Is a two-year follow-up after total shoulder arthroplasty really necessary?

The use of reverse total shoulder arthroplasty (RTSA) and anatomic total shoulder arthroplasty (TSA) and the associated additional costs for routine follow-up examinations have increased significantly in recent decades. In order to reduce the burden on the healthcare system without increasing the risk for patients by missing relevant complications, targeted recommendations for follow-up examination schedules are needed. Overall, we hypothesize that a two-year routine check-up is only necessary in a small, well-defined patient population. A retrospective single center cohort study of prospectively collected patient data of all RTSA and TSA from January 2017 to December 2021 was carried out. Revisions and complications were recorded, as well as the therapeutic consequences of the one- and two-year check-ups, such as prescription of physiotherapy, therapeutic infiltrations or indication for revision surgery. The absolute Constant score (aCS) was determined at one, two and five years and predictive cut-off values using ROC analysis were calculated to find out which patients require a two-year follow-up. Subgroup analyses were performed between non fracture RTSA, TSA, and fracture RTSA (Fx). 211 patients were included in the qualitative analysis (111 RTSA, 37 TSA, 63 Fx) and 123 patients with a complete aCS in the quantitative analysis (69 RTSA, 23 TSA, 31 Fx). Revision rate was 4.3% after two years (2.6% TSA, 5.4% RTSA, 3.2% Fx). Mean age was 71.8 (31–93) and aCS was 31 (6–68) preoperative, 70 (35–97) at one-year and 71 (21–95) at two-year follow-up. No revision surgeries were indicated at the routine one- and two-year follow-up appointments but non-operative therapeutic interventions were necessary for 18 patients at the one-year follow-up and for 6 patients at the two-year follow-up. The one-year aCS was a significant predictor for therapeutic intervention or poor shoulder function at two-year follow-up (p = 0.012/<0.001). With a cutoff for aCS < 66.5 in the one year follow-up the need for therapeutic intervention after two years could be predicted with a sensitivity of 100%, and a specificity of 70%, while a cut off for aCS < 55.5 could predict a poor shoulder function with a sensitivity of 95% and a specificity of 73%. The routine two-year follow-up examination after RTSA rarely leads to a therapeutic and almost never to a surgical consequence. The convention of routinely scheduling a two-year follow-up appointment for RTSA and TSA should be fundamentally reconsidered. To identify patients with a higher need for follow-up care, an aCS of < 66 can predict the need for a non-interventional therapeutic consequence and an aCS of < 55 can predict a poor shoulder function with a sensitivity of more than 95%. Implementing this screening procedure would allow follow-up appointments after two years to be reduced by at least 75% without missing any relevant complications or therapeutic interventions. Level of Evidence: III