For Investigators

TRIAD is a pragmatic, multicentre, registry-nested, cluster randomised crossover trial evaluating dilute povidone-iodine lavage versus saline lavage in primary hip and knee arthroplasty. The study is conducted through the Australian Orthopaedic Association Clinical Studies Unit Platform (RAPID) and linked AOANJRR infrastructure.

Investigator focus

This section provides investigators and site teams with an overview of trial design, workflow, site responsibilities, data collection, safety reporting, and trial governance. TRIAD has been designed to evaluate a low-cost, widely used intraoperative intervention in real-world Australian practice.

Key operational points

  • Hospital-level cluster randomised crossover design

  • Standardised lavage protocol for intervention and control periods

  • Registry-linked outcome capture with RAPID-based follow-up

  • PROMs collection before surgery and at follow-up timepoints

  • Site training, delegation, monitoring, and audit readiness requirements

How the trial works

Participating hospitals are randomised to one of two treatment approaches for an initial recruitment period and then cross over to the alternate approach. Randomisation occurs at the hospital level rather than the individual patient level. Patients undergoing primary elective total hip or total knee arthroplasty for osteoarthritis at participating hospitals are eligible for enrolment, subject to protocol criteria.

The intervention arm receives an additional 500 mL lavage of 0.35% dilute povidone-iodine for a minimum of 3 minutes before wound closure, followed by saline evacuation and application of 10% povidone-iodine to exposed skin edges during closure. The control arm receives normal saline lavage according to standard practice.

Outcome collection

The primary outcome is validated surgical site infection at 3 months after surgery. Secondary outcomes include surgical site infection at 12 months, revision for infection, wound complications, readmissions, other adverse events, mortality, and patient-reported outcomes. PROMs include EQ-5D-5L, Oxford Hip Score or Oxford Knee Score, and patient-rated satisfaction and improvement measures.

Data are collected through RAPID, AOANJRR-linked sources, hospital and surgeon verification, and patient questionnaires. Follow-up occurs at baseline, 90 days, 6 months, and 12 months.

Site responsibilities

Site investigators and research teams are responsible for implementing the allocated treatment protocol, maintaining local training and delegation records, supporting patient registration and follow-up processes, and ensuring protocol adherence at site level. All study personnel must be trained in the protocol and aware of their delegated responsibilities before undertaking study activities.

Sites must also maintain study documentation, support monitoring and audit activity, and ensure that governance requirements are met before recruitment commences. Ethical approval does not replace the requirement for separate site authorisation.

Safety, governance and compliance

Serious adverse events identified at participating sites must be reported to the AOA Clinical Studies Unit. Referred events are reviewed by the trial management structure and, where required, escalated to the independent Data Safety Monitoring Committee. The study also includes outcome verification, adherence auditing, and formal oversight of data quality and protocol compliance.

Investigators should ensure that delegation logs, protocol-specific training logs, essential documents, and audit readiness processes remain current throughout the study. Annual reporting, amendment submission, and safety reporting must be completed in accordance with ethics and governance requirements.

Support and contact

For study coordination, site processes, or operational queries, please contact the AOA Clinical Studies Unit at clinicalstudiesunit@aoa.org.au or 1800 068 419.