Introduction: Articular cartilage injuries are very common, and if untreated can become symptomatic and progressively lead to premature osteoarthritis. It is well known that damaged cartilage has very limited potential to heal itself, and repair and regeneration of hyaline cartilage remain a clinical and scientific challenge. There are no pharmacological methods that can regenerate cartilage, and currently clinical treatments of debridement, chondrocyte transplantation and marrow stimulation have not been shown to restore consistently a durable articular surface. Tissue engineering and gene therapy concepts may improve cartilage repair by introducing cells, scaffolds, growth factors and other potential modulators of cartilage healing process. When analyzing cartilage treatment outcomes, traditionally we use macro- and microscopic assessment, immunohistochemistry, biochemical characterization etc. Recently, it has been postulated that biomechanical properties of newly formed cartilage are just as important, and novel methods of measurements have been proposed.

Materials and methods: 38 defects were created on weight-bearing part of the medial femoral condyle in sheep. The sheep were randomly assigned to one of four groups. In the bone marrow clot (BMC) group, the sheep were implanted with untreated autologous bone marrow clot that was aspirated from iliac crest of respected animal. In the bone marrow transduced with Ad. GFP (GFP) group, the sheep were implanted with autologous bone marrow clots genetically modified to over express green fluorescent protein (GFP). In the bone marrow transduced with Ad. TGF-β1 (TGF) group, the sheep were implanted with autologous bone marrow clots genetically modified to over express transforming growth factor-β1. Untreated sheep served as a control (defect without implant), and native cartilage served as positive control. Specimens were collected after 6 months and analyzed by single-impact micro-indentation (SIMI), atomic force microscope (AFM) and scanning electron microscope (SEM).

Results: SIMI and AFM measurements showed that repair tissue has greater Young’s elastic modulus then native cartilage. There was a statistically significant difference between TGF-β1, GFP and BMC groups. SEM analysis showed presence of structurally organized collagen molecules in TGF-β1, GFP and BMC groups.

Conclusion: The results of this study showed that it is possible to enhance cartilage repair process by means of genetically modified bone marrow. Furthermore, biomechanical data obtained with SIMI, AFM and SEM provided more detailed insight into articular cartilage function and structure, and in future may be of practical importance for a better understanding of both cartilage mechanics and cartilage disease progression.

Aims of the study: The purpose of this paper was to evaluate the long term results of the open Bankart procedure for an anterior shoulder instability in heterogenic non selected patients.

Material and Methods: Hundred and seventy seven patients were operated on at our instutution using open Bankart technique without using suture anchors, between 1993 and 2002. Hundred and sixty nine patients were evaluated. Average follow up was nine years and seven months (4–13 years). Average age at the time of operation was 27 (15 – 67). 89 % of shoulders had more than 3 dislocations, 60 % had more than 10 and 37 % more than 20 dislocations. American Shoulder and Elbow Society Scoring System and Constant Scoring System were used for assessment.

Results: 155 patients (92 %) had Bankart lesion and 150 patients (89%) had Hill-Sachs lesion. Five patients (2.9%) had redislocation of the operated shoulder caused by new trauma, two of them underwent reoperation. 164 patients were satisfied and very satisfied with the results. None of patients needed a shoulder arthroplasty because of symptomatic osteoarthritis. Average Constant score was 92 and American Shoulder and Elbow Society Scoring System was 90. Average loss of external rotation in adduction was 6 degrees and loss of external rotation in 90 degrees abduction was 3 degrees comparing to contra lateral shoulder.

Discussion/Conclusion: The Bankart procedure for anterior shoulder instability gives reliable long-term results.