Use of the Harmonic System in Total Hip Arthroplasty: A prospective,Comparative,Observational Study

We compared technical issues, postoperative outcomes and surgical complications of total hip arthroplasty when using the harmonic scalpel (HS) when compared with conventional techniques (CT) in a prospective, comparative observational study. Thirty patients undergoing total hip arthroplasty were assessed. Operative time, blood loss in drains, postoperative pain, soft tissue injury and complications were recorded. We found no significant differences between the HS and CT groups at baseline. Mean operative time was longer in the HS group compared with the CT of total hip arthroplasty (61 minutes vs. 54 minutes; P<0.05). We found no difference in postoperative pain using a visual analogue scale score, or use of paracetamol. The use of tramadol was reduced in the HS group compared to CT group at the 7^th day (83.3mg vs. 113.3 mg; P<0.05). Drainage volume was significantly lower in the HS group at 24 hours (332 ml vs. 429 ml; P<0.05) and at 48 hours (429 vs. 537 ml; P<0.05). C-reactive protein blood levels were significantly lower in the HS group 75mg/l vs. 96mg/l at the third day (P<0.05) and 26mg /l vs. 54mg /l at the seventh day (P<0.01). Creatine kinase blood levels were significantly lower in the HS group at 3 and 7 days (2.4 ukat/l compared to 5.3 ukat/l at the 3^rd day (P<0.01), respectively 1.1 ukat/l compared to 1.8 ukat/l at the 7^th day (P<0.01). We found no significant differences in blood myoglobin levels between the two groups. The use of the HS may reduce postoperative pain, drainage volume, and soft tissue injury in patients undergoing total hip arthroplasty, which may justify the cost of the technique. The use of HS may have further applications in revision hip arthroplasty and tumour surgery.