Response to ‘Does primary treatment of proximal humerus fractures show favourable functional outcomes over secondary treatment with reverse shoulder arthroplasty?'

Blaas and colleagues compared reverse shoulder arthroplasty (RSA) treatment within 3 months of proximal humerus fracture to RSA treatment provided more than 3 months after fracture (mean time to surgery of 51 weeks) and found better external rotation and forward flexion without any differences in complications and patient-reported outcome measures (the Disability of the Arm, Shoulder and Hand score, Oxford Shoulder Score, and Constant–Murley Score). ¹ We wanted to praise the authors for their hard and valuable work, but we also wanted to highlight a few concerns about the study which readers must keep in mind when interpreting the results.

First, patients who undergo selective delayed arthroplasty related to dissatisfaction with nonoperative treatment or open reduction and internal fixation may have a different mindset and circumstances than the average patient with a fracture. If people that choose to switch from nonoperative to operative treatment are experiencing more unhelpful thoughts and distress regarding their fracture, they will also experience greater levels of discomfort and incapability, regardless of fracture characteristics (pathophysiology severity). In other words, there may be psychosocial differences associated with shoulder arthroplasty outcomes.^2–4 It would be helpful to understand the role of psychosocial factors in requests for delayed arthroplasty.

Second, the authors revealed that tuberosity healing between both groups was similar. As the RSA procedure and type of fracture were also identical in each cohort, patient-related factors are likely to have determined outcomes. Aside from psychosocial factors – and variables which may yet be unknown for us – biomechanical stability may have played a role. For example, rotator cuff muscles and scapula mobility are important determinants of successful non-operative treatment and were not further evaluated.

Third, for every patient requesting a delayed procedure, there is some unknown, but notable number of patients with acceptable results of non-operative treatment. It would be interesting to know how many surgical procedures could be avoided with an initially non-operative treatment strategy.

Fourth, patients in the delayed treatment group could have more problematic fractures or more disadvantageous medical comorbidities such as diabetes or smoking that might be associated with adverse outcomes and adverse events.

For these reasons, and perhaps others, we know that the outcomes of routine initial operative treatment will be better than the outcomes of selected delayed surgeries without doing a study. We write in the hope that readers, editors, and reviewers will understand these shortcomings in this type of comparative study. The merits of routine non-operative treatment and selective delayed RSA are best evaluated in a randomised controlled trial that accounts for all patients treated with that strategy.