Background: Diabetes is a well-established risk factor for complications following total knee arthroplasty (TKA), and the incidence of type-2 diabetes is increasing. Metformin is considered first-line therapy for type-2 diabetes and has been shown to reduce all-cause mortality and to possess anti-inflammatory properties. The impact of metformin use as it relates to outcomes following TKA is unknown. The purpose of this study was to investigate this relationship. Methods: This is a retrospective cohort study using the Truven MarketScan database. Adult patients undergoing unilateral, primary TKA were identified. We included only patients with a preoperative diagnosis of type-2 diabetes and established 2 cohorts based on metformin status. Propensity score matching was performed to match patients who used metformin to those who did not (1-to-1). Patients were matched on factors including age, sex, insulin status, other diabetic medications, comorbidities, complexity of diabetes, and smoking status. Regression analysis was then performed on matched cohorts to examine 90-day outcomes. A subgroup analysis was performed on 1-year revision rates. Results: After matching, there were 32,186 patients in both the metformin group and the no-metformin group, resulting in a total of 64,372 included patients. Baseline characteristics were similar between groups. Regression analysis, performed on matched cohorts, demonstrated that the no-metformin group had increased odds of readmission (odds ratio [OR], 1.09 [95% confidence interval (CI), 1.04 to 1.15]; p < 0.001), emergency department presentation (OR, 1.09 [95% CI, 1.04 to 1.14]; p < 0.001), extended length of stay (OR, 1.12 [95% CI, 1.06 to 1.15]; p < 0.001), periprosthetic joint infection (OR, 1.30 [95% CI, 1.13 to 1.50]; p < 0.001), deep vein thrombosis (OR, 1.17 [95% CI, 1.09 to 1.26]; p < 0.001), acute kidney injury (OR, 1.21 [95% CI, 1.09 to 1.33]; p < 0.001), hypoglycemic events (OR, 1.25 [95% CI, 1.01 to 1.54]; p = 0.039), and 1-year revision (OR, 1.16 [95% CI, 1.01 to 1.33]; p = 0.033). Conclusions: Metformin use in patients with type-2 diabetes undergoing TKA appears to be associated with lower odds of multiple complications and resource utilization parameters, including periprosthetic joint infection and 1-year revision rates. Given the frequency with which TKA is performed in patients with type-2 diabetes, this knowledge has the potential to improve optimization protocols and outcomes in this group of patients. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Study Design: Systematic Review and Meta-Analysis. Objectives: To compare complication incidence in patients with or without the use of recombinant human Bone Morphogenic Protein-2 (BMP2) undergoing anterior cervical discectomy and fusion (ACDF) for degenerative conditions. Methods: A systematic search of eight online databases was conducted using PRISMA guidelines. Inclusion criteria included English language studies with a minimum of 10 adult patients undergoing instrumented ACDF surgery for a degenerative spinal condition in which BMP2 was used in all patients or one of the treatment arms. Studies with patients undergoing circumferential fusions, with non-degenerative indications, or which did not report post-operative complication data were excluded. Patients with and without BMP2 were compared in terms of the incidence of dysphagia/dysphonia, anterior soft tissue complications (hematoma, seroma, infection, dysphagia/dysphonia), nonunion, medical complications, and new neurologic deficits. Results: Of 1832 preliminary search results, 27 manuscripts were included. Meta-analysis revealed the relative risk of dysphagia or dysphonia (RR = 1.39, CI 95% 1.18 – 1.64, P = <.001), anterior soft tissue complications (RR = 1.43, CI 95% 1.25-1.64, P = <.001), and medical complications (RR = 1.32, CI 95% 1.06-1.66, P = .013) were statistically significant in the BMP2 group while the relative risk of non-union (RR = .5, CI 95% .23 - 1.13, P = .09) trended lower in the BMP2 group. Neurological deficit (RR = 1.06, CI 95% .82-1.37, P = .66), and additional medical complications (RR = 1.53, CI 95% .98-2.38, P = .06) were not found to be statistically different between the groups. Conclusions: This meta-analysis identified a high rate of arthrodesis when BMP2 was used in ACDF, but confirmed increased rates of dysphagia and anterior soft tissue complications. Surgeons may consider reserving BMP2 implementation for cases with a high risk of non-union, and should be aware of the risk of airway compromise.

» The proximal humerus is a common location for primary bone tumors, and the goal of surgical care is to obtain a negative margin resection and subsequent reconstruction of the proximal humerus to allow for shoulder function. » The current evidence supports the use of reverse total shoulder arthroplasty over hemiarthroplasty when reconstructing the proximal humerus after resection of a bone sarcoma if the axillary nerve can be preserved. » There is a lack of high-quality data comparing allograft prosthetic composite (APC) with endoprosthetic reconstruction of the proximal humerus. » Reverse APC should be performed using an allograft with donor rotator cuff to allow for soft-tissue repair of the donor and host rotator cuff, leading to improvements in shoulder motion compared with an endoprosthesis.