Orthopaedic Trauma: Introduction

Orthopaedic Trauma: Introduction

An injury to the musculo-skeletal system can result in damage to bones, joints, muscles and tendons. In addition, the neurovascular bundle of the limb may be damaged. This section will outline the broad principles used in the diagnosis and management of these injuries. These principles can be applied, with suitable modifications, in the management of any musculo-skeletal injury.

 

CLASSIFICATION OF FRACTURES

A fracture is a break in the continuity of a bone.  It can be classified on the basis of aetiology, the relationship of the fracture with the external environment, the displacement of the fracture, and the pattern of the fracture.

 

ON THE BASIS OF AETIOLOGY

Traumatic fracture: A fracture sustained due to trauma is called a traumatic fracture*. Normal bone can withstand considerable force, and breaks only when subjected to excessive force. Most fractures seen in day-to-day practice fall into this category e.g., fractures caused by a fall, road traffic accident, fight etc.

Pathological fracture: A fracture through a bone which has been made weak by some underlying disease is called a pathological fracture. A trivial or no force may be required to cause such a fracture e.g., a fracture through a bone weakened by metastasis.

Although, traumatic fractures have a predictable and generally successful outcome, pathological fractures often go into non-union.

Stress Fracture: This is a special type of fracture sustained due to chronic repetitive injury (stress) causing a break in bony trabeculae. These often present as only pain and may not be visible on X-rays.

ON THE BASIS OF DISPLACEMENTS

Undisplaced fracture: These fractures are easy to identify by the absence of significant displacement.

Displaced fracture: A fracture may be displaced. The factors responsible for displacement are: (i) the fracturing force; (ii) the muscle pull on the fracture fragments; and (iii) the gravity. While describing the displacements of a fracture, conventionally, it is the displacement of the distal fragment in relation to the proximal fragment which is mentioned. The displacement can be in the form of shift, angulation or rotation.

ON THE BASIS OF RELATIONSHIP WITH EXTERNAL ENVIRONMENT

Closed** fracture: A fracture not communicating with the external environment, i.e., the overlying skin and other soft tissues are intact, is called a closed fracture.

Open fracture: A fracture with break in the overlying skin and soft tissues, leading to the fracture communicating with the external environment, is called an open fracture. A fracture may be open from within or outside, the so called internally or externally open fracture respectively.

  1. Internally open (from within): The sharp fracture end pierces the skin from within, resulting in an open
  2. Externally open (open from outside): The object causing the fracture lacerates the skin and soft tissues over the bone, as it breaks the bone, resulting in an open

Exposure of an open fracture to the external environment makes it prone to infection. This risk is more in externally open fracture.

 

ON THE BASIS OF COMPLEXITY OF TREATMENT

Simple fracture: A fracture in two pieces, usually easy to treat, is called simple fracture, e.g. a transverse fracture of humerus.

Complex fracture: A fracture in multiple pieces, usually difficult to treat, is called complex fracture,

e.g. a communited fracture of tibia.

ON THE BASIS OF QUANTUM OF FORCE CAUSING FRACTURE

High-velocity injury: These are fractures sustained as a result of severe trauma force, as in traffic accidents. In these fractures, there is severe soft tissue injury (periosteal and muscle injury). There is extensive devascularisation of fracture ends. Such fractures are often unstable, and slow to heal.

Low-velocity injury: These fractures are sustained as a result of mild trauma force, as in a fall. There is little associated soft tissue injury, and hence these fractures often heal predictably. Lately, there is a change in the pattern of fractures due to shift from low-velocity to high-velocity injuries. The latter gives rise to more complex fractures, which are difficult to treat.

 

ON THE BASIS OF PATTERN

Transverse fracture: In this fracture, the fracture line is perpendicular to the long axis of the bone. Such a fracture is caused by a tapping or bending force (Fig-1.2).

Oblique fracture: In this fracture, the fracture line is oblique. Such a fracture is caused by a bending force which, in addition, has a component along the long axis of the bone.

Spiral fracture: In this fracture, the fracture line runs spirally in more than one plane. Such a fracture is caused by a primarily twisting force.

Comminuted fracture: This is a fracture with multiple fragments. It is caused by a crushing or compression force along the long axis of the bone.

Segmental fracture: In this type, there are two fractures in one bone, but at different levels.

A fracture may have a combination of two or more patterns. For example, it may be a comminuted but primarily a transverse fracture.

 

FRACTURES WITH EPONYMS

Some fractures are better known by names, mostly of those who first described them. Some such fractures are as follows:

Monteggia fracture-dislocation: Fracture of the proximal third of the ulna, with dislocation of the head of the radius (page 110).

Galeazzi fracture-dislocation: Fracture of the distal third of the radius with dislocation of the distal radio-ulnar joint (page 111).

Night-stick fracture: Isolated fracture of the shaft of the ulna, sustained while trying to ward off a stick blow.

Colles’ fracture: A fracture occurring in adults, at the cortico-cancellous junction of the distal end of the radius with dorsal tilt and other displacements (page 111).

Smith’s fracture: A fracture occurring in adults, at the cortico-cancellous junction of the distal end of the radius with ventral tilt and other displacements (reverse of Colles’).

Barton’s fracture (Marginal fracture): Intra-articular fractures through the distal articular surface of the radius, taking a margin, anterior or posterior, of the distal radius with the carpals, displaced anteriorly or posteriorly (page 114).

Chauffeur fracture: An intra-articular, oblique fracture of the styloid process of the radius.

Bennett’s fracture-dislocation: It is an oblique, intra- articular fracture of the base of the first metacarpal with subluxation of the trapezio-metacarpal joint (page 117).

Boxers’ fracture: It is a ventrally displaced fracture through the neck of the 5th metacarpal, usually occurs in boxers.

Side-swipe fracture: It is an elbow injury sustained when one’s elbow, projecting out of a car, is ‘side- swept’ by another vehicle. It has a combination  of fractures of the distal end of the humerus with fractures of proximal ends of radius and/or ulna. It is also called baby car fracture.

Bumper fracture: It is a comminuted, depressed fracture of the lateral condyle of the tibia.

Pott’s fracture: Bimalleolar ankle fracture.

Cotton’s fracture: Trimalleolar ankle fracture.

Massonaise’s fracture: It is a type of ankle fracture in which fracture of the neck of the fibula occurs.

Pilon fracture: It is a comminuted intra-articular fracture of the distal end of the tibia.

Aviator’s fracture: Fracture of neck of the talus.

Chopart fracture-dislocation: A fracture-dislocation through inter-tarsal joints.

Jone’s fracture: Avulsion fracture of the base of the 5th metatarsal.

Rolando fracture: Fracture of the base of the first metacarpal (extra-articular).

Jefferson’s fracture: Fracture of the first cervical vertebra.

Whiplash injury: Cervical spine injury where sudden flexion followed by hyperextension takes place.

Chance fracture: Also called seat belt fracture, the fracture line runs horizontally through the body of the vertebra, through and through, to the posterior elements.

March fracture: Fatigue fracture of the shaft of 2nd or 3rd metatarsal.

Burst fracture: It is a comminuted fracture of the vertebral body where fragments ‘‘burst out’’ in different directions (page 268).

Clay-Shoveller fracture: It is an avulsion fracture of spinous process of one or more of the lower cervical or upper thoracic vertebrae.

Hangman’s fracture: It is a fracture through the pedicle and lamina of C2 vertebra, with subluxation of C2 over C3, sustained in hanging.

Dashboard fracture: A fracture of posterior lip of the acetabulum, often associated with posterior dislocation of the hip.

Straddle fracture: Bilateral superior and inferior pubic rami fractures.

Malgaigne’s fracture: A type of pelvis fracture in which there is a combination of fractures, pubic rami anteriorly and sacro-iliac joint or ilium posteriorly, on the same side.

Mallet finger: A finger flexed at the DIP joint due to avulsion or rupture of extensor tendon at the base of the distal phalanx.

 

PATHOLOGICAL FRACTURES

A fracture is termed pathological when it occurs in a bone made weak by some disease (Fig-1.3). Often, the bone breaks as a result of a trivial trauma, or even spontaneously.

 

CAUSES

A bone may be rendered weak by a disease localised to that particular bone, or by a generalised bone disorder. Table–1.1 gives some of the common causes of pathological fractures. Osteoporosis is the commonest cause of pathological fracture. The bones most often affected are the vertebral bodies (thoracic and lumbar). Other common fractures associated with osteoporosis are fracture of the neck of the femur and Colles’ fracture.

A local or circumscribed lesion of the bone, responsible for a pathological fracture, may be due to varying causes in different age groups (Table–1.2). In children, it is commonly due to chronic osteomyelitis or a bone cyst. In adults, it is often due to a bone cyst or giant cell tumour. In elderly people, metastatic tumour is a frequent cause.

 

Table–1.1: Causes of pathological fractures

 

Localised Diseases

Inflammatory

•       Pyogenic osteomyelitis

•       Tubercular osteomyelitis

Neoplastic

•       Benign tumours

–          Giant cell tumour, Enchondroma

•       Malignant tumours

–          Primary

Osteosarcoma, Ewing’s tumour

–          Secondary

In males: lung, prostate, kidney In females: breast, lung, genitals

Miscellaneous

•       Simple bone cyst

•       Aneurysmal bone cyst

•       Monostotic fibrous dysplasia

•       Eosinophilic granuloma

•       Bone atrophy secondary to polio etc.

Generalised Diseases

Hereditary

•       Osteogenesis imperfecta

•       Dyschondroplasia (Ollier’s disease)

•       Osteopetrosis

Acquired

•       Osteoporosis

•       Osteomalacia

•       Rickets

•       Scurvy

•       Disseminated malignancy in bones

–          Multiple myeloma

–          Diffuse metastatic carcinoma

•       Miscellaneous

–          Paget’s disease

–          Polyostotic fibrous dysplasia

 

DIAGNOSIS

A fracture sustained without a significant trauma should arouse suspicion of a pathological fracture.

Often the patient, when directly questioned, admits to having suffered from some discomfort in the region of the affected bone for some time before the fracture. The patient may be a diagnosed case of a disease known to produce pathological fractures (e.g., a known case of malignancy), thus making the diagnosis of a pathological fracture simple. At times, the  patient  may  present  with a pathological fracture, the cause of which is determined only after a detailed work up.

 

TREATMENT

Treatment of a pathological fracture consists of:

(i) detecting the underlying cause of the fracture; and (ii) making an assessment of the capacity of the fracture to unite, based on the nature of the underlying disease.

A fracture in a bone affected by a generalised disor- der like Paget’s disease, osteogenesis imperfecta or osteoporosis is expected to unite with conventional methods of treatment. A fracture at the site of a bone cyst or a benign tumour will also generally unite, but the union may be delayed. Fractures occur- ring in osteomyelitic bones often take a long time, and sometimes fail to unite despite best efforts. Fractures through metastatic bone lesions often do not unite at all, though the union may occur if the malignancy has been brought under control with chemotherapy or radiotherapy.

With the availability of facilities for internal fixation, more and more pathological fractures are now treated operatively with an aim to: (i) enhance the process of union by bone grafting (e.g. in bone cyst or benign tumour); or (ii) mobilise the patient by surgical stabilisation of the fracture. Achieving stable fixation in these fractures is difficult because of the bone defect caused by the underlying pathology. The defect may have to be filled using bone grafts or bone cement.

Causes of pathological fractures at different ages

 

Age Causes
•   At birth Osteogenesis imperfecta
•   0-5 years Osteogenesis imperfecta
  Osteomyelitis
•   5-20 years Osteomyelitis
  Simple bone cyst
  Primary bone malignancy
•   20-50 years Cystic lesions of the bone
  Malignancy
  Osteomalacia
  Giant cell tumour
•   After 50 years Osteoporosis
  Multiple myeloma
  Secondaries in the bone

INJURIES TO JOINTS

Joint injuries may be either a subluxation or a dislocation. A joint is subluxated when its articular surfaces are partially displaced but retain some contact between them (Fig-1.4).

A joint is dislocated when its articular surfaces are so much displaced that all contact between them is lost. A dislocated joint is an emergency, and should be treated at the earliest.

 

INJURIES TO LIGAMENTS

An injury to a ligament is termed as a sprain. This is to be differentiated from the term ‘strain’ which means stretching of a muscle or its tendinous attachment.

CLASSIFICATION

Sprains are classified into three degrees (Fig-1.5):

First-degree sprain is a tear of only a few fibres of the ligament. It is characterised by minimal swelling, localised tenderness but little functional disability.

Second-degree sprain is the one where, anything from a third to almost all the fibres of a ligament are disrupted. The patient presents with pain, swelling and inability to use the limb. Joint movements are normal. The diagnosis can be made on performing a stress test as discussed subsequently.

Third-degree sprain is a complete tear of the ligament. There is swelling and pain over the torn ligament. Contrary to expectations, often the pain in such tears is minimal. Diagnosis can be made by performing a stress test, and by investigations such as MRI or arthroscopy.

PATHOLOGY

A ligament may get torn in its substance (mid- substance tear) or at either end. In the latter case, it often avulses with a small piece of bone from its attachment (Fig-1.6).

 

DIAGNOSIS

A detailed history, eliciting the exact mechanism of injury, often indicates the likely ligament injured. The examination helps in finding the precise location and severity of the sprain, which can then be confirmed by investigations.

Clinical examination: A localised swelling, tenderness, and ecchymosis over a ligament indicates injury to that ligament. Usually, a haemarthrosis is noticed in second and third-degree sprains within 2 hours. It may be absent* despite a complete tear, or if the torn ligament is covered by synovium (e.g., intra-synovial tear of anterior cruciate ligament).

Stress test (Fig-1.7): This is a very useful test in diagnosing a sprain and judging its severity. The ligament in question is put to stress by a manoeuvre. The manoeuvre used for testing of individual ligaments will be discussed in respective chapters. When a ligament is stressed, in first and second- degree sprains, there will be pain at the site of the tear. In third-degree sprain, the joint will ‘open up’ as well.

INVESTIGATIONS

A plain X-ray of the joint is usually normal. Sometimes, a chip of bone may be seen in the region of the attachment of the ligament to the bone. An X-ray taken while the ligament is being stressed (stress X-ray) may document an abnormal opening up of the joint in a third-degree sprain.

Other investigations required in a few cases are

MRI or arthroscopy.

TREATMENT

There has been a significant change in the treatment of sprains. All sprains are treated initially with rest, ice therapy, compression bandage, elevation (RICE). Suitable analgesics and anti-inflammatory medica- tion is given. This is enough for first-degree sprains. Second and third-degree sprains are immobilised in a brace or a plaster cast for a period of 1-2 weeks, mainly for pain relief. No longer is plaster immo- bilisation advised for long periods. In fact, early mobilisation and walking with support enhances healing of ligaments. In some third-degree sprains, surgery may be required.

 

INJURIES TO MUSCLES AND TENDONS

Muscles are ruptured more often than tendons in young people, while the reverse is true in the elderly. The most frequent cause of partial or complete rupture of a muscle or a tendon is sudden vigorous contraction of a muscle. It may be by overstretching of a muscle at rest. Such an injury to muscle is termed strain (and not sprain, which is ligament injury). A muscle or tendon injury may also be produced by a sharp object such as a sword.

PATHOLOGY

Arupture occurs within a tendon only if it is abnormal and has become weak, either due to degeneration or wear and tear. Degenerative tendon ruptures commonly occur in rheumatoid arthritis, SLE, senile degeneration, etc. Tendon rupture related to wear and tear commonly occurs in the biceps (long head), and in extensor pollicis longus tendons. Some tendons known to rupture commonly are as given in Table–1.3. Diagnosis of a ruptured tendon is usually easy. The patient complains of pain and inability to perform the movement for which the tendon is meant.

TREATMENT

The best treatment of a fresh rupture is to regain continuity by end-to-end repair. When the gap is too much, it can be filled with the help of a tendon graft. In cases where the repair is not possible, a tendon transfer may be performed. In some old tendon ruptures, especially in the elderly, there may be only a minimal functional disability. These patients do well without treatment.

•         Supraspinatus tendon

•         Achilles tendon

•         Biceps tendon – long head

•         Extensor pollicis longus tendon

•         Quadriceps tendon

•         Patellar tendon

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