Trauma, including major Orthopaedic Surgery, results in an immuno-inflammatory response which is variable in systemic effects.This response is patient specific. The systemic effects may be exaggerated and cause distal organ damage. This study assesses the effects of elective hip and knee arthroplasty on liver function tests.

A prospective study of liver function in 316 patients (168 males and 148 females) undergoing elective total hip and knee joint replacement was undertaken by one surgeon using standardised anaesthetic, surgical and post-operative protocols. Alanine aminotransferase (ALT), Aspartate transaminase (AST), Alkaline phosphatase (ALP) and Gammaglutamyl transpeptidase (GGT) were assessed pre-operatively and at one day, one week and six weeks following surgery. There were 166 hip and 150 knee replacement patients. Of the hip replacements, 35% were cemented, 35% hybrid and 30% cementless. All knee replacements were cemented:

ALT levels (IU) pre-operatively were 20, one day 17, one week 45.5 and at six weeks 17.

AST levels (IU) pre-operatively were 21, one day 22, one week 38 and at six weeks 19.

ALP levels (IU) pre-operatively were 77, one day 57, one week 88.5 and at six weeks 90.

GGT levels (IU) pre-operatively were 24, one day18, one week 68 and at six weeks 29.

For all enzymes there was a highly significant (p < 0.001) increase in values at one week. ALT and AST levels had returned to normal and GGT nearly normal at six weeks.

ALP, also a bone enzyme, remained elevated at six weeks. There was no significant difference for age or gender. There was no significant difference for cemented, hybrid or cementless hips. Liver function tests become elevated one week following elective joint replacement.

This is not related to cement. The cause is probably multifactorial and major likely contributory factors are patients' immuno-inflammatory response and drug effects. Surgeons should be aware of this phenomenon and undertake pre-operative LFT screening routinely.