Mittelfristige klinische und radiologische Ergebnisse der anatomischen Hüftschaftprothese Optan nach 3 - 5 Jahren, in unzementierter und zementierter Verankerungstechnik
This prospective follow-up study presents and compares the clinical and radiological results of the anatomic hip stem Optan (Zimmer) in cementless and cemented fixation technique after 3-5 years of implantation. 157 cementless stems were examined after a mean follow up of 3,7 years (2,8-5,2 y.) with a mean patient age at surgery of 53,1 years. 129 cemented stems were followed up at a mean period of 3,5 years (2,7-5,5 y.) with a mean patient age of 69,9 years. Regardless of the reason for stem failure 5 stems in the cementless and 2 in the cemented group have been explanted or are indicated to. Due to the criteria of aseptic loosening only one stem in each group failed, which results in a Kaplan-Meier-Survival rate of 99,3% in the cementless and 98,1% in the cemented group. The differences were statistically not significant. At latest follow-up, mean total Harris hip score was 96,0 points for the cementless and 94,8 for the cemented stem. The mean Merle d"Aubigné score was 17.4 points for the cementless and 17,2 for the cemented stem. The differences were statistically not significant. The DMA-Method could found no significant radiological stem migration or varus-valgus-tilt in both groups. Cement mantle was optimal in 80%. Non-optimal cement mantle with thickness < 2mm were found in Gruen-zone (z) 1,5,8,12 in 10-25%. Valgus-tilt > 5° was significant correlated with thin cement mantle in z 2,5,9,12 and should be avoided. In the cementless group reactive endostal lines were found in 8-21% in z 3,4,5,10,11,12 and sclerosis and cortical hypertrophy in 10-23,6% in z 3,4,5,10,12 which is interpreted as still too much distal force introduction in the femur. Distal overreaming during stem implantation is considered to be able to avoid these bone reactions. This study confirmed the excellent mid-term results achieved with the Optan-stem regardless of the kind of fixation. Further studies must show whether these results are stable in long-term follow up.
Subject HeadingsAseptische Lockerung [GND]
Arthroplasty, replacement, hip [MeSH]
Hip prosthesis [MeSH]