1.6m patients worldwide undergo total hip arthroplasty (THA) each year, accounting for an estimated global hip replacement market of $6.5b globally. Osteoarthritis, obesity, osteoarthritis and prolonged life expectancy are among the factors that increase the demand for THA. In fact, osteoarthritis is one of the top ten diseases in developed countries.
Though current hip implants already enhance the quality of life of many patients, the high dislocation risk, possibility of reduced mobility, and limited implant lifespan mean there is a significant opportunity for improvement. The increasing demand for replacement revision surgery (estimated at 8-10% and growing) indicates a pressing need for better and longer lasting implants.
Standard ball-and-socket prostheses last for approximately 10-25 years, meaning some patients may undergo the procedure multiple times in their lives. There is a significant risk of chance of dislocation, loosening and the need for revision surgery that further complicate a patient’s recovery and quality of life.
Our total hip joint replacement, The Malta Hip, was developed around the principles of an ankle joint.
Although the ankle joint carries higher stresses than the knee and hip joints, it is prone to less arthritis. We explored the idea of a radical prosthesis design that mimics the unidirectional motion of the ankle whilst maintaining the anatomical degrees of freedom of the hip.
Using knowledge of anatomy, biomechanics and biomaterials, the team managed to develop a novel hip joint prosthesis with a radical new design.
The MaltaHip improves upon standard prostheses by incorporating 4 independent parts that hinge in 3 directions, improving the range of motion of the hip and drastically reducing wear.
The implant also reduces dislocation risk, while making the surgical assembly easier. The MaltaHip prototypes were developed using the same biomaterials as used in commercially available systems and tested in an accredited laboratory.
The results show outstanding wear resistance due to its novel design, compared to conventional hip prosthesis with the same materials and tested under the same conditions.