Synthetic Screws Enhance Musculoskeletal Tissue Repair

An innovative bioresorbable tendon interference screw system with biological and biomechanical benefits aids tissue attachment during orthopedic procedures.

The Acuitive Technologies (Allendale, NJ, USA) CITRELOCK Interference Screw System is intended to reattach musculoskeletal host tissue during orthopedic surgeries, such as fixation of ligaments or tendon graft tissue repairs of the shoulder, elbow, wrist, hand, knee, ankle, and foot extremities. The system, which is based on proprietary Citregen, a thermoset bioresorbable synthetic polymer made of citrate, a natural anti-microbial and anti-inflammatory molecule that plays a crucial role in bone regeneration by regulating cellular metabolic processes and the formation of mineral structures.


Designed on the molecular level, Citregen guides tissue regeneration by replicating the body’s intrinsic cellular biochemical and structural support network, releasing molecules essential for bone formation throughout its bioresorption, leaving behind a biomimetic ceramic structure to be metabolized by the host tissue. This avoids the potential for bulk degradation and chronic inflammation seen in currently available biodegradable polymers. CITRELOCK is available with both reusable surgical instruments and single-use instruments, and in a full range of device sizes.

“Citregen is based on an unprecedented and innovative bioresorbable biomaterial technology developed to support the body's normal healing processes and promote tissue regeneration,” said Professor Guillermo Ameer, ScD, founding director of the Center for Advanced Regenerative Engineering at Northwestern University (Chicago, IL, USA). “When used to fabricate devices for reconstruction of tissues such as ligaments, blood vessels, bladder and bone, results have been impressive and beyond expectations.”

About 90% of the total citrate in the body is in the bones, which function as its major reservoir. In the bone, citrate is synthesized and excreted by osteoblasts, and it is an important component (1%) of bone apatite crystals. Citrate is released to into plasma during bone resorption.