Does post-operative C-reactive protein predict length of stay in total hip arthroplasty?
Author(s): Edmund Farrar
Statement of the Problem: C-reactive protein (CRP) is an inflammatory biomarker that is released in response to inflammation, infection or trauma. Its role in the post-operative phase of elective orthopaedic surgery is unclear. Current guidance recommends a number of pre-operative investigations. However, whilst blood tests are routinely requested in the post-operative surgical plan, there is no guidance outlining which of these are relevant. We aimed to assess whether CRP is a useful and cost effective post-op blood test in elective total hip arthroplasty.
Methodology & Theoretical Orientation: A retrospective review of patients undergoing elective total hip arthroplasty over six months, including comparison of day 1 post operative CRP and length of stay. We also considered associated cost. Correlation between Day 1 post-operative CRP and length of stay was analysed using a Spearman r coefficient.
Findings: A hundred and thirteen patients were identified with median age 70 and median length of stay three days (range 0-28 days). There was no significant correlation between day one CRP and length of stay (R = 0.1801, p = 0.0563). However, there was statistical significance between day one post-operative CRP and age (R=0.2098, p=0.029), and age and length of stay (R=0.5098, p<0.0001). At a unit CRP cost of £1.69 and extrapolating on the number of total hip replacements undertaken over 6 months, over a year long period a routine day one post-op CRP for all patients undergoing elective total hip replacement would cost our centre £743.60