CT imaging findings in symptomatic patients with and without revision surgery after reverse shoulder arthroplasty.

Objectives: To evaluate CT imaging findings in symptomatic patients with and without revision surgery (RS) after reverse shoulder arthroplasty (RSA).

Materials and methods: In this retrospective study, two radiologists assessed CT imaging findings in symptomatic patients with RSA over 5 years, including material fracture and loosening of the peg, baseplate, screws, and humeral stem, screw positioning, prosthesis dislocation, glenoid notching, fractures, and deltoid muscle quality. The primary outcome parameter was RS. Patients were assigned Group 1 (RS) or Group 2 (No RS).

Results: Ninety-nine patients (mean age 70.4 ± 10.3 years, 61 females) met the inclusion criteria. Fifty-two patients (29 females) received RS after 34.0 ± 38.3 months. The only CT imaging finding significantly associated with RS was prosthesis dislocation (P = .007, odds ratio (OR) 10.95, 95% CI 1.34-89.24). All other evaluated CT imaging findings were not associated with RS. Yet, loosening of the peg (30% vs. 16%), baseplate (15% vs. 6%), and superior screw (18% vs. 7%) and periprosthetic humeral fractures (29% vs. 13%)-as common reasons for RS-were more frequent in patients with RS than in those without, however not reaching significance (P ≥ .11). The large majority of patients had glenoid notching (79% vs. 94%), irrespective of RS.

Conclusion: In this cohort of symptomatic patients after RSA, prosthesis dislocation was the only CT imaging finding associated with RS. Besides, there was a trend with higher numbers of loosening of the peg, baseplate, and superior screw, as well as periprosthetic humeral fractures in patients with RS, though not reaching significance.