Audit on Ultrasound Technique for Screening of Hip Effusion

Audit of image adequacy and report documentation for ultrasound screening of hip effusion

Ultrasound is a non-invasive, non-ionizing, easily available, and cost-effective real-time dynamic imaging technique for screening of hip effusion¹. It is more sensitive than clinical examination for evaluation of effusion and is the modality for choice for patients with pain and mechanical symptoms of the hip region without a definitive diagnosis on clinical examination². Ultrasound screening for hip effusion is essential before arthrocentesis³.

The British Medical Ultrasound Society and The Society of College of Radiographers (2021) published a guideline for professional ultrasound practice regarding the standard to be achieved⁴.

The examination is performed with the patient in a supine position with the hip in neutral and slight abduction. The transducer is placed in a longitudinal-oblique plane to image the anterior recess ^2,5. The distance between the anterior layer and the femoral neck is measured on ultrasound for detecting the effusion. Joint effusion is diagnosed when the distance between the anterior layer of synovium and the femoral neck is greater than 7 mm, or a difference between both hips is greater than 1 mm⁵.

The standard: 

1. A correct aligned image focusing on longitudinal anterior hip joint of symptomatic side with or without colour box to show any effusion or synovitis¹.

2. Correct document of any pathology found, including measurement and vascularity¹.

3. Any pathology found should be documented in two planes^1,2.

4. Comparison image on contralateral hip with documentation¹.

Target: 

100% of ultrasound scans and reports for hip effusion should meet these standards.

Indicators: 

The percentage of ultrasound scans and reports which adhere to each of the standards.

Data items to be collected: 

1.  Is the image on longitudinally anterior hip joint of symptomatic side correctly taken?

2.  Is there a correct measurement and documentation of any effusion?

3. Is there any colour Doppler image taken for documentation of synovitis?

4. Is image taken on two planes if there is pathology identified?

5. Is contralateral side image taken for comparison?

Suggested number: 

Ultrasound scans of hip effusion for both pediatrics and adults should be collected and reviewed. All cases performed during the preceding six months, or the most recent 50 consecutive cases (whichever number is greater). Non-hip-joint centered fluid collection or post-operative cases should be excluded.

1. Publicise the standards for hip effusion ultrasound scanning technique and reporting, through in-person departmental radiology meetings and dissemination of written material to radiologists and sonographers.

2. Create an automated hip effusion ultrasound report template for use during electronic report transcription, in order to improve standardisation of scanning techniques and comprehensive reports.

3. Re-audit six months after intervention, to assess for improvement in practise. Continue the audit spiral, to ensure sustained compliance with the standards.

1. Radiology information system (RIS) to review administrative details and reports.

2. Picture archiving computer system (PACS) to review saved ultrasound images.

3. Statistical computer software, such as Microsoft Excel, for recording and analysing data.

1. Society and College of Radiographers and British Medical Ultrasound Society: Guidelines for Professional Ultrasound Practice - revised December 2021

2. Backhaus M, Burmester GR, Gerber T, Grassi W, Machold KP, Swen WA, Wakefield RJ, Manger B; Working Group for Musculoskeletal Ultrasound in the EULAR Standing Committee on International Clinical Studies including Therapeutic Trials. Guidelines for musculoskeletal ultrasound in rheumatology. Ann Rheum Dis. 2001 Jul;60(7):641-9. doi: 10.1136/ard.60.7.641. PMID: 11406516; PMCID: PMC1753749.

3. McAlindon T, Kissin E, Nazarian L, Ranganath V, Prakash S, Taylor M, Bannuru RR, Srinivasan S, Gogia M, McMahon MA, Grossman J, Kafaja S, FitzGerald J. American College of Rheumatology report on reasonable use of musculoskeletal ultrasonography in rheumatology clinical practice. Arthritis Care Res (Hoboken). 2012 Nov;64(11):1625-40. doi: 10.1002/acr.21836. PMID: 23111854.

4. European Society of Skeletal Radiology (ESSR), Musculoskeletal Ultrasound Technical Guidelines IV. Hip https://essr.org/content-essr/uploads/2016/10/hip.pdf

5. Koski JM, Anttila PJ, Isomäki HA. Ultrasonography of the adult hip joint. Scand J Rheumatol. 1989;18(2):113-7. doi: 10.3109/03009748909099926. PMID: 2660254. 

Dr. HM Kwok

Co-authors

Dr FH Ng

Dr NY Pan