About TRIAD

TRIAD is a multicentre, registry-nested, cluster randomised crossover trial investigating whether dilute povidone-iodine wash before wound closure reduces surgical site infection after primary hip and knee replacement compared with saline.

Study Rationale

Wound irrigation with normal saline is standard practice in orthopaedic surgery, but

there has been a trend towards utilisation of antiseptic irrigation solutions to

decontaminate the surgical field following total hip arthroplasty (THA) and total knee

arthroplasty (TKA), although high-quality evidence remains lacking. Dilute povidone-

iodine (PVP-I) lavage is a low cost, low risk and potentially effective intervention to

reduce surgical site infection by reducing bacterial contamination. High-quality

evidence is required to determine the clinical effectiveness, cost-effectiveness and

safety of dilute PVP-I lavage compared with normal saline lavage for reduction in SSI

after THA and TKA.

Primary objective

The primary objective of this study is to evaluate the efficacy of dilute PVP-I lavage in

reducing surgical site infections (SSI) occurring within 90 days in adults undergoing

primary, elective THA or TKA for osteoarthritis (OA).

Choice of intervention

PVP-I has long been used across surgical specialties as a topical skin antiseptic. More

recently, dilute PVP-I (0.3–0.35%) has been investigated as an intraoperative lavage to

sterilise the surgical field prior to wound closure and reduce surgical site infection. In-

vitro studies consistently demonstrate rapid and complete eradication of common

arthroplasty pathogens, including Staphylococcus aureus (MRSA and MSSA),

Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans,

Cutibacterium acnes and Staphylococcus epidermidis. Exposure times as short as

2–3 minutes at 0.3–0.35% with this dilution of PVP-I achieve the antimicrobial effect

while showing low cytotoxicity to fibroblasts, chondrocytes and osteoblasts compared

with alternatives such as chlorhexidine, with animal data indicating no adverse impact

on osseointegration. A single 500 mL lavage is sufficient to flood the wound and

bathe implants and recesses without undue excess, and this volume has been

employed in the majority of clinical studies evaluating its efficacy.

Sponsor

Australian National University. Coordination: Australian Orthopedic Association Clinical Trials and Analytics Unit. Funding: Medical Research Future Fund.

Registration: ACTRN12626000076370p. Ethics: Sydney Local Health District HREC (RPAH Zone), X26-0020, HREA 2025/ETH02793, final approval 12 March 2026.

Study Investigators

Principal Investigator

Professor Paul Smith

Co-Investigators

Prof Richard de Steiger

Prof Chris Vertullo

Prof Ian Harris

Prof Michael McAuliffe

A/Prof Chris Wall

A/Prof David Dewar

Dr Andrew Fraval*

Dr Janney Wale

Dr Catherine McDougall

Ms Alicia Norman

Ms Durga Bastiras

Dr Sophie Corfield

  • Dr Andrew Fraval is an orthopaedic surgeon involved in this project as part of his PhD,

which is supervised by Professor Richard de Steiger (University of Melbourne).