Abstract
Background
It is unclear which form of anaesthesia is the most favourable in primary total hip replacement (THR) surgery. A recently published systematic review of modern anaesthesia techniques in primary THR surgery (Macfarlane 2009) was not able to show any convincing benefit of regional or general anaesthesia. One retrospective study that examined anaesthesia and leg length (Sathappan 2008), found an increased incidence of leg length difference > 5 mm in those patients who were operated with regional anaesthesia. Our department used a mini invasive approach in supine as standard procedure in THR. The type of anaesthesia that is chosen is up to the individual anaesthetist.
Purpose
We wanted to see if there was any correlation between type of anaesthesia and leg length, total time spent in theatre and recovery room, postoperative hospital stay, blood loss or operating time in primary THR surgery with a mini invasive approach in supine.
Materials and Methods
Our study was a retrospective study of 170 primary THR patients. All patients received an uncemented Corail stem and a cemented Marathon cup. Patients with abnormal anatomy, BMI > 46, simultaneous removal of internal fixation or incomplete data were excluded in the analysis. Radiograpic leg length was measured using the inter teardrop line and the lesser trochanter.
Results
99 patients were operated on with spinal anaesthesia and 71 with total intravenous anaesthesia (TIVA). There were 65% women in both groups. Average age was 74 years (32–95) in the spinal anaesthesia group and 67 years (38–93) in the TIVA group. We found no significant difference in the average operating time (spinal 65 min, TIVA 64 min), drop in haemoglobin to the first postoperative day (spinal 16%, TIVA 16%), postoperative hospital stay (Spinal 1.4 days, TIVA 1.4) or in transfusion rate (spinal 1%, TIVA 1.4%). We found a significant difference in the proportion of patients with a leg length difference of more than 7 mm (Spinal 22%, TIVA 6%, p = 0.02) and the average total time spent in theatre and post-operative department (spinal 325 min, TIVA 293 min, p < 001).
Discussion
The study is retrospective and is therefore fettered by the limitations inherent in such a study. Our study seems to confirm the earlier findings that the type of anaesthesia can affect leg length in primary THR. It is speculated that spinal anaesthesia has a more unpredictable effect on muscular tension which could explain this.
