Technology

NOVEL TECHNOLOGY

Cambridge Orthopaedics Labs has developed and patented a new concept in facture management, the first innovation in this space in over 15 years, the PolyArmour (PA) non-invasive external fixation technology.

PolyArmour utilizes the concepts of three-point fixation, dynamisation and conformity described in the orthopaedic literature but instead of ridged casting materials or invasive surgical plates, PA applies a set of linkages that can be adjusted to fit any patient anatomy at any suitable fracture location.  The materials used in the PA system are biocompatible and radiolucent.  The PA linkages are contained in multiple cuffs, lined with biocompatible spacer fabric to apply appropriate compression to a fracture site without compromising blood flow of nerve function.  Application of the PA cuff technology linked by high-strength carbon rods (again adaptable to the patient’s anatomy) stabilizes a fracture that has undergone closed reduction under x-ray or fluoroscopy and holds the reduced fracture in place throughout the healing process.

MICRO-MOTION

Unique to PA is the capability of the system to allow micro-motion at the fracture site in an amount deemed appropriate by the clinician.  Micro-motion is a known factor in improved fracture healing.  Adjustment of the PA system to enhance the micro-motion at the fracture site can be done post application at time frames (2-3 weeks) as determined by the patient’s healing rate and the clinical opinion of the surgeon.

Providing patients and clinicians with a clinically demonstrated new alternative to simple casting or invasive surgery will allow for better outcomes for patients and reduced use of operating room resources limited by clinical staffing and non-injury related circumstances.

The PolyArmour technology is designed for use in fractures of the wrist (Distal Radius), Forearm, Shoulder (Proximal humerus), Foot and Ankle, and other appropriate fractures that can undergo closed reduction by a skilled clinician.  The first iteration will be for wrist fractures (Distal Radius) The technology maybe particularly suited to use in paediatric population. PA is designed to be used in the Hospital (OR and ER), surgery center, stand-alone acute care facility and in physician offices equipped with the appropriate radiological resources.

WRIST FRACTURES

The first planned submission for the PA system will be for use in the treatment of wrist fractures (distal radius). The PolyArmour Dynamic Wrist Non-Invasive External Fixation System is single use orthopaedic device to support the wrist joint during the healing process, following a fracture. The PA system can be used in the majority of wrist fractures that can effectively undergo closed reduction.

The PA wrist system consists of three cuff sections, two strapped to the forearm, the other to the hand, which are joined by a set of carbon fibre linkages that tie the three  cuffs together. The cuff bracelets are made of a polymer specifically designed for the PA system that has appropriate strength (with unique formula for optimal glass filled ratio) and yet remains radiolucent, allowing the unencumbered use of x-ray or fluoroscopy for clinical follow-up and healing evaluation. Each cuff (bracelet) has multiple adjustable links on regular intervals allowing for conformity around the limb and optimized 3-point pressure distribution on the limb and around the fracture site. Critical soft tissue structures at the fracture site are protected by a cushion of poly-latticed membrane (cuff lining material), which is multi-layered fabric offering > 2.5 mm of cushion to further protect any pressure points. The material for the cuff lining/padding is a unique polylattice membrane with silicone printing.

The clinical performance of the PA wrist system was demonstrated in a clinical case series performed at a major trauma center in the UK where the PA system performed at least as well as, the invasive standard of care, the Volar locking plate.  This clinical series was published in a Société Internationale de Chirurgie Orthopédique et de Traumatologie Journal (SICOTJ) after rigorous peer review. [1]

The mechanisms described above provide uniform pressure that is spread across the limb and prevents any excessive pressure effects on the skin. The same mechanisms allow for circulation to be maintained and healing to progress at an optimized rate.

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.