoris most often were healed to bone . In the majority of patients , scar tissue between the piriformis and conjoined tendons and bone matured to achieve orientation and signal intensity resembling native tendon . We believe the enhanced posterior soft tissue repair facilitates this process . Our results provide a plausible explanation for improved postoperative stability observed in patients receiving an enhanced soft tissue repair compared with those in whom a repair is not performed . Level of Evidence Level IV , therapeutic study
Conclusion Based on the current data , the use of DM acetabular components are effective in minimising the risk of instability after both primary and revision THA .
This benefit must be balanced against continuing concerns about the additional modularity , and the new mode of failure of intraprosthetic dislocation .
Aims The aim of this systematic review was to report the rate of dislocation following the use of dual mobility ( DM ) acetabular components in primary and revision total hip arthroplasty ( THA ) .