The Clinical And Biomechanical Study Of Intertrochanteric Fractures Treated With Hemiarthroplasty

To analyze the functional outcomes of intertrochanteric hip fractures treated with hemiarthroplasty retrospectively, provide the mechanical evidences for the arthroplasty in treatment of communited intertrochanteric fractures by assessing the initial stability which received the conventional femoral stem prosthesis,with lesser trochanter fixed or not.(1) Follow up 77 patients of intertrochanteric fractures treated with hemiarthroplasty admitted to PLA General Hospital from 1993 to 2008, statistically analysis the information before,during and after surgery of the patient, access the clinic therapeatic result and the related postoperative complication.(2) 18 fresh-frozen cadaveric femurs wereselected in this study and divided into 3 groups randomly. In normal cemented hemiarthroplasty group,the femoral head were removed using the guides for the implant systems.The lesser trochanter fixation group and the cement reinforced group were simulated intertrochanic fractures(classified type IV by Jensen-Evans).In lesser trochanter fixation group, isolated displaced fragment of the lesser trochanter was reduced and fixed with stainless steel;the defect of calcar femorale was reinforced by cement in cement reinforced group. Both of the groups were treated with cemented femoral prosthesis following the standard cemented hemiarthroplasty procedure.The pecimens were tested mechanically for 10000 times cyclic loads.The vertical migration of components were measured and recorded every 1000 times.(1) All operations were successful and the duration of the operation was 45 to 80 minutes with an average of 65 minutes.Blood was transfused in 73 patients during the operation between 200-600 ml with an average 360.9 ml.The patients got out of the bedwithin 3 days in 33 cases,4-7 days in 36 cases,more than 8 days in 6 cases, and 2 patients couldn't get out of the bed, Harris scores 75.6±12.0.(2) The circle-migration curve show that with the increase of cycles, the vertical migration of the three test groups were increased.The normal cemented hemiarthroplasty group at all circle times had the smallest mean of migration, and the migration mean of cement reinforced group were the largest. Between lesser trochanter fixation group and cement reinforced group, the migration both mean and variation of cement reinforced group were greater. The migration mean of 3 test groups after 10000 cycles was not statistically significant.(1) It's an effective method to treat the unstable intertrochanteric fractures in elderly patients with hemiprosthesis arthroplasty. It can quickly restore the hip joint function,get the ambulation early,decrease the complications and reduce the mortality.It can be applied to elderly patients with the severe osteoporosis comminuted fracture, patients who need a salvage operation after the failure of internal fixation, and patients with the hip joint disease require surgery.(2) The components subsidence of the two intertrochanteric fractures treated with cemented hemiarthroplasty groups were greater than the normal cemented hemiarthroplasty group. In the two intertrochanteric fractures groups, the migration variation of cement reinforced group was greater, subsidence trend was also greater.