Overuse of knee ultrasound in acute knee injury pathways in primary care: a quality improvement report

Introduction Knee injuries are a common presentation in primary care in Aotearoa New Zealand (NZ). Knee ultrasound (US) is widely available, despite evidence and Accident Compensation Corporation (ACC) guidelines indicating limited diagnostic value in most acute knee trauma. Aim This study aimed to evaluate the quality of imaging pathways prior to specialist review. Methods A retrospective audit of consecutive patients referred to a sport and exercise physician-led Acute Knee Clinic (AKC) was undertaken to assess the appropriateness of pre-referral knee US use against ACC imaging guidelines. Results Of 305 patients reviewed, 9.8% had undergone knee US prior to specialist assessment. Only one scan met ACC guideline criteria. Most USs were requested by physiotherapists (80%, P = 0.015) and performed at US-only clinics (66%). One in five patients had no prior imaging, and 21% had not received a knee X-ray. There was a trend suggesting that having an US increased the time to MRI; however, this difference was not statistically significant (P = 0.173). Discussion Potential improvement strategies identified include targeted education and individual feedback on imaging pathways, increased use of guideline-based decision support, and system-level safeguards for US referral. Knee US represents a low-value investigation in most acute knee injury presentations. Improving adherence to evidence-based imaging pathways in primary care may reduce unnecessary imaging and costs, and streamline care of patients presenting with acute knee injuries in primary and community settings.