Effects of Motion-Sparing Versus Nonmotion-Sparing Cervical Spine Surgery on Total Shoulder Arthroplasty.

Abstract

Retrospective cohort study. This study investigates the impact of cervical spine procedures on postoperative outcomes of TSA, considering the growing evidence of interconnected cervical and shoulder pathologies. The increasing prevalence of both total shoulder arthroplasty (TSA) and cervical spine surgeries indicates a possible overlap in patient populations and related pathologies. We analyzed the TriNetX database records from 86 health care organizations, spanning January 1, 2012, to March 12, 2024, for patients who had undergone either motion-sparing cervical procedures or cervical fusion before TSA using CPT and ICD-10 codes for cohort identification. Patients were then categorized according to their cervical procedure; 1:1 propensity score matching was performed to adjust for variables including age, race, sex, diabetes, heart failure, chronic kidney disease, liver disease, and chronic obstructive pulmonary disease. The study assessed 90-day medical complications and 2-year mechanical outcomes, comparing categorical variables using the χ2 exact test with univariate regressions. Patient outcomes, odds ratios, 95% CIs, and P-values were reported. The study examined 4509 patients, with 2702 receiving motion-sparing procedures and 1807 undergoing cervical fusion before TSA. After propensity matching to adjust for demographic and comorbidity differences, the 90-day outcomes showed a significantly higher infection rate in the motion-sparing group compared with the fusion group [2.0% vs. 1.1%; OR: 1.806, CI (1.026, 3.179), P=0.038]. No significant differences were observed in other short-term outcomes or in 2-year mechanical complications such as periprosthetic dislocation, joint infection, aseptic loosening, or revision surgeries, all showing comparable rates. These findings suggest that although infection rates may differ depending on the type of cervical surgery performed, these surgeries do not impact the long-term mechanical outcomes of TSA. Consequently, the type of cervical surgery should not influence the assessment of a patient's suitability for TSA.