Faculty Bibliography

BACKGROUND: The episode-of-care concept promulgated by the federal government requires hospitals to assume the cost burden for all care rendered up to 30 days after discharge, including all readmissions occurring in that time. Although surgical site infections (SSIs) are a leading cause of readmission after total joint arthroplasties (TJA) and spine surgery, it is unclear whether these readmissions occur relative to the 30-day period. QUESTIONS/PURPOSES: We determined whether (1) most readmissions for SSIs occurred in 30 days, (2) the type of procedure performed affected the timing of readmission, and (3) the type of infecting organism influenced the timing of readmission. METHODS: From our hospital database we identified 91 patients treated with elective TJAs and spine surgery from 2007 through 2010 who were readmitted with SSIs. Of the 91 patients, 46 had undergone spine surgery and 45 had TJAs. For each of these readmissions, we determined the type of surgery, the length of time from initial discharge to readmission, and the type of infecting organism. RESULTS: Readmissions after spine surgery were more likely to occur within 30 days of discharge (80.4% for spine, 58.3% for TJAs). In the TJA cohort, there was a trend toward readmissions occurring within 30 days of discharge more often in the THA subset. We identified no correlation between type of infecting organism and timing of readmission. CONCLUSIONS: With the episode-of-care model, SSIs pose a substantial cost burden for hospitals since the majority would be included in the 30-day period included in the bundled reimbursement.

OBJECTIVE: The purpose of this review is to gain insight into the latest methods of articular cartilage implantation (ACI) and to detail where they are in the Food and Drug Administration approval and regulatory process. DESIGN: A PubMed search was performed using the phrase "Autologous Chondrocyte Implantation" alone and with the words second generation and third generation. Additionally, clinicaltrials.gov was searched for the names of the seven specific procedures and the parent company websites were referenced. RESULTS: Two-Stage Techniques: BioCart II uses a FGF2v1 culture and a fibrinogen, thrombin matrix, whereas Hyalograft-C uses a Hyaff 11 matrix. MACI uses a collagen I/III matrix. Cartipatch consists of an agarose-alginate hydrogel. Neocart uses a high-pressure bioreactor for culturing with a type I collagen matrix. ChondroCelect makes use of a gene expression analysis to predict chondrocyte proliferation and has demonstrated significant clinical improvement, but failed to show superiority to microfracture in a phase III trial. One Step Technique: CAIS is an ACI procedure where harvested cartilage is minced and implanted into a matrix for defect filling. CONCLUSION: As full thickness defects in articular cartilage continue to pose a challenge to treat, new methods of repair are being researched. Later generation ACI has been developed to address the prevalence of fibrocartilage with microfracture and the complications associated with the periosteal flap of first generation ACI such as periosteal hypertrophy. The procedures and products reviewed here represent advances in tissue engineering, scaffolds and autologous chondrocyte culturing that may hold promise in our quest to alter the natural history of symptomatic chondral disease.