Stability and clinical results are similar after BTB and BT reconstruction but anterior knee pain and kneeling down difficulties are significantly smaller after harvesting the BT graft.
It is technically difficult to measure objectively especially the rotational stability of the knee in vivo in weight-bearing condition. Navigation systems give us such an option. The aim of this prospective controlled blinded randomised study was to evaluate knee stability at least 2 years after anatomic single-bundle (SB) anterior cruciate ligament (ACL) reconstruction using bone-tendon-bone (BTB) graft from the patellar ligament and bone-tendon (BT) quadriceps graft in comparison to the contralateral healthy knee joint. We have postulated two hypotheses: 1) ACL reconstruction using BT graft restores the knee stability in internal rotation and ventral translation sufficiently without significant difference in comparison to the healthy knee; 2) ACL reconstruction using BT graft restores the knee stability in internal rotation and ventral translation without significant difference in comparison to the BTB reconstruction.
Material And Methods
In both groups (BT and BTB), 40 patients selected prospectively at random were evaluated. Only cases with isolated ACL lesions and healthy contralateral knees were included. The mean follow-up after the surgery was 25 months (range, 24 to 35 months). For all measurements, the navigation system was used. Measurements were done by the blinded investigator. Patients were asked to perform (in 30° weight-bearing flexion) the maximal external trunk rotation to develop the reverse (internal) rotation (IR) of the tibia against the femur. All measurements were taken on both the reconstructed and healthy knee (control data). All measurements were repeated 3 times for each knee joint. KT-1000 was used to evaluate ventral translation. To evaluate clinical results, Cincinnati, Lysholm, and IKDC scores were used. VAS for anterior knee pain and kneeling down possibility were added (0 – 10 points). The nonparametric Wilcoxon test was used to evaluate results.
After the BTB reconstruction, the mean IR of the tibia was 9,8°. In the contralateral healthy knee joint, IR was 9,7°. We didn´t find any statistically significant difference in IR stability between reconstructed and healthy knees (p > 0,05). After the BT reconstruction, the mean IR was 9,5°. In the contralateral healthy knee joint, IR was 10,5°. We didn´t find any statistically significant difference in IR stability between reconstructed and healthy knees (p > 0,05). We observed no significant difference between both groups in terms of preoperative and postoperative IR stability values (p > 0,05). Ventral translation was 6,9 mm at average in BTB group and 7,1 mm in BT group (p > 0,05).
Regarding clinical scores there were no significant differences between both groups (p > 0,05). However, anterior knee pain and kneeling down were significantly worse in BTB group (p < 0,05).
The data confirmed both hypotheses and shows that the BT reconstruction of the ACL restores the stability of the knee joint without any significant difference in comparison to the BTB technique. Clinical results are similar after both techniques. Anterior knee pain and kneeling down difficulties are significantly smaller after harvesting the BT graft.