The incidence of dislocation after primary total hip arthroplasty using posterior approach with posterior soft-tissue repair

Background. Dislocation after total hip arthroplasty (THA) is one of the most common major complications, and occurs more often through a posterior approach. We performed a retrospective study to determine the incidence of early dislocation and the relationship to the type of prosthesis and the surgeon's experience.

Methods. A group of 884 consecutive primary THAs (746 cemented and 138 cementless) approached through a posterior incision with repair of the posterior soft tissues was followed for a mean of 30 months.

Results. The overall dislocation rate was 1.36% (cemented: 1.1%; cementless: 2.9%). All dislocations were posterior and occurred within 6 months after surgery, 91% within 6 weeks. Dislocations were most common in rheumatoid patients (3.8%). Two revisions (0.23%) of the acetabular cup were performed for recurrent dislocations. The dislocation rate was not higher in the operations performed by less experienced surgeons.

Conclusion. The early dislocation rate after primary THA through a posterior approach with repair of the posterior soft tissues was low, especially in cemented THA. Less experienced surgeons were not associated with a higher dislocation rate.