Core Set of Radiographic Parameters for Shoulder Arthroplasty Monitoring: Criteria Defined by an International Delphi Consensus Process

Some unfavorable local events following shoulder arthroplasty occur without the patient experiencing symptoms and yet may be detected on diagnostic imaging, thereby serving as indicators of complications that may require revision. Our aim was to create a standardized protocol for an image-based monitoring process for assessing patients who are asymptomatic following shoulder arthroplasty. METHODS: A Delphi exercise was implemented with the participation of an international panel of experienced shoulder surgeons. On the basis of expert opinion from a core steering group, an initial list of imaging parameters for shoulder arthroplasty monitoring of asymptomatic patients was developed and reviewed by panel members. The most appropriate imaging modality was identified. Between each survey, all feedback was considered in order to revise the proposed core set with its definitions and specifications. Consensus was reached upon a two-thirds agreement. RESULTS: Three online surveys were administered, with 98 surgeons responding to the first and/or the second survey. The response rate for the final survey was 74%. Final parameter definitions were organized in 7 categories (implant migration, radiolucency around implant and implant loosening, signs of shoulder displacement, bone resorption and formation, wear of implant articular surfaces, fractures around the implant, and implant breakage and disassembly) and approved with 85% to 100% agreement. Seventy-eight percent of the panel members agreed on a minimum radiographic imaging schedule: standard anteroposterior and axial (alternatively, Y) views made within 6 weeks after implantation and between 3 and 6 months as well as at 12 months post-surgery. CONCLUSIONS: Our work presents a monitoring tool developed with international consensus for the assessment of asymptomatic patients after shoulder arthroplasty and including a structured core set of radiographic parameters. Clinical application and scientific evaluation of the monitoring process are needed. CLINICAL RELEVANCE: This represents a major step toward the standardization of shoulder arthroplasty radiographic monitoring for routine quality controls and research investigations.