The most commonly used graft during ACL reconstruction is hamstring tendons harvested from the injured knee. These tendons are folded and stitched in such a way as to recreate a new cruciate ligament. Hamstring tendon harvested from your own body in this way is called a hamstring tendon “autograft”. In some circumstances, Mr Gibb will recommend harvesting the hamstring tendon graft from your un-injured knee. The recovery following hamstring tendon harvest is rapid, the hamstrings behind and on the inside of the thigh sometimes a little tender and bruised (this is called donor site morbidity) for three or four weeks following surgery. “Hamstring pulls” are not uncommon during the early weeks following surgery and hamstring strength is usually a little depressed for several months following harvest. Autografts incorporate rapidly and usually provide a graft as strong as or stronger than the original anterior cruciate ligament.
In some circumstances, hamstrings supplied by organ donors will be used. These grafts are called “allografts” and are specially treated to ensure their safety. Allografts have several advantages over autografts and these include ease of use and lack of donor site morbidity. Multiple tendons donated by the same individual can be used when reconstructing multiple ligaments at one sitting. Allografts are also commonly used during revision reconstruction because in these circumstances your hamstring tendons may already have been harvested. Disadvantages include a slower incorporation than with autograft, a slight reduction in strength caused by the specialised cleaning process employed and a theoretical risk of disease transmission.