Clinical Study Of Proximally Coated Stem

Objective:To study the clinical results of a proximally coated stem (Omnifit-HA stem) that were applied in china.In this experiment,we also analysis some elements that may affect the clinical results.To analysis the stem fit of proximally coated stem and some elements that may affect the stem fit of this kind of stem. Methods: 1.We reviewed 53 primary total hip replacements in 52 patients with Omnifit-HA stems. Omnifit PSL-HA cups were used concomitantly.The prosthesis had been in situ for an average of 36 months(24-47months).The observation contents clinical behaving and radiographic manifest.We also analysis effect of the age and the fit on the results.2.We detected the stem fit of six proximally coated stems which were used in china and analyzed some elements that affect the stem fit. Results: 1 .No revisions were performed to treat instability of the stem,pain,or osteolysis by the time of the latest follow-up examinations.The mean Harris hip score was 60 (range,20-71) before surgery and 94(range,80-I00) at final followup,with all patients having an excellent or good outcome.Thigh pains were occurred in 5 lamps,4 lamps had mild pains, I lamp had modem pain.One stem was in evert.The other stems all were aligned in neutral.Endosteal condensation occurred in 46 hip(87%),most of which appeared on proximally hydroxyapatite coating.A sclerotic reactive line adjacent to the distal nonhydroxyapatite portion of the stem occurred in 32 hip(60%) but was not adjacent to the hydroxyapatite coated portion of any stem.Endosteal lysis adjacent to or distal to the hydroxyapatite coating did not occur.Subsidence occurred in 7 stems(range,1-4.5mm),the average subsidence was 0.27mm. Bone absorption at the calcar occurred in 5(9%).Cortical hypertrophy occurred in II hip(19%),which most manifest in distal part. Stable bone ingrowth fixation was evidence at the hydroxyapatite coated portion in 100%.The average abductin angle of cup was 47(range,33-64).The average anevesion angle of cup was l7(range7-26).No cuPwas disPlaced.all cup wer assessed Stable bone ingrOWth fixation.The meanpolyethylene wear rate was 0. l9mm per yearHeerotopic ossification occurred in 8hips.The mean stem fit was 42%0ange,0-88%).The age was nO correated withHarris hip score and some radiograPhic manifest.The stem fit was observed inassociation with stem subsidence,but nOt with HAns hip score,thigh pain andendoSteal condensation.2.The W stem fits of six Predmally coated Stem were not similar Omnifit-HA stem was 47%, ABG stem was 54%, Matabloc Stem was 49%, PLUS steIn wa53%, hibbed stem was 49%, SL Stem was 39%.The Stem fit of ABG was better thanthat of OmnifitHA or Metabloc (P<0.05 ) .The stem fit was poor Whe medial canalnare index(McFI) was under 3.2,in this sitUation,The stem fit of ABG was better thanthat of OmnifitMA or Metabloc (P<0.05). When MCFI was over 3.2,the stem fit ofthese three stem was not evident1y differrent (P>0.05 ) .The Stem fit of Omnifit-HAand Matabloc were best whe MCFI was 3.84.4,the Stem fit of ABG was beSt WhenMCFl was '.'-. When the difference of McFI and medial stem nare indexpesFI)was po.3)-0.3,the stem fits of Omnifit-HA, Metabloc and ABG all were beSt.Whenthe differnce was over l.5,the stem fit of ABG was good than twO Other Stem.Thestem fit of the firSt grOup which wer used firSt was POorer than than of the arendgroup which wer used secondlyConcfusiont The short4erm clinical outcome of OmnifitHA Stems which wereused in china is satified.From our obSerVation,we can anticipate this Stem wilI getgood long-term cIinical outcome.This exPeriment confirms the poor Stem fit iscotrilated with subsidence of stem.2.The stem fit of anaomic Stem is better than thatof straight Stem.When MCFI...