[Minimally invasive total hip arthroplasty with anterior incision].

OBJECTIVE: To report the clinical outcome of minimally invasive total hip arthroplasty with anterior incision.

METHODS: One hundred and twenty cases were randomly divided into two groups. Sixty cases (group 1) who had undergone a mini-invasive THA were compared with 60 cases (group 2) who had undergone THA with standard posterolateral incision. The operation time, length of incision, blood loss, anteversion angle of acetabulum cup, Harris score and complications were observed.

RESULT: The average operation time was almost the same; The average length of incision for group 1 was 7.9 cm (7.4 - 9.0 cm) and 16.3 cm (14 - 22 cm) for group 2 (P < 0.01). The average blood loss for group 1 was 350 ml (250 - 530 ml) and 650 ml (400 - 1200 ml) for group 2, there was significant difference between two groups (P < 0.05). According to the postoperative X-ray, the mean anteversion angles of cup were 24 degrees (19 degrees - 27 degrees) for group 1 and 19 degrees (15 degrees - 22 degrees) for group 2. The average length of post-operative hospital stay was 7 days (5 - 8 days) in group 1 and 13.5 days (12 - 16 days) in group 2 (P < 0.05). The Harris score of group 1 was 91.4 (67 - 94) and 78.5 (67 - 91) for group 2 at the 3 month follow-up (P < 0.05). At the last follow up, there were no significant difference (P > 0.05), but the average ROM of group 1 were definitely more greater than that of group 2 (110.0 degrees +/- 3.2 degrees vs. 90.0 degrees +/- 2.9 degrees P < 0.05). There was 1 case of cup reinsertion in group 1 because of large anteversion angle; 2 cases of symptomatic DVT and 1 case of lethargy because of cerebral infarction happened in group 2.

CONCLUSIONS: Minimally invasive total hip arthroplasty using anterior approach is a safe and effective technique with the advantages of less soft tissue damage and less blood loss.