Risk Factors And Research Progress In Dislocation Of Bipolar Hemiarthroplasty

1 Research ObjectivesBipolar hemiarthroplasty(BHA)is one kind of Hip Joint Arthroplasty(HA),compared with Total Hip Arthroplasty(THA),BHA could provides extra range of motion(ROM)through the bipolar femoral head,less operation time and trauma,hence the risk of dislocation might be lower.As a common complication of BHA,dislocation occurs now and again,caused by the poor physical condition of the gerontal patients.In spite of the low rate,more patience and skills are required when dealing with dislocation of BHAThis retrospective study reviewed 317 elderly patients(>65 yrs)underwent BHA in Shanghai No.6th Hospital,keep track of their gender,age,general physical condition,neuromuscular system disease,local condition of the hip joint,the operation,therapy,prognosis,dislocation conditions,in order to find out the progress and risk factors in dislocation of BHA.2 Methods And MaterialsThis study included 317 elderly patients aged over 65 years who underwent artificial bipolar femoral replacement from July 2013 to March 2016.The statistics included gender,age,preoperative diagnosis,body mass index(BMI),neuromuscular chronic diseases,hip shape,prosthesis type(cemented or uncemented),femoral off-set(compared to the other side),postoperative limb length(compared to the other side),dislocation,dislocation time,treatment and outcome.The regression analysis was carried out to analyze the correlation between dislocation and each factor.3 ResultsThe average age of the patients was 79.77 ± 8.948 years old,including 90 males(28.39%)and 227 females(71.61%).The average follow-up time was 16.44 ± 4.45 months and the minimum follow-up time was 9 months.11patients(3.47%)come up dislocation situation at least one time after surgery,including 6 cases of general anesthesia closed surgical reduction was successful,3 cases of open reduction surgery after failure to closed reduction,2 cases went to the dislocation of bipolar prosthesis after failure to closed reduction,then carried out elective total hip arthroplasty.The average dislocation time(33.91 ± 37.206 days)wasfound in 11 patients,3 cases were dislocated after tumbles,3 cases were dislocated due to adduction and flexion of the hip,3 cases were due to simple hip flexion,1 case was due to adduction of the hip.4 ConclusionIn this study,the incidence of dislocation was significantly higher than non-exposed group which related to these research factors: CE angle less than 25 °;femoral off-set / limb length less than contralateral;neuromuscular disorders.According to the statistical analysis,the CE angle,the size of the femoral off-set and dislocation occurred in a significant correlation,the existence of these exposure factors when a surgeon think about bipolar hip replacement need to consider again;the dislocation incidence between neuromuscular disease group was higher than control group,but in the case of good perioperative management and surgical technique,the dislocation incidence between the neuromuscular disease group and the non-exposed group was no significant statistical difference.5 Level Of EvidenceLevel ?,retrospective study.