Python tooth-inspired system doubles power of rotator cuff repairs

Most individuals, when they consider pythons, visualize the massive snake constricting and swallowing victims complete. However do you know that pythons initially maintain onto their prey with their sharp, backward-curving tooth? Medical researchers have lengthy been conscious that these tooth are excellent for greedy delicate tissue quite than reducing by way of it, however nobody has but been in a position to put this idea into surgical apply. Through the years, mimicking these tooth to be used in surgical procedure has been a frequent matter of dialogue within the lab of Dr. Stavros Thomopoulos, a professor of orthopedics and biomedical engineering at Columbia College.

Biomimicry key to new examine

A number one researcher centered on the event and regeneration of the tendon-to-bone attachment, Thomopoulos is especially excited about advancing tendon-to-bone restore, crucial for rotator cuff restore and anterior cruciate ligament reconstruction. In a paper revealed immediately by Science Advances, his group experiences that they’ve developed a python-tooth-inspired system as a complement to present rotator cuff suture restore, and located that it almost doubled restore power. 

“As we get older, greater than half of us will expertise a rotator cuff tear resulting in shoulder ache and decreased mobility,” stated Thomopoulos, who has joint appointments at Columbia Engineering and Columbia’s Vagelos School of Physicians and Surgeons because the Robert E. Carroll and Jane Chace Carroll Professor of Biomechanics (in Orthopedic Surgical procedure and Biomedical Engineering). “The perfect medical intervention is rotator cuff surgical procedure, however a remarkably excessive share of those repairs will fail inside simply a few months. Our biomimetic method following the design of python tooth helps to reattach tendons to bone extra securely. The system not solely augments the power of the restore however will also be custom-made to the affected person. We’re actually excited concerning the potential of our system to enhance the care of rotator cuff accidents.”

Rotator cuff accidents

Among the many most prevalent tendon accidents, rotator cuff tears have an effect on greater than 17 million individuals in the US every year. The incidence of harm will increase with age: greater than 40% of the inhabitants over 65 years outdated expertise a rotator cuff tear.

As a result of rotator cuff tears sometimes happen on the tendon-to-bone insertion website, rotator cuff restore is geared toward anatomically restoring the tendon attachment. Surgical restore is the first therapy for restoring shoulder operate, with greater than 600,000 procedures carried out yearly in the US at a price of $3 billion.

Nonetheless, efficiently reattaching tendon to bone stays a major medical problem. Excessive failure charges happen following surgical procedure, with charges rising with affected person age and tear severity. These charges vary from 20% in youthful sufferers with minor tears to a staggering 94% in aged sufferers with large tears. The most typical failure of rotator cuff repairs is sutures tearing by way of the tendon on the two or 4 greedy factors the place forces focus.

Whereas there have been developments in rotator cuff restore methods over the previous 20 years, the elemental method of stitching two tissues collectively has remained largely unchanged, nonetheless counting on sutures transferring pressure at high-stress greedy factors. Following tendon-to-bone reattachment surgical procedure, sutures can tear by way of tendons at these factors of excessive stress, a phenomenon generally known as “suture pull-through” or “cheesewiring,” resulting in repair-site gapping or rupturing.

“We determined to see if we may develop a tool that mimics the form of python tooth, that may successfully grasp delicate tissues with out tearing, and assist cut back the chance of tendon re-tearing after rotator cuff restore,” stated Iden Kurtaliaj, the examine’s lead writer and a former biomedical engineering PhD pupil within the Thomopoulos’ lab.

The system

The group’s authentic thought was to repeat the form of python tooth, however they went a lot additional, utilizing simulations, 3D printing, and ex vivo experiments on cadavers to discover the connection between tooth form and greedy vs. reducing mechanics. Kurtaliaj manufactured a spread of tooth designs, optimized particular person tooth, arrays of tooth, and at last a rotator cuff-specific array of tooth. The tip outcome was a biomimetic system, manufactured from a biocompatible resin — an array of tooth atop a curved base — able to greedy, not reducing, tendon. The tooth are comparatively small — 3mm excessive for a human rotator cuff, about half the size of a regular staple — in order that they will not poke by way of the tendon. The bottom could be custom-made through 3D printing to match the patient-specific curvature of the humeral head on the supraspinatus tendon attachment website (probably the most generally torn rotator cuff tendon).

We designed it particularly in order that surgeons will not have to abandon their present approach–they can merely add the system and improve the power of their restore.”

Iden Kurtaliaj, examine’s lead writer

The group

Kurtaliaj led the analysis as a PhD pupil beneath the mentorship of Drs. Stavros Thomopoulos and Man Genin, the Harold and Kathleen Faught Professor of Mechanical Engineering at Washington College in St. Louis, with enter for medical implementation from Dr. William Levine, Chair of the Division of Orthopedic Surgical procedure at Columbia College’s School of Physicians and Surgeons. 

“On account of our laboratory’s shut collaboration with orthopedic surgeons, we had been particularly lucky to get enter from Dr. Levine, together with different surgeons at Columbia, all through the system’s design growth course of,” stated Thomopoulos. 

Subsequent steps

The researchers at the moment are working to develop a bioabsorbable model of the system that may degrade because the rotator cuff heals again to bone, additional enhancing its medical applicability. They’re additionally getting ready for a pre-submission assembly with the FDA to facilitate the transition of their system into the market.