Changes in patellar tendon length during passive knee flexion in the menstrual cycle / 体力科学

The purpose of this study was to investigate the changes in patellar tendon length during passive knee flexion in the menstrual cycle. The right knee joints of 10 adult women with stable menstrual cycles were evaluated. Measurement of patellar tendon length was performed when the knee joint was bent flexibly at six angles (0°, 30°, 60°, 90°, 110°, and 130°), and the long-axis image of the patellar tendon was transversely superimposed at each angle. A photograph was taken with an ultrasonic device. Measurements were performed once during each of the four phases of the menstrual cycle (menstrual, follicular, ovulatory, and luteal phases) classified by the basal body temperature method. There were no significant differences in patellar tendon length at each knee flexion angle in each phase of the menstrual cycle. In the luteal phase, the patellar tendon was stretched significantly at 90° and 130° compared to knee flexion of 0°.

A Comparison of the Fixation Strengths Provided by Different Intraosseous Tendon Lengths during Anterior Cruciate Ligament Reconstruction: A Biomechanical Study in a Porcine Tibial Model

BACKGROUND: The purpose of this study was to determine the tibial fixation strength provided by different intraosseous soft tissue graft lengths within the tibial tunnel. METHODS: Porcine tibial bones and digital flexor tendons were used for testing. Bone mineral densities of proximal tibial medial condyles were measured, and two-strand tendon bundles of 8 mm diameter were used. An intraosseous graft length of 2 cm was used in group 1 (n = 10), and a graft length of 4 cm was used in group 2 (n = 10). Tunnels were 4 cm in length and 8 mm in diameter. Tibial fixation was performed using a suture tied around a screw post with a washer and an additionally inserted 7 x 20 mm bioabsorbable screw. After applying preconditioning loading of 10 cycles, 1,000 cycles between 70-220 N were applied at a frequency of 1 Hz. Graft slippage and total graft movement were recorded. Ultimate tensile strength was measured by pull-out testing at an Instron crosshead speed of 1,000 mm/min. RESULTS: No significant intergroup difference was found for total graft movement after cyclic loading (slippage in group 1, 1.2 mm and group 2, 1.2 mm, respectively, p = 0.917; and total graft movement in group 1, 3.3 mm and group 2, 2.7 mm, respectively, p = 0.199). However, mean ultimate tensile strength in group 2 was significantly higher than that in group 1 (group 1, 649.9 N; group 2, 938 N; p = 0.008). CONCLUSIONS: In a porcine model, ultimate tensile strength was greater for a 4 cm long intraosseous flexor tendon in the tibial tunnel. However, no intergroup difference in graft slippage or total graft movement was observed. The results show that a 2 cm intraosseous graft length in the tibial tunnel is safe and has sufficient strength (> 450 N) for adequate rehabilitation after anterior cruciate ligament reconstruction.

The Length of the Patellar Tendon in Normal Adults

PURPOSE: This study was conducted to measure the length of the patellar tendon in normal adults and to analyze the effect of several anthropological variables on the patellar tendon length. MATERIALS AND METHODS: The study included 316 knees (278 males, 38 females) that were undergoing anterior cruciate ligament reconstruction with a bone-patellar-bone autograft. The patellar tendon length was measured on the middle 1/3 of the ipsilateral patellar tendon taken during the operation and we analyzed the relationships between the tendon length and age, weight, height and gender using simple correlation tests and linear regression analysis. RESULTS: The mean tendon length was 42.6 mm (range: 30~60 mm) and the mean age, mean weight and mean height was 32.7 years, 72.8 kg and 170.2 cm, respectively. There was weak negative correlation between the tendon length and age (Pearson correlation r=-0.187) and weak positive correlation between the tendon length and weight (r=0.288) but there was no significant correlation between tendon length and the body mass index (p=0.282) There was a positive correlation between tendon length and height (r=0.434). There was a significant difference between the males and females for the length of tendon (p<0.001), yet after removing the variance of height, the difference was statistically insignificant (beta=-0.041, p=0.491). The linear regression equation for the patellar tendon length (y, in centimeters) as a function of height (x, in centimeter) can be expressed as y=0.032x1.183. CONCLUSION: The length of the patellar tendon is correlated with height, and a patient's height can predict the length of the patellar tendon.

Patellar Tendon Length Change after Donor Tendon Repair in ACL Reconstruction

PURPOSE: Shortening of the patellar tendon after ACL reconstruction has been one of the causes of postoperative complieations such as anterior knee pain, patellar baja syndrome because of that reason, donor tendon defect was not closed generally. It took at least two years far the tendon to fill the gap by regenerated tendon tissue. But, sometimes protrusion of infra-patellar fat pad may prohibit the regenera-tion of patellar tendon, This study was designed to assess the amount of actual tendon shortening after tendon closure and complications because of it. MATERIALS AND METHODS: Thirty-two cases of arthroscopically assisted midthird patella tendon autograft ACL reconstruction were studied. Patella tendon defect was closed in all cases and the follow-up duration was more than 12 months. The patellar tendon length was measured before and after the defect site closure in operating room, Also, radiolagic tendon length changes were assessed using Insall-Salvati technique. RESULT: The mean patellar tendon length that had been measured in operating room was 51.5mm, 49.8mm (before and after the tendon defect closure). So, the mean shortening was 1.71mm(3.3%). The mean LT/LP ratio was 0.922, 0.894, 0.898(pre-operative and post-operative 6months, 12months). so, the radiologic mean shortening was 3.0%(6months), 2.6%(12months). There were only 4 cases of anterior knee pain and other complications were not found. CONCLUSION: Patellar tendon length change after donor tendon defect closure was about 3% and there were no complications associated with it.