Mandrekar, Jay

Aims Extensor mechanism disruption is a major complication following total knee arthroplasty, with treatment often consisting of extensor mechanism reconstruction utilizing monofilament polypropylene mesh (Marlex mesh, C. R. Bard, Inc). Infection following this procedure is devastating, often resulting in revision surgery and mesh removal, with permanent limb dysfunction. This study evaluated the in vitro ability of vancomycin-loaded polypropylene mesh to inhibit growth of isolates of three Staphylococcus species from patients with periprosthetic joint infection. Methods The mesh was prepared in two configurations – single-layer and eight-layer – and soaked for ten minutes in either sterile water (control) or vancomycin solution (50 mg/ml), after which the mesh was placed on tryptic soy agar plates inoculated with staphylococci and incubated at 37°C for 18 to 24 hours. Zones of inhibition were measured daily over seven days, with mesh transferred to freshly inoculated plates daily. Testing was performed in triplicate, with experiments repeated three times for each bacterial isolate. A total of 30 clinical isolates were tested (five methicillin-susceptible Staphylococcus epidermidis , five methicillin-resistant S. epidermidis , ten methicillin-resistant Staphylococcus aureus , and ten Staphylococcus lugdunensis ). Results Across all species, the eight-layer vancomycin-loaded mesh produced statistically significantly larger median zones of inhibition than the single-layer mesh. The antibacterial activity of the eight-layer mesh persisted through to day 7, while the single-layer mesh showed reduced activity by days 4 to 5. Conclusion Compared with single-layer vancomycin-loaded mesh, multilayer vancomycin-loaded mesh, which mimics clinical application, provides enhanced and sustained antibacterial activity in vitro. Cite this article: Bone Joint Res 2026;15(8):998–1004.

Abstract Background and aims Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by recurrent thunderclap headaches and reversible multifocal cerebral arterial narrowing. Although prognosis is generally favorable, a subset of patients develops cerebrovascular complications that may drive long-term disability; this study aims to identify factors associated with these complications. Methods We retrospectively reviewed 348 patients with probable or definite RCVS evaluated at Mayo Clinic between 2010-2023. Diagnostic criteria were adapted from RCVS2 and ICHD-3. The primary outcome was a composite of ischemic stroke, non-aneurysmal subarachnoid hemorrhage, and intracerebral hemorrhage; secondary outcome was poor functional status (modified Rankin Scale ≥2 within one year). Univariable and multivariable logistic regression identified predictors of these outcomes. Results Cerebrovascular complications occurred in 37.6% of patients and were the strongest determinant of poor functional outcome (aOR 5.05, 95% CI 2.04–12.51). On multivariable analysis, older age (aOR per year 1.02, 95% CI 1.00–1.04) and angiographically visible vasoconstriction (aOR 3.14, 95% CI 1.85–5.33) were independently associated with higher risk of cerebrovascular complications, whereas male sex (aOR 0.55, 95% CI 0.30–0.99), thunderclap headache at presentation (aOR 0.30, 95% CI 0.11–0.86), and sexual activity as a trigger (aOR 0.19, 95% CI 0.08–0.42) were associated with lower risk of these complications. Conclusions Cerebrovascular complications are common and strongly predict disability. Angiographic vasoconstriction and older age identify patients at higher risk, whereas thunderclap headache and sexual activity as a trigger mark a more benign phenotype. These findings may guide early risk stratification and help tailored monitoring strategies. Conflict of interest Name of author: nothing to disclose.