Objective:tostudytheclinicalinfluenceoffemoralqualityoncementlesshipreplacementandtoevaluatecorticalindex(CI)forfemoralqualityinordertoguideprosthesischoiceandrehabilitation.Methods:forth-ninecasesofcementlesshipreplacementwerefollowedupforaverage3.5years,42ofwhonhadX-rayfilmsonpreoperationoroperationday.Results:Harrisscoresandpatients'satisfactionwerelowbutpainwassignificantandprolongedwhencorticalindiceswerelow.Conclusions:CIisareliablesemi-quantityparameterforclinicalevaluationoffemoralquality.Osteoporosispatientspredisposetothighpain.Lagforfull-weightloadingandavoidancefortorsionmotioncancontributetolesspainwhenCI≤2.2.