Shoulder & Elbow

High BMI a risk for shoulder arthroplasty complication

Obesity is a well-documented risk factor for complications in a multitude of orthopaedic interventions, being implicated as a risk for complications in pretty much any surgical procedure one cares to name, from cancer surgery through to hip arthroplasty. Nonetheless, the evidence behind this widely held belief is often little better than circumstantial. With case series failing to account for other associated comorbidities such as diabetes and hypertension, it is far from clear in many surgical disciplines what exactly is the scale of the problem is with obesity (if indeed there is one). The lack of quality evidence is a particular problem in the upper limb, and we were delighted to see this paper from Rochester, Minnesota (USA), which examines the potential association between obesity and complications following shoulder arthroplasty.⁶ There are few places in the world that are able to draw on their own experience of their past 4500 cases to answer a simple question such as ‘does increasing body mass index (BMI) have an adverse effect on outcomes?’ However, the Mayo clinic is one of those places. Their series is formed from the institutional experience of 4567 consecutive shoulder arthroplasties of various designs, undertaken over four decades, from 1970 to 2013. Patients had a mean BMI of 29.7 kg/m² (14 to 66). In this series at least, increasing BMI was associated with an increased risk of a revision surgical procedure, re-operation, revision for mechanical failure, and superficial infection. Interestingly, the risk of a revision procedure rose by 5% for every single unit increase in BMI, and this effect was seen even when a multivariable model was used to account for potential confounders. It is somewhat difficult to quantify exactly how large an increase in BMI presents an unacceptable risk. Clearly, increased BMI does have an adverse effect on outcomes, and, when taking other risk factors into consideration on an individual level, this study should inform patient counselling. However, the more profound question of who is too obese to receive a shoulder arthroplasty is more a philosophical than a scientific one, given the data presented here.

Psychological status and shoulder arthroplasty

Another oft-studied part of the outcomes picture has been given another look by the team in Boston, Massachusetts (USA): that of psychological well being.⁷ There is again a large volume of data pertaining to other areas of orthopaedics (most notably hands and spines) that essentially establishes that outcomes are, to a great extent, dependent on the psychological well being of the patient. However, despite the significant amount of work published, little concerns outcomes in upper limb orthopaedic surgery. Given that the effect on psychological and physical well being is an often-overlooked dimension when measuring the results of orthopaedic interventions, we were delighted to come across this prospective evaluation of the impact that total shoulder arthroplasty has on a range of psychological outcome metrics. This prospective cohort study focuses on the outcomes of 46 patients who underwent total shoulder arthroplasty and reports measures of depression, anxiety and Health-Related Quality of Life (HRQoL) scores for osteoarthritis. The authors hypothesise that, given the impact pain can have on psychological well being and quality of life, both would improve as a result of the shoulder arthroplasty. There were significant improvements seen from three months post-surgery in the Hospital Anxiety and Depression Scale (HADS), along with the World Health Organization Quality of Life (WHOQOL-bref) measure. As would be expected, these were accompanied by improvements in pain scores and the American Shoulder and Elbow Surgeons Shoulder (ASES) functional scores. Perhaps most interestingly, not only did surgery improve the patients’ psychological well being, but pre-operative depression and anxiety scores did not appear to predict poor post-operative outcome.

Tranexamic acid in shoulder arthroplasty

The use of tranexamic acid (TXA) in lower limb arthroplasty is well documented; its use in upper limb arthroplasty less so. This prospective randomised placebo-controlled study from Vienna (Austria) set out to evaluate the effect that TXA has on blood loss following total shoulder arthroplasty.⁸ The team randomised 54 patients undergoing primary unilateral total shoulder arthroplasty to either standard care with placebo or a 1000 mg TXA infusion prior to skin incision. Outcomes assessed included drain-measured blood loss, post-operative Visual Analogue Scale (VAS) pain scores and adverse events. The infusion of TXA in this setting resulted in a reduction in peri-operative blood loss, post-operative pain and haematoma formation. The authors examined both anatomic total and reverse polarity prostheses and, unusually for shoulder arthroplasty, a drain was placed in the deltopectoral interval. There were no transfusions required in either group, nor were there any adverse events. Given the lower propensity to deep vein thrombosis in upper limb surgery, this is an intervention that should be routine in the absence of contra-indications.