The effect of initial graft tension on postoperative clinical outcome in anterior cruciate ligament reconstruction with semitendinosus tendon.

INTRODUCTION: The goal of this study is to establish the influence of tensioning the graft during anterior cruciate ligament (ACL) reconstruction, with a semitendinosus tendon graft, on postoperative stability. TYPE OF STUDY: Prospective controlled clinical trial. MATERIAL AND METHODS: Forty-eight patients were randomly allocated to three groups in which three different tensions, 8, 12, or 15 kg force, was applied on the reconstructed ACL during the operation. The patients were observed for 1 year or more after surgery (min. 1 year, max. 2 years 8 months). Clinical outcome was evaluated using the visual analogue scale, anterior knee laxity (using the KT2000 arthrometer) and the torque of the knee extensor. RESULTS: Postoperatively, the average side-to-side differences in anterior laxity were 1.3 mm in the 8 kg group, 2.1 mm in the 12 kg, and 2.4 mm in the 15 kg group. The visual analogue scale averaged 84, 83, and 79 mm, respectively. There were no significant differences among the three groups. There were also no significant differences between the groups for muscle strength recovery during isokinetic and isometric contraction at 1 year postoperatively. CONCLUSION: There were no significant differences among the groups in subjective clinical results, anterior laxity, and knee extensor strength in the ACL reconstructions that used the autogenous semitendinosus tendon graft.

Development and application of an inside-to-out drill bit for anterior cruciate ligament reconstruction.

We report a novel drilling device for anterior cruciate ligament (ACL) reconstruction that has been developed. We invented a special inside-to-out drill bit that can make a bone socket in an inside-to-out fashion. A blade at the tip of a 4.5-mm diameter drill bit closes when the drill bit is in orthograde rotation, but the blade opens when the drill bit is in reverse rotation. The special drill bit is introduced into the joint through a 4.5-mm diameter bone tunnel rotating the bit in the orthograde direction. Then the drill bit is switched to reverse rotation and is pulled backward so that it bores the bone from the inside out. We have used this special drill bit in treating 31 ACL-injured knees and have experienced no problems or complications with the procedure.

Analysis of the risk factors regarding anterior cruciate ligament reconstruction using multiple-looped semitendinosus tendon.

The purpose of this study was to investigate the risk factors regarding anterior cruciate ligament (ACL) reconstruction using autogenous semitendinosus tendon by subjective evaluation of the patients. We studied 63 patients who had been followed for 18 months or longer after surgery. They comprised 31 men and 32 women aged 15-45 (mean, 25.5) years. The patients were divided into two groups by subjective scores. Subjective clinical evaluation was performed using 100 mm visual analogue scale (VAS). In the high score group (group H), the VAS score was 80 mm or higher, and in the low score group (group L), the score was less than 80 mm. Forty three patients were in group H and 20 patients were in group L. The parameters examined were age, gender, sports activity level, preoperative period, complicated meniscus injury, articular cartilage status, graft tendon size, joint stability, and knee extension muscle strength. There were 26 men and 17 women in group H, and 5 men and 15 women in group L. There were significantly more women in group L (p<0.01). The mean preoperative period after injury was 23+/-38 months in group H, and was 52+/-67 months in group L (p<0.05). The average side-to-side differences in anterior laxity were 1.3+/-1.0 mm in group H and 2.2+/-1.6 mm in group L (p<0.01). There were no significant differences in other parameters between the two groups. In this study the risk factors for poor subjective outcome following hamstring ACL surgery was female gender and prolonged delay from injury to operation.