Introduction: Anatomical observation and biomechanical studies have shown that the anterior cruciate ligament (ACL) mainly consists of two distinct bundles, the anteromedial (AM) bundle and posterolateral (PL) bundle. Conventional single-bundle ACL reconstruction techniques have focused on the restoration of the AM bundle while giving limited attention to the PL bundle. The purpose of this prospective, randomize clinical study is to compare the outcomes of ACL reconstruction when using either double-bundle or single-bundle technique and bioabsorbable interference screw fixation, and similar rehabilitation, with both techniques.

Methods: Sixty-five patients were randomized into either double-bundle (n = 35) or single-bundle (n=30) ACL reconstruction with hamstring tendons and bio-absorbable screw (Hexalon, Inion Company, Finland) fixation in both group. The evaluation methods were clinical examination, KT-1000 arthrometer measurements, radiographic evaluation, as well as International Knee Documentation Committee (IKDC), and Lysholm knee scores. There were no differences between the study groups preoperatively. For an average of 14 months of follow-up (range, 12 to 20 months), 30 patients of the double-bundle group and 29 patients of the single-bundle group were available (91%).

Results: At the follow-up, the rotational stability, as evaluated by pivot shift test, was significantly better in the double-bundle group than in the single-bundle group. Also, the early anterior stability tended to be better with double-bundle technique, although at the 14-month follow-up, no significant difference between the groups was found anymore. In addition, none of the patients in the double-bundle group had graft failure, while four patients in the single-bundle group had. However, knee scores were equal at the follow-up, and all the results were significantly better at the follow-up than preoperatively, in both groups.

Conclusions: Rotational stability and early anterior stability were better with double-bundle technique than with single-bundle technique in ACL reconstruction with hamstring autografts and bioabsorbable screw fixation. However, both fixation techniques improved patients’ performance.

We compared the strength of fixation of a biodegradable screw with that of two metal screws in a bone-patellar-tendon-bone (BPTB) graft in the bovine knee. We used 33 fresh BPTB specimens with a circular tibial bone plug of 9 mm in diameter which were anchored in a tibial metaphyseal bone tunnel with either an interference screw (n = 11), an AO cancellous screw (n = 11) or a fibrillated, self-reinforced biodegradable poly-L-lactide screw (n = 11). The mean force to failure (+/- SD) in the three groups was 1358 +/- 348 N, 1081 +/- 331 N and 1211 +/- 362 N, respectively. There was no significant difference in the groups with regard to the linear load or the elastic moduli of the fixation. We conclude that the biodegradable screw is as good as either of the two metal screws in the fixation of a BPTB graft in the bovine knee and can be recommended for ACL reconstruction using this type of graft.

We analysed 131 fractures of the tibial condyles in 130 patients, using a modification of the classification of Schatzker, McBroom and Bruce (1979). The patients were reviewed at an average of 7.6 years after the injury. Fifty-five (42%) fractures had been treated conservatively and 76 (58%) operatively. Medial unicondylar and medially tilted bicondylar fractures tended to redisplace into varus position and lateral unicondylar and laterally tilted bicondylar fractures into valgus. There were significant differences when the results were evaluated according to the methods of Hohl and Luck (1956) and Rasmussen (1973). Using our method in conservatively treated cases, the subjective results were acceptable in 49.1%, the functional results in 60.0% and the clinical results in 52.7%. In cases treated by operation the equivalent figures were 57.9%, 73.7% and 52.6%. The poorest results followed displaced medial condylar and medially tilted bicondylar fractures. Varus alignment of the tibial plateau was tolerated worse than valgus alignment.

The effect of tenotomy and of immobilisation in lengthened and shortened positions on the intramuscular connective tissue of the calf muscles of the rat was studied morphometrically and with a scanning electron microscope. Both tenotomy and immobilisation produced a marked increase in both the endomysial and the perimysial collagen networks, with a simultaneous decrease in intramuscular capillary density. The increase in connective tissue volume was more pronounced and occurred more rapidly in the soleus, which consists mainly of type I, slow-twitch fibres than in the gastrocnemius, which is mainly of type II, fast-twitch fibres. The relative volume of connective tissue increased in parallel with the duration of immobilisation or after tenotomy. There was slightly more increase after immobilisation in a shortened rather than in a lengthened position.

We have reviewed 32 patients who sustained a substantial knee ligament injury during adolescence when their knee epiphyses were open. They were all treated non-operatively and re-examined and evaluated in detail after an average of eight years. There were 25 Grade II partial tears and seven Grade III complete tears. After Grade II injuries the functional results were excellent or good, though static instability had not improved from the initial post-traumatic examination. The long-term results of Grade III injuries were poor, because of chronic functional instability, with continuous symptoms and some post-traumatic osteoarthritis. The results of non-operative treatment for Grade III ligament injuries were not acceptable.