Treatment of cartilage defects in the patellofemoral joint with matrix-associated autologous chondrocyte implantation effectively improves pain, function, and radiological outcomes after 5-7 years.

INTRODUCTION: The aim of the present study was to evaluate midterm outcomes 5-7 years after matrix-associated autologous chondrocyte implantation (MACI) in the patellofemoral joint. MATERIALS AND METHODS: Twenty-six patients who had undergone MACI using the Novocart® 3D scaffold were prospectively evaluated. Clinical outcomes were determined by measuring the 36-Item Short-Form Health Survey (SF-36) and International Knee Documentation Committee (IKDC) scores and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) values preoperatively and 3, 6, and 12 months, and a mean of 6 years postoperatively. At the final follow-up, the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score was evaluated. RESULTS: Twenty-two patients with 23 focal cartilage defects (19 patella and four trochlea) were available for the final follow-up. The mean defect size was 4.0 ± 1.9 cm2 (range 2.4-9.4 cm2). All clinical outcome scores improved significantly until 5-7 years after MACI (SF-36 score, 61.2 ± 19.6 to 83.2 ± 11.6; P = 0.001; IKDC score, 47.5 ± 20.6 to 74.7 ± 15.5; P < 0.001; and WOMAC, 29.8 ± 15.7 to 8.2 ± 10.3; P < 0.001). The mean MOCART score was 76.0 ± 11.0 at the final follow-up. Nineteen of the 22 patients (86.4%) were satisfied with the outcomes after 5-7 years and responded that they would undergo the procedure again. CONCLUSION: MACI in the patellofemoral joint demonstrated good midterm clinical results with a significant reduction in pain, improvement in function, and high patient satisfaction. These clinical findings are supported by radiological evidence from MOCART scores. LEVEL OF EVIDENCE: IV-case series.

Plasma concentration of prophylactic cefazolin best correlates with lean body mass measured by bioimpedance analysis in lumbar spine surgery: Results of a pilot study.

The aim of this study was to determine the association between measures of body composition and the concentration of plasma and paraspinal muscle cefazolin. Secondly, we aimed to confirm the efficacy of our hospital dosing regimen in achieving the minimum inhibitory concentration (MIC) at the surgical site. Patients undergoing posterior-based lumbar spine surgery had body composition analysed using bioimpedance analysis. All received 2 g of cefazolin at anaesthetic induction in line with hospital guidelines. Cefazolin concentration was measured in plasma (30-minites) and muscle (30- and 60-minuites) using high-performance liquid chromatography. 20 patients were recruited (mean age 61.5 years; 12 female). Mean plasma cefazolin concentrations were 34.1 +/- 10.2 mg/L; mean muscle concentrations 44.4 +/- 18.6 mg/kg and 43.8 +/- 20.4 mg/kg at 30- and 60-minutes respectively. Univariate analysis showed significant correlation between plasma cefazolin concentration and lean mass weight, absolute body weight, height, dry lean mass, total water, total body water, extracellular and intracellular water volume. Linear regression analysis showed lean mass weight the best predictor of plasma cefazolin concentration. Muscle cefazolin concentration was dependent on the plasma concentration. Using a MIC of 2 mg/L and 2 mg/kg for Staphylococcus aureus, MIC was achieved in all samples. In summary, plasma cefazolin concentration was best predicted by lean body mass. Further work should consider the influence of body composition on antibiotic delivery in extremes of body mass index. Local hospital guidelines are effective at achieving MIC against S. aureus.