Disposable plastic device aids knee replacement
Updated: Jan 24, 2014 12:13:59pm
New Delhi, Jan 24 (KNN) A new disposable plastic device could help knee operation patients regain smooth movement of their joints and reduce the risk of misalignment and imbalance following surgery.
The OrthoSensor Verasense is a sterile, disposable plastic sensor that does away with the guesswork when quantifying soft tissue balance during Total Knee Arthroplasty (TKA) and is intended to reduce the incidence of misalignment and imbalance in the procedure.
In the past getting the alignment of the joints correct has taken a mixture of experience and educated guesswork, without specific metrics to aid in the alignment.
Up until now, plastic tibial trial spacers and other instrumentation were used to aid the surgeons, but without any concrete data as to load and alignment.
Professor Peter Walker of New York University’s Langone Medical Center explained: “At the moment the surgeon relies on skill, experience and a lot of instrumentation to shape the bones so that they will accept the components very accurately. But one of the more difficult parts of the surgery is getting the knee to move very, very smoothly after the components are placed – a very, very difficult job since every patient is different.”
“You are dealing with structures that have been arthritic, the joint surfaces have been arthritic, you have to put the components in a very perfect alignment to restore what the knee was like when the knee was healthy. Placed between both plates of the replacement joint, the polycarbonate-cased OrthoSensor Verasense device uses proprietary sensor and accelerometer technologies to sense dynamic loads, the contact point of the femur in both medial and lateral compartments through a full range of motion (ROM) and verify the alignment of limbs,” he said.
Inter-compartmental loads and centre-of-load data provide a reference to determine the optimum placement of tibia and femur and optimum balance of ligaments through a full ROM. Thus a doctor can make evidence-based decisions regarding component position, soft tissue releases and limb alignment, rather than relying on experience.
“The idea is to get the forces exactly equal on both sides of the knee, so the knee is perfectly balanced,” continued Professor Walker, “so when you use it later on, in function, it will move very smoothly and be very stable.”
The disposable device connects wirelessly to a transceiver. The device is first calibrated on a flat surface to “zero” it, so there is a baseline for orientation and load bearing. Information from the device is sent, via the transceiver, to control software on the surgeon’s PC. Because of its direct contact with exposed tissue, biocompatibility of the device was crucial.
The case is injection moulded from Bayer MaterialScience’s Makrolon Rx1851 polycarbonate. Makrolon was chosen because of the grade’s flow, lubricity, ease of release, strength and the option of providing custom colour formulations.
The Verasense is available in four translucent colours – brown, green, blue and yellow – each indicating a specific surgical size. The devices can also be used with four shim sizes which increase the thickness of the device allowing for variations in patient anatomy.
Bruce Fine, market segment leader, medical and consumer products – polycarbonates at Bayer MaterialScience, said: “In the creation of OrthoSensor’s Knee Balancer, we worked with an adhesives formulator and moulder to safeguard the integrity of the material and assure that OrthoSensor’s high standards were met.”
The Verasense received US Food and Drug Administration clearance for limb alignment in June 2013 and received European CE approval in October 2013, since when it has launched the product in the European market.
“We’re pleased to have successfully achieved CE Mark for our Verasense technology,” said Jay Pierce, president and chief executive of OrthoSensor.
“This enables us to provide OrthoSensor’s innovative technology to orthopaedic surgeons and patients in markets outside the US and creates significant growth opportunities for our business,” he added. (KNN Bureau)
The OrthoSensor Verasense is a sterile, disposable plastic sensor that does away with the guesswork when quantifying soft tissue balance during Total Knee Arthroplasty (TKA) and is intended to reduce the incidence of misalignment and imbalance in the procedure.
In the past getting the alignment of the joints correct has taken a mixture of experience and educated guesswork, without specific metrics to aid in the alignment.
Up until now, plastic tibial trial spacers and other instrumentation were used to aid the surgeons, but without any concrete data as to load and alignment.
Professor Peter Walker of New York University’s Langone Medical Center explained: “At the moment the surgeon relies on skill, experience and a lot of instrumentation to shape the bones so that they will accept the components very accurately. But one of the more difficult parts of the surgery is getting the knee to move very, very smoothly after the components are placed – a very, very difficult job since every patient is different.”
“You are dealing with structures that have been arthritic, the joint surfaces have been arthritic, you have to put the components in a very perfect alignment to restore what the knee was like when the knee was healthy. Placed between both plates of the replacement joint, the polycarbonate-cased OrthoSensor Verasense device uses proprietary sensor and accelerometer technologies to sense dynamic loads, the contact point of the femur in both medial and lateral compartments through a full range of motion (ROM) and verify the alignment of limbs,” he said.
Inter-compartmental loads and centre-of-load data provide a reference to determine the optimum placement of tibia and femur and optimum balance of ligaments through a full ROM. Thus a doctor can make evidence-based decisions regarding component position, soft tissue releases and limb alignment, rather than relying on experience.
“The idea is to get the forces exactly equal on both sides of the knee, so the knee is perfectly balanced,” continued Professor Walker, “so when you use it later on, in function, it will move very smoothly and be very stable.”
The disposable device connects wirelessly to a transceiver. The device is first calibrated on a flat surface to “zero” it, so there is a baseline for orientation and load bearing. Information from the device is sent, via the transceiver, to control software on the surgeon’s PC. Because of its direct contact with exposed tissue, biocompatibility of the device was crucial.
The case is injection moulded from Bayer MaterialScience’s Makrolon Rx1851 polycarbonate. Makrolon was chosen because of the grade’s flow, lubricity, ease of release, strength and the option of providing custom colour formulations.
The Verasense is available in four translucent colours – brown, green, blue and yellow – each indicating a specific surgical size. The devices can also be used with four shim sizes which increase the thickness of the device allowing for variations in patient anatomy.
Bruce Fine, market segment leader, medical and consumer products – polycarbonates at Bayer MaterialScience, said: “In the creation of OrthoSensor’s Knee Balancer, we worked with an adhesives formulator and moulder to safeguard the integrity of the material and assure that OrthoSensor’s high standards were met.”
The Verasense received US Food and Drug Administration clearance for limb alignment in June 2013 and received European CE approval in October 2013, since when it has launched the product in the European market.
“We’re pleased to have successfully achieved CE Mark for our Verasense technology,” said Jay Pierce, president and chief executive of OrthoSensor.
“This enables us to provide OrthoSensor’s innovative technology to orthopaedic surgeons and patients in markets outside the US and creates significant growth opportunities for our business,” he added. (KNN Bureau)
Loading...
