Study Of Clinical Characteristics And Risk Factors Of Periprosthetic Femoral Fractures About Total Hip Arthroplasty Prostheses

Objective:To study clinical characteristics and associated risk factors of intraoperative and postoperative periprosthetic femoral fractures (PFF) of primary and revision total hip arthroplasty (THA).Materials and Methods:1、 Study of clinical characteristics:We retrospectively analyzed clinical data of 89 PFF patients in orthopaedic department of PLA general hospital from January 2010 to December 2014, there were 38 males and 51 females. According to the time when fracture occurred, all the patients were divided into four groups:30 patients occurred during primary THA,8 occurred after primary THA,46 occurred during revision THA and 5 occurred after revision THA. The clinical data including incidence of PFF, general characteristics, primary disease of THA, reason for revision, Vancouver type of PFF, implant, the interval between operation and fracture, treatment and so on.2、Analysis of risk factors:We designed a case-control study to examine the impact of patients’general characteristics including sex, age, BMI and so on, bone quality of proximal femur, preoperative diagnosis, type of implant, previous surgery, femoral deformity and comorbidities on the risk of PFF, all factors were analyzed by Logistic regression method. Controls, matched 2:1 to cases, were selected from patients who did not develop PFF at the same period.Results:1、Clinical characteristics:The overall incidence of intraoperative and postoperative PFF was 1.77% and 0.30% respectively, the incidence of PFF was higher in revision THA than in primary THA (13.60% vs.0.97%). The most common primary disease of patients who suffered PFF during primary THA was DDH, Vancouver type A2 fractures was the most common type of fracture (19/30), as for the revision THA, the most common disease was implant loosening, type B3 and A3 were the most common type (24/46; 12/46). There are 6 patients who had femoral deformities, all the fracture were accordance to the site of deformities.12 of 13 patients had a history of low energy fall, most of whose fractures type were type B. Wire or cable was the most common choice for intraoperative PFF, whereas the open reduction and plate fixation was most used in postoperative PFF. The bone quality of proximal femur can be assessed by CBR (Canal bone ratio), when CBR≥0.49, the patient maybe considered as poor bone quality, this kind of patients occupied 66.7% in all PFF patients who underwent primary THA.2、Risk factors:The logistic regression analysis shows that DDH and CBR≥0.49 are associated with PFF during primary THA, the older age can increase the incidence of PFF after primary THA. The number of previous operation, periprosthetic joint infection, uncemented implant preoperatively and femoral deformity are all related to the increasing rate of PFF during revision THA. Besides, revision is one of the risk factors of PFF.Conclusion:PFF is one of the important complications of both primary and revision THA, identifying the risk factors of PFF is of great importance to it’s prevention, by which will allow surgeons to do well in pre-operative planning, careful operation and pay more attention to discharge instructions. The treatment options should depend on Vancouver classification system to choose wire, plate, strut graft or revision surgery.