Device inspired by python teeth revolutionizes rotator cuff repair surgery – Surgical Techniques

Image: Python tooth-inspired device design sandwiched between tendon and bone dramatically improves standard rotator cuff repair (Photo courtesy of Iden Kurtaliaj/Columbia Engineering)

Rotator cuff tears are among the most common tendon injuries, affecting millions of people each year, especially as people age. More than 40% of people over the age of 65 suffer from these injuries, which usually occur at the tendon-to-bone insertion point. This makes surgical repair, which aims to anatomically reattach the tendon, the primary treatment for restoring shoulder function. However, successful reattachment of the tendon to bone poses considerable challenges, with high failure rates that increase with the age of the patient and the severity of the tear. These rates can be as low as 20% in young patients with minor tears and as high as 94% in older patients with massive tears.

Despite advances in rotator cuff repair techniques over the past two decades, the basic method of using sutures to sew two tissues together has not changed significantly. This method often fails due to “suture pullout” or “cheesewiring,” where sutures tear tendons at points of high stress, causing gaps or ruptures at the repair site. Now, a team of engineers has developed a python-inspired device to complement existing rotator cuff suture repair that nearly doubles the strength of the repair. In a recent paper by Scientists progressThe researchers described their biomimetic approach that mimics the design of python teeth to more effectively secure tendon-to-bone attachments, while allowing the device to be tailored to each patient.

The innovation was achieved by a team from Columbia Engineering (New York, NY, USA) who extended their original idea of ​​simply replicating the shape of a python’s teeth to the implementation of advanced simulations, 3D printing and ex vivo experiments on cadavers to refine the interaction between the shape of the teeth and its mechanics. They designed different tooth models, optimizing individual teeth, rows of teeth and, finally, a specific row adapted to rotator cuff applications. The resulting biomimetic device, constructed from biocompatible resin, features a set of teeth placed on a curved base that grips without cutting the tendon.

Each prong is approximately 3 mm high, about half the length of a standard staple, ensuring that it does not penetrate the tendon. The base of the device is 3D printed to precisely fit the patient-specific curvature of the humeral head at the attachment site of the supraspinatus tendon, the most commonly injured rotator cuff tendon. The researchers are now focused on developing a bioresorbable version of this device that would degrade as the tendon naturally heals back to the bone, with the goal of further improving clinical outcomes. They are also preparing for an upcoming pre-submission meeting with the FDA to discuss the potential market introduction of their innovative device.

“We decided to see if we could develop a device that mimics the shape of python teeth, that would effectively grip soft tissue without tearing and help reduce the risk of tendon tears after rotator cuff repair,” said Iden Kurtaliaj, the study’s lead author. “We designed it specifically so that surgeons don’t have to abandon their current approach: they can simply add the device and increase the strength of their repair.”

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