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Posts Tagged ‘pain management’

The inter-vertebral discs are made up of two main segments: the outer shell called the annulus fibrosis and the inner material called the nucleus pulposus. The outer lining is tough and has many layers like those of an onion with the different layers being oriented at differing angles to give strength in many directions. The layers of the annulus pass through the vertebrae above and below them, binding them all strongly together and meaning that a disc cannot actually slip out. The outer layers of the annulus are supplied with nociceptors and proprioceptive nerves, an indication they can send both pain and positional information back up to the nervous system.

The nucleus of the disc is encompassed by the inner layers of the annulus and this gives compressive strength to the structure. About two-thirds of the disc is made up of the nucleus and it supports about 75% of the compressive loading. 2.5 times their weight in water can be attracted and held by the large molecules which make up the nucleus, which is 90% water until we get into our 20s, when it starts a slow decline over the next four decades to sixty-five percent. A blood supply is only present in the outer one third of the annulus so the remainder of the annulus and the nucleus must rely on the diffusion of water and nutrients from the vertebrae to remain healthy.

The annulus can be stressed repeatedly by loading and twisting forces which cause microscopic trauma to the fibres and result in annular tears developing. Circumferential tears track around the disc between the layers and radial tears cross the layers from inside to out, with a combination of these tears sometimes developing into larger splits from the inside nuclear material to the exterior. This can permit extrusion of the disc material out of the disc and inflammation or compression of the exiting nerve roots, leading to severe leg pain known as sciatica.

Of the weight being transmitted through the spine, 80 to 90 percent of it goes through the back third of the disc in the first twenty years of life. As we age the spine alters and degenerative changes narrow the lumbar discs, pushing the forces onto the posterior facet joints. The facet joints respond to the increased stresses by becoming arthritic and increasing in size with arthritic changes and development of osteophytes at the joint margins. The exit foramens of the spinal nerves and the main spinal canal itself can be compromised by the degenerative changes in the discs, joints and ligaments, leading to nerve compression and leg symptoms, referred to as spinal stenosis in older patients.

The intervertebral disc and other spinal structures around the spinal segments have been shown to be potential causes of pain. Direct stimulation of the outer layers of the disc has been shown to produce pain in a proportion of patients undergoing operation. The large water attracting molecules break into smaller molecules as the disc ages and repair of this process is slow. The tears and fissures in the annular fibres increase the gradual breakdown and dehydration of the disc structure, with the poor blood supply to the outer disc layers insufficient to prevent the continuing internal disc degeneration.

Chronic spinal lesions may be related to poor blood supply across the endplates but the correlation between spinal pain problems and the degenerative stages is not good. This complicates the ability to relate the changes found on imaging such as MRI scanning and x-ray to the patient’s symptoms and so come up with a plausible cause for the pain.

Pain problems in the intervertebral discs may also involve biochemical and other factors and a lower pH has been found in painful as compared to non painful discs. In animal studies reduction in the pH of the discs heightens pain reactions and increases the pain behaviour of the creatures. Increased neuropeptide levels have been produced in the experimentally deformed discs of animals and could be involved in modulation and transmission of pain in the central nervous system. Mechanical stresses, micro-trauma and biochemical changes may increase production of inflammatory chemicals and enzymes which can breakdown tissues. These factors may all increase the disc and other spinal structure changes.

If you happen to look at a large majority of people sitting on chairs, you are going to see that they are either slouching, lounging or just leaning back, relaxing in a manner which does no good to their spinal cord.

There are many meditations and special things that you can do to help relieve pain. However, most of these different things you can do, will do absolutely nothing to help your posture , spinal cord, back, neck, or your stomach. Where the pain usually starts is from someone having a bad posture and putting strain on the spine, and the only way to correct it, is to correct your posture.

Many of us have a 9-to-5 job, and find ourselves slouching in front of a computer, definitely not bothered about the chair we are sitting in, or our posture. Our job is to leer away at the monitor, not being bothered much about the effect that slouch has upon our shoulders, neck, back and stomach. And then we go complaining to our doctor about neck problems.

The muscles in the body will degenerate over time if you are not exercising. These same muscles are the ones that most people do not realize are the ones that best support your back, which can lead to bad posture. The best way to combat this, if it is happening to you is to find an ergonomic chair to support the posture in your back.

Most chairs that you sit in, will seem comfortable while sitting there, but that is because the body is so used to that slouching position. If are reading this in your favorite chair at home look at how you are sitting now and determine if you’re posture is good or bad.

Laying back in a chair and kicking you’re feet up, can also be bad for posture, as you will be putting a lot of strain your tailbone by doing this. Keeping your feet on the ground, and on a solid surface will allow them to support your body in a way to correct your posture.

People tend to change their posture for specific occasions but as soon as that occasion has past they go back to slouching and hurting their body. This can be found in many cases in an interview, because most people trying to get a job know that interviewers pay attention to that.

Most of us have our keyboards right next to our monitor. Not only does it mean that we have to raise our shoulders to ear level, while we are typing, but it also means that the shoulders are not in their right position. If we place the keyboard at a lower level, say, at an angle of 20 degrees, our shoulders are automatically going to drop down the moment we start to type. Make sure that the elbows are not pointing backwards, while you are typing. You should also have a little reach, but your keyboard should not be positioned too far away.

One thing that will help tremendously is getting your body strength to a point in which it will allow you to correct posture. Doing simple exercise around the house or at work to strengthen your neck will help a lot.

Many of us are going to find it extremely difficult to get into the habit of sitting up straight on a chair, especially as our back muscles and stomach muscles fall into slouch position the moment we sit down. Continuous practice is going to help us here.

Post-operative therapy after hip replacement is mostly performed by the patient getting on with normal life but in most cases it’s useful to quickly analyse their progress and suggest avenues for improvement. It is important to assess any deficiencies in the patient’s performance and correct them early as arthritis of the hip causes several problems to develop. Muscle power drops around a painful joint, reducing the stability and support for the joint as the pain inhibits natural movement and activity. Lack of normal full movement allows joint restrictions to develop, leading to an abnormal walking pattern.

Pre-operative education and rehabilitation is important so the person knows what they are trying to achieve with their exercises and gait practice. Range of motion and strengthening exercises can be given along with gait correction. If the gait cannot be easily corrected by instruction, consideration should be given to using a walking aid. Either a stick or a crutch can be used depending on the degree of support needed, held in the opposite hand to the arthritic joint. If the patient walks with a good pattern this is sufficient, but if they still walk poorly they may need two sticks or crutches to achieve a reasonable gait pattern.

On the first post-operative day the physiotherapist assesses and treats the patient both in the bed and up mobilising. Quadriceps and buttock muscle contractions performed hourly allow the leg to regain muscle control to enable movement. Repeated gentle hip flexions by sliding the heel up and down in the bed can help the patient regain control of the leg and restore this functional activity which they need to master bed mobility. Circulatory improvement is also encouraged by pumping movements of the ankles routinely but the size of this effect may not be very great.

Hourly contractions and gentle movements of the hip will get the joint moving and restore some confidence in the patient that they can independently move their leg around, which initially feels very heavy. The physiotherapist and an assistant will mobilise the patient as their condition allows, using crutches or a frame. Early sitting out in a chair is encouraged with a seat high enough to prevent too much hip flexion. As the side of the thigh has been operated this can limit the amount of knee bend so patients are encouraged to regularly slide their feet back towards themselves in sitting.

Initially mobilisation should produce a safe and acceptable walking pattern and after the initial period the physiotherapist will progress to teaching as close to a normal gait as possible. Once the patient has achieved a step-through gait and are walking well their gait pattern should be very close to normal with the addition of a pair of crutches the only clue they have had an operation. Muscle activation is normalised by the natural rhythm of an automatic activity such as walking and a correct sequence of muscle activity lowers the energy requirements for walking and increases muscle strength.

The physiotherapist may prescribe an exercise regime for the patient if he or she identifies a particular weakness in the hip musculature. The upright position with the patient holding onto a solid object is the safest starting position and promotes stability and confidence. Three movements can be used to start with: bringing the thigh up towards horizontal in front of the body; making a sideways movement of the leg outwards whilst keeping it straight; pushing the leg behind the body whilst keeping the body upright and the leg straight. The main hip and pelvic muscles which control hip stability are worked by these movements.

In some cases these exercises will need to be supplemented by harder ones or by prescribing hydrotherapy. Pool therapy is very useful for patients after their joint replacement as they feel supported and in control of the leg but the water gives significant resistance to muscular activity. Resistance can be increased by using floats attached to the foot and the water resists the practice of the gait pattern, resisting the whole process. Care must be taken not to exercise hip replacements unduly or this can loosen the cement-bone interface and reduce the life expectancy of the replacement.

You may be familiar with the picture, either personally or from a story somebody told you. A young man goes out for the evening, all dressed up and smelling of aftershave. He meets his mates in the pub and has a few beers, starting off the process of intoxication which continues most of the night. After the pub there is the nightclub and more drinking until it’s time to roll out and round to the kebab house to have a snack. After a bit more hanging about he goes home or to one of his mates’ houses to watch television, chat and perhaps drink a little more.

He’s going to have a hangover in the morning but there is no surprise there and he certainly won’t be. The thing he doesn’t expect is falling asleep for some time in the odd position he last happened to adopt whilst watching the TV. He’s sitting sideways on a chair and has draped his arm over the back of the chair and that’s how he has fallen asleep. Some hours later he wakes up and finds himself in the same position. The arm is numb but he shakes it about and rubs it to get it back to life like we often have to when we lie on our arm at night.

If we adopt an odd or stressful position when we sleep the increasing discomfort in the part wakes us up or we naturally just move to a better posture. When we are drunk however we may not do this and this was the problem which allowed the bodily structures in his armpit to suffer significantly increased stresses for perhaps some hours before he finally woke. The arm will hardly move at all and he becomes concerned when it does not respond to shaking and rubbing by recovering its movement.

Reacting to stimuli is what nervous tissues are designed to do but they can react in negative fashion if the applied stimulus is too large or lasts too long. Pressure applied for a long period or a direct blow to an area can both cause nerve trauma, with honeymooners’ palsy being the term for nerve damage caused by one partner using the other’s arm as a pillow during sleep. Longer term nerve pressure can disrupt the blood supply to the nerve and compromise the function of the nerve, a condition called neurapraxia.

Nerve damage is classified into three categories: axonotmesis, neurotmesis and neurapraxia. Neurapraxia is the mildest variety of nerve trauma and there is internal biochemical damage to the nerve but no break in the internal axon or the nerve itself. The nerve being intact, it does not need to regenerate but recover. Nerve impulse conduction is disrupted by the area of nerve trauma and gives paralysis of the muscle with some difference in feeling. Compression may cause avascular damage to the nerve, resulting in inflammatory changes.

While the arm will recover from the nerve insult which it has suffered, sometimes quite quickly, an average recovery time to good function is between six and eight. The major functional disruption is the loss of the ability to move the arm and the ability to feel the arm and control the circulation and sweating to it are either less affected or not affected. Examination by a doctor is useful to exclude more severe injury to the nerve and to caution the patient in how to look after their arm until it recovers, particularly if there is feeling loss.

The non-functional arm will need to be supported as its muscles are paralysed, with a sling keeping the shoulder protected and holding the arm in a safe position. Loss of sensibility in the arm can mean that the person can damage it against something like a hot object without knowing, so they need to be advised to look after it. Activities such as sport can produce these kinds of injuries as can related palsies such as falling asleep whilst sitting on a toilet.

The increase in porosity of our bones and the consequent loss of strength is known as osteoporosis and reduces our bones’ capacity to counteract normal functional activities. The bone’s outer layer is called the cortex and is dense and strong to resist mechanical stresses. The inner bone structure is more like a structural meshwork known as cancellous bone, with bone marrow, blood vessels and collagen tissue filling the interstices. The bony interstices become larger as osteoporosis progresses and there is a reduction in bone strength with the loss of the cross connecting struts. The whole skeleton is affected by the disease but it exhibits itself mostly in the hip, spine and wrist.

Being active and dynamic is not the typical view of the bony skeleton but it is a growing and changing tissue which is constantly renewed over time, taking between seven and ten years to complete the whole replacement. The renewal process is called bone turnover and it can be much faster to replace the entire skeleton in a child, a process which can be as short as two years. The growth plates of our long bones close around sixteen to eighteen years of age and at this time we stop gaining height and size. It is however not before the middle of our twenties that the process of increasing our bone density reaches its highest level.

Bone turnover then maintains a balance between the building up and breaking down processes which remain stable for the period of our early adult lives. Reaching middle age starts a phase of bone life in which the breakdown process becomes more dominant and we begin to lose a proportion of our bone mass. The loss of bone density is more accelerated and more profound in particular patient groups, most obviously in older women after menopause. Osteoporosis does occur in men and risk factors for this include long-term steroid treatment, poor nutrient absorption from colitis, long term immobility, alcohol abuse, being too thin, low male hormone levels and smoking.

One in three women is affected by osteoporosis in their lifetime so it is often thought to be a disease affecting women. However men are affected as well, with one in twelve having this at some time, even though only 20% of spinal fractures and 30% of hip fractures occur in men. Men may suffer from osteoporosis less for several reasons: they attain a higher bone mass to start with so have a higher level to start from and men suffer a much less dramatic bone loss in the middle years of life. Men in particular lose smaller amounts of the structural cortical bone than women.

Osteoporosis is a silent disease and the first indication many people get that they have the disease is the acute pain of fracture such as in the spine or wrist, often because of a trivial fall or blow. Spinal fractures cause wedging of the thoracic spine in particular, with acute pain which can be very disabling, and in some cases becomes chronic. The process of crushing and wedging can also occur quietly without dramatic pain, showing itself by the development of a spinal curvature called a kyphosis or a significant loss of height. A severe kyphosis can restrict the space in the ribcage, causing breathing and digestive problems.

45% of men with osteoporosis have no identifiable cause for their disease, with genetic factors likely to be important in the large majority of cases. Having a history of osteoporosis in the close family predisposes to having a lower bone density and an increased risk of spinal fracture. Levels of testosterone are important in the maintenance of bone density and a low concentration is a major risk for osteoporosis, with a 70 year old man only producing about half the testosterone of someone of 30 years old. Testosterone can be replaced as a treatment if a hormone specialist thinks it is necessary.

Corticosteroid treatment is used to counter the inflammatory effects of ulcerative colitis and asthma as well as other less well known disorders. The levels of bone loss can increase with only six months treatment with a steroid such as prednisolone so they are only prescribed when essential to combat an illness. Individuals should not change their steroid doses with consulting with their medical advisers as this could produce severe side effects.

Plate types vary with different bones and different fracture locations. One of the common types is a dynamic compression plate or DCP. The screw holes in this kind of plate are angled away from the centre of the device so when they are tightened up the bone fragments are pulled towards the centre, providing compression. The smaller plates are only 1mm thick which permits bending to fit the bony area and is mostly used for fractures of the distal ulna and lateral malleolus. Plates have been designed to fit fractures which occur near joints, reducing the size of the devices and increasing the options for fixation.

Ninety-five degree angled plates are typically used in fixation of fractures of the upper femoral areas so that the normal alignment of the bone can be restored. Surgeons need to be three dimensional thinkers to insert this kind of fixation and accurately recreate the anatomical relationships in the area. Pelvic and acetabular fractures are more often fixed with reconstruction plates as they are thinner than dynamic compression plates and more easily mouldable. Fractures often occur close to or just below the prostheses of joint replacements and they may be fixed by bigger plates and cerclage wiring.

High levels of fracture stability can be provided by compression of the fragments and a good restoration of anatomical alignment by the fixation. If firmly stabilised and without any fragment gap then the fracture will heal by primary healing. Absorption of the dead bone at the site of fracture occurs by the action of osteoclasts, with blood vessels growing into the region and then bone producing cells proliferating. Disruption of the blood supply by the plate can produce some osteoporosis under the plate, leading to reduced bone strength from this and the screw holes once the plate is removed, necessitating careful decisions about the amounts of force to be applied to the area.

The initial part of performing internal fixation is the exposure of the fracture site and the removal of the accumulated haematoma, followed by aligning the fragments as close to their original position as possible. Fracturing a bone disrupts the blood supply and the periosteal membrane provides the remaining blood supply to the area, a blood supply the surgeons take care not to disrupt by stripping the membrane from the bone during operation. This could delay the healing process due to reduction of blood supply. Fractures which are unstable or have multiple fragments have to be spanned by a bridge plate to restore bone length, rotation and alignment although this fixation cannot take significant load.

The LISS (Less Invasive Surgical Stabilisation) plating system is a recently developed technique which reduces the contact between the metal and the bone or periosteum, reducing the potential for disruption of the blood supply in the fracture area. Modern designs contour more effectively to the bony anatomy and allow for locking of the screws, which are both advantageous by maintaining the fracture in the correct position whilst allowing increased forces to be applied to it in the healing period. These new designs are most useful in fixing the ends of the bones in fractures of the tibia, femur, radius and humerus.

If there is enough room for easy fixation and the fracture is of a more stable type then conventional plating techniques may be used for fixing breaks of the shafts of bones such as the radius, ulna and humerus. Locking screws are more appropriate if the bone is osteoporotic or the fixation options are limited. Future development will likely lead towards locking techniques being the first option for all fractures, but they are much more expensive and wider use awaits reduction in costs. If the costs of revising the fixation due to malunion by conventional plating are factored in then the more expensive initial system looks more cost neutral.

Nails

It was in the 1930s that Kuntscher refined the intramedullary nailing technique which then became the treatment of choice for shaft fractures of the femur. Humeral and tibial fractures as well as femoral breaks nearer the bone ends were the next progression. Early joint movement and weight bearing walking is allowed by this.

Osteoporosis means that our bones are more porous than normal and have lost some of their strength to resist the forces we put on them in normal life. The outer shell of a bone is known as the cortex and is denser to provide strength and resistance to bending. The inner, honeycomb-like mesh is called cancellous bone and has its holes filled with collagen tissue, blood vessels and bone marrow. When osteoporosis occurs the holes inside the bone become larger, with fewer cross-connecting support struts, reducing the strength of the bone. The effects are usually widespread but fractures typically occur in the spine, hip and wrist.

Being active and dynamic is not the typical view of the bony skeleton but it is a growing and changing tissue which is constantly renewed over time, taking between seven and ten years to complete the whole replacement. The renewal process is called bone turnover and it can be much faster to replace the entire skeleton in a child, a process which can be as short as two years. The growth plates of our long bones close around sixteen to eighteen years of age and at this time we stop gaining height and size. It is however not before the middle of our twenties that the process of increasing our bone density reaches its highest level.

The balance of bone turnover then enters a phase where there is equilibrium between the rate of bone breakdown and the rate of bone formation. From middle age this balance shifts in favour of bone breakdown and we begin to lose bone as we age, with osteoporosis occurring in some cases, especially in women after the menopause due to hormonal changes. Factors which may increase the likelihood of a man getting osteoporosis are low levels of male hormones, low body weight, smoking, high alcohol intake, being very immobile, diet absorption problems from conditions such as ulcerative colitis and long term steroid use for asthma.

Osteoporotic change occurs in one in every three women during their lifetimes and so is often viewed as being a disease of women. Men are however affected by this bone condition but at a frequency of one in twelve, with 20 percent of spinal fractures and 30 percent of hip fractures attributable to lowered bone density. The lesser frequency of osteoporosis in men may be for a couple of reasons: first they develop a higher bone density to start with so start off from a better position, and they lose bone much less significantly in middle age, especially cortical bone.

Osteoporosis is a silent disease and the first indication many people get that they have the disease is the acute pain of fracture such as in the spine or wrist, often because of a trivial fall or blow. Spinal fractures cause wedging of the thoracic spine in particular, with acute pain which can be very disabling, and in some cases becomes chronic. The process of crushing and wedging can also occur quietly without dramatic pain, showing itself by the development of a spinal curvature called a kyphosis or a significant loss of height. A severe kyphosis can restrict the space in the ribcage, causing breathing and digestive problems.

Genetic factors may be responsible, at least partly, for the fact that no diagnostic cause can be found for 45 percent of men with osteoporosis. If someone in the close family has a history of osteoporosis then a man has a higher likelihood of developing lowered bone density and an elevated risk of spinal fractures developing. The maintenance of bone density is partly under the control of the testosterone levels in the body and osteoporosis is a risk if the levels of the hormone are low. Seventy year olds produce only fifty percent of the testosterone levels of men of thirty years of age. Testosterone replacement therapy can be prescribed if appropriate.

Steroids are strong anti-inflammatory medications used for asthma and ulcerative bowel disorders as well as for a number of less common conditions. Six months treatment with a steroid such as prednisolone can increase the levels of bone loss but steroids are only used when they are vital for health. Steroid doses should never be changed by the individual without careful consultation with a doctor or the side effects of the change could be severe.

Rehabilitation after a hip replacement is usually straightforward but it is important to be aware of the priorities at each stage of the operation and recovery for the best outcome. Because an osteoarthritic hip is painful this has a series of knock-on effects. A painful joint means the musculature which controls that joint cannot work properly so tends to lose some of its strength and support for the joint. The joint may also become tight as the natural movements are not performed and the person may adopt an abnormal gait which becomes an ingrained habit.

Pre-operative education and rehabilitation is important so the person knows what they are trying to achieve with their exercises and gait practice. Range of motion and strengthening exercises can be given along with gait correction. If the gait cannot be easily corrected by instruction, consideration should be given to using a walking aid. Either a stick or a crutch can be used depending on the degree of support needed, held in the opposite hand to the arthritic joint. If the patient walks with a good pattern this is sufficient, but if they still walk poorly they may need two sticks or crutches to achieve a reasonable gait pattern.

Physiotherapy assessment and treatment of the patient begins on the first day after the operation with encouragement to perform hourly contractions of the major quadriceps and buttock muscles. This aids restoration of the patient’s leg control and enables joint movement to be performed. Sliding the knee and heel up and down the bed allows practice of repeated hip flexion and joint control which improves the ability to mobilise both around the bed for self care and in and out of bed. Routine ankle pumping exercises are traditionally taught for the same reason and to improve circulation but the effect of this may be small.

Hourly contractions and gentle movements of the hip will get the joint moving and restore some confidence in the patient that they can independently move their leg around, which initially feels very heavy. The physiotherapist and an assistant will mobilise the patient as their condition allows, using crutches or a frame. Early sitting out in a chair is encouraged with a seat high enough to prevent too much hip flexion. As the side of the thigh has been operated this can limit the amount of knee bend so patients are encouraged to regularly slide their feet back towards themselves in sitting.

Initial mobilisation concentrates on getting the person going with an acceptable gait pattern for their confidence and safety. Once they are more mobile then it is important to teach a natural gait, moving on from the step-to gait to the step-through gait. When the patient is skilled at this they should look like they are walking entirely normally but just happen to have a pair of crutches with them. A natural gait pattern promotes the natural rhythms of muscle activation which reinforces the correct muscle patterns and contributes towards strengthening the muscles and reducing the work of walking by promoting an efficient gait.

Specific exercises can be added to the patient’s regime if a significant weakness in one or more muscles is identified. Standing and holding on to a firm object in front is the best position to start with from a balance and safety point of view. The exercises consists of three movements: raising the knee up in front so the thigh eventually is close to horizontal; abducting the leg to the side whilst kept straight; maintaining an upright posture whilst moving the straight leg behind the body. These exercises strengthen the major moving and stabilising muscles around the hip and pelvis and can easily be performed even by elderly and less strong patients.

In some cases these exercises will need to be supplemented by harder ones or by prescribing hydrotherapy. Pool therapy is very useful for patients after their joint replacement as they feel supported and in control of the leg but the water gives significant resistance to muscular activity. Resistance can be increased by using floats attached to the foot and the water resists the practice of the gait pattern, resisting the whole process. Care must be taken not to exercise hip replacements unduly or this can loosen the cement-bone interface and reduce the life expectancy of the replacement.

Plate types vary with different bones and different fracture locations. One of the common types is a dynamic compression plate or DCP. The screw holes in this kind of plate are angled away from the centre of the device so when they are tightened up the bone fragments are pulled towards the centre, providing compression. The smaller plates are only 1mm thick which permits bending to fit the bony area and is mostly used for fractures of the distal ulna and lateral malleolus. Plates have been designed to fit fractures which occur near joints, reducing the size of the devices and increasing the options for fixation.

Fractures of the upper femur are fixed by using plates with a 95 degree angle so that the mechanical axis of the upper femur can be restored at this angle. Inserting this kind of fixation requires that the surgeon thinks in three dimensions as are all must be correctly aligned to restore normal anatomy. Reconstruction plates are less thick than dynamic compression plates and can be contoured in three dimensions for the acetabulum and pelvis. Fractures close to or next to prostheses such as hip replacements or knee replacements are fixed with larger plates with the addition of cerclage wires.

High levels of fracture stability can be provided by compression of the fragments and a good restoration of anatomical alignment by the fixation. If firmly stabilised and without any fragment gap then the fracture will heal by primary healing. Absorption of the dead bone at the site of fracture occurs by the action of osteoclasts, with blood vessels growing into the region and then bone producing cells proliferating. Disruption of the blood supply by the plate can produce some osteoporosis under the plate, leading to reduced bone strength from this and the screw holes once the plate is removed, necessitating careful decisions about the amounts of force to be applied to the area.

In normal fixation using a plate the area is opened up and the blood clot is removed and the fracture fragments are restored to the best anatomical alignment possible. After a fracture the blood supply through the bone has been interrupted so the main blood supply around the fracture comes from the periosteum, the bone membrane lining. It is essential that this membrane is not disturbed or stripped off in the operation as this could reduce the blood supply to the fracture area and delay healing. If unstable fractures with many fragments are to be fixed then a plate which bridges across the gap can be used, with limited operative exposure. It is fixed to the major fragments and works by keeping the bone length, alignment and rotation but cannot suffer much in the way of load.

More modern plating techniques include the LISS (Less Invasive Surgical Stabilisation) which makes less contact with the bone surface along its length, limiting potential disturbance in the membranous blood supply. Locking screw methods are typical newer designs, which offer great advantages over older systems by adhering to bony contours better also. These designs should allow greater forces to be tolerated while the fracture is still being held in the desired position. These are of particular use in fractures of the distal and proximal humerus, distal femur, distal radius and distal tibial fractures.

Conventional plating techniques are adequate to fix fractures where access to the areas is easy and in cases where the fractures are of a stable type, incorporating fractures of bony shafts such as the ulna, humerus and radius. With osteoporotic bone and difficult fixation options the locking systems will be more appropriate. As they are much more expensive than the conventional systems they are not yet the default choice in all cases but look likely to be more widely used as the cost comes down. They may well be cost effective if cases of malunion which require revision are taken into account.

Nailing

It was in the 1930s that Kuntscher refined the intramedullary nailing technique which then became the treatment of choice for shaft fractures of the femur. Humeral and tibial fractures as well as femoral breaks nearer the bone ends were the next progression. Early joint movement and weight bearing walking is allowed by this.

If there is only a small degree of force through the fracture it might be fixed by using fixation wires or pins, and they are also employed to add to the effect of inserting an external fixator or a plate. The most common fractures for which fixation with pins or wires are used are those of the wrist, upper humerus, hand and fingers. Fractures of the ankle, elbow and kneecap are also assisted by k-wiring to add to the tension band technique often used here. Pins can be inserted through the skin without performing an open operation by using an x-ray guidance system.

Steinmann pins, often threaded and thicker than K-wires, have been routinely employed to engage and maintain skeletal traction predominantly in the bones of the leg. The pin is inserted through the bone and this is attached to a traction cord via a stirrup device, holding the bone in the correct position until enough healing callus has formed to allow removal. Modern techniques of fixing fractures sooner and more accurately have meant that the application of traction for long periods, with the risks of bed rest, can now be avoided.

Screws

A basic tool in the armoury of managing orthopaedic and trauma injuries and conditions is the use of bone screws to effect fixation or to aid other techniques of fixation. Pre-drilling can be performed before insertion or a self tapping implant used. The amount of physical stress which can pull a screw out of the bone is affected by a series of matters of which the most influential is the density of the bone into which it is implanted. The surface area of contact between the bone and the screw threads determines a degree of the fixation achieved. Screw insertion is performed in a clockwise direction either along a drilled path or self tapped and produces force once the hard bone cortex is contacted by the head of the screw.

Bone is an active and dynamic body organ and can adapt to the stresses formed by the application of the screws, allowing a gradual reduction in fixation force with time. However, the fracture is usually healed before the fixation is likely to loosen. The two main kinds of screws available are cancellous and cortical bone screws, the denser bone of the cortex being fixed with cortical screws and the more honeycomb bone of the bone ends fixed with cancellous screws. The surface areas of contact between thread and bone are greater in cancellous screws, allowing cancellous screws to achieve purchase in less dense bone.

Tapping the hole or drilling it before insertion may not be necessary in cancellous bone as it can usually be easily screwed being relatively porous and low in density. Screwing a screw directly into the bone may be good as it may compress the local bone track and increase the density of the interface between the screw threads and the bone, allowing an increased hold for the screw. Plates can be held in position by positional screws which compress it against the bone, pilot holes being drilled beforehand and tapped or self tapping screws used.

A degree of compression can be produced by inserting lag screws across the line of a fracture to increase alignment and stability of a long bone fracture and to produce and maintain reduction of a fracture across a joint. To provide the greatest degree of stability requires the screw to be placed at right angles to the line of the break. It is unlikely that lag screws will give sufficient stability alone so they are often supplemented with added stability from an external fixator or a plate.

Cannulated screws are often used to fix hip fractures and can be inserted percutaneously without needing a full open operative technique, inserting the screw along the track already identified by a guide wire and performed under x-ray control for positional control. To limit the potential damage to the soft tissues and the size of the operation, cannulated screws are employed in operations with limited open surgery. Modern screws are self tapping and self drilling as they are inserted and are much more costly than normal screws which are not cannulated.