Hello, I am going to present our work on a cadaveric biomechanical comparison of triple versus quintuple hemisection Achilles tendon lengthening. I am Shuyuan Li, the corresponding author of the paper. Achilles tendon lengthening is commonly performed percutaneously under the triple hemisection cut technique proposed by Hooke in the most commonly used method. Despite its popularity, Hooke's technique has been found to have limited lengthening capacity compared to the traditional used open lengthening technique and therefore is only used in treating mild Achilles contracture. The senior author developed a five-step percutaneous hemisection technique for lengthening of the Achilles. We call it quintuple. It demonstrated to be a reliable procedure. Here are some illustrations of how the triple and the quintuple cuts are made. They all follow the medial lateral medial order. The purpose of this cadaveric study was to evaluate the efficacy and safety of the quintuple compared to the triple cut technique. Ten matched pairs of above-knee specimens were randomly assigned to the triple and the other to the quintuple hemisection group. The tendon lengthening was measured with optical markers at the most distal cut and 15 centimeters approximately. All measurements were performed on a universal testing machine called Instron with a forefoot and femur fixed under the knee-in extension. The ankle was dorsiflexed under a constant load to 45 newtons. Lengthening was performed 1 cm above the Achilles insertion following a medial lateral order at 3 cm intervals. The load was gradually increased until maximum dorsiflexion. Here you can see the illustration with the quintuple cuts on the left side and the triple cuts on the right side. We measured the following parameters, that is, the maximum dorsiflexion angle of the ankle, the tendon lengthening, the load needed to achieve the maximum ankle dorsiflexion, and any rupture of the Achilles was recorded. Here are our results. All specimens had equal baseline to start with, from there were no statistic difference between the dorsiflexion angle of the two groups under 45 newton load with an intact Achilles, and the quintuple precision was achieved with the minimum dorsiflexion. The quintuple procedure achieved more lengthening than the triple group, which reflected in both the maximum dorsiflexion angle of the ankle under 45 newtons and the lengthening of the tendon between the optical markers. With regards to the lengthening, the quintuple cut achieved 3-4.41 mm in average lengthening, and the triple cut achieved 11.36 mm lengthening under 45 newton force. In terms of dorsiflexion of the ankle, the quintuple group achieved 16.58 degrees of dorsiflexion in maximum, and the triple cut group achieved 10.53 degrees maximum dorsiflexion under 45 newton force. And you can also see that the load required to reach the maximum ankle dorsiflexion in the quintuple group was less than that in the triple group. The first one, the former one was 222.9 newton, and the latter one was 334.6 newtons, and there were no ruptures of the Achilles in the quintuple group, but there were two tendon ruptures in the triple technique group. And here the video illustration of the lengthening following the triple cut and the lengthening on the other contralateral side limb with a quintuple lengthening. And there is much more lengthening in the quintuple group than the triple group. Conclusion. The quintuple lengthening is safe and has an increased capacity for tendon lengthening, and it has an advantage over the triple hemisection technique. Also, excessive force on the foot attempting to gain more dorsiflexion using the triple cut technique can be avoided with the quintuple technique in all cases, particularly when adequate dorsiflexion cannot be obtained. Here are our references. Thank you.

cadaveric biomechanical comparison

triple hemisection

quintuple hemisection

Achilles tendon lengthening

efficacy and safety