Preliminary Clinical Results Of Total Hip Arthroplasty With A Tapered,Modular Neck Hip Stem

Objective To analyze and summarize the preliminary clinal results and complicationof total hip arthroplasty with a tapered,modular neck hip stem.Methods From October2010to December2011,50patients (56hips) underwenttotal hip arthroplasty. There were36females and14males, with an average age of60.5±11.7years. Preoperative diagnosis included developmental dysplasia of the hip in15cases,femoral neck fractures in12cases, avascular necrosis of the femoral head in10cases,osteoarthritis in9cases, rheumatoid arthritis in2cases and mal-union of femoral neckfracture in1case, femoral head fracture with hip dislocation in1case. The adoptedfemoral component was a tapered modular stem(Zimmer, Warsaw, Ind). Clinical andradiographic evaluations were performed on every follow-up.Results The mean follow-up was11months (range,6to19).The mean preoperativeHarris hip score was36.1±18.0, which were improved to88.6±8.8（t=22.471，P=0.000）at the time of follow-up. At the time of follow-up,1patient (2%) suffered from slight pain,1(2%) moderate pain and no one severe or very severe pain. The X-ray films showed thatno socket demonstrated migration and loosening, and that bone ingrowths fixation in53hips (98%) and fibrous stable fixation in1hips (2%). One of the54stems had subsidenceof less than2mm. Intraoperative complications included acetabulum collapse in1hips(2%), and periprosthetic femoral fracture in1hips (2%). Heterotopic ossification was ratedin2hips（4%）.Conclusion The tapered, modular neck hip stem gives surgeons the flexibility tooptimize hip joint mechanics intraoperatively and address patient specificity. The preliminary clinal results of total hip arthroplasty was encouraging and had lesscomplication. However, the medium and long-term results still need further follow-up.