233 Blood Tests and Radiographs After Hip and Knee Arthroplasty – We May Not Always Need Them

Abstract

Aim Routine blood tests and radiographs are routinely performed after total joint arthroplasty as a pre-discharge requirement. This study aims to explore whether there might be sub-group of patients undergoing arthroplasty for whom post-operative blood tests and radiographs might not be mandated in the absence of clinical concern. Method A retrospective study of 612 ASA 1 and 2 patients underwent total hip or knee arthroplasty at a single orthopaedic centre. Variables purported to be of interest were sodium and Potassium levels, Haemoglobin concentration and eGFR. Return to theatre and alterations of the routine Physiotherapy rehabilitation were matched to post-operative radiographs. Results 42 (6.9%) patients had post-operative haemoglobin below 10 g/L. Of these 4 were symptomatic, which required treatment. Acute kidney injury was identified in 13 patients (2.1%); 11 had pre-existing renal disease. The other two had both suffered pro-longed post-operative hypotension. Two patients had severe hyponatraemia and one of whom had pre-existing renal disease. Two patients had hypokalaemia and one of whom had metabolic syndrome but normalised within 24 hours after oral supplement. No patient had abnormal post-operative radiography that altered management. Conclusions Our study indicates that routine post-operative blood tests and radiographs may not be necessary in ASA 1 and 2 patients with normal pre-existing blood tests. Where patient is clinically symptomatic or there is evidence of pre-operative renal dysfunction, metabolic syndrome, electrolyte imbalance or anaemia, we would suggest blood tests are necessary. If there is no surgical concern, it is safe to delay check radiography until their first post-operative follow up.