Summary

Patient-acceptable symptom states for Oxford Shoulder Score, Constant-Murley Score and University of California Los Angeles Shoulder Score was determined after reverse shoulder arthroplasty via receiver operating characteristic analysis allowing for meaningful interpretation of the scores and to power future statistical analysis.

Abstract

Aim

To determine Patient-acceptable symptom states (PASS) for Oxford Shoulder Score (OSS), Constant-Murley Score (CMS) and University of California Los Angeles (UCLA) Shoulder Score at 3-month, 6-month, and 1-year intervals after reverse shoulder arthroplasty. Patient-acceptable symptom states (PASS) represent the level on a patient-reported outcome measure (PROM) at which patients are satisfied with postoperative outcomes.

Materials And Methods

Patients who underwent reverse shoulder arthroplasty for massive irreparable cuff tear and cuff tear arthropathy by a fellowship trained surgeon were prospectively followed up between January 2011 and January 2021. Inclusion criteria was of patients who have completed any of the PROM and satisfaction question at any of the 3-month, 6-month, and 1-year intervals postoperatively. A total of 129 patients were assessed at 3, 6 and 12 months postoperatively. Functional outcome was assessed by the OSS, CMS, and UCLA shoulder score and a question on satisfaction was asked to serve as an anchor in the analysis. The respectively PASS thresholds were derived with receiver operating characteristic analysis using the 80% specificity method with secondary analysis done with Youden and 75th percentile method.

Results

74.2%, 83.9%, and 89.3% of patients reported having a satisfactory symptom state at 3 months, 6 months and 1 year after surgery, respectively.
At 3-month, 6-month, and 1-year intervals, PASS thresholds were 32, 23 and 18 for OSS, 40, 57 and 55 for CMS and 24, 28 and 29 for UCLA score.

Conclusions

PASS thresholds varied with time after surgery for CMS, OSS and UCLA shoulder scores. There was an increase in threshold from 3 to 6 month but minimal change from 6 month to 1 year for CMS and UCLA shoulder scores whereas OSS decreased with time after surgery. Theses established thresholds represent the levels at which the average patient is satisfied with surgical outcomes after Reverse Shoulder Arthroplasty and the PASS established in this study can be used for the interpretation of these scores to help in statistical power analysis for future studies.

Keywords: Patient Acceptable Symptom State, Constant-Murley Score, University of California Los Angeles Shoulder Score, Oxford Shoulder Score, Reverse Shoulder Arthroplasty

Level of Evidence: III (Retrospective cohort study)