Anaesthetic management of a patient for femoral correction using a new multi-axial fixation system

Abstract

Editor—Multi-axial correction (MAC) monolateral external fixation system (Biomet, Parsippany, NJ, USA) is a non-circular fixator that was developed as a response to the difficulties, for both patients and physicians, of placing, managing, and tolerating a circular fixator, in elongation and correction of deformities in the lower limb.1McCarthy JJ Ranade A Davidson RS Pediatric deformity correction using a multiaxial correction fixator.Clin Orthop Relat Res. 2008; 466: 3011-3017Crossref PubMed Scopus (25) Google Scholar 2Pandya NK Clarke SE McCarthy JJ Horn BD Hosalkar HS Correction of Blount's disease by a multi-axial external fixation system.J Child Orthop. 2009; 3: 291-299Crossref PubMed Scopus (19) Google Scholar Surgical correction of deformities of lower limb alignment is highly invasive, and requires good anaesthetic management both during the surgery and for postoperative pain. We report the case of a patient undergoing corrective surgery by using the MAC fixation system for epiphysiolysis of the femoral head, performed under general anaesthesia combined with sciatic and femoral nerve blocks. A 15-yr-old (69 kg) male was undergoing osteotomy and placement of MAC fixation system due to shortening and varus deviation of his right knee (Fig. 1). As a result of distal epiphysiolysis in both femurs at 4 yr old, he had had several major orthopaedic procedures, including (age 11 yr) osteotomy for varus correction using an external fixator with lengthening adapter. The patient was premedicated with oral midazolam 0.5 mg kg−1, 90 min before surgery. In the operating theatre, in addition to the standard monitoring, bispectral index, oesophageal temperature, and neuromuscular function were monitored. Body temperature was maintained between 35°C and 36°C. The patient received oxygen 100% for 3 min. Anaesthetic induction was performed with atropine 0.01 mg kg−1, propofol 2 mg kg−1, and mivacurium 0.2 mg kg−1 and a laryngeal mask number 4 (Supreme®) was inserted. Anaesthesia was maintained with oxygen and air (FiO2 0.5), expired sevoflurane 1.5%, and remifentanil 0.2–0.3 µg kg−1 min−1 in the 40–60 BIS range. Femoral and sciatic nerve blocks were performed using the anterior approach with ultrasound guidance (Sonosite S-Nerve®), and bupivacaine 0.25% (50 mg) used for each nerve block. In addition, a catheter was placed with stimulation device (Arrow®) at the femoral nerve with continuous infusion system of bupivacaine 0.125% (7 ml h−1) for treatment of postoperative pain. The surgery lasted 150 min and was uneventful. The patient's postoperative course was satisfactory, with adequate pain control with continuous infusion of bupivacaine and acetaminophen 1 g i.v. as rescue analgesia. Maximum visual analogue scale score in the first 24 h was 2. There was no evidence of local anaesthetic toxicity. The MAC fixation system is a new concept of external fixator developed for correction of lower limb deformities, which allows a monolateral approach to elongation and displacement correction in multiple planes. The presence of proximal and distal webbing associated with the osteotomy required good intra- and postoperative analgesia, which was achieved with femoral and sciatic nerve blocks and continuous infusion through a femoral nerve catheter. We consider general anaesthesia combined with loco-regional anaesthesia as an effective alternative in the anaesthetic management and postoperative pain in patients undergoing highly invasive surgery for the lower limb.