THE MEDIAL APPROACH IN PRIMARY TOTAL HIP REPLACEMENT SURGERY

Abstract

Ludloff’s medial approach has never been used for other hip surgeries especially not for THR.

47 patients (26 men/21 women) provided informed consent to participate in the study. The inclusion criterion for the study was the diagnosis of osteoarthritis of the hip joint. The average age at operation was 53.7±10.4years. All patients were provided with a CUT^® prosthesis.

All patients were examined clinically and X-rayed preoperatively as well as postoperatively at three days, two weeks, six weeks and six months. The functional hip scores according to Harris and the Oxford hip score were obtained preoperatively and at the defined intervals postoperatively. The surgical duration and the intraop-erative as well as the postoperative blood loss were measured for each patient. Abductor muscle function and the number of steps a patient was able to walk without walking aids on a treadmill at a velocity of 5km/h (a maximum of 100steps was measured) were assessed.

Multifactorial analyses of variance and Chi-square tests were performed.

Based on the numbers available there were no significant differences between the two groups in the distribution of patient age (p=0.604), gender (p=0.654), weight (p=0.180) and height (p=0.295). No significant differences in the calculated Harris score (p=0.723) were found pre-operatively. The amount of steps the patient was able to walk was not different between the approach groups (p=0.636).

The total amount of blood loss (intra- + post-OP) was even significantly lower in the medial approach group (p=0.009).

Three days post-operatively the leg lengths were assessed. The difference was not statistically significant based on the numbers available (p=0.926). The overall correlation between Harris and Oxford score was significant (r²=0.63, p< 0.001).

Three days post-operatively a slight, but significant better Harris (p< 0.001) and Oxford scores (p=0.001) could be observed in the medial approach group. The number of steps the patient was able to walk without help or crutches was significantly higher in the medial approach group (p=0.001). The Trendelenburg sign (p< 0.001) and the limping criterion (p< 0.001) were significantly less in the medial approach group.

Two weeks post-operatively the Harris (p=0.001) and the Oxford (p=0.046) scores were significantly better for the medial approach group. The number of steps the patient was able to walk without help or crutches was significantly higher in the medial approach group (p< 0,001).

The medial approach is clinically feasible to perform the implantation of a femoral neck prosthesis. The accuracy of the stem implantation reflected in both the leg lengths and the postoperative X-ray alignment was not different between the groups.

After six months there was no significant difference between the conventional anterolateral approach and the medial approach in the presented study.