Prior cervical spine fusion impairs early clinical outcomes following total shoulder arthroplasty and may be associated with increased fusion burden: a matched cohort analysis.

Background: Cervical spine pathology may influence outcomes following total shoulder arthroplasty (TSA) through its biomechanical and neurologic effects on shoulder motion and function. This study compared post-operative clinical outcomes after TSA in patients with a history of cervical spine fusion vs. a matched cohort without cervical pathology. Methods: Patients who underwent anatomic or reverse TSA between 2016 and 2021 at a tertiary care institution were retrospectively reviewed. Nineteen patients with prior cervical spine fusion and complete pre-operative and post-operative patient-reported outcome measures were identified and matched 1:1 to controls without cervical pathology based on age, sex, laterality, diagnosis, and implant type. The American Shoulder and Elbow Surgeons (ASES) and Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function 10-item (PROMIS-PF 10) scores were analyzed. The Minimal Clinically Important Difference (MCID) for ASES improvement was defined as ≥ 12 points. Results: Both groups demonstrated significant ASES improvement ( Conclusion: Patients with a history of prior cervical spine fusion experience reduced clinical improvements following TSA at early follow-up compared to a matched cohort of patients without history of cervical spine pathology. Further studies are needed to assess whether this impairment is proportional or commensurate with the number of levels fused or their location within the cervical spine.