Radiological and histological tissue reaction to different kinds of ACL graft

ABSTRACT

A retrospective study of tissue reaction had been evaluated to three different kinds of grafts used to reconstruct ACL deficient knee. The grafts had been implanted using a modified over the top technique. An artificial ligament of Trevira band was inserted in the first group of patients, while augmented combined graft of semitendinosus and gracilis tendons+ Trevira ligament was implanted in the second group and pure autogenous graft was used in the 3rd group. As a routine for post operative evaluation a radiological changes was noticed at the tibial tunnel at one and half month, 6 months and one year after operation, histological study [intra-articular synovial biopsy and graft tunnel junction biopsy] was obtained from only cases available for second look arthroscopy due to certain reason and covered by patients consent. Early and late radiological finding at the tibial tunnel in cases of artificial ligament showed neither opacification nor sclerosis, while in cases of augmented ligament, a late opacification and sclerosis was a common finding, in contrary opacification was regularly noticed as early radiological changes in patients with pure autageonous graft. Histological study at the ligament bone tunnel interface showed only weak fibrous tissue heeling in patients with artificial ligament, while it showed feature nearly of chondral enthesis with poorly developed fibrocartilage layer in augmented and pure autogenous graft group. The synovial study showed in most of the cases no reaction, Grade [0] in autogenous graft, but in artificial or augmented grafts Grade 1 and 2 were often seen. In conclusion, the presence of artificial ligament as a replacement for ACL alone initiate chronic synovitis and needs a permanent extra tunnel fixation device, while augmented and pure autogenous graft derived a tissue reaction in the tunnel that makes grafts more independent for their outside fixation device