Introduction. The ACTIVE(Advanced Cartilage Treatment with Injectable-hydrogel Validation of the Effect) study investigates safety and performance of a novel dextran-tyramine hydrogel implant for treatment of small cartilage defects in the knee (0.5-2.0cm2). The hydrogel is composed of a mixture of natural polymer conjugates that are mixed intra-operatively and which cross-link in situ through a mild enzymatic reaction, providing a cell-free scaffold for cartilage repair. Method. The ACTIVE study is split into a safety (n=10) and a performance cohort (n=36). The Knee Injury and Osteoarthritis Outcome Score (KOOS), pain (numeric rating scale, NRS), Short-Form Health Survey (SF-36) were compared at baseline and 3, 6, and 12 months after surgery. The primary performance hypothesis is an average change in the KOOS from baseline to 12 months (ΔKOOS) greater than a minimal clinically important change (MIC) of 10. No statistical tests were performed as these are preliminary data on a smaller portion of the total study. Result. All patients of the safety cohort (n=10, mean age±SD, 30±9 years) were treated with the hydrogel for a symptomatic (NRS≥4) cartilage defect on the femoral condyle or trochlear groove (mean size±SD, 1.2±0.4cm2). No signs of an adverse foreign tissue reaction or serious adverse events were recorded within the safety cohort. At final follow-up mean KOOS±SD was 66.9±23.5, mean NRS resting±SD was 1.3±1.9, NRS activity±SD was 3.8±2.9 and mean SF-36±SD was 72.0±10.9. ΔKOOS was 21. One patient sustained new knee trauma prior to final follow-up, affecting final scores considerably. When excluded, ΔKOOS was 24(n=9). Conclusion. These promising initial findings provide a solid basis for continuation and expansion of this unique cartilage treatment. The MIC of 10 was surpassed. Though, results should be interpreted cautiously as they are based solely on preliminary data of the first 10 patients. Acknowledgements. Study is sponsored by Hy2Care, producer of the CartRevive®(dextran-tyramine) Hydrogel implant

Introduction. Acetabular fractures are a challenging problem. It has been published that outcome is dependent upon the type of fracture, the reduction of the fracture and concomitant injuries. The end-points of poor outcome include avascular necrosis of the femoral head, osteoarthritis. However, we lack definitive statistics and so counselling patients on prognosis could be improved. In order to achieve this, more outcome studies from tertiary referral centres are required. We present the first long term follow up from a large tertiary referral centre in Ireland. Methods. We identified all patients who were ten years following open reduction and internal fixation of an acetbular fracture in our centre. We invited all of these patients to attend the hospital for clinical and radiographic follow-up. As part of this, three scoring systems were completed for each patient; the Short-form 36 health survey (SF36), the Merle d'Aubigné score and the Short Musculoskeletal Functional Assessment (SMFA). Results. The data represents one year's activity at a new tertiary referral unit. We identified a total of 44 patients who were ten years following ORIF of acetabular fractures in our unit. 21 patients (48%) replied to written invitation and attended the hospital for clinical and radiographic follow-up. A further 7 patients were contacted by telephone and interviewed to gauge their rehabilitation. 3 patients had passed away. The remaining 13 patients were not contactable. Of those who attended in person for follow-up; 18 were male and 3 were female. The mean age at follow-up was 40.5 years (Range 27-60). In terms of fracture pattern epidemiology, 43% of patients sustained posterior column and wall fractures, 29% posterior wall, 14% posterior column alone, 9.5% transverse with posterior wall and 9.5% bicolumnar. 2 patients in the follow-up group had total hip replacements. Of the remaining patients the overall mean SF36 score was 78.8% (SD 16.4). The mean SMFA was 14.1% (SD 5). The mean Merle d'Aubigné score was 14.9 (SD 3.2) with 63% graded as good or excellent. Comparison of outcome between sub-groups according to fracture classification showed no significant difference. Traumatic sciatic nerve injury was sustained by four patients in the follow-up group and all patients continued to complain of ongoing weakness. Of the patients who were contacted via telephone, 2 had total hip replacements. The remaining 5 reported no significant problems with their hips and cited this as the reason for not attending follow-up. Conclusion. Overall the outcome of the patients was more favourable than expected. This was supported by the results of the clinical scoring systems. In some patients this also appeared to be despite poor radiographic findings. Our observations suggest that concomitant injuries, especially sciatic nerve injury have a profound negative influence on the patients' ability to fully rehabilitate. These data provide a valuable tool for the trauma surgeon in providing the patient with an educated prognosis