Bone ingrowth is desired with uncemented hip implants. Infection is clearly undesirable. We have worked on developing a nanofiber coating for implants that would enhance bone formation while inhibiting infection. Few studies have focused on developing an implant surface nanofiber (NF) coating to prevent infection and enhance osseointegration by local drug release. In this study, coaxial doxycycline (Doxy)-doped polycaprolactone/polyvinyl alcohol (PCL/PVA) Nanofibers were directly deposited on the titanium (Ti) implant surface during electrospinning. The interaction of loaded Doxy with both PVA and PCL NFs was characterized by Raman spectroscopy. The bonding strength of Doxy-doped NF coating on Ti implants was confirmed by a stand single-pass scratch test. The improved implant osseointegration by PCL/PVA NF coatings in vivo was confirmed by scanning electron microscopy, histomorphometry and micro computed tomography at 2, 4 and 8 weeks after implantation. The bone contact surface (%) changes of NF coating group (80%) is significantly higher than that of no NF group (< 5%, p<0.05). Finally, we demonstrated that Doxy-doped NF coating effectively inhibited bacterial infection and enhanced osseointegration in an infected (Staphylococcus aureus) tibia implantation rat model. Doxy released from NF coating inhibited bacterial growth up to 8 weeks in vivo. The maximal push-in force of Doxy-NF coating (38 N) is much higher than that of NF coating group (6.5 N) 8 weeks after implantation (p<0.05), which was further confirmed by quantitative histological analysis and micro computed tomography. These findings indicate that coaxial PCL/PVA NF coating doped with Doxy and/or other drugs have great potential in enhancing implant osseointegration and preventing infection.
Total knee prostheses are continually being redesigned to improve performance, longevity and closer mimic kinematics of the native knee. Despite continued improvements, all knee implants even those with proven design features, have failures. We identified a cohort of patients with isolated tibial component failures that occurred in a popular and successful knee system. Our purpose was to (1) characterize the observed radiographic failure pattern; (2) investigate the biologic response that may contribute to the failure; and (3) to determine if the failure mechanism was of a biological or a mechanical nature. Twenty-one knees from 19 patients met the inclusion criteria of having isolated tibial component failure in a commonly used knee implant system. Radiographs from the primary and revision knee surgery were analyzed for implant positioning and failure pattern, respectively. Inflammatory biomarkers IL-1β, IL-6 and TNF-α were available in 16/21 knees and peripheral CD14+/16+ monocytes were measured in 10 of the above mentioned 16 knee revisions. Additionally, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were measured to rule out infection as the cause of the cytokine upregulation.Background
Methods
The ability to identify those at risk for longer inpatient stay helps providers with postoperative planning and patient expectations. Decreasing length of stay in the future will be determined by appropriate patient selection, risk stratification, and pre-operative patient optimization. The purpose of this study was to identify factors that place patients at risk for extended postoperative lengths of stay. The prospective study cohort included 2009 primary total knee arthroplasty (TKA) patients and 905 total hip arthroplasty (THA) patients. Patient comorbidities were prospectively identified and the length of stay for each patient was tracked following a primary arthroplasty. Statistical analysis was performed to correlate which comorbidities were associated with longer inpatient stays.Background
Methods
