Clinical and Radiological Outcomes of Rectangular Tapered Cementless Stem According to Proximal Femoral Geometry in...

A retrospective analysis of mid- to long-term clinical and radiological outcomes of Korean patients over 60 years of age who underwent hip arthroplasty using a cementless rectangular tapered stem according to Dorr proximal femur geography.

From January 2007 to December 2013, 107 patients (112 hips) underwent hip arthroplasty using the C2 stem. The mean age of patients was 77.4 years (range, 60-91 years) and the mean follow-up duration was 91.1 months (range, 60-116 months). All patients were evaluated clinically and radiologically with special attention to Dorr femoral bone classification, implant fixation, radiolucent line (RLL), and thigh pain.

All implants demonstrated radiographic evidence of stable fixation by bone ingrowth without any change in position. The mean Harris hip score improved from 65.5±16.0 (preoperative) to 90.5±15.9 (final follow-up) (P<0.001). Incidence of RLLs, stress shielding, and thigh pain was highest in patients with Dorr type A (RLL, P=0.021; stress shielding, P=0.030; thigh pain, P<0.001). One stem revision was performed due to deep infection. The Kaplan-Meier survival rate of the femoral stem was 97.6%.

The overall survival rate of the C2 stems was greater than 97%; there were no significant differences in survival of the C2 stem according to the Dorr classification. The incidences of RLL of thigh pain and RLL were significantly different among Dorr classifications and (highest in patients with Dorr type A).