Research

MATERIALS

Cambridge Orthopaedic Labs has undertaken in depth research work into finding appropriate polymers with optimal stiffness to form articulated cuffs made of multiple intricate parts. This has led to development of articulated cuffs that are radiolucent under X-rays or fluoroscopy. The tensile and compressive strength is suitable for stabilising the fracture yet not too rigid. This allows biological healing via the route of relative stability.

Our team and partners have developed an innovative polylattice lining membrane. This biocompatible material has spacer fabric properties. The polylattice lining membrane is designed to protect the pressure areas next to the skin while the optimal thickness helps maintain the circulation. The material is hydrophobic and breathable. It has been impregnated with additional coating to optimise coefficient of friction.

The PolyArmour System utilises suitable metal alloys to achieve connecter devices that offer 3-degree freedom of movement. The metal connectors are able to house optimal strength carbon fibre rods.

DESIGN INNOVATIONS

Cambridge Orthopaedic Labs has patented designs for non-invasive dynamic external fixation system. We have developed designs that will be able to conform to virtually any shape or size of the limb. The universal conformity is a great logistical asset but more importantly affords relatively uniform pressure over the limb. This universal conformity, combined with inter-linked cuff system that has multiple pores and channels, allows for optimal circulation to be maintained. It is further aided by the biocompatible polylattice lining membrane.

We have created 3-point micro-fixation that is coupled with 3-point macro-fixation to refine the known concept to achieve relative stability to enhance non-invasive biological healing.

The PolyArmour system has built in design features to offer selective and incremental range of movement at the joint adjacent to the fracture. The innovative technology aims to enable micro-motion at the fracture site.

CLINICAL

The original clinical study with the PolyArmour non-invasive dynamic wrist fixator showed the results to be comparable to Volar locking plates in distal radius. The study was published in Société Internationale de Chirurgie Orthopédique et de Traumatologie Journal (SICOTJ). [1] The non-invasive dynamic external fixator not only effectively stabilised the distal radius fracture but allowed for incremental and selective range of movement to optimise fracture healing and aid the restoration of function and movement at the same time.  In this study, there was reduced need for physical therapy after treatment with the non-invasive dynamic external fixator.

In a  randomised controlled study with healthy volunteers, that was presented at the American Academy of Orthopaedic, Surgeons, researchers found that the non-invasive dynamic wrist fixator, offered more effective control of the limb and less displacement than casts. [2] The innovative technology had better gap and cast-indices. [2]

Scientists and surgeons are engaged in further clinical and biomechanical studies.

References:

  1. Bajwa A, Rammappa M, Lee L,Nanda R. Treatment of unstable distal radius fractures: non-invasive dynamic external fixator versus volar locking plate – functional and radiological outcome in a prospective case-controlled series.SICOT J. 2015; 1: 34. [doi: 10.1051/sicotj/2015033]
  2. Rammappa M, Port A, Gregg PJ, Bajwa A. Comparison of new bracing technology to traditional casts in forearm and wrist cast models. Proceedings AAOS, Las Vegas 2009.