Erick Marigi MD, Ian Marigi BA, Matthew Crowe MD, Cedric J Ortiguera MD, Cameron Ledford MD, Jean-David Werthel MD, John W Sperling MD MBA, Joaquin Sanchez-Sotelo MD PhD, and Bradley Schoch MD

Journal of Shoulder & Elbow Surgery, 2021 Feb 8;S1058-2746(21)00085-9
DOI: 10.1016/j.jse.2020.12.025

Summary by Daniel Hameed, B.A.

Metabolic syndrome is a constellation of medical conditions which increase the risk for several health problems, primarily cardiovascular disease, type 2 diabetes, and fatty liver. In orthopaedic surgery it has been identified as an independent risk factor for short term complications, wound issues, and readmission regardless of obesity class.

In the shoulder literature, two studies have previously demonstrated the impact of Metabolic Syndrome in patients undergoing shoulder arthroplasty. Murphy et al. concluded that patients with metabolic syndrome had elevated perioperative medical complications, surgical site infections and prolonged hospital stay. Conversely, Garcia et al. demonstrated that metabolic syndrome was not a significant predictor of postoperative complications or extended length of stay. Because of this, the data on outcomes regarding metabolic syndrome continue to remain unclear.

In this study, Marigi et al. evaluated the effect of metabolic syndrome (MetS) on infection, postoperative complications, and implant survivorship free from reoperation and revision.  Between January 2007 and December 2017, 714 patients were identified as having shoulder arthroplasty with metabolic syndrome (289 anatomic TSA and 425 RSA) and 3921 patients were identified without (1736 anatomic TSA and 2185 RSA). A retrospective chart review was performed comparing primary outcome measures of postoperative surgical complications and implants survivor ship free from revision and reoperations as well as secondary outcome measures of postoperative infections (superficial and deep).

Sixty-seven (9.4%) MetS patients and 343 (8.7%) non-MetS patients sustained at least one postoperative complication (p= 0.851). Postoperative infection was observed in 10 patients with MetS and in 58 non-MetS patients (p=0.913). However, within the RSA group, deep infection (1.9% vs 0.7%, p=0.04), instability (3.1% vs 1.5%, p=0.05), and DVT/PE (0.5% vs. 0.3%; p=0.03) were found to be significantly higher in patients with MetS compared to those who did not have MetS. Kaplan-Meier five -year survivorship free from reoperation, revision, and prosthetic joint infection was not statistically different between groups.

This study showed complications in the RSA subgroup to be more common in patients with MetS. It should be noted that patients who overall underwent primary arthroplasty were not shown to have increased complications, infection, reoperation, or revision for patients with MetS. The overall lack of associations could be due to the retrospective analysis, which is subject to selection bias, lack of randomization, and unable to capture patients unfit for surgery. In contrast, it could be also that there is no actual relationship between MetS and adverse outcomes of shoulder arthroplasty. 

References:

1. Klein A, Jauregui JJ, Raff E, Henn RF, Hasan SA, Gilotra M. Early outcomes and 312 complications of obese patients undergoing shoulder arthroplasty: A meta-analysis. J Clin 313 Orthop Trauma. 2020 Mar;11(Suppl 2):S260-S264. doi: 10.1016/j.jcot.2019.09.002.
2. Guofeng C, Chen Y, Rong W, Ruiyu L, Kunzheng W. Patients with metabolic syndrome 301 have a greater rate of complications after arthroplasty: A systematic review and meta-analysis. 302 Bone Joint Res 2020;9:120-129. https://doi.org/10.1302/2046-3758.93.BJR-2019-0138.R1
3. Murphy AB, Menendez ME, Watson SL, Ponce BA. Metabolic syndrome and shoulder 341 arthroplasty: epidemiology and peri-operative outcomes. Int Orthop 2016;40:1927-1933. 342 https://doi.org/10.1007/s00264-016-3214-3
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