PROGNOSTIC FACTORS (PRE-OPERATIVE FUNCTION)
Moderate quality evidence suggests that, while both higher and lower pre-operative functioning patients with glenohumeral joint osteoarthritis will likely experience improvement following arthroplasty, patients with higher pre-operative function may experience less functional improvement.

Rationale

One moderate quality study (Mahony et al 2018) and one low quality study (Somerson et al 2017) have evaluated the outcomes of patients with GJO undergoing shoulder arthroplasty and determined a relationship between the level of preoperative function and its correlation to postoperative function as determined by patient-reported outcomes (PRO). The study by Mahony et al was a retrospective review of prospectively collected data on 459 patients who underwent total shoulder arthroplasty (TSA) at minimum 2 years follow up. They identified a subgroup of 41 patients (8.9%) who failed to reach the minimal clinically important difference (MCID) on ASES scores (less than 16.1point change preop to postop) and analyzed these patients for factors associated with this unsatisfactory outcome. They identified a higher baseline preoperative ASES score as one such factor in their multi-variate analysis. Additional factors for poor response after TSA included prior shoulder surgery, rotator cuff tear at the time of arthroplasty and diabetes.

Similarly, Somerson et al analyzed prospectively collected data from a series of 101 patients who had undergone ream and run hemiarthroplasty surgery for factors associated with clinical outcomes at a minimum of 2 years follow up. They determined that a lower simple shoulder test (SST) score preoperatively was associated with a more significant improvement in the postoperative score using multivariate statistics. It must be noted that the purpose of the study was to determine patient and surgical factors associated with humeral component medialization and whether the outcomes were associated with this potential medialization if/when it occurred.

 

Strength of Evidence (quality of evidence): Moderate

 

Outcome Importance:

The strength of the recommendation is low; however, this guideline demonstrates that high functioning patients with GJO (which are usually younger and more active patients wishing higher levels of function) remain a challenging patient population as there appears to be a “ceiling” effect in terms of their functional improvement after shoulder arthroplasty. This information is important to understand when counseling these patients regarding their expected outcomes after shoulder arthroplasty.

 

Future Research:

Further study is needed in this area of clinical outcomes after shoulder arthroplasty to help advance our understanding of this ceiling effect of higher functioning patients with glenohumeral joint osteoarthritis.