The "tipping point" for 931 elective shoulder arthroplasties.

BACKGROUND: A patient with arthritis usually experiences the progression of symptoms over time. At some stage, the patient may decide that the symptoms have reached a level of severity that leads him or her to elect to proceed with joint replacement; we refer to this degree of symptom severity as the "tipping point." Our goal was to study the factors that influenced the tipping point for patients undergoing elective shoulder arthroplasty.

METHODS: We analyzed the characteristics of 931 patients undergoing shoulder arthroplasty to determine the factors affecting the tipping point as characterized by the patients' comfort and function at the time they determined their symptoms had progressed to the point when this elective surgery was merited.

RESULTS: The preoperative Simple Shoulder Test (SST) score for all patients averaged 3.6 ± 2.7. The average tipping points were different for the ream-and-run procedure (mean SST score, 5.0 ± 2.5), hemiarthroplasty (mean SST score, 3.1 ± 3.3), total shoulder arthroplasty (mean SST score, 3.0 ± 2.4), cuff tear arthropathy arthroplasty (mean SST score, 2.8 ± 2.5), and reverse total shoulder arthroplasty (mean SST score, 1.5 ± 1.8). A number of other factors were significantly associated with a higher tipping point: younger age, better health, male sex, commercial insurance, married, nonuse of narcotics, use of alcohol, and shoulder problem not related to work.

CONCLUSIONS: Analysis of the tipping point-the patients' self-assessed comfort and function at the point they decide to undergo shoulder joint replacement-provides a means by which surgeons can understand the factors influencing the indications for these procedures.