Case Studies
Anterior Cruciate Ligament Tibial Fixator
Introduction
The anterior cruciate ligament (ACL) is in the centre of knee joint and helps to stabilise the knee joint when changing direction. ACL injury affects 1 in 3500 people, resulting in 95,000 new ACL ruptures per year. The ACL is commonly reconstructed using the patient’s own hamstring tendons to form a quadruple graft that is secured in the tibia and femur. Approximately 60,000-75,000 ACL reconstructions are performed in the US alone each year.
The Problem
The most common way of securing the tendon graft in the tibia is to use an interference screw. The most effective of which is the Intrafix™ tibial system. However, the failure rate of ACL reconstruction is between 5 and 25%, and the main cause of graft failure in the early post-operative period is loss of graft fixation within the tibia.
The Solution
A new ACL tibial fixation device (figure 1) was developed by Mr Martyn Snow, an Orthopaedic registrar at the University Hospital of South Manchester NHS Foundation Trust in collaboration with mechanical engineers, Dr Bin Wang and Dr Mahmoud Chizari, based at the University of Manchester. The development work was funded by a TrusTECH Pathfinder Development Fund award and some funding from the University of Manchester.
The Process
The TrusTECH Pathfinder Development and University funding was used to: refine the initial design; carry out some computer modelling of the performance of the device; and perform testing of early prototypes. The funding also paid for the drafting and filing of a UK patent application. A number of companies were then approached about the device and several met with one of the inventors and TrusTECH to learn more about the device. One of the companies expressed an interest in the device after testing some of the prototypes, so a licence agreement was drafted and negotiated by TrusTECH. The device is now under licence and is being refined for manufacture.
Where can I get one?
The patent has been licensed to an orthopaedic company who are now developing the device into a commercial product.
For more information, please contact:
Dr Joanne Thomas
Senior Technology Manager
TrusTECH, Innovation Unit
1st Floor, Postgraduate Centre
Manchester Royal Infirmary
Manchester
M13 9WL
Tel: 0161 276 6965