The aim of the study is to compare the results after arthroscopic anterior cruciate ligament (ACL) reconstruction using central-third, bone-patellar tendon-bone (BTB group) (n = 28) and four-strand semitendinosus/gracilis (ST/G group) (n = 31) autografts in female patients. The type of study was non-randomised prospective consecutive series. A consecutive series of 61 female patients, all with unilateral ACL ruptures, was included in the study. In both groups, interference screw fixation of the graft was used at both ends, and 59/61 (97%) of the patients returned for the follow-up examination after a period of 26 (23-31) months. The pre-operative assessments in both groups were similar in terms of the Lysholm score, KT-1000 measurements, one-leg-hop test, and knee-walking test. At the 2-year follow-up, the knee-walking test was significantly worse in the BTB group than in the ST/G group (P = 0.003). Furthermore, the knee-walking test was significantly worse at follow-up than pre-operatively in the BTB group (P < 0.005). The corresponding finding was not made in the ST/G group. A reduction in knee laxity compared with the pre-operative assessments was found in both groups. No significant difference in the post-operative knee laxity measurement was found between the groups. A significant increase in activity level and subjective scores was found in both groups compared with pre-operative values, without any significant differences between the groups. Two years after ACL reconstruction, the groups displayed no significant differences in terms of functional outcome and knee laxity. However, the use of ST/G autografts rendered significantly less discomfort during the knee-walking test than the use of BTB autografts.

Prospective MRI examinations revealed that the patellar tendon at the donor site had not normalized 6 years after harvesting its central third. The reharvesting of the patellar tendon can therefore not be recommended.

It is previously known that the patellar tendon does not normalise histologically in the short term after harvesting its central third. The aim of the study was to obtain long-term serial biopsies from the central and peripheral parts of the patellar tendon after the harvesting procedure. Our hypothesis was that in the long term after harvesting its central third, the patellar tendon does not regain normal histological appearance. Seventeen consecutive patients, who had undergone anterior cruciate ligament reconstruction using patellar tendon autografts, were included. Percutaneous biopsies were obtained under ultrasonographic guidance 27 (24-29) months and 71 (68-73) months after the index procedure, respectively. The sections were stained with haematoxylin and eosin. The biopsies were evaluated using light microscope. Both at 27 months and 71 months, the fibre structure was deteriorated and the vascularity and cellularity were increased compared with normal tendon. This was seen in both the central and peripheral parts of the tendon. In conclusion, nearly 6 years after harvesting its central third, the patellar tendon had still not normalised histologically, neither in the central nor peripheral parts of the tendon.

Six years after harvesting its central third and leaving the defect open, the patellar tendon revealed a "more heterogeneous matrix" with changes in ultrastructural morphology and relative fibril diameter distribution compared with normal control tendon.

No abstract