Aim: The purpose of this paper was to describe the biological reaction imposed by a prosthetic ligament.

Materials-Methods: Polyester-carbon synthetic matrices were implanted into 29 rabbits. The implants were transected centrally and reconstructed with resorbable suture material. At regular intervals from 4th day to 29 weeks, tissue samples from the ingrown implants were obtained for histology and mechanical testing. Light microscopy, DNA cytometry, immunohistochemical analysis of the collagen types, transmission and scanning electron microscopy were carried out. Ultimate tensile strength (UTL), elongation to failure (EF) and structural stiffness (SS) were determined at intervals of 8, 16 and 29 weeks.

Results: The ingrowth of tissue into the scaffold provided a significant increase in tensile strength, which improved with time. The UTL significantly increased from 18.86 N ±14.69 at 8 weeks to 51.4 N ±14.64 at 29 weeks. Light microscopy showed no infl ammation or foreign body reaction. At 4th day the first fibroblast cells settled on the matrix. The DNA cytometry showed an increase of the number of the fibroblast cell mitoses up to 16 days. After 2 weeks a mesh of connective tissue was formed around the scaffold, but the number of fibroblast cells remained constant. At 4 weeks the connective tissue started to infiltrate in between the artificial fibres. Type I, III and V collagens were identified. Electron microscopically the collagen weave was irregular with a mean fibril diameter of 28.4 ± 5.2 nm of a monophasic distribution. Collagen type I accumulated progressively and more and more dense collagenous fascicles appeared in the mesh in the proximity of the artificial fibres.

Conclusion: The subcutaneous tissue may act as a bio-reactor and the skin fibroblast seeding of a synthetic matrix appears to be transformed a dense connective tissue during the first 4 weeks, providing tensile strength improvement to the tissue envelope with time.

Aim: The aim of our study was to evaluate the results of the Soffix Mark I and Mark II hamstring fixation devices, placed transtibially with an “over the top” femoral route when applied to revision anterior cruciate ligament (ACL) surgery secondary to synthetic ligament failure.

Patients and Methods: 29 ACL revisions performed between 1992 and 2000 were evaluated. Twenty six failed prosthetic ligaments, 2 failed semitendinosus/gracilis (STG) and one BTB autografts were revised using hamstring grafts in 26, quadriceps in 2, and patella bone tendon bone (BTB) in 1 patient. Mark I and II fixation devices were employed. Follow up included clinical examination, KT 2000 arthrometric assessment, Lysholm, Tegner and IKDC scoring. The average follow up time was 50 months ±22.4.

Results: Arthrometric examination showed a mean side to side difference (SSD) of 2.98 mm ±1.5. The mean Lysholm score was 86.5 ±10.5 and 21 patients had a B rating (nearly normal) on IKDC scoring, while 3 score A (normal). The mean Lysholm score was 86.5 ±10.5. The lowest clinical scores were noted in 4 multiply operated knees.

Conclusions: We concluded that a revision technique using the STG Soffix fixation device can restore stability with good functional outcomes following failed primary ACL reconstruction. Multiply re-operated knees had the worst functional results despite restoration of stability.

Aim. The purpose of this paper is to report on the results of ACL hamstring reconstruction using a novel fixation device.

Patients-Methods. We reviewed a total of 132 patients with anterior cruciate ligament reconstruction, operated between 1998 and 2002, with a mean follow up time of 51 ± 9 months. A uniform arthroscopically assisted surgical technique with an instrument guided impingement free tibial tunnel placement and “over the top” femoral routing was employed. An autologous four strand semitendinosus-gracilis tendon graft in combination with a polyester graft suspension tape and cortical fixation device was used. An accelerated rehabilitation was instructed. All patients were examined in a dedicated Research Clinic on a 6 month basis. IKDC, Lysholm and Tegner scoring were employed to validate the end results. Arthrometric evaluation was performed with the KT 2000 device.

Results. The over all analysis showed a mean side to side difference of 2.9 mm ± 1.8 and the International Knee Documentation Committee score rating was 91.6 % normal or nearly normal (121 patients). Complications included one graft rupture, one deep infection and 5 case of loosening.

Conclusion. These findings suggest that the described method of anterior cruciate ligament replacement produces good early functional results and restores knee stability.