Introduction. The aim of this study was to investigate whether methylene blue dye, commonly used in sterile surgical marker pens, would have an effect on human chondrocyte viability, when cultured on a collagen membrane in-vitro. Methods. Bilayered collagen membranes were seeded in duplicate with 12 million human chondrocytes per ml and cultured for 24 hours under standard conditions. Group A consisted of a membrane marked with methylene blue ink on its smooth side, group B marked on its porous side, and group C acting as an unmarked control. At the end of the culture period the membranes were qualitatively analysed for cell survival by live/dead fluorescent staining under confocal microscopy. Results. The control membranes of group C showed normal ‘live’ staining of cells. A marked reduction in chondrocyte viability was seen in groups A and B, with a significant reduction in viability seen opposite to the ink mark on the smooth side in A, and practically no cell viability in the same position on the porous side in group B. Conclusions. Methylene blue dye in surgical marker pen ink has been shown to be cytotoxic to chondrocytes cultured on bilayered collagen membranes. Sterile surgical marker pens are commonly used in cartilage repair surgery to aid in the placement of periosteal patches or collagen membranes in autologous chondrocyte transplantation. Surgeons need to be aware of the potential harmful effects of methylene blue dye when using surgical marker pens in cell based regenerative therapies

We evaluated the long-term outcome of isolated endoscopically-assisted posterior cruciate ligament reconstruction in 26 patients using hamstring tendon autografts after failure of conservative management. At ten years after surgery the mean International Knee Documentation Committee subjective knee score was 87 (sd 14) of a possible 100 points. Regular participation in moderate to strenuous activities was possible for only seven patients pre-operatively; this increased to 23 patients post-operatively. The mean Lysholm score improved from 64 (sd 15) to 90 (sd 14) at ten years (p = 0.001).

At ten years endoscopic reconstruction of the posterior cruciate ligament with hamstring tendon autograft is effective in reducing knee symptoms. Of the series, 22 patients underwent radiological assessment for the development of osteoarthritis using the Kellgren-Lawrence grading scale. In four patients, grade 2 changes with loss of joint space was observed and another four patients showed osteophyte formation with moderate joint space narrowing (grade 3). These findings compared favourably with non-operatively managed injuries of the posterior cruciate ligament.

This procedure for symptomatic patients with posterior cruciate ligament laxity who have failed conservative management offers good results.

Autologous chondrocyte implantation is an established method of treatment for symptomatic articular defects of cartilage. CARTIPATCH is a monolayer-expanded cartilage cell product which is combined with a novel hydrogel to improve cell phenotypic stability and ease of surgical handling. Our aim in this prospective, multicentre study on 17 patients was to investigate the clinical, radiological, arthroscopic and histological outcome at a minimum follow-up of two years after the implantation of autologous chondrocytes embedded in a three-dimensional alginate-agarose hydrogel for the treatment of chondral and osteochondral defects.

Clinically, all the patients improved significantly. Patients with lesions larger than 3 cm² improved significantly more than those with smaller lesions. There was no correlation between the clinical outcome and the body mass index, age, duration of symptoms and location of the defects. The mean arthroscopic International Cartilage Repair Society score was 10 (5 to 12) of a maximum of 12. Predominantly hyaline cartilage was seen in eight of the 13 patients (62%) who had follow-up biopsies.

Our findings suggest that autologous chondrocyte implantation in combination with a novel hydrogel results in a significant clinical improvement at follow-up at two years, more so for larger and deeper lesions. The surgical procedure is uncomplicated, and predominantly hyaline cartilage-like repair tissue was observed in eight patients.