Impact of proximal femoral shape on leg length discrepancy after total hip arthroplasty / 中国骨伤

OBJECTIVE@#To investigate the effect of different proximal femoral shapes on leg length discrepancy(LLD) after total hip arthroplasty(THA).@*METHODS@#Total 131 patients with osteoarthritis or osteonecrosis received unilateral biological total hip arthroplasty from June 2013 to June 2019. All patients' age, sex, side and pelvis anteroposterior digital radiography were retraspectively analyzed. There were 69 males and 62 females, 57 cases of left hip and 74 cases of right hip. The age ranges from 25 to 89 with an average age of 62 years. There were 48 cases of osteoarthritis and 83 cases of osteonecrosis. In this study, femoral cortical index (FCI) was used as the classification of proximal femoral shape, and bilateral lower limb length differences were measured by preoperative and postoperative pelvis anteroposterior digital radiography. Grouping according to FCI:> 0.6 was Dorr A group, 0.5 to 0.6 was Dorr B group, 0.6, the postoperative LLD was 6.30 mm (IQR 1.00 to 10.95 mm). When FCI was 0.5 to 0.6, the postoperative LLD was 5.85 mm(IQR-0.55 to 8.90 mm). FCI<0.5, the postoperative LLD was 1.95 mm(IQR -2.50 to 6.68 mm). LLD comparison of different proximal femoral shape was statistically significant (@*CONCLUSION@#High FCI increases the risk of lower extremity prolongation after surgery on the affectedside, while low FCI reduces the risk of lower extremity prolongation after surgery on the affected side. The surgeon can assess the shape of the proximal femur of the patient preoperatively and inform the patient in advance of possible changes in leg length of both lower extremities after total hip replacement.

Analysis of Femoral cortical Indices in Cementless Femoral Stem / 대한정형외과학회잡지

Preperative radiologic indices, such as cortical index of Engh, morphological cortical index of Sportono and Romagnoli, canal flare index of Noble, and their relationship to the postoperative canal filling, femoral stem fitness, stability and clinical result at last follow up were analyzed in 111 hips of 96 patients treated with bipolar or total hip arthroplasty at the Department of Chthopedic Surgery, Korea University Hospital, between January 1985 and May 1993. The results obtained were as follows: 1. The cortical index had no correlations with age, metaphyseal filling and clinical result but isthmic filling was proportional to the cortical index. In femoral stem fitness and stability, most cases of press fit and optimal stability were obtained in group 3 and 4 that have thick cortex. 2. The morphological cortical index had no correlation with age, canal filling and clinical results. But it was proportional to the postoperative femoral stem fitness and stability. 3. The canal flare index had no correlation with age. The metaphyseal filling was increased in the stove piped canal group(less than 3.0 canal flare index), but isthmic filling was increased in normal canal group(3.0-4.7 canal flare index). The most cases of press fit and optimal stability were obtained in normal canal group. More satisfactory clinical results were obtained in nomal canal group. Above results suggest that straight type of cementless femoral component could get better press fit fixation, postoperative stability and more satisfactory clinical results in the cases of cortical index larger than 2.0, mophological cortical index larger than 2.7 and canal flare index larger than 4.0 but metaphyseal filling is unsatisfactor.