Radiostereometric analysis of keeled versus pegged glenoid components in total shoulder arthroplasty: a randomized feasibility study

• Published in: Canadian Journal of Surgery 2017-08, Vol.60 (4), p.273-279
• Main Authors: Gascoyne, Trevor C, McRae, Sheila M B, Parashin, Sara L, Leiter, Jeff R S, Petrak, Martin J, Bohm, Eric R, MacDonald, Peter B
• Format: Article
• Language: English
• Subjects: Arthroplasty; Arthroplasty, Replacement, Shoulder - adverse effects; Arthroplasty, Replacement, Shoulder - methods; Cement; Feasibility Studies; Follow-Up Studies; Glenoid Cavity; Humans; Joint surgery; Medical device industry; Medical equipment; Outcome and Process Assessment, Health Care; Patient satisfaction; Polyethylene; Prostheses; Prosthesis Design - adverse effects; Prosthesis Design - standards; Prosthesis Failure; Radiography; Radiostereometric Analysis - methods; Reoperation; Shoulder; Shoulder Prosthesis - standards; Statistical analysis; Studies; Surgery
• ISSN: 0008-428X; 1488-2310
• DOI: 10.1503/cjs.001817

This study aimed to assess differences in the fixation and functional outcomes between pegged and keeled all-polyethylene glenoid components for standard total shoulder arthroplasty. Patients were randomized to receive a keeled or pegged all-polyethylene glenoid component. We used model-based radiostereometric analysis (RSA) to assess glenoid fixation and subjective outcome measures to assess patient function. Follow-up examinations were completed at 6 weeks and 6, 12 and 24 months after surgery. Modifications to the RSA surgical, imaging and analytical techniques were required throughout the study to improve the viability of the data. Stymied enrolment resulted in only 16 patients being included in our analyses. The RSA data indicated statistically greater coronal plane migration in the keeled glenoid group than in the pegged group at 12 and 24 months. Functional outcome scores did not differ significantly between the groups at any follow-up. One patient with a keeled glenoid showed high component migration after 24 months and subsequently required revision surgery 7 years postoperatively. Despite a small sample size, we found significant differences in migration between glenoid device designs. Although clinically these findings are not robust, we have shown the feasibility of RSA in total shoulder arthroplasty as well as the value of a high-precision metric to achieve objective results in a small group of patients.