Medium-to Long-Term Results Of Total Hip Revision With The Cementless Modular Tapered Stem

Objective:To evaluate medium-to long-term results of the revision total hip replacement with the cementless modular tapered stem.In order to provide clinical basis for prosthesis selection in total hip revision.Methods:37 patients(39 hips)underwent revision total hip althroplasty from May 2000 to May 2011 were reviewed.This study includes 21 hips revised with the Lima(Lima-Lto,Udine,Italy)prosthesis and 18 hips revised with the Link MP(Waldemar Link,Hamburg,Germany)prosthesis.The time from revision to total hip arthroplasty was 4 to 15 years(mean,10.4 years).First revision was given in all patients.The causes of revision were aseptic loosening with femoral defects.Pre-revision diagnosis showed type Ⅲa(Paprosky classification)in 28 hips,type Ⅲb in 11 hips,no cases of type I or type IV defects.All bearing surfaces using ceramic-ceramic hip bearings.Results:The mean follow-up was 11.6 years(range,6～16 years).Of the 26 patients evaluated at a minimum of 10 years.The average Harris hip score is 43.4±10.2 preoperatively and maintain 90.2±3.3 at the latest follow-up(P<0.05).There was no significant difference in the average Harris score between the two kinds of revision prosthesis during the last follow-up(Lima revision prosthesis:89.7±3.3,Link MP prosthesis:90.7±3.5,P>0.05).Preoperative VAS score for thigh pain was 4.4±1.4.At the last follow-up,only one patient with a Lima revision prosthesis had mild thigh pain and the VAS score of 2.The X-ray films showed bone ingrowths fixation in 38 hips(97.4%)and fibrous stable fixation in 1 hip(2.6%).The average stem subsidence was 2.1 mm(range,0～10mm).There was no significant difference in the average stem subsidence between the two kinds of revision prosthesis(P>0.05).Compared with pre-revision X-ray films,the area of bone defect around the prosthesis was obviously repaired.No stress shielding and osteolysis were found in all patients at the last follow-up.There were no re-revisions of the femoral stem for any reason.Conclusion:The medium-to long-term results of revision total hip replacement with the cementless,modular,tapered stem in Paprosky type Ⅲa and Ⅲb femoral defect is encouraging.Although the design details of Lima and Link MP femoral prosthesis were different,the general design principles were the same.There was no significant difference in medium-to long-term clinical effect and imaging manifestation between the two groups.