ANTERIOR SUPINE INTERMUSCULAR APPROACH FOR TOTAL HIP ARTHROPLASTY: A 90 DEGREE TURN-AROUND

Abstract

The anterior supine intermuscular (ASI) approach enables total hip arthroplasty (THA) without dissection of muscles or insertions. This could be beneficial in patient recovery and satisfaction. Study-aim was to assess the learning-curve for the ASI-approach and show short-term results.

Two surgeons performed uncemented THA on 23 (17 and six respectively) consecutive patients. The Taperloc stem, Recap-cup and Magnum head (Biomet, Warsaw, USA) were used. THA was performed without the use of a traction-table. Data was gathered till 3 months follow-up.

Average patient age was 61 years (36–74), ASA-classification was two (one-four). There was a decrease in surgical time from 140 at the beginning to 80 minutes at the end of our series. Average blood-loss was 788 ml. Three patients received erythrocyte-transfusion. Minor non-orthopaedic complications all resolved within 48 hours. Average length of stay was five-and-a-half days. Functional score-lists showed improvement comparing pre-operative scores with scores on 12 weeks follow-up: Harris-Hip-Score from 56 to 94, Oxford-Hip-Score from 43 to 19, Hip-disability-and-Osteoarthritis-Outcome-Score from 109 to 18. On six weeks follow-up 65% and on 12 weeks 100% of patients showed unaided mobilisation. At follow-up we saw one superficial wound-infection, one partial non-disabling sartorius-lesion, one paraesthesia and one transient anaesthesia of the lateral femoral cutaneous nerve area.

ASI-approach for uncemented THA showed good results and rapid patient-mobilisation. This may in part be due to the non-dissecting of muscles or insertions, thus non-compromising the propriocepsis. Off course tissue-damage occurs, though this is likely to be of a fast reversible nature. There were no serious adverse events. We saw a rapid decline in session-duration suggesting a moderate learning-curve. Further research will have to prove the beneficiality of the ASI-approach.