Standardized Process Measures in Radiographic Hip Surveillance for Children with Cerebral Palsy

Abstract

Detection of hip migration in children with cerebral palsy (CP) through radiographic surveillance can prevent dislocations. Migration Percentage (MP) is the accepted method for quantifying hip subluxation in CP on pelvis x-ray but was not being reported at our institution. Our objective was to improve care for children with CP by standardizing radiographic techniques and reporting radiographs obtained as part of a hip surveillance program.

Methods: A baseline retrospective review of CP surveillance pelvis x-ray reports was performed. We then educated radiologists and technologists, standardized imaging techniques, and required structured radiology reporting to include MP measurement and dislocation risk categories. We tracked compliance with the reporting template for 10 months. Images and reports were also assessed for quality and accuracy by an orthopedic surgeon.

Results: Baseline period reports showed no consistency. In total, 449 children with CP (mean age: 7.3 years ± 4.2) had a surveillance pelvis radiograph during the postintervention study period (May 2019-February 2020). An estimated 90% reporting compliance was achieved and sustained by 5 months. Eight (89%) of the children with high-risk hips were newly diagnosed during our study period; all had a progressive increase in MP from prior examinations. All clinicians surveyed agreed that the standardized reports, including MP, were helpful to their practice.

Conclusions: Using evidence-based process measures and quality improvement methodology, we standardized hip surveillance for children with CP. Radiology reports that include MP and risk category for hip dislocation enable clear communication for referrals across specialties and early detection and treatment for better outcomes.

Fig. 1.

Standardized reporting template created for surveillance hip radiographs in children with CP. The Findings section requires quantification of hip migration using a numeric value, the MP. The Impression section requires a risk category assignment for each hip.

Fig. 2.

Key driver diagram for instituting and maintaining a radiographic hip surveillance program.

Fig. 3.

Technique for measurement of MP using the measuring tool on a picture archiving and communication workstation. a: A horizontal line along the ischia is drawn. b: Six lines are then drawn perpendicular to the ischial line. Cobb angle calculator can be used to ensure that lines are drawn 90 degrees to the ischial line. c: Two lines are moved out to frame the medial and lateral borders of each femoral epiphysis (solid line and dotted line, respectively), with the third line marinating the lateral border of the bony acetabulum (dashed line). d: Finally, horizontal lines A and B are drawn to calculate the percent femoral head lateral to the bony acetabulum, A/B × 100 = MP. Acta Orthop Scand Suppl 1980;184:1–1000 and Acta Orthop 2018;89:652–655.^,

Fig. 4.

Run chart displays the variation in our process over time. By 5 months (September 2019), we had met and sustained our goal of 90% compliance with standard templated reporting in surveillance pelvis radiographs in children with CP. The dashed line indicates “goal” line of 90%. The solid line indicates the process mean. There is no shift change.