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Glossary of broken Leg terms

Author Dr J.F.M.Clough MD, D.Phil., FRCSC
Orthopaedic Surgeon, Kamloops, British Columbia, Canada
Clinical Instructor, Department of Orthopaedics, University of British Columbia
Editor, Orthopaedic Web Links (OWL)
President, Internet Society of Orthopaedic Surgery and Trauma [was www.isost.org]
Web Editor, Canadian Orthopaedic Asssociation

All rights reserved.

First posted 29 Dec 2001
Current revision Mar. 2003
Please email any comments.



The following terms are quite likely to be used in a discussion of broken legs. Words in bold are described elsewhere in the glossary.

These terms are described to help you communicate with the doctors who are treating you. Many terms are used by orthopaedic surgeons which have very specific meanings; but they are meanings which are subtly different from everyday usage. Reduction has one meaning in everyday usage but means something very specific when used by an orthopaedic surgeon talking about a fracture. This glossary gives the meaning of the words as an OS uses them.

Inevitably there are some digressions and statements in this page. They are the opinions of the author and should not be taken as advice or commentary on your case or any particular case. There are many differing opinions and methods of treatment in the management of broken legs. Remember, this glossary is to help you communicate with orthopaedic surgeons not to second guess them.

Most of the subjects here are treated quite superficially. We have a frequently asked questions FAQ page in which some of the subjects are treated in greater depth. The glossary is to establish that we are using the same words and can find out what they mean.

 

Acute

Happening right away. (Does not mean severe) Acute swelling occurs within the first day or so. (cf chronic)

Alignment

Description of how well the bone is lined up across the fracture. Good alignment means the bone is straight (however, it may still be rotated or displaced)

Anatomical Reduction

The situation in which the fracture fragments have been manipulated (reduced) into exactly the positions they occupied before the fracture.

Angulation

Description of how poorly the bone is lined up across the fracture. Angulation is often measured - eg the fracture is angulated, apex anteriorly, about 20 degrees malalign.gif (2581 bytes)

Ankle Joint

The joint between the lower end of the shin and the talus (a foot bone). A fractured ankle normally involves fracture of the tibia, fibula or both. The fracture line usually enters the joint. Curiously, a fractured talus is often not considered an ankle fracture.

Note that the ankle joint forms ring of bone and ligament. The medial malleolus is connected to the talus by the deltoid ligament. The talus is connected to the lateral malleolus by the lateral ligaments. The fibula is connected to the tibia by the tibio-fibular syndesmosis (ligament) completing the ring. The significance is that it is rare to break a ring on only one side. Usually an ankle fracture involves damage on both the inner and outer sides. When that damage is to the ligaments you cannot see it on Xray but it may still be a serious problem.

anklegif.gif (3681 bytes)

Front view of the bones and ligaments
of the ankle joint

Ankle Fracture

Injuries that involve the ankle joint. The fracture line usually goes through the joint surface of the tibia or fibula or both.

Ankle Replacement

The operation to replace the arthritic joint surfaces with artificial ones. It has a bad reputation for early failure. A few centres are experimenting with new designs but most OS worry that doing this operation makes the fall-back operation of ankle fusion more difficult to do.

Antegrade Nailing of the Femur

The more common technique of passing the IM Rod from the top end of the femur to the bottom. Retrograde Nailing is done in the reverse manner (bottom to top)

Anterior

Front. The kneecap is on the anterior aspect of the knee.

Arthritis

Inflammatory breakdown of the joint surface. There are dozens of causes but the commonest and the one that most concerns us is wear. Wear of the specialized joint surface results from damage or roughness (malunion) of the joint, from infection, from abnormal loading of the joint or from the passage of time. Wear is progressive and irreversible in our current state of knowledge. Post-traumatic osteoarthritis of a joint is wear of the joint surface secondary to an injury.

Arthrogram

An Xray or MRI test in which dye is injected into a joint. The dye coats the joint surfaces and, since it shows up on Xray, any irregularities of the joint surfaces are shown.

Arthroscope

An instrument used by an orthopaedic surgeon to visualize the inside of a joint. This is most commonly done in the knee but the ankle and occasionally the hip joints can be "scoped". This image is an arthroscopic view of the inner side of the left knee.

m6.jpg (7349 bytes)

Articular Cartilage

Joint surface

Avascular Necrosis

Death of part of the bone through losing its blood supply. In injuries it happens because the blood supply is cut off by the fracture. It occurs most commonly in the ball of the hip after a hip fracture and in the talus but any fracture fragment may become avascular and undergo necrosis as a result. In many instances avascular bone can recover with new bone cells using the dead framework of the old bone and reestablishing continuity and function. In other situations the bone does not recover and gradually crumbles.

Avulsion Fracture

An injury in which a muscle pulls off a piece of bone off its attachment, or pulls a bone apart. Probably the commonest avulsion fracture in the leg is when the inner side of the ankle (medial malleolus) is pulled off in an eversion ankle fracture. Many fractures of the kneecap are also avulsion fractures. Avulsion fractures are usually unstable because the pull of the muscle that caused the injury also prevents reduction.

Back Slab

A splint made from plaster or fibreglass which doesn't go round the whole limb. The usual reason is to allow swelling to occur without causing increased pressure in the limb.

Bone Scan

An imaging test in which a minute amount of Technicium is injected into the bloodstream. This material accumulates wherever bone is most active. It gives off gamma rays which can be detected by a special imaging device. The image shows where the bone is most active - healing fractures, stress fractures, infections and growth plates. A bone scan can be useful where a fracture is undetected on Xray or where there may be a problem with blood supply (avascular necrosis)

Bone Graft

Pieces of bone transferred from another part of the body to assist with bone healing. It is controversial whether this works by providing living bone cells,  by providing the framework for bone to grow on or by providing a substance call Bone Morphogenic Protein which stimulates bone formation. Probably it's all three.
Bone graft can be whole chunks of bone with or without its blood supply. More commonly bone graft is ground up into small pieces and packed into the site which hasn't been healing.
"Bone Graft" as an operation means the harvesting of bone graft, usually from the crest of the pelvis, and packing it into the site of nonunion or delayed union.

Bone Matrix

The tissue which forms the structure of a bone. It is made of collagen, very like gristle or scar tissue. The hard crystals of bone mineral are embedded in the matrix making it rigid. If you dissolve the mineral out of bone with some acids, the bone matrix is found to be rubbery.

Bone Mineral

Calcium Hydroxyapatite is an insoluble calcium salt. Crystals of this substance are laid down in the bone matrix by bone cells making the tissue hard, strong and rigid.

Bony Callus

The tissue in a healing fracture in which bone mineral is being laid down. (See Healing, Hard Callus)

Brace

A device for supporting an injured limb or joint. Braces may be hinged to allow motion in a desirable direction while limiting abnormal movement. They are made from neoprene, fibreglass, plastic and (rarely) plaster. They can be custom made or off the shelf. "Functional bracing" is a method of treatment of fractures popularized by Sarmiento. It involves early transfer from a cast to a custom made hinged brace which supports the fracture and allows movements at the foot and ankle.

Break

See fracture. Many people think there is a difference between crack, fracture and break. They are all fractures.

Bridging Callus

An Xray finding during fracture healing. Bony callus (hard callus) has formed and extends like a bridge from one fragment to another. It is a sign that healing is progressing but isn't very strong yet.

Broken leg

A lower limb with a fracture in the hip, thigh bone, kneecap, shin bone, ankle or foot.

Calf Muscle

The powerful muscle at the back of the shin which attaches, via the heelcord or Achilles tendon to the heel. Because the foot is relatively rigid pulling up the heel causes the ball of the foot to go down and this is how we walk, run and jump. Because the calf muscle is often injured when the leg breaks and because it undergoes disuse atrophy during the healing period, you need to exercise the calf muscle to recover function after the bone has healed.

Callus

The tissue that grows at a healing fracture. Soft callus is scar tissue that is laid down early on. Hard callus or bony callus has bone mineral deposited in it and is stronger.

CAM Walker

Brace used during weight bearing phase of rehabilitation from an ankle or tibial shaft fracture. The bone is supported but the ankle can move in the brace stabilized by hinges. pincam_walker.jpg (18446 bytes)

from Breg Inc.

see also  Zinco

Cancellous bone

Spongy or trabeculated bone that occupies the upper and lower ends of long bones like the femur and tibia. It is more likely to be crushed, compressed or impacted by injury. There are specially designed screws called cancellous screws which are used to fix cancellous bone.

Cannulated Screw

Fixation method in which small pins are placed across the fracture then overdrilled by a drill bit with a hole in the middle of it. The drill goes over the pin which thus guides it to the correct position. Then a cannulated screw (also with a hole down the middle) goes over the pin and is screwed home. This technique minimizes the exposure needed to place the screw and fix the fracture.

Cartilage

a) The tissue which makes up joint surfaces and growth plates. It is also found during the soft callus phase of healing and in pseudarthrosis. It is quite like bone but does not have any bone mineral deposits so is softer, weaker and rubbery.

b) The menisci are also called cartilages - which is confusing. They are gristly crescent shaped objects which sit in the knee joint between the thigh and shin bones. They act to reduce wear by spreading the weight and helping with lubrication.

Cast

A splint made by wrapping casting material (plaster or fibreglass) around the limb and letting it harden

Causalgia

A specific form of pain, often burning in nature, which results from injury or compression to a nerve. Causalgia is one of the forms of reflex sympathetic dystrophy

Chronic

Lasting a long time or occuring some time after the acute stage of the injury. Chronic is from the Greek Chronos (time) and usually implies months or years after the event. It doesn't mean especially bad.

Closed Fracture

An injury which has resulted in a fracture of a bone without a break in the skin. Contrast open fracture or compound fracture.

Closed Reduction

Method of treatment in which the fracture is straightened (reduced) by manipulating the limb without operating on it. Closed reduction may be followed by casting, by percutaneous fixation, or by operative fixation as in the case of intramedullary rod fixation

Closed Treatment

Treatment of the injury without opening it up to do an operation. Basically straightening (reducing) the fracture and supporting it with a splint or cast.

Closure

The treatment of a wound to close it up. Usually sutures but sometimes a flap, free flap or skin graft is needed to provide closure.

Comminuted Fracture

Fracture with more than two fragments. Comminuted fractures are more unstable. Purists prefer the term multifragmentary.

Compact Bone

Normal bone has two main different types of architecture spongy or trabecular bone and compact bone. See illustration. Compact bone is dense, heavy and strong. The matrix is packed with very few holes in it. This type of bone forms the cylidrical shaft of most long bones.

Compartment Syndrome

Serious but quite rare complication after injury. Bleeding or compression from a dressing or splint raises the pressure inside inelastic muscle compartments in the leg, arm or hand. The raised pressure reduces the circulation resulting in reduced blood supply and lower oxygen to the muscles. This causes the muscles to swell raising the pressure yet further (and so on). Recognizing that this is happening is difficult but important. The most reliable sign of acute compartment syndrome is relentlessly increasing pain when the muscles are stretched or used. Surgery to decompress the muscle compartment is the treatment.

Chronic compartment syndrome may also occur and is a source of mysterious pain months or years after the injury. Characteristically it comes on with exercise. Compartment pressure can be measured fairly simply and again, the treatment is surgery to decompress the compartment.

Complication

Adverse occurence that results from the injury or treatment. Complications of a fracture might include all the events that might interfere with healing and recovery of function. They might include delayed union, malunion or nonunion of a fracture, neurological or vascular injury, compartment syndrome, reflex sympathetic dystrophy, deep vein thrombosis or infection. If the fracture has been operated on the complications of surgery include all of the above, plus failure of fixation. In short, complications are things that don't often happen but cause trouble when they do.
Some consequences of injury, like haemorrhage and swelling, always happen and are part of the healing process. Although they may be a problem they are not considered a complication.

Compound Fracture

An injury in which the bone breaks and protrudes through the skin. Wherever there is a skin laceration and an adjacent fracture it is wise to assume the skin injury and the bone injury communicate with one another. I have seen a closed fracture which became infected through spread of bacteria in the bloodstream but that is very rare. The risk of a fracture being contaminated and becoming infected  increased many hundredfold if it is compound. The aims of treatment of compound fractures are first to reduce the chance of infection, second safely to get closure of the wound and only third to make sure the fracture heals straight.

Consolidation

The final phase of fracture healing in which woven bone is replaced by compact bone with normal architecture.

Contracture

Shortening of soft tissue, particularly muscles and ligaments. If a limb is injured then held immobile for a period of time the injured soft tissues heal and contract. This means that the full normal range of motion cannot be achieved without stretching the contractures. Since this is painful it can be difficult. Avoidance of contractures is one of the main benefits of fracture fixation and early movement.

CPM - Continuous Passive Motion

A technique for speeding recovery of healing and range of motion. The affected joint is placed on a machine which slowly moves the limb through a pre-set range of motion. It goes slowly enough to be comfortable and can be gradually adjusted to increase the range of motion over time.

Crack

See fracture. Many people think there is a difference between crack, fracture and break. They are all fractures.

CT Scan

An imaging test. An Xray beam is fired at the limb from all angles. The image is reconstructed by computer analysis of the amount of xray absorption. The resulting image is much more detailed than plain Xrays and they can be reconstructed into 3D images of the bone or "slices" through the area of interest. CT scans are used for planning when the anatomy of a fracture is complex and for diagnosis of difficult fractures or nonunions. The quality of a CT image is degraded when there is metal hardware in the area.

Delayed Union

We normally see evidence of healing on xray 6 to 8 weeks after the injury. If there is no sign by that time union is said to be delayed. It doesn't mean that the fracture won't heal but some things (like weight bearing) may be held up until there is better evidence that the fracture is healing.

Diastasis

A tear of the ligaments that go between the distal tibia and fibula close to the ankle allows those two bones to move apart. This is called a diastasis and would result in loss of the normal anatomy of the ankle mortise. To treat this problem a "diastasis screw" is passed from the fibula into the tibia to keep them close together while the ligaments heal. The diastasis screw must be taken out before the patient starts to bear weight otherwise the movement that takes place between the distal tibia and fibula during normal walking, would cause fatigue failure of the screw.

Diastasis Screw

A threaded screw passed from the fibula into the tibia to hold the two bones together after an injury to the distal ligaments. More than one screw may be used. They are usually removed once the ligaments have had time to heal. Otherwise the fixation is likely to break due to fatigue failure.

Dislocation

An injury in which the bones of a joint are moved out of their normal alignment without necessarily breaking. Dislocations can occur between the bones of the foot, at the ankle, knee and hip. If a joint dislocates the ligaments which normally prevent that from happening must be ruptured and may need to be repaired or protected until they heal again.

Displacement

The situation when the fracture fragments are not accurately lined up. They may be angulated and rotated as well but not neccessarily. malalign.gif (2702 bytes)

Distal

Away from the body. Towards the toes.

Distraction

Situation in which the fracture fragments are pulled or fixed apart so that the bone would heal longer than the original

Disuse Atrophy

When a muscle is not used because it is sore or because the limb is immobilized it becomes weaker and some of the muscle tissue is reabsorbed. The underused muscle protein is transfered to somewhere else where it is need more (like the arm muscles for crutch walking!). As a result the leg looks spindly when you start rehabilitation. Disuse atrophy recovers as you use the leg more normally but recovery is hastened by muscle building exercises.

Dorsiflexion

The ankle movement which involves raising the foot so the toes move towards the knee. Full dorsiflexion is difficult to recover after ankle fractures. Without it you will have to limp or walk with your foot turned out.

DVT - deep vein thrombosis

A serious complication of injury, surgery and immobility. The body's ability to coagulate the blood is increased after injury. This is a normal adaptation which in nature prevents excessive blood loss. However it is continued into the recovery phase. As a result blood in the veins may clot. This is especially likely if the circulation is stagnant and the muscles are not working. DVT may cause pain in the calf, swelling and tenderness. Many times the condition is assymptomatic and cannot be distinguished from the normal pain and swelling of an injured leg. The major concern is that parts of the blood clot can break off from the veins in the thigh and end up in the lungs causing major problems (pulmonary embolism). This problem is relatively common after hip fractures but rarer in other types of broken legs.
The risk of DVT is reduced by early mobilization, by wiggling the toes, by avoiding sitting for long periods. Some orthopaedic surgeons use blood thinning medications after certain operations and injuries.

Dynamization

Locking screws in intramedullary rods may have the effect of holding the fracture fragments apart. Bone heals better if there is some compression at the fracture site. Accordingly the locking screws are sometimes removed if union is delayed. This process allows some dynamic compression of the fracture site and is therefore known as dynamization.

Epiphysis

The growth plate of a bone. In children the bone grows from a region at either end. This region is not as hard as the rest of the bone so it can expand as it grows. As it gets larger it is partly obliterated by bone so it never gets very large. The epiphysis is often injured in children's fractures and care must be taken to ensure that the growth process is not stopped. At puberty the epiphysis closes and the bones cannot grow any more.

Eversion

Outward rotation movement of the foot and ankle (so that the sole turns away from the other foot). Forcible eversion causes an avulsion fracture of the medial malleolus and a bending fracture of the fibula. As the foot everts the talus is pulled away from the tibia. The Medial Malleolus is pulled on by the deltoid ligament and is avulsed from the rest of the tibia. Meanwhile the bending force has broken the fibula. ankle.jpg (18516 bytes)

External Fixation

Method of fracture treatment in which the fracture fragments are transfixed by pins which go through the skin into the bone. The pins are joined to each other by a framework outside the leg. Some of the frames can be elaborate and allow for correction of deformities and mal-alignment. The pins and frame is usually maintained until the fracture starts to heal. frame.jpg (24870 bytes)

Failure of Fixation

The situation when the chosen method of fixation doesn't do the job. The pins, plates, rods or screws cut out, break, bend or pull out before the fracture heals. This is commoner when union is delayed and almost inevitable if there is a nonunion. Metal fatigue will nearly always cause failure of fixation if the fracture doesn't heal. In consequence, if fixation fails you have to wonder if the fracture is healed.

Femur

The thigh bone. Largest and strongest bone in the body. Fractures of the upper end of the femur are often called hip fractures.

Fibula

The small bone on the outer side of the shin. It goes from the knee to the ankle. It mainly acts as a point of attachment for muscles and doesn't bear weight over much of its course. At the lower end it forms part of the ankle. It is commonly broken in ankle fractures and has to be accurately reduced in these injuries. It is also very often broken when the tibia is broken in the middle of the shin. In this situation it does not have to be accurately reduced and is often left to heal without treatment. An isolated fracture of the shaft of the fibula occurs from a blow on the side of the leg. It is rare and doesn't need to be treated elaborately.

Fixation

Method of fracture treatment in which the fracture fragments are fixed in position by metal pins, plates, screws or rods. Most often this requires operation to place the hardware, but in external fixation or percutaneous fixation a closed reduction is done then the pins are placed throught the skin without opening up the fracture site.

Flap

A piece of skin, with its underlying layer of fat, and sometimes with muscle, which is lifted from its normal position and rotated around to effect closure of the wound. This is done when the wound cannot be closed simply be sewing it up. The flap needs to have an intact blood supply to heal.

Fluoroscopy

Xray technique using an image intensifier to "see" what is happening to the fracture and the fixation devices during surgery. When doing a reduction the fluroscope can be used to see if the reduction is anatomic. We can also check the position of screws, pins and rods. Operations such as Locked IM nailing would be difficult or impossible to perform safely without fluoroscopy.

Fracture

Loss of structural integrity of a bone. Although it may be very narrow, a fracture line of separation between two or more fragments results. The bone hurts and can no longer perform its function of supporting the limb.

Fracture Healing

See Healing

Fracture Line

The gap between fracture fragments. On Xray this gap is seen as a radiolucent line (dark in conventional Xrays). Identification of where the fracture line goes is the key to planning treatment.

Fragment

Portions of a broken bone which are still intact (i.e. do not have a fracture line going through them). In a simple fracture there are only two fragments. In a comminuted one there are more than two. Understanding the shape of the fracture fragments is important in working out if the fracture is stable and how to perform fixation

Free Flap

A piece of tissue complete with its blood supply which is transferred from one area of the body to cover a wound. The blood vessels have to be re-connected to the local blood vessels to re-establish circulation so it is a complex and lengthy operation. Free flap coverage has revolutionized the care of compound fractures with major loss of tissue.

Fusion

The operation to promote growth of bone over a joint to stop movement. It is indicated when the joint is so arthritic, painful and stiff that the remaining movement is of no value to the patient. The remaining joint surface is removed, the raw surfaces of the bone ends are held together with some form of fixation and bone graft is used to help the two bones unite together

Greenstick Fracture

An injury which occurs in children's bones as a result of a bending force. One side of the bone breaks but the other stays in continuity. It is important to realize that the concave side of the injury is not normal and has undergone a plastic deformity, bending it out of shape. The fracture may need to be reduced. This is often quite simple to do but the area of plastic deformity may fully break as the bone is straightened. If it does, it will make no difference to the eventual outcome. greenstick.jpg (8499 bytes)
greenstick_xray.jpg (5640 bytes) <-
This Xray is of a greenstick fracture in the wrist of a 10 year old snowboarder. It shows the break on the convex (lower) side of the injury and the plastic deformity of the concave side.

(by permission T.T. )

Growth Plate

See Epiphysis

Haematoma

Collection of clotted blood in the tissues.

Haemorrhage (Hemorrhage in USA)

Bleeding; loss of blood

Hamstrings

The thigh muscles which bend the knee. Rehabilitation of the hamstrings is important following knee ligament injuries. The hamstrings start on the pelvis and attach distally below the knee

Hard Callus

The second last stage of fracture healing. The scar tissue and cartilage of soft callus is transformed into bone (ossifies) as bone mineral is laid down in the matrix. This stiffens the tissue and makes it hard, rigid and stronger. Early hard callus is laid down almost at random and is known as woven bone. This stage is followed by consolidation.

Hardware

Devices used to keep fracture fragments in position while the healing process proceeds. They are usually made of metal, stainless steel or titanium are popular choices.

Plate and screws. The fracture is reduced, the plate is bent to the shape of the bone then fixed across the fracture with screws plate.gif (2532 bytes)
Interfragmental screws. The fracture is reduced then a screw is passed which has a thread at one end only. As the screw is tightened the fragments are compressed together. screw.gif (3355 bytes)
Locked Intra Medullary Rod. This device is placed inside the bone across the fracture. The bone lines up along the rod and the fragments are held in alignment by proximal and distal locking screws rod.gif (3123 bytes)

Hardware Removal

It is frequently advisable to undertake a subsequent procedure to remove the hardware after it has done its job. Removal of percutaneous pins, diastasis screws and external fixation devices is virtually universal. Removal of screws, plates and intramedullary rods is done frequently and does usually require local or general anaesthetic.

The reasons for removing hardware include discomfort from the metal objects under the skin and impingement when muscles or tendons rub on the metal pieces. Occasionally the fixation is holding the fracture apart and is removed to "dynamize" a fracture, allowing compression and healing at the fracture site. Some surgeons hold that all plates should be removed because the bone under the plate may be weakened by "stress shielding".

Healing

The process that occurs after injury that restores continuity and function of the tissues. There is a gradual replacement of the injured and necrotic tissue by living tissue which then differentiates into bone, muscle, tendon etc. The process will be described in detail elsewhere. Basically there are 4 stages

  1. Inflammation: The damage to the bone and muscle, as well as the bleeding sets off an inflammatory reaction. The bleeding from the injury stops when the blood coagulates forming a blood clot. The early clot stimulates the growth of small capillary blood vessels from the surrounding normal tissue into the damaged area. As the blood supply increases the area swells and hurts. The vessels bring with them cells which lay down collagen fibres. (0-7 days)
  2. Soft Callus: The volume which was originally blood clot and dead tissue is replaced by scar tissue, collagen fibres laid down in a random fashion with a rich blood supply and nerve supply. Cartilage tissue may develop in soft callus. The rubbery tissue is strong enough to keep the bone fragments together as long as it isn't stressed too much. (7 days to 6 weeks)
  3. Hard Callus: Some of the cells in the soft callus differentiate into bone forming cells which produce bone mineral. This is laid down in the scar tissue to stiffen it. The result is "woven bone" bridging across from one fragment to another. It is 80% as strong as normal bone. (6 to 12 weeks)
  4. Consolidation: The woven bone is gradually remodelled into compact bone around the circumference of the bone and a medullary cavity is reformed. As a result the bone recovers almost all of its pre-injury strength. Remodelling is stimulated by stressing the bone moderately. (3 months to 18 months)

Links

Hemiarthroplasty

A treatment for a specific type of fractured hip in the elderly. The broken part is removed and replaced with a metal implant which replaces the original femoral head (top end of the thigh bone).

Hip

Strictly speaking the hip is the joint between the femur (thigh bone) and the pelvis. However, the term hip fracture means a fracture of the upper end of the thigh bone, close to the hip joint.

Hip Replacement

The operation to replace an arthritic hip joint with an artificial joint using metal, ceramic or plastic components. It is rare to do this primarily for treatment of a fractured hip but it is done sometimes when the joint has pre-existing arthritis. Replacement of just the thigh bone part of the hip joint is called hemiarthroplasty and is quite a common treatment for a certain type of hip fracture.

Hyaline Cartilage

Joint surface

Hybrid Fixator

An external fixation device which combines a ring with fine transfixion wires similar to the Ilizarov apparatus and a more conventional part with threaded half pins. (will look for a picture). The hybrid fixator is used quite often for tibial plateau fractures and pilon fractures of the ankle.

Ilizarov treatment

Ilizarov was a Russian surgeon who was sent to the remote area of Kurgan shortly after WW II and had no training or equipment for handling complex orthopaedic problems. With the assistance of the local bicycle shop he worked out a way of immobilizing fractures using fine wires tensioned to a ring like the spokes of a wheel. This framework proved so stable that he was able to undertake very complex reconstructive procedures and treatment for nonunion. He showed that you can remove the ununited segment of bone, dock the fresh ends together and then lengthen another part of the bone to restore length.
Except in major trauma centres the number of cases which need Ilizarov treatment is not very high, so most Western OS do not have much experience with the technique. It takes a long time and can be quite painful.

In this illustration an Ilizarov external fixation frame has been applied to the tibia. It has three rings, one proximal, one central and one distal. The orange line is where the nonunion has been excised and the fragments are being compressed. The red line is a cut in the bone so that the proximal fragment can be gradually lengthened. frame.jpg (24870 bytes)

Infection

A complication of wounds and surgery. Once the skin is breached bacteria in the environment can contaminate the wound. Even in the "sterile" conditions of the operating theatre there are bacteria in the air and all around. Each square mm of skin has millions of bacteria on it. So it's likely that all wounds are contaminated to some degree. In most situations the body's defences and the wound care of the surgeon are enough to prevent bacteria establishing themselves in the wound and multiplying.
If they do establish themselves the wound is said to be infected. There is increased inflammation, redness, drainage and pus formation. Infection of a fracture makes it difficult to heal and may cause nonunion. OS take infections very seriously. If you see signs of an infection you should inform your OS as soon as you can.

Internal Fixation

Fracture fixation using an operative technique which leaves all the hardware under the skin. Contrast to external fixation and percutaneous fixation.

Intramedullary (IM) Nail/IM Rod Fixation

The technique of fixing fractures by "skewering" them with a metal rod inside the bone. The thickness of the rod is selected so that it is tight against the compact part of the bone. If the bone was straight originally a straight rod will restore the alignment. rod.gif (2583 bytes)

Impacted Fracture

A fracture where the broken ends are compressed together by the force of the accident. The result, often, is that the bone is slightly shorter but the fragments are in good position otherwise and likely to stay there (stable). Impacted fractures more commonly occur at the ends of bones where most of the bone is spongy or trabecular bone which crushes more easily than it splinters.

Inversion

Movement of the foot and ankle rotating the foot inwards (so that the sole of the foot points towards the other foot). Forced inversion is a common mechanism of injury for ankle fractures.

Intra-Articular

Into the joint. The term is used to describe fractures where the fracture line goes into the joint. The implication is that the fracture should be reduced anatomically to minimize the risk fo future wear of the joint surface and post traumatic osteoarthritis.

Joint

The gap between bones is called a joint. The bone ends are shaped to allow movement between the bones. This movement is restrained by inelastic fibrous ligaments which go across the joint from one bone to another and prevent abnormal movement. Where one bone touches another the bone is covered with joint surface which has unique mechanical properties.

Joint Surface

Also known as articular cartilage or hyaline cartilage, this material is smooth, slippery, self lubricating and very resistent to wear in the normal course of events. You see joint surface most commonly on the end of a chicken bone (drumstick) as the blueish white glistening stuff which covers the end of the bone. (Apologies if you are vegetarian). The unique mechanical properties of the joint surface allow low friction movement and minimal wear.

This arthroscopic image from inside the knee shows normal joint surface on the end of the thigh bone (upper right) and top of the shin (lower left). The meniscus is seen in the upper left part of the picture between the two bones.

m6.jpg (130745 bytes)

This is a view of the same part of another knee which has severe osteoarthritis. Note that the joint surface is broken up and bone is exposed (arrows). The meniscus is also badly damaged. The shin has completely lost joint surface. Everything you see is bone.

Joint surface does not grow again or repair itself so this situation is irretrievable. This patient went on to have a joint replacement operation.

oa2.jpg (125080 bytes)

Damage to joint surface as a result of trauma is one of the most serious long term consequences of an injury.

Knee

Strictly speaking the knee is the joint between the thigh and the shin (including the kneecap). "Knee fractures" include fractures of the kneecap, the supracondylar region of the femur and the tibial plateau. Knee ligament injuries, which may not involve fracture, affect the ligaments which prevent abnormal movement of the knee.

Kneecap

The patella or kneecap is a heart shaped bone that rests on the lower end of the thigh bone (femur). It acts to transmit the force of the massive quadriceps (thigh) muscle across the knee joint. The kneecap is attached below to the patella tendon which in turn is attached to the shin bone. You can feel the bump of bone just below the front of the knee. When the quads pull the kneecap upwards, the force is transmitted through the kneecap and the patella tendon to the shin bone - thus straightening the knee. When the knee is bent this mechanism puts a big force on the front of the knee. That is why the kneecap is made of bone. It can stand the compressive load against the front of the femur when you straighten a bent knee. If it was muscle or tendon it would fray.

With your (good) knee straight and relaxed you can move the kneecap side to side. It truly is a floating bone. But if you lift your ankle off the ground the whole system tightens up and you can feel the patella tendon as a tight bar going from the kneecap to the shin.

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Knee from the side

Knee Replacement

The operation to replace the normal knee joint with artificial surfaces of metal and plastic. This is rarely done for broken legs but when the knee joint is severely injured the OS may be thinking that a knee replacement may be needed down the road and plan treatment with that in mind.

Lateral

The outer side - away from the mid line. The little toe is lateral to the big toe.

Ligament

The tough inelastic fibrous structure that forms the attachment between two bones. Ligaments prevent a joint from dislocating and restrict the joint to movement within a certain range. Thus if the ligament is disrupted by injury the joint may be more likely to dislocate or have abnormal movements. This is appreciated as an unstable feeling. An unstable joint is more likely to wear.

Locked IM Nail

An internal fixation device. Once the rod is inserted a hole is drilled through the bone and the rod and a locking screw inserted. It prevents the bone from moving relative to the rod. See IM Rod
The term may be used to denote the operation to insert this device.

Locking Screws

The screws which are used to lock an intramedullary (IM) rod. (See Locked IM Nail and IM Rod)

Lymphatic system

Lymph is an ultrafiltrate of blood. When blood circulates through the capillaries (the smallest blood vessels) some of the fluid leaks out of the vessel. This is the tissue fluid which nourishes the cells in the area. Some of the tissue fluid is collected again by the capillary circulation but much of it isn't. It is normally collected by lymphatic system and the fluid in the lymphatic system is called lymph. The lymphatic system is the way most of the fluid from swollen areas is collected because the blood supply of these areas is often disrupted or clotted. Unfortunately the lymph vessels are also quite fragile and may be disrupted. Swelling also may occlude lymph drainage. Until the lymphatic system and the blood circulation system has fully recovered (regrown) after an injury the limb will tend to swell.

Mal-alignment

The situation in which the fracture fragments do not line up exactly. It may not be bad enough to require a change in treatment.

Mal-position

Mal-alignment either displacement, angulation  or rotation (or any combination). The implication is that the position is not acceptable

Malleolus

The bumps of bone, one either side of the normal ankle. They stick down on each side of the talus to form a mortice and tenon joint which is very stable side to side but allows movement up and down.

See further information in the entry on the ankle joint

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Front view of the bones and ligaments
of the ankle joint

Malunion

Healing with the fracture fragments mal-positioned

Medial

Inner; towards the mid line. The big toe is on the medial side of the foot.

Meniscus

The menisci (cartilages) are gristly crescent shaped objects which sit in the knee joint between the thigh and shin bones. They act to reduce wear by spreading the weight and helping with lubrication. Menisci are made of fibrocartilage and do not have a blood supply. They are nourished by the synovial fluid. This means that they do not grow and do not repair themselves
Tears of the meniscus occur when it is compressed between the bones. The upper part of the meniscus binds to the thigh bone and the rim is already attached to the shin. If the two bones rotate on one another one part of the meniscus goes with the thigh bone and the other stays with the shin. The tear makes the meniscus rough and makes it an irritant in the joint, not a help.

MR Scan/MRI

An imaging test using magnetic resonance. Water is a weak magnet so when it is subjected to an intense magnetic field, tissue with water in it begins to vibrate. The amount of vibration is detected as alterations in the magnetic field. Thus tissues like muscle, with a lot of water and a jelly like consistency vibrate a lot, give up a lot of magnetic resonance and show up dark in an MR scan. Bone has less water and is rigid so it shows up pale. In fact all the different tissues show up differently on an MR scan resulting in images which show the anatomy very well. Even the health of the tissues can be seen. You can tell, for example, the difference between bone with a blood supply and avascular bone. MR scans are not used routinely in the investigation of ordinary fractures.

Multifragmentary

The preferred term for comminuted - meaning more than 2 fracture fragments.

Nail

Intra Medullary Rod; an internal fixation device which is placed inside the bone across the fracture to line it up. rod.gif (2583 bytes)

Neurovascular Injury

Injury to major nerves or blood vessels. This may occur as a result of the injury or as the result of the surgery.

Nonunion

The situation when a fracture has failed to heal and (in the opinion of the doc) will not heal without further intervention. Usually the gap between the fracture fragments has formed scar tissue or cartilage but has not gone on to form bone. A nonunion is mobile, at least to a small degree, and is usually painful.
Deciding when delayed union has turned into nonunion, with the implication that waiting longer is a waste of time, is difficult. If there are no signs of union (bridging callus) by six months or if the bone ends are reacting to movement and forming a pseudo-joint (pseudarthrosis) most OS would diagnose nonunion. Sometimes it needs special imaging tests like CT scan or MR to see whether the fracture has healed or not.
Nonunion may (rarely) be accepted; more often it is treated with bone graft, fixation, or Ilizarov treatment.

Oblique Fracture

A simple fracture in which the fracture line goes obliquely across the bone. Contrast with transverse, spiral and segmental fractures

Open Fracture

see Compound Fracture; there is a wound in the skin which communicates with the fracture.

Open Reduction

An operation to correct the displacement of the fracture fragments and restore the anatomy. Usually but not always combined with Internal Fixation to hold the reduction.

Open Treatment

Management plan which involves operating on the fracture to effect an open reduction or to undertake fixation.

Osteoarthritis

Wear of the joint surface. Osteoarthritis is the commonest form of arthritis and results when the joint surface wears away as in this knee joint. Note that the surface on the shin is completely worn away. On the thigh bone side there is some degenerated joint surface left but it is breaking up and bone is revealed where the arrows are.

In the context of trauma, osteoarthritis is commonly caused by fractures which enter a joint. The joint surface is damaged by the injury and unless it is possible to restore the smoothness of the joint exactly there will be roughness or irregularity of the joint surface. This will increase the wear in the joint and lead eventually to osteoarthritis.

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Osteopaenia

Thin bone or lack of bone. This actually refers to the bone mineral not the substance of the bone. When bone is unloaded (as in non-weightbearing after a fracture) calcium salts are reabsorbed from the bone and laid down elsewhere or excreted. So some weeks after a major injury the body loses calcium overall and most of it comes from the region of the fracture and the distal part of the affected limb. Increased circulation also "washes out" bone mineral. This phenomenon is called osteopaenia and is completely reversible. By contrast in osteoporosis the substance of the bone is lost as well as the mineral and this is much less easy to reverse.

Osteoporosis

A condition which weakens bone by removing bone matrix and making it more porous. The bone itself is normal but there is less of it. Osteoporosis occurs to everyone in time. The thickness of the cortex of the femur in 80 year old people is always much less than the thickness of a corresponding piece of bone in a 20 year old. However, osteoporosis is commoner in post-menopausal women and is a major contributor to the fact that elderly women fracture their bones more easily. Its cause is multifactorial and involves hormones, exercise, genetic predisposition and diet.

Out to Length

The situation in which the fracture fragments are positioned accurately lengthwise and do not overlap. If the bone heals like that it will be the right length.

Overlap

Mal position of the fracture fragments with shortening. If the injury heals like that it will be shorter than the original bone. This is often acceptable in children because they will grow and remodel the bone.

Patella

Kneecap

Patella Tendon

The strong, fibrous inelastic structure which goes from the lower end of the kneecap to the top of the shin (tibia). Strictly speaking it is a ligament joining two bones together, but because it transmits the force of the quadriceps muscle to straighten the knee it is usually called a tendon.

Percutaneous Fixation

The technique where a closed reduction is done and the fracture is fixed by pins or screws passed through the skin.

Pilon Fracture

A serious intra-articular fracture of the ankle. The hallmark of the pilon fracture is damage to the weight bearing part of the tibial joint surface (plafond). Pilon is French for hammer.
Treatment of pilon fractures aims to make the joint surface smooth again and hold the fragments in a good position until they heal. However, this may not be achievable if there are many crushed fragments and if the joint surface is damaged.

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Pins

Smooth or threaded metal wires used to transfix fracture fragments to hold them in position.

Plantarflexion

The downward movement of the foot at the ankle joint (away from the knee)

Plaster

Plaster of Paris is an partly anhydous Calcium Sulphate salt (Gypsum) When Gypsum is heated it loses water and becomes powdery. In plaster casting bandages, this powder is bonded to a bandage. When it is wetted the material absorbs water to become a liquid paste then quite rapidly hardens forming a new hydrated form with larger crystals which "set". As a result plaster can be rolled onto a leg when wet and will form a snuggly fitting, hard, strong splint (cast) when it dries.
In many areas "a plaster" is a term for a cast.

Plate

Flat metal object with holes in it. It is usually made of stainless steel or titanium. The fracture is reduced, the plate is bent to conform to the shape of the bone then laid on the bone across the fracture. The plate is then fixed to the bone with screws. The rigidity of the plate holds the bone in the correct position until healing occurs.

plate.gif (1792 bytes)

Posterior

At the back. The heel is the posterior part of the foot.

Proximal

Top, nearest the body. The knee is at the proximal end of the shin.

Pseudarthrosis

When a fracture has failed to heal because of continued movement at the fracture site, the tissue between the fracture fragments may differentiate into cartilage making the area look like a joint. If this happens the condition is called a pseudarthrosis (pseudo-joint). A pseudarthrosis will not heal without intervention.

Pulmonary Embolism

The condition in which an intravascular blood clot breaks off and floats off in the blood stream to lodge in the circulation of the lung. It can be a very serious problem since the clot can be big enough to block the blood supply to large parts of the lung.

Quadriceps (Quads)

The big thigh muscle which straightens the knee. There are four muscles. Most of them start on the shaft of the femur but Rectus Femoris begins on the pelvis. They attach in an arc around the upper margin of the kneecap. The quadriceps mechanism includes all the structures that are involved in straightening the knee, the quads, the kneecap and the patella tendon

Range of Motion (ROM)

The angles through which a joint can move. Full ROM is the range which is normal for that joint. Range of motion exercises aim to recover full ROM

Reconstruction

Surgical techniques to restore the function of an injured bone. This may be for nonunion or may take place after healing has occured and is done to correct shortening, angulation, rotation or other forms of malunion.
Reconstruction often involves cutting the bone, re-aligning it in a better position and using internal or external fixation to hold the reconstruction in the corrected position until healing occurs.

Reduction

Replacing the fracture fragments into the position they occupied before the fracture. A fracture is reduced if it is back in position. There are degrees of reduction - anatomical reduction is perfect, acceptable reduction is not perfect but function will be normal if the bone heals in that shape. Unacceptable reduction means that something more must be done to restore normal appearance and/or function.
Reduction is accomplished by manipulating the fracture fragments and may be open or closed.

Reflex Sympathetic Dystrophy

A complication of injury. After injury inflammation is the first stage in the healing process. This requires an increased blood supply. Following injury a reflex mediated by the sympathetic nerve system results in the blood vessels opening up to deliver an increased volume of blood to the area. It swells as a result. Once the inflammatory phase of healing is over the reflex is reversed and the blood supply goes back to normal. In some people this doesn't happen until much later and they get stuck in the inflammatory phase of healing. The result is prolonged or recurrent swelling, redness and stiffness of the limb. There is a vicious cycle of stiffness causing pain on movement; swelling is increased because movement pumps the tissue fluid away; the patient holds everything still and it gets stiffer.
The key to treatment is to restore movement to the affected area. This is difficult because it is so painful but if the patient succeeds in recovering movement the vicious cycle reverses. The more it moves the less it swells and the less it hurts.

Remodelling

The process whereby the bone grows back into a more normal shape after healing with some mal-position. Children's fractures remodel better than adults. Angulation in the plane of movement of an adjacent joint remodels the best. Rotational malunion does not usually remodel.

Retrograde Nailing of the femur

This technique of internal fixation of femur fractures involves passing the IM rod from inside the knee up into the bone and across the fracture.

Rod

An internal fixation device inserted inside the bone. See IM Rod

Rotation

Mal-position of a fracture. One fragment is rotated relative to another. This type of mal-position will not remodel. It should be reduced if possible.

Screws

Metal screws are often used in internal fixation of fractures

Segmental Fracture

A multifragmentary fracture with a separate fragment forming a significant segment of the bone. These fractures are unstable and difficult to treat by closed reduction

segmental.gif (1836 bytes)

Shin/Shin bone

The section of the leg between the knee and the ankle. The bones of the shin are the tibia and the fibula. Anyone referring to the shin bone is likely to be talking about the tibia.

Shortening

The situation in which the bone fragments are not out to length and overlap to some extent

Simple Fracture

A fracture with only two fragments. Opposite of comminuted/multifragmentary

Skin graft

A very thin slice of skin cut off by a special knife. It is thick enough to have living cells which will begin to grow when the skin graft is applied to a clean wound. Once it starts to grow it will seal the wound and protect it against infection. The skin graft is thin enough to leave living cells behind at the donor site to heal that area. It is also thin enough to be nourished by the tissue fluid in the wound and does not require a blood supply.
Skin graft is quite often used to close large wounds and compound fractures

Soft Callus

The scar tissue that develops in place of the blood clot and necrotic tissue in a fracture. Soft callus has collagen fibres to bind the fracture fragments together and there may be some cartilage tissue as well. In normal fracture healing soft callus will develop into hard callus as bone mineral is deposited.

Soft Tissue

All the parts of the leg which aren't bone or joint surface. These include skin, muscle, tendon, nerves, blood vessels, ligaments and fatty tissue.

Soft Tissue Injury

Bones are what you see on Xray and the part that the OS focuses on. However, any force severe enough to break the bone will also damage the muscles and other soft tissue in the vicinity. Healing of the soft tissue injury is very important, may take a long time and may cause symptoms of pain, swelling, stiffness and weakness quite apart from the bone injury.

Spiral Fracture

An injury caused by a twisting force on a bone. The fracture line circles round the outside of the bone then joins up with its origin with a straight segment. Spiral fractures are often quite stable.

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Splint

An inflexible or hinged device applied to the outside of the limb. Its purpose is to reduce pain, hold the joint in a position of function, hold the fracture fragments in the reduced position, prevent contractures or protect the region. Splints include casts, braces, back slabs, CAM walkers and may be made of plaster, fibreglass or plastic with any combination.

Spongy Bone

Bone in the form of spicules forming a highly porous region. This bone is sometimes called cancellous or trabecular. It is the predominant form at the ends of bones adjacent to the ankle and knee. It is more likely to be crushed, compressed or impacted by injury.

Stable

A stable fracture is one which is unlikely to shift out of position unless you fall again, or apply some other outside force. It is a function of the geometry of the fracture. Simple, spiral, transverse and impacted fractures are often stable. Multifragmentary, oblique, segmental and avulsion fractures are unstable.

Staples

The outer layer of a wound may be closed with sterile stainless steel staples. These are normally removed when the wound has healed (2 weeks approx)

Occasionally, large metal staples are used as a form of internal fixation.

Stiffness

Loss of range of motion of a joint. This is a common source of misunderstanding between OS and patients. If the OS asks if the joint is stiff he/she is asking whether the range of movement is full not whether it is sore. However, people who have pain when they move the joint commonly describe this as stiffness. If the joint moves normally it isn't stiff, no matter how much it hurts. Conversely, if it doesn't move it is stiff even if it is completely painless. When responding to a question about stiffness, keep pain on movement and restriction of movement separate in your answer.

Stress Fracture

A fracture occuring as a result of fatigue failure of the bone. This is relatively rare because bone repairs itself so quickly. Stress fractures occur when repetive stress is applied to a bone that isn't used to it. It is therefore commoner in heavy people and those who have had a sudden increase in their level of physical activity. Stress fractures rarely occur as the result of a sudden injury or accident.

Sutures

Filamentous or thread-like material used to close the layers of a wound. Most suture material is sold in a sterile (use once) package bonded to a needle. Suture material may be absorbable, in which case the body breaks them down and removes the suture material in about 6 weeks. Examples of absorbable suture material include catgut, Dexon and Vicryl. Non-absorbable sutures may be made from nylon, silk, mersilene or stainless steel. Skin sutures of these material are removed - usually after 10 days or more. Most of these materials are inert and can stay in the skin a long time (for example under a cast) without any harm.
It is important to realize that the layer of skin sutures is only one part of the closure of the wound. There is likely to be at least one other layer of absorbable sutures deeper in the wound. Some of the symptoms of pain and tightness in a wound may be due to these other layers. However, pain from sutures should ease when they are taken out or when the body has reabsorbed them.

Swelling

Enlargement of the limb usually because of accumulation of fluid. Swelling has many causes and an account of the reasons for swelling and what to do about it will be produced shortly.

Syndesmosis

The distal joint between the tibia and fibula is held together by two ligaments, the anterior and posterior distal tibio/fibular ligaments. Together these ligaments form the syndesmosis (literally "keeping together"). In most ankle fractures these ligaments remain intact, or only one tears. If both tear the distal fibula is displaced away from the tibia widening the ankle joint (see illustration below). If this problem is recognised the OS will usually recommend some form of syndesmotic fixation. If not treated, the ankle heals wider than usual and may feel unstable or sloppy.

Syndesmotic fixation

If the syndesmosis between the tibia and the fibula is completely disrupted by an ankle fracture it is common to compress the fibula back to the tibia using one or more syndesmosis screws.
Once the syndesmosis is healed the syndesmotic fixation is taken out because there is a small amount of movement at the distal tibio/fibular joint. If this movement is prevented, the ankle may not recover full range of motion or (more likely) the syndesmotic fixation will break.
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Talus

The foot bone which forms part of the ankle joint with the tibia and fibula

Tendon

The structure which joins the contractile part of a muscle to the bone it moves. Tendons are made of tough fibrous tissue (collagen) and are flexible so they can go round corners (eg the ankle) but inelastic so all the muscle pull is transmitted to the bone. Tendons can be lacerated in an injury but more commonly trouble arises because a tendon is trapped between fracture fragments. If this happens the fracture cannot be reduced and the muscle cannot function. Surgery is need to free up the entrapped tendons and obtain a reduction. In the recovery period tendons which have been bathed with blood from the injury may get scarred down and not be able to slide normally. Early motion and use of the muscles avoids this problem.

Thigh

The part of the leg between the hip and the knee. The thigh bone is the femur, the longest and strongest bone in the body. The thigh muscles are the quadriceps which straighten the knee and the hamstrings which bend it. These muscles often waste (atrophy) because of disuse during the healing period.

Tibia

The large weight bearing bone that extends from the knee to the ankle. It is one of the bones most commonly fractured when you break your leg. It is also involved in most ankle fractures, pilon fractures and tibial plateau fractures.

Tibial Plateau Fracture

An intra-articular fracture of the top end of the tibia. It involves the joint surface of the knee and may also be associated with ligament or meniscus injuries. If the damage to the joint surface is severe post traumatic osteoarthritis of the knee is very likely. The aim of treatment of tibial plateau fractures is to get the fractures to heal with a smooth joint surface. If that is impossible, the secondary aim is to heal the fractures with as normal a shape as possible so that knee replacement will be possible if needed.

Trabecular Bone

Spongy or cancellous bone that occupies the upper and lower ends of long bones like the femur and tibia. It is more likely to be crushed, compressed or impacted by injury.

Traction

A method of treatment of long bone fractures. If you pull a string of beads they will straighten out. The same is true of fractured bones. The standard treatment for broken femur used to be traction for six weeks. A pin was passed through the distal end of the bone or below the knee. Weights were attached to the pin by cords going over a pulley system. The traction kept the bone straight and out to length while it began to heal. After callus was seen on Xray the patient could be mobilized in a cast.
Traction is used for children's fractures and in parts of the world where the skills or equipment for internal fixation are not available. Western OS think that internal fixation is better for most situations because the fracture is usually better reduced and because the patient can be mobilized earlier. The economics are different as well. In the third world it may be cheaper to keep someone in hospital for a prolonged period than to obtain the devices and equipment needed to do internal fixation.

Transverse Fracture

A simple fracture in which the fracture line is straight across the bone. If an anatomical reduction can be obtained this fracture is stable

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Union

Healing of the fracture with bone tissue extending from one fracture fragment to the others uniting the fragments together and making it one bone again. The word union is also found in the terms

  • delayed union - healing is taking longer than expected
  • malunion - the fracture has healed but the position of the fragments is not anatomical
  • nonunion - the fracture has failed to unite.

Unstable

a) When applied to a fracture this means that it is unlikely to stay reduced. Examples of unstable fractures are

Oblique fractures

The distal fragment "slides" up the proximal fragment causing shortening and displacement

oblique.gif (3129 bytes)

Multifragmentary fractures

If this type of fracture is loaded the small triangular piece (often called a butterfly fragment) will displace to the side and the fracture will angulate

The more fragments there are the more unstable the fracture pattern is likely to be.

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Segmental fractures

Like other forms of multifragmentary fractures there is nothing to keep a segmental fracture from angulating, shortening and displacing

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b) When applied to joints the term unstable means likely to dislocate, move in an abnormal way or feel unreliable and likely to give way. Unstable joints often have had ligament injuries.

Wear

The process whereby damaged joint surface gets rubbed away and more damaged. Once the integrity of the joint surface is lost and it gets pitted, eroded, broken or scarred, progressive wear is likely to occur. Worn out joints hurt and this is the commonest form of osteoarthritis.

Wire

Flexible wire is sometimes used to fix fractures of the kneecap and ankle. Stiff fine wires are used in external fixation apparatus. Wires and pins are terms often used synonymously. Kirschner Wire or K Wire is the common term for a pin and commemorates a famous pioneer orthopaedic surgeon.

Wound

A skin defect caused by the injury or by surgery. Wounds contaminated by dirt at the time of the accident have to be cleansed. All dead and devitalized tissue must be removed to reduce the risk of infection. Wound closure is also a big topic. Some wounds can be closed with sutures or staples. Others require skin graft or more elaborate plastic surgery procedures such as flaps or free flaps.

Wound Healing

Wounds heal when the blood in the wound coagulates, forms a blood clot and is gradually transformed into scar tissue. The process involves growth of blood vesssels into the region and the action of fibroblasts to lay down collagen fibres. It takes time, which is why wounds take a while to heal.

Xray

The imaging test performed by shooting a beam of Xrays through the injured leg and onto a photographic plate. Xrays are stopped by the calcium (bone mineral) in bones so the plate is less exposed in the shadow of bone and therefore looks pale. An Xray plate is a negative (reversed) image of the density of the bone. A fracture line shows up on Xray as a dark line as the Xrays go straight through that area. The information that can be obtained from an Xray depends critically on the quality of the films. Skilled Xray technicians take standard views with the xrays beam lined up with (for example) the ankle joint to show the injury in a standardized way. Most fractures can be fully diagnosed and evaluated by Xray alone but some need the added detail of CT scanning to reveal where the fracture lines go. The main difficulty with interpreting Xrays is that they are 2 dimensional representations of a 3 dimensional object. The other limitation is that Xrays don't show soft tissues so soft tissue injuries can only be deduced indirectly if at all.


First posted 29 Dec 2001
Current revision Mar. 2003
Please email any comments

Author Dr.J.F.M.Clough MD, D.Phil., FRCSC
Orthopaedic Surgeon, Kamloops, British Columbia, Canada
Clinical Instructor, Department of Orthopaedics, University of British Columbia
Editor, Orthopaedic Web Links (OWL)
President, Internet Society of Orthopaedic Surgery and Trauma
Web Editor, Canadian Orthopaedic Asssociation

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