Lower limb orthopaedic surgery results in changes to coagulation and non-specific inflammatory biomarkers, including selective clinical outcome measures

BACKGROUND With an aging society and raised expectations, joint replacement surgery is likely to increase significantly in the future. The development of postoperative complications following joint replacement surgery (for example, infection, systemic inflammatory response syndrome and deep vein thrombosis) is also likely to increase. Despite considerable progress in orthopaedic surgery, comparing a range of biological markers with the ultimate aim of monitoring or predicting postoperative complications has not yet been extensively researched. The aim of this clinical pilot study was to test the hypothesis that lower limb orthopaedic surgery results in changes to coagulation, non-specific markers of inflammation (primary objective) and selective clinical outcome measures (secondary objective). METHODS Test subjects were scheduled for elective total hip replacement (THR) or total knee replacement (TKR) orthopaedic surgery due to osteoarthritis (n = 10). Platelet counts and D-dimer concentrations were measured to assess any changes to coagulation function. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured as markers of non-specific inflammation. Patients were monitored regularly to assess for any signs of postoperative complications, including blood transfusions, oedema (knee swelling), wound infection, pain and fever. RESULTS THR and TKR orthopaedic surgery resulted in similar changes of coagulation and non-specific inflammatory biomarkers, suggestive of increased coagulation and inflammatory reactions postoperatively. Specifically, THR and TKR surgery resulted in an increase in platelet (P = 0.013, THR) and D-dimer (P = 0.009, TKR) concentrations. Evidence of increased inflammation was demonstrated by an increase in CRP and ESR (P ≤ 0.05, THR and TKR). Four patients received blood transfusions (two THR and two TKR patients), with maximal oedema, pain and aural temperatures peaking between days 1 and 3 postoperatively, for both THR and TKR surgery. None of the patients developed postoperative infections. CONCLUSIONS The most noticeable changes in biological markers occur during days 1 to 3 postoperatively for both THR and TKR surgery, and these may have an effect on such postoperative clinical outcomes as oedema, pyrexia and pain. This study may assist in understanding the postoperative course following lower limb orthopaedic surgery, and may help clinicians in planning postoperative management and patient care.