Revision Hip Arthroplasty With Use Of The Cementless Prothesis

BackgroundsWith the extensive clinical application of total hip arthroplasty(THA),a lot of patient's pain has been relieved.However,with the passage of time,some artificial hips which implanted into body earlier developed some complications,such as prothesis loosening,subsidence,displacement and osteolysis.To this patients,some of whom need a revision hip arthroplasty to restore the function of hip again.Young patients who received revision probably need more than one re-revision operations in the future.The outcomes of using cementless prothesis in primary total hip arthroplasty has been proved good,but there is a dispute that whether cementless prothesis should be used in revision hip arthroplasty,especially in infective cases. This study was conducted to review 41 hips in 36 patients who received revision hip arthroplasty from 1997 to 2007 by a single surgeon using cementless prothesis in Nanfang Hospital,observe the midterm clinical and radiographic outcomes of cementless prothesis,and provide references for orthopedists to select prosthesis in revision hip arthroplasty.ObjectiveThis study evaluated the clinical and radiographic results of revision hip arthroplasty with cementles prothesis.Methods 1.Patient dataThere were 21 males and 15 females with an average age of 56 years(21-77 years).The mean BMI was 21(15-32).The mean interval between the primary arthroplasty and revision was 3 months to 20 years(mean 6.7 years).The causes for revision were pain without evident component loosing in 5 hips(all underwent an artificial femoral head replacement),infective loosing in 8,aseptic loosening in 21, femoral fracture in 2,ankylosing spondylitis in 2 and dislocation in 3 hips.In the 41 hips,29 hips underwent a revision total hip arthroplasty,8 hips only replaced the acetabular component while 4 hips only did the stem revision.2.Operation methodsAAOS and Paprosky classification were used respectively to evaluate the bone defect before operation.Proper prothesis was chosed according to the bone defect found during the operation after treating the bone-bed.Acetabular reinforcement ring, titanium threaded cups or hemispherical acetabular prosthesis were used to reconstruct acetabular part,and titanium alloy rectangular revision stems was used as femoral component,bone grafting and circle wire were used when necessary.In the infection cases,one-stage revision was performed in 4 cases,two-stage revision was performed in 3 cases.3.Evaluation methodsBoth clinical evaluation and radiological evaluation were performed.Harris hip score,pain extinction time,crutch walking time,functional capabilities,patient satisfaction and complications were the clinical items involved while the radiological items included heterotopic ossification,cortical hypertrophy,medullary sclerosis, radiolucent lines,osteolysis and wear rate.Data collection and evaluation was accomplished by an independent investigator.Linear wear was measured on radiograghs and was corrected for magnification by comparing the diameter of the femoral head on each individual radiogragh with the known diameter of 28 mm. Kaplan-Meier survivorship analysis was used to estimate the probability of survival of the prothesis.Results1.Clinical resultsTwenty-two patients(26 hips) were available for complete clinical and radiographic analysis.2 patients were followed only by telephone and 8 patients were completely lost.The mean follow-up period was 4.6 years(1-11 years).The mean Harris hip score improved from 38(11-76) points preoperatively to 88(60-99) points at the time of final follow-up,the pain and function score improved from 16.9 and 17.3 to 40.4 and 39.9 respectively.All patients had moderate to severe limp before revision.At the time of final follow-up,eight patients still had slight limp and 4 patients had moderate limp.2.Radiographic resultsTwenty-one hips(75%) had an excellent result.A 1mm width radiolucent line was found in one femoral component without any symptome.Osteolysis and migration were seen in 4 hips(three in acetabular and one in femoral component), which need re-revision(12.5%failure).Heterotopic ossification developed in 8 hips (31%).The mean polyethylene liner wear was 0.27mm(0.02-0.87mm) in all and 0.08mm(0-0.25mm) per year.In the infective cases,no re-infection was found, femoral component exsertion was found in one patient but without any symptom.In the eight patients who received ARR treatment,seven of which were followed,five hips had an excellent result.Infective osteolysis and migration was seen in 2 hips, which needed re-revision(29%failure).3.Statistic resultsThe coincidence of bone defect classification in AAOS is better than Paprosky. Kaplan-Meier survivorship at 4.6 years was 89%with repeat revision for any reason as the end point and 81%with repeat revision or radiographic loosening as the end point.With revision for any reason or radiographic loosening as the end point,the 4.6-years survival rate of the cementless prothesis was 0.89 and 0.81 respectively.Conclusions1.Cementless prothesis appears to be a good alternative to other revision systems in revision total hip arthroplasty.2.It is possible to have satisfactory clinical outcome by one-stage or two-stage revision using cementless prothesis for postoperative infection after total hip arthroplasty.3.Whether the original prothesis can be saved when fixed tightly with femur or acetabular bone needs more experience to confirm in infected hip arthroplasty.4.ARR with impaction bone grafting is an effective approach to treat massive acetabular bone defect in revision hip arthroplasty,the midterm result is acceptable, but any possible reason for infection must be monitored.