Osteoarthritis: some hints

sources: Orthopaedic Research Society and PR Newswire

According to Wikipedia, Osteoarthritis (OA) is a type of joint disease that results from breakdown of joint cartilage and underlying bone. The most common symptoms are joint pain and stiffness. Initially, symptoms may occur only following exercise, but over time may become constant. Other symptoms may include joint swelling, decreased range of motion, and when the back is affected weakness or numbness of the arms and legs. The most commonly involved joints are those near the ends of the fingers, at the base of the thumb, neck, lower back, knee, and hips. Joints on one side of the body are often more affected than those on the other. Usually the symptoms come on over years. It can affect work and normal daily activities. Unlike other types of arthritis, only the joints are typically affected.

OA affects the entire joint, progressively destroying the articular cartilage, including damage to the bone. Patients suffering from OA have decreased mobility as the disease progresses, eventually requiring a joint replacement since cartilage does not heal or regenerate. According to a 2010 Cleveland Clinic study, OA is the most prevalent form of arthritis in the United States, affecting more than 70% of adults between 55 and 78 years of age (that is, millions of people).

“My father was in major pain from his osteoarthritis,” explains Riccardo Gottardi, a scientist at the University of Pittsburgh supported by a Ri.MED Foundation fellowship.  “He was in so much pain that he had to undergo a double hip replacement followed by a knee replacement soon afterwards. I could see the debilitating and disabling effects the disease had on him, as he was restricted in his mobility and never fully recovered even after surgery. This was very different from the person that I knew, who had always been active and never shied away from long hours of work in his life – he just could not do it anymore.“

For scientists like Gottardi, a key obstacle in understanding the mechanisms of osteoarthritis and finding drugs that could heal cartilage, is that cartilage does not exist separately from the rest of the body. Cartilage interacts with other tissues of the joint, especially with bone. Bone and cartilage strongly influence each other and this needs to be taken into account when developing new drugs and therapies.

Gottardi and a team of researchers at the Center for Cellular and Molecular Engineering, led by Dr. Rocky Tuan, have developed a new generation system to produce engineered cartilage, bone and vasculature, organized in the same manner as they are found in the human joint.  This system is able to produce a high number of identical composite tissues starting from human cells. The team will use this system to study the interactions of cartilage with vascularized bone to identify potential treatments for osteoarthritis. The team’s research has two main objectives: to help understand how cartilage interacts with the other joint tissues, especially bone; and to help develop new effective treatments that could stop or even reverse the disease.  Their patent pending system is the first of its kind, and offers a number of advantages including the use of human cells that replicate native tissues. This system more closely matches the effects on humans than standard animal testing could achieve.

The team of scientists is further developing their system to produce tissues composed of more and different cell types that could better replicate the human joint. They have also started a number of collaborations with other research groups and companies that are interested in using the system to investigate other joint diseases and to test their product. “After seeing what my father went through,” says Gottardi, “I decided that I did not want to just watch by working on diagnostics, but rather, I wanted to be able to do something about osteoarthritis and contribute to the improvement of current treatment options.“

Gottardi’s work was recently presented at the Annual Meeting of the Orthopaedic Research Society. Founded in 1954, the Orthopaedic Research Society strives to be the world’s leading forum for the dissemination of new musculoskeletal research findings.

Formation à la chirurgie robotique

source: ce site internet

Saviez-vous qu’il n’y a aucune obligation légale à se former à la chirurgie robotique ? Autrement dit, n’importe quel chirurgien peut s’assoir à une console de robot da Vinci et opérer. Il n’y a aucune obligation de formation. Prendriez-vous un avion dont le pilote n’a pas de licence de vol ?

Le 13 novembre 2015, un panel d’experts de la chirurgie robotique s’est réuni au sein de l’Académie Nationale de Chirurgie (ANC) pour débattre sur la formation en chirurgie robotique. Les conclusions principales mettent en avant des besoins fondamentaux :

• Il faut se caler sur le protocole de formation à la chirurgie robotique élaboré par les équipes de Nancy.
• Il est impératif de prévoir l’arrivée de nouveaux robots.
• Il n’est pas utile de multiplier les centres de formation, il faut se contenter de quelques centres experts de formation bien équipés en matériel et en personnel et développer les registres.

Les principes conducteurs de la chirurgie moderne assistée par ordinateur, et par conséquent robotique doivent être les suivants :

• Savoir opérer
• Connaître les machines utilisées
• Être convaincu de la nécessité du partenariat avec les industriels
• Conserver son éthique et son indépendance en évitant tout conflit d’intérêts
• Justifier scientifiquement les évolutions thérapeutiques choisies pour convaincre les décideurs économiques et défendre les chirurgiens mis en cause par l’intermédiaire de la HAS

La formation en chirurgie robotique assurée actuellement par les industriels n’a pas de base légale. Celui-ci a simplement pour obligation, comme tout fabricant de matériel, d’expliquer son fonctionnement à un acquéreur. Cette formation, trop courte si l’on se réfère aux résultats publiés, ne comporte aucune évaluation des capacités de ces chirurgiens à utiliser le robot. Il est du rôle des sociétés savantes et des universités de contrôler cet enseignement et l’évaluation des équipes utilisatrices de ces nouvelles technologies, en partenariat avec les industriels. La formation en chirurgie robotique peut être assurée soit par des écoles publiques, soit par des écoles privées, en étant conscient de l’importance du coût du matériel nécessaire. Il apparait que ce coût ne peut être assumé par les seules finances des universités et que des partenariats sont nécessaires avec des entreprises privées, pour les écoles publiques.

La chirurgie robotique est mise en œuvre par des chirurgiens et leurs équipes et leur formation comporte 5 volets :

1. La formation chirurgicale de base relève de toutes les écoles de chirurgie.
2. La formation élémentaire à l’usage d’un “robot” est commune à toutes les spécialités utilisatrices des robots. Elle est validée par un document attestant de la participation du chirurgien à la formation élémentaire, apprentissage de la machine, des gestes avec des mises en application sur simulateur et sur robot en “dry” et “wet lab”. Cette étape de la formation doit être conclue par une évaluation.
3. La chirurgie robotique est caractérisée par la distance physique établie entre le chirurgien et le champ opératoire, ainsi que par la disparition de la communication visuelle avec le reste de l’équipe. Une formation des autres membres de l’équipe chirurgicale (team training) est par conséquent indispensable.
4. La formation clinique spécifique à chaque spécialité se fera dans des centres équipés de “robots” et disposant de “proctors” (“Advanced Courses”).
5. La chirurgie est un apprentissage permanent qui nécessite un maintien de compétences tout au long de sa pratique. La question de la recertification telle qu’elle est imposée aux pilotes d’avion après une période d’inactivité ou lorsqu’ils n’ont pas une pratique régulière n’existe pas actuellement en Médecine. Il est vraisemblable qu’à l’avenir le développement des simulateurs permettra aux chirurgiens soumis à des situations similaires de rafraîchir ou de maintenir leur technicité.

CORTEX 3D-printed cast

source: this website

3D-printed casts for fractured bones could replace the usual bulky, itchy and smelly plaster or fibreglass ones in this conceptual project by Victoria University of Wellington graduate Jake Evill. The prototype Cortex cast is lightweight, ventilated, washable and thin enough to fit under a shirt sleeve.

A patient would have the bones x-rayed and the outside of the limb 3D-scanned. Computer software would then determine the optimum bespoke shape, with denser support focussed around the fracture itself. The polyamide pieces would be printed on-site and clip into place with fastenings that can’t be undone until the healing process is complete, when they would be taken off with tools at the hospital as normal. Unlike current casts, the materials could then be recycled.

Jake has just graduated from the Architecture and Design faculty at Victoria University of Wellington, with a Major in Media Design and a Minor in Industrial Design. After working with the orthopaedic department of his university on the project, he is now looking for backing to develop the idea further. “At the moment, 3D printing of the cast takes around three hours whereas a plaster cast is three to nine minutes, but requires 24-72 hours to be fully set,” says the designer. “With the improvement of 3D printing, we could see a big reduction in the time it takes to print in the future.”

After many centuries of splints and cumbersome plaster casts that have been the itchy and smelly bane of millions of children, adults and the aged alike, the world over, we at last bring fracture support into the twenty-first century.

The Cortex exoskeletal cast provides a highly technical and trauma-zone-localised support system that is fully ventilated, super light, shower friendly, hygienic, recyclable and even stylish!

other sources: one and two

3D-printing human body parts

In a previous post we saw how new technologies aim at printing human body parts by means of 3D printers. Recently, an amazing result has been achieved by some Doctors at the University of Michigan: they managed to print in 3D a tracheal splint for a 20-month-old patient in order to restore his bronchus functionality. This website offers the description of the surgical operation they performed, step by step.

Abstract – Tracheobronchomalacia in newborns, which manifests with dynamic airway collapse and respiratory insufficiency, is difficult to treat. In an infant with tracheobronchomalacia, we implanted a customized, bioresorbable tracheal splint, created with a computer-aided design based on a computed tomographic image of the patient’s airway and fabricated with the use of laser-based three-dimensional printing, to treat this life-threatening condition.

Description – At birth at 35 weeks’ gestation, the patient did not have respiratory distress and otherwise appeared to be in normal health. At 6 weeks of age, he had chest-wall retractions and difficulty feeding. By 2 months of age, his symptoms progressed and he required endotracheal intubation to sustain ventilation. The workup revealed the following:

• an anomalous origin and malposition of the pulmonary arteries, with crisscross anatomy;
• right pulmonary-artery hypoplasia;
• compression of the left mainstem bronchus between an abnormally leftward-coursing ascending aorta and an anteriorly displaced descending aorta;
• air trapping;
• postobstructive pneumonia.

Despite placement of a tracheostomy tube, mechanical ventilation, and sedation, ventilation that was sufficient to prevent recurring cardiopulmonary arrests could not be maintained.

We reasoned that the localized tracheobronchomalacia was the cause of this physiological abnormality and made a custom-designed and custom-fabricated resorbable airway splint. Our bellowed topology design, similar to the hose of a vacuum cleaner, provides resistance against collapse while simultaneously allowing flexion, extension, and expansion with growth. The splint was manufactured from polycaprolactone with the use of a three-dimensional printer.

The institutional review board of the University of Michigan consulted with the Food and Drug Administration and approved the use of the device under the emergency-use exemption, and written informed consent was provided by the patient’s parents. After transposition of the right pulmonary artery and failed aortopexy, sutures were placed around the circumference of the malacic left bronchus and tied through interstices of the splint, and the bronchus was expanded. Subsequent bronchoscopy revealed normal patency of the bronchus without dynamic collapse and normal ventilatory variation in the size of the left lung. The partial pressure of carbon dioxide in venous blood decreased from 88 to 48 mm Hg. Seven days after placement of the airway splint, weaning from mechanical ventilation was initiated, and 21 days after the procedure, ventilator support was discontinued entirely and the child was discharged home with the tracheostomy in place. One year after surgery, imaging and endoscopy showed a patent left mainstem bronchus . No unforeseen problems related to the splint have arisen. Full resorption of the splint was estimated to occur in 3 years.

This case shows that high-resolution imaging, computer-aided design, and biomaterial three-dimensional printing together can facilitate the creation of implantable devices for conditions that are anatomically specific for a given patient.

other sources: one and two

let’s take stock of … the lower limb !

Hello everybody! Since the number of daily readers (and followers) of my blog is (surprisingly) increasing day after day (Thank you everybody!), I thought it could be useful to take stock of some important posts I wrote about the lower limb. Let’s start from the top -the hip- and go down to the bottom -the ankle-, with 9 posts that got many views and some funny comments 🙂

Obviously, since my PhD project is about a knee prosthesis, most of the posts (5 out of 9) are about the knee joint. But in general I tried to give an overall view of some interesting topics related to the biomechanics of the lower limb. Enjoy! 🙂

the Hip Joint: some hints

hammers, screws and Intramedullary nails

the Knee Bursae: some hints

the Meniscus: some hints

the Patella: some hints

Knee Alignment Conditions

Patellar Reflex

How many limbs do you actually perceive?

the Ankle Joint: some hints

Mallet Finger: don’t try this at home

There are a few everyday life experiences that everybody is destined to go through every now and then. Like correctly plugging a USB device only at the third attempt (despite there are only two possibilities), or directly setting the alarm clock half an hour earlier because we know we’re used to putting it off at least four times, or having Mallet Finger.

Mallet Finger is probably one of the most painful and annoying injuries of all time. Technically, it is an injury of the extensor digitorum tendon of the fingers at the distal interphalangeal joint (DIP). In more simple terms, it is the typical injury that occurs when we play basketball and the ball suddenly hits our extended finger. Besides the immediate sensation of pain, within a few minutes our finger will start swelling and we won’t be able to straighten it for a while. We then leave the court with an awesome facial expression (it really hurts, you all know…), but do we know what happened inside our finger?

The distal interphalangeal joint (DIP) of the hand is nothing more than a hinge joint between the two last phalanges of the finger. This kind of joint only admits one degree of freedom, which is the rotation about the joint axis. As a result, our phalanges are allowed to make flexion and extension movements. Thus, the DIP is the last joint of the finger. A sudden high force acting at the tip of the finger (the ball we were trying to catch) strongly solicits the thin DIP extensor tendon. In case of rupture, or tearing, of this tendon from the bone, the finger usually gets painful, swollen, and bruised. Occasionally, blood can collect beneath the nail. In the worst case, the force of the blow may even pull away a piece of bone along with the tendon. The loss of extensor tendon continuity might lead to severe consequences and must be carefully treated. In a first moment, ice should be immediately applied and the hand should be elevated above the level of the heart. Medical attention should be sought within a week after injury. Most mallet finger injuries can be treated without surgery. Normally, X-rays are necessary in order to look for potential bone fractures or joint misalignment. The presence of blood beneath the nail and nail detachment may be a sign of nail bed laceration or open (compound) fracture. A splint can be applied to hold the fingertip straight (in extension) until it heals (8 weeks full-time, 3-4 further weeks less frequently). With this treatment plan, the finger usually regains an acceptable function and appearance. Despite that, it is not guaranteed that the patient will be able to regain full fingertip extension.

If nonsurgical treatment fails, after consultation with an orthopaedic surgeon the patient may consider to resort to surgical repair. In case of very severe deformity or inability to properly use the injured finger, surgery is done to repair the fracture using pins, pins and wire, or even small screws. Surgical treatment of the damaged tendon can include tightening the stretched tendon tissue, using tendon grafts, or even fusing the joint straight.

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sources: mainly this website and this website, and then Google Images

the Ankle Joint: some hints

The ankle is the region where the foot and the leg meet. The ankle joint is actually composed by three smaller joints:

1. the ankle joint proper, commonly called ankle mortise joint (but also talocrural joint).  It is a synovial hinge joint that connects the distal ends of both the tibia and the fibula in the lower limb with the proximal end of the talus.
2. the subtalar joint, that occurs at the meeting point of the talus and the calcaneus.
3. the inferior tibiofibular joint, between the fibula and the tibia. More precisely, it is formed by the rough, convex surface of the medial side of the distal end of the fibula, and a (corresponding) rough concave surface on the lateral side of the tibia.

The boney architecture of the ankle consists of three bones: the tibia, the fibula (in the leg) and the talus (in the foot). The talus is also called the ankle bone since it’s the most important bone in the ankle articulation. In normal health conditions, the articulation between the tibia and the talus (ankle mortise joint) bears the greatest part of body weight: it is the region where ankle efforts are mostly concentrated.

The medial malleolus is a boney process extending distally off the medial tibia. There is also a lateral malleolus, generated by a distal-most aspect of the fibula. Together, the two malleoli, along with their supporting ligaments, stabilize the talus underneath the tibia.

The ankle joint is bound by the strong deltoid ligament (it is attached at the medial malleolus of the tibia and supports the medial side of the whole joint) and three lateral ligaments: the anterior and posterior talofibular ligaments (they support the lateral side of the joint, from the lateral malleolus to the dorsal and ventral ends of the talus) and the calcaneofibular ligament (it is attached at the lateral malleolus and to the lateral surface of the calcaneus).

The calcaneus is also attached to the Achille’s tendon (also known as the calcaneal tendon or the tendo calcaneus), that is a tendonous extension of gastrocnemius and soleus muscles of the leg. It attaches the heel to the posterior leg.

Concerning the joint motion, the ankle joint theoretically admits 1 degree of freedom: movements of plantar flexion and dorsiflexion.

In addition to these, the geometry of the different bones that form the articulation permits other more limited movements, such as foot eversion and inversion.

sources: Wikipedia and this website

the Hip Joint: some hints

The femur head (Latin: caput femoris) is the highest part of the thigh bone (femur). It has a roughly semispherical shape, with a short “neck of the femur” angling the head anteriorly, medially and superiorly to fit into the acetabulum of the pelvis bone.

The acetabulum, also called socket, is the cavity in the pelvis which “hosts” the femur head. It is formed by three innominate bones: the ilium, the ischium and the pubis.

The femur head’s surface is smooth and normally coated with cartilage. It is supported by the neck of the femur and gives attachment to one single intracapsular ligament, the “ligament of head of femur” (ligamentum teres, on the top of the femur head in the figure on the left). It may be not that important as a ligament (it is only stretched when the hip is dislocated, and may then prevent further displacement) but can often be vitally important as a conduit of a small artery to the head of the femur. This small artery is not present in everyone but can become the only blood supply to the bone in the head of the femur when the neck of the femur is fractured or disrupted by injury in childhood.

The femur head together with the acetabulum form the Hip Joint. The hip joint has three degrees of freedom, since it can move in three different planes:

1. sagittal plane: flexion/extension of the leg.
   With just this movement, approximately 3 to 3½ times the body weight acts on the hip joint. An example of this motion is shown by the figure on the right.
2. frontal plane: abduction/adduction of the leg. Regardless of the direction, the respective supporting leg is then subject to approximately 3 times the body weight. This kind of motion is represented by the figure on the left.
3. transverse plane: external/internal rotation of the femur with respect to the pelvis bone. This motion, typical when crossing  legs, makes the femur head rotate in several directions. An example is shown by the figure on the right.

The head of the femur is attached to the femur shaft by a thin neck region that is often prone to fracture in the elderly, which is mainly due to the degenerative effects of osteoporosis. If there is a fracture of the neck of the femur, the blood supply through the ligament becomes crucial. In orthopedic surgery, the Total Hip Arthroplasty surgery consists in removing the femur head and the acetabulum and replacing them with a total prosthesis.

Normally, the two involved prosthetical components are:

1. the Acetabular Cup, a shell that fits the pelvis bone to replace the acetabulum. It is usually attached to the bone by using friction or cement. Additional fixation can be achieved by means of screws.
   
2. the Femoral Component, that is a stem with attached prosthetic femoral neck and head (a ball that fits the Acetabular Cup). Femoral bone is removed and the femur is shaped to accept the femoral stem.

The figure below shows the difference between a healthy hip (on the left) and a prosthetic hip (on the right).

sources: Wikipedia, this website and this other website

the Knee Bursae: some hints

The bursae of the knee can be defined in a very simple way: they are fluid sacs, or synovial pockets. This second definition comes from the sinovial fluid that fills them.

Synovial fluid is made of hyaluronic acid and lubricin, proteinases and collagenases. Its main functions are reducing friction by lubricating the joint, absorbing shocks and properly “feeding” joint cartilage. In the case of the knee, the Knee Capsule encloses the Knee Cavity which is filled with synovial fluid. Knee Bursae surround and sometimes communicate with the Knee Cavity, as we can see in the picture.

Usually Knee Bursae are thin-walled and represent the weak point of the joint. At the same time, their presence is really important since they enlarge the joint space. They can be grouped according to:

• their characterization as communicating and non-communicating bursae. A communicating bursa is when a bursa is located adjacent to a joint, thus having the synovial membrane in communication with the joint itself.
• their location (frontal, lateral, medial).

In pathological conditions, such as excessive local friction, infection, arthritides or direct trauma, fluid and debris collect within the bursa or fluid extends into the bursa from the adjacent joint. As a consequence, the walls of the bursa thicken as the bursal inflammation becomes longstanding. The term bursitis refers to pathological enlargement of the bursa. Clinically, bursitis mimics several peripheral joint and muscle abnormalities.

   

<–prepatellar bursitis

          elbow bursitis–>

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sources: Wikipedia and this website

The world’s most advanced Prosthetic Hand

bebionic3 is the culmination of many years of development and is the most advanced commercially available bionic hand in the world today.

Reliable, speedy and versatile, bebionic3 is a myoelectric prosthetic hand that can be configured to handle almost any everyday life activity. It is designed to be stronger and more durable than other hands available, meaning that it can be worn daily, and withstand the stresses and strains of constant use.

The arm uses some of the most advanced medical technology to date. It consists of two electrodes in a socket, with one connected to the biceps and the other linked to the triceps. Electronic impulses from the muscles and nerve endings create a current, which triggers movement in the hand. So, for example, a biceps tensioning closes the hand while a triceps action opens it again.

Moreover, thanks to the programming software bebalance, which is supplied with every prosthetic hand, bebionic3 can be managed, monitored and configured wirelessly, using smart electronics and easy-to-use flexible interfaces. With bebalance, it is possible to customise everything about bebionic3 quickly and easily. From tweaking grip power and speed, to selecting and ranking the different patterns, it is possible to set up the prosthetic hand to meet the exact desired requirements. Working alongside a clinician, bebalance can also be used as a training aid to assess and develop the patient’s ability to use the device. The clinician will be able to modify the operating thresholds and change signalling features, to ensure that the hand fits the patient’s needs. The software is also available for free download.

The bebionic3 prosthetic hand has been designed to look as real as possible, with a rounded shape and profile that gives the hand a natural appearance, especially when covered with one of the available lifelike silicone skins. Soft and durable, these gloves are easy to remove and clean.

They are available in 19 different lifelike colour shades, but additional detailing on the palms, knuckles, nails and joints can be added in order to enhance the natural appearance of the hand.

When we created bebionic, we wanted to […] transform the lives of amputees worldwide, and help them to regain independence and control in their everyday lives.

Have a look at Nigel Ackland’s experience:

sources: this website and this website