Orthopaedics Flashcards
Garden classification
1+2 = no displacement (1 = partial fracture, no displacement, 2 = full fracture, no displacement) 3+4 = a degree of displacement (3 = full fracture, partial displacement, 4 = full fracture, full displacement) These groups also help with management - 1+2, use a screw, 3+4, displaced, replace
GRUsome MURder
G: Galeazzi R: radius fracture U: ulna dislocation.
M: Monteggia U: ulna fracture R: radial head dislocation.
Osteoarthritis
Osteoarthritis is often described as “wear and tear” in the joints. It occurs in the synovial joints and results from genetic factors, overuse and injury. Osteoarthritis is thought to result from an imbalance between cartilage damage and the chondrocyte response, leading to structural issues in the joint. Risk factors include obesity, age, occupation, trauma, being female and family history.
Commonly affected joints in osteoarthritis
Hips
Knees
Distal interphalangeal (DIP) joints in the hands
Carpometacarpal (CMC) joint at the base of the thumb
Lumbar spine
Cervical spine (cervical spondylosis)
X-ray changes in osteoarthritis
The four key x-ray changes in osteoarthritis can be remembered with the “LOSS” mnemonic:
L – Loss of joint space
O – Osteophytes (bone spurs)
S – Subarticular sclerosis (increased density of the bone along the joint line)
S – Subchondral cysts (fluid-filled holes in the bone)
X-ray reports might describe findings of osteoarthritis as degenerative changes. X-ray changes do not necessarily correlate with symptoms. A patient might have significant signs on an x-ray but minimal symptoms, or the reverse.
Presentation of osteoarthritis
Osteoarthritis presents with joint pain and stiffness. The pain and stiffness tend to worsen with activity and at the end of the day. This is the reverse of the pattern in inflammatory arthritis, where symptoms are worse in the morning and improve with activity. Osteoarthritis leads to deformity, instability and reduced function of the joint.
General signs of osteoarthritis are:
Bulky, bony enlargement of the joint
Restricted range of motion
Crepitus on movement
Effusions (fluid) around the joint
Signs in the Hands
Heberden’s nodes (in the DIP joints)
Bouchard’s nodes (in the PIP joints)
Squaring at the base of the thumb (CMC joint)
Weak grip
Reduced range of motion
The carpometacarpal joint at the base of the thumb is a saddle joint, with the metacarpal bone sitting on the trapezius bone, using it like a saddle. It gets a lot of use and is very prone to wear.
TOM TIP: Patients may present with referred pain, particularly in the adjacent joints. For example, consider osteoarthritis in the hip in patients presenting with lower back or knee pain.
Diagnosing osteoarthritis
The NICE guidelines (2022) suggest that a diagnosis can be made without any investigations if the patient is over 45, has typical pain associated with activity and has no morning stiffness (or stiffness lasting under 30 minutes).
Managing osteoarthritis
Non-pharmacological management involves patient education and lifestyle changes, such as:
Therapeutic exercise to improve strength and function and reduce pain
Weight loss if overweight, to reduce the load on the joint
Occupational therapy to support activities and function (e.g., walking aids and adaptations to the home)
Pharmacological management recommended by the NICE guidelines (2022) are:
Topical NSAIDs first-line for knee osteoarthritis
Oral NSAIDs where required and suitable (co-prescribed with a proton pump inhibitor for gastroprotection)
Weak opiates and paracetamol are only recommended for short-term, infrequent use. NICE (2022) recommend against using any strong opiates for osteoarthritis.
Intra-articular steroid injections may temporarily improve symptoms (NICE say up to 10 weeks).
Joint replacement may be used in severe cases. The hips and knees are the most commonly replaced joints.
Medication Notes
NSAIDs (e.g., ibuprofen or naproxen) are very effective for musculoskeletal pain. However, they must be used cautiously, particularly in older patients and those on anticoagulants, such as aspirin or DOACs. They are best used intermittently, only for a short time during flares. They have several potential adverse effects, including:
Gastrointestinal side effects, such as gastritis and peptic ulcers (leading to upper gastrointestinal bleeding)
Renal side effects, such as acute kidney injury (e.g., acute tubular necrosis) and chronic kidney disease
Cardiovascular side effects, such as hypertension, heart failure, myocardial infarction and stroke
Exacerbating asthma
There is little evidence that opiates help with chronic pain. They are associated with side effects, risks, tolerance, dependence and withdrawal. They often result in dependence without any objective benefits.
TOM TIP: The WHO pain ladder is not helpful in chronic pain. Paracetamol and opiates are not recommended for regular use in osteoarthritis. Remember that NSAIDs cause hypertension by blocking prostaglandins (prostaglandins cause vasodilation) and should be used very cautiously with a history of high blood pressure.
Elective joint replacement
The most common joints replaced electively are the hip, knee and shoulder. The most common indication is osteoarthritis. Most patients that have joint replacements are over 60.
The artificial joints are built to last more than 10-15 years. However, they may be affected by loosening, wear and dislocation. Some patients may require further surgery and replacement of the artificial joint at some point.
Joint replacement is major surgery. Patients need to have the alternatives discussed before deciding to undergo surgery. The other options usually include analgesia, steroid injections and physiotherapy.
Indications for joint replacement
Osteoarthritis is the most common indication for an elective joint replacement. It is not usually performed until symptoms are severe and not manageable with conservative treatments.
Joints may also require replacement for:
Fractures
Septic arthritis
Osteonecrosis
Bone tumours
Rheumatoid arthritis
Joint replacement options
There are several options for elective joint replacement surgery:
Total joint replacement – replacing both articular surfaces of the joint
Hemiarthroplasty – replacing half of the joint (e.g., the head of the femur in the hip joint)
Partial joint resurfacing – replacing part of the joint surfaces (e.g., only the medial joint surfaces of the knee)
Total hip replacement
Usually, a lateral incision over the outer aspect of the hip is used. The hip joint is dislocated (separated) to give access to both articular surfaces.
The head of the femur is removed. A metal or ceramic replacement head of femur, on a metal stem, is used to replace it. The stem can either be cemented into the shaft of the femur or carefully pushed into the shaft to make a tight enough fit to hold it securely in place. Uncemented stems have a rough surface that holds them tightly in place.
The acetabulum (socket) of the pelvis is hollowed out and replaced by a metal socket, which is cemented or screwed into place. A spacer is used between the new head and socket to complete the new artificial joint.
Total Knee Replacement
Usually, a vertical, anterior incision is made down the front of the knee. The patella is rotated out of the way to allow access to the knee joint.
The articular surfaces (the cartilage and some of the bone) of the femur and tibia are removed. A new metal surface replaces these. They can be either cemented or pushed tightly into place.
A spacer is added between the new articular surfaces of the femur and tibia to complete the new artificial joint.
Total Shoulder Replacement
Usually, an anterior incision is made down the front of the shoulder, along the deltoid. The shoulder joint is dislocated (separated) to give access to both articular surfaces.
The head of the humerus is removed and replaced with a metal or ceramic ball. This replacement head is attached to the humerus either by a metal stem or screws (stemless).
The glenoid (socket) is hollowed out and replaced by a metal socket. This completes the artificial shoulder joint.
Reverse Total Shoulder Replacement
A reverse total shoulder replacement involves adding a sphere in place of the glenoid (socket) and a spacer with a cup to replace the head of the humerus. This reverses the normal ball-in-cup structure of the shoulder joint, but the joint function remains the same.
Joint replacement surgery
Before Surgery
Planning for joint replacement surgery will involve:
X-rays
CT or MRI scans may be required for a more detailed assessment
Pre-operative assessment (pre-op)
Consent for surgery
Bloods (including group and save and crossmatching of blood)
Medication changes if needed (e.g., temporarily stopping anticoagulation)
Venous thromboembolism assessment
Fasting immediately before surgery
The limb will be marked with the patient awake to ensure the operation is performed on the correct joint
During Surgery
Joint replacement surgery requires a general anaesthetic. Alternatively, a spinal anaesthetic may be used for lower limb surgery.
Prophylactic antibiotics are given before the procedure to reduce the risk of infection.
Tranexamic acid may be used to minimise blood loss during the procedure.
After Surgery
Post-operative management after joint replacement surgery involves:
Analgesia
Physiotherapy to guide when and how to mobilise
VTE prophylaxis
Post-operative x-rays
Post-operative full blood count (to check for anaemia)
Monitoring for complications (e.g., deep vein thrombosis or infection)
VTE prophylaxis usually involves low molecular weight heparin (LMWH). The 2018 NICE guidelines on VTE prophylaxis have specific recommendations on potential regimes that can be used after joint replacement surgery (see full national and local guidelines when treating patients). This involves the option of LMWH for:
28 days post elective hip replacement
14 days post elective knee replacement
Other measures that may be used for VTE prophylaxis after joint replacement surgery are:
Aspirin
DOACs (e.g., rivaroxaban)
Anti-embolism stockings
Risks
The generic risks of joint replacement surgery are:
Risks of the anaesthetic
Pain
Bleeding
Infection – infection of the prosthesis can be highly problematic (see below)
Damage to nearby structures (e.g., nerves or arteries)
Stiffness or restricted range of motion in the joint
Joint dislocation
Loosening
Fracture during the procedure
Venous thromboembolism (DVT or PE)
Prosthetic Joint Infections
Infection in a prosthetic joint is a big problem. This occurs in around 1% of joint replacements and extensive measures are taken to prevent it, such as perioperative prophylactic antibiotics. It is more likely to occur in revision surgery rather than during the initial joint replacement. The most common organism is Staphylococcus aureus (a common skin organism).
Risk factors for prosthetic joint infection are:
Prolonged operative time
Obesity
Diabetes
Symptoms include:
Fever
Pain
Swelling
Erythema
Increased warmth
Diagnosis involves a combination of clinical findings, x-rays, blood tests (raised inflammatory markers), cultures (e.g., blood or synovial fluid) and findings during further operations.
Management involves repeat surgery and prolonged antibiotics (over months). Surgery may involve joint irrigation, debridement or complete replacement.
Types of fractures
A compound fracture is when the skin is broken and the broken bone is exposed to the air. The broken bone can puncture through the skin.
A stable fracture refers to when the sections of bone remain in alignment at the fracture.
A pathological fracture refers to when a bone breaks due to an abnormality within the bone (see below).
There are terms used to describe in what way a bone breaks:
Transverse
Oblique
Spiral
Segmental
Comminuted (breaking into multiple fragments)
Compression fractures (affecting the vertebrae in the spine)
Greenstick
Buckle (torus)
Salter-Harris (growth plate fracture)
Greenstick and buckle fractures typically occur in children rather than adults. Salter-Harris fractures only occur in children (adults do not have growth plates).
Wrist fractures
A Colle’s fracture refers to a transverse fracture of the distal radius near the wrist, causing the distal portion to displace posteriorly (upwards), causing a “dinner fork deformity”. This is usually the result of a fall onto an outstretched hand (FOOSH).
A scaphoid fracture is often caused by a FOOSH. The scaphoid is one of the carpal bones and is located below the base of the thumb. A key sign of a scaphoid fracture is tenderness in the anatomical snuffbox (the groove between the tendons when extending the thumb). It is worth noting that the scaphoid has a retrograde blood supply, with blood vessels supplying the bone from only one direction. This means a fracture can cut off the blood supply, resulting in avascular necrosis and non-union.
TOM TIP: Some key bones have vulnerable blood supplies, where a fracture can lead to avascular necrosis, impaired healing, and non-union. These are the scaphoid bone, the femoral head, the humeral head and the talus, navicular and fifth metatarsal in the foot.
Ankle fractures
Ankle fractures involve the lateral malleolus (distal fibula) or the medial malleolus (distal tibia).
The Weber classification can be used to describe fractures of the lateral malleolus (distal fibula). The fracture is described in relation to the distal syndesmosis (fibrous join) between the tibia and fibula. This tibiofibular syndesmosis is very important for the stability and function of the ankle joint. If the fracture disrupts the syndesmosis, surgery is more likely to be required in order to regain good stability and function of the joint.
The Weber classification defines fractures of the lateral malleolus as:
Type A – below the ankle joint – will leave the syndesmosis intact
Type B – at the level of the ankle joint – the syndesmosis will be intact or partially torn
Type C – above the ankle joint – the syndesmosis will be disrupted
Pelvic ring fractures
The pelvis forms a ring. When one part of the pelvic ring fractures, another part will also fracture (similar to fracturing a polo mint).
Pelvic fractures often lead to significant intra-abdominal bleeding, either due to vascular injury or from the cancellous bone of the pelvis. This can lead to shock and death, so needs emergency resuscitation and trauma management.
Pathological fractures
Pathological fractures occur due to an underlying disease of the bone, such as a tumour, osteoporosis or Paget’s disease of the bone. They may occur with minor trauma or even spontaneously without any history of trauma. Common sites are the femur and the vertebral bodies.
The main cancers that metastasise to the bones are (mnemonic: PoRTaBLe):
Po – Prostate
R – Renal
Ta – Thyroid
B – Breast
Le – Lung
Fragility fractures
Fragility fractures occur due to weakness in the bone, usually due to osteoporosis. They often occur without the appropriate trauma that is typically required to break a bone. For example, a patient may present with a fractured femur after a minor fall.
A patient’s risk of a fragility fracture over the next 10 years can be predicted using the FRAX tool.
Bone mineral density can be measured using a DEXA scan.
The WHO criteria for osteopenia and osteoporosis are:
T Score at the Hip
Bone Mineral Density
More than -1
Normal
-1 to -2.5
Osteopenia
Less than -2.5
Osteoporosis
Less than -2.5 plus a fracture
Severe Osteoporosis
The NOGG guidelines can be used to guide the medical treatments appropriate for an individual based on their FRAX score. The first-line medical treatments for reducing the risk of fragility fractures are:
Calcium and vitamin D
Bisphosphonates (e.g., alendronic acid)
Bisphosphonates work by interfering with osteoclasts and reducing their activity, preventing the reabsorption of bone. There are a few key side effects to remember:
Reflux and oesophageal erosions (oral bisphosphonates are taken on an empty stomach sitting upright for 30 minutes before moving or eating to prevent this)
Atypical fractures (e.g. atypical femoral fractures)
Osteonecrosis of the jaw
Osteonecrosis of the external auditory canal
Denosumab is a monoclonal antibody that works by blocking the activity of osteoclasts. It is an alternative to bisphosphonates where they are contraindicated, not tolerated or not effective.
Imaging fractures
X-rays are the initial imaging investigation when a bone fracture is suspected. Two views (two x-rays taken from different angles) are always required, as a single view may miss a fraction.
CT scans give a more detailed view of the bones when the x-rays are inconclusive or further information is needed.
Principles of fracture management
The first principle is to achieve mechanical alignment of the fracture by:
Closed reduction via manipulation of the limb
Open reduction via surgery
The second principle is to provide relative stability for some time to allow healing to occur. This can be done by fixing the bone in the correct position while it heals. There are various ways the bone can be fixed in position:
External casts (e.g., plaster cast)
K wires
Intramedullary wires
Intramedullary nails
Screws
Plate and screws
Managing fractures
Patients presenting to A&E will be investigated with x-rays to establish the diagnosis.
Patients with fractures require appropriate pain management.
Straightforward fractures may be managed in A&E (e.g., a Colle’s fracture in a young adult). They may require closed reduction if the bones are out of alignment. A plaster cast may be applied, and the patient can be discharged with a follow-up appointment in the fracture clinic.
Complex fractures and those requiring surgery (e.g., hip fractures) are referred to the on-call trauma and orthopaedics team. They are admitted and made nil by mouth if they may need an operation. They are discussed at the trauma meeting the following day (typically, this starts at 7.45 am), then seen on the morning ward round. A plan will be made for further management at this stage.
Complications of fractures
The complications will depend on the location and nature of the fracture.
Possible early complications include:
Damage to local structures (e.g., tendons, muscles, arteries, nerves, skin and lung)
Haemorrhage leading to shock and potentially death
Compartment syndrome
Fat embolism (see below)
Venous thromboembolism (DVTs and PEs) due to immobility
Possible longer-term complications include:
Delayed union (slow healing)
Malunion (misaligned healing)
Non-union (failure to heal)
Avascular necrosis (death of the bone)
Infection (osteomyelitis)
Joint instability
Joint stiffness
Contractures (tightening of the soft tissues)
Arthritis
Chronic pain
Complex regional pain syndrome
Fat embolism
Fat embolism can occur following the fracture of long bones (e.g., femur). Fat globules are released into the circulation following a fracture (possibly from the bone marrow). These globules may become lodged in blood vessels (e.g., pulmonary arteries) and cause blood flow obstruction.
Fat embolisation can cause a systemic inflammatory response, resulting in fat embolism syndrome.
It typically presents around 24-72 hours after the fracture. Gurd’s criteria can be for the diagnosis.
Gurd’s major criteria:
Respiratory distress
Petechial rash
Cerebral involvement
There is a long list of Gurd’s minor criteria, including:
Jaundice
Thrombocytopenia
Fever
Tachycardia
Operating early to fix the fracture reduces the risk of fat embolism syndrome.
It can lead to multiple organ failure. Management is supportive while the condition improves. The mortality rate is around 10%.
Hip fractures
Hip fractures are an important topic in trauma and orthopaedics. They are common and lead to significant morbidity and mortality. The 30-day mortality is 5-10%. Half of patients become less independent after a hip fracture.
Increasing age and osteoporosis are major risk factors for hip fractures. Females are affected more often than males.
Due to the morbidity and mortality with hip fractures, they are generally prioritised on the trauma list with the aim to perform surgery within 48 hours. There is also a specialty called orthogeriatrics, who focus on identifying and optimising the medical co-morbidities and complications of inpatients on the orthopaedic ward, particularly elderly patients with hip fractures.
Hip fractures can be categorised into:
Intra-capsular fractures
Extra-capsular fractures
Anatomy of the hip
There are some basic structures of the top of the femur:
Head
Neck
Greater trochanter (lateral)
Lesser trochanter (medial)
Intertrochanteric line
Shaft (body)
The capsule of the hip joint is a strong fibrous structure. It attaches to the rim of the acetabulum on the pelvis and the intertrochanteric line on the femur. It surrounds the neck and head of the femur.
The head of the femur has a retrograde blood supply. The medial and lateral circumflex femoral arteries join the femoral neck just proximal to the intertrochanteric line. Branches of this artery run along the surface of the femoral neck, within the capsule, towards the femoral head. They provide the only blood supply to the femoral head. A fracture of the intra-capsular neck of the femur can damage these blood vessels, removing the blood supply to the femoral head, leading to avascular necrosis. Therefore, patients with a displaced intra-capsular fracture need to have the femoral head replaced with a hemiarthroplasty or total hip replacement.
TOM TIP: It is worth understanding and remembering the concept of the retrograde blood supply to the head of the femur and how this determines the choice of operation (explained below). When I did an FY1 job in trauma and orthopaedics, the juniors were questioned on this concept almost every time a patient with a hip fracture was admitted. Being able to identify the type of hip fracture on an x-ray (intra-capsular or extra-capsular) and justify the choice of operation made trauma meetings much less stressful.
Intra-capsular hip fractures
Intra-capsular fractures involve a break in the femoral neck, within the capsule of the hip joint. This affects the area proximal to the intertrochanteric line.
The Garden classification is used for intra-capsular neck of femur fractures:
Grade I – incomplete fracture and non-displaced
Grade II – complete fracture and non-displaced
Grade III – partial displacement (trabeculae are at an angle)
Grade IV – full displacement (trabeculae are parallel)
Non-displaced intra-capsular fractures may have an intact blood supply to the femoral head, meaning it may be possible to preserve the femoral health without avascular necrosis occurring. They can be treated with internal fixation (e.g., with screws) to hold the femoral head in place while the fracture heals.
Displaced intra-capsular fractures (grade III and IV) disrupt the blood supply to the head of the femur. Therefore, the head of the femur needs to be removed and replaced.
Hemiarthroplasty involves replacing the head of the femur but leaving the acetabulum (socket) in place. Cement is used to hold the stem of the prosthesis in the shaft of the femur. This is generally offered to patients who have limited mobility or significant co-morbidities.
Total hip replacement involves replacing both the head of the femur and the socket. This is generally offered to patients who can walk independently and are fit for surgery.
Extra-capsular hip fractures
Extra-capsular fractures leave the blood supply to the head of the femur intact. Therefore, the head of the femur does not need to be replaced.
Intertrochanteric fractures occur between the greater and lesser trochanter. These are treated with a dynamic hip screw (AKA sliding hip screw). A screw goes through the neck and into the head of the femur. A plate with a barrel that holds the screw is screwed to the outside of the femoral shaft. The screw that goes through the femur to the head allows some controlled compression at the fracture site, whilst still holding it in the correct alignment. Adding some controlled compression across the fracture improves healing.
Subtrochanteric fractures occur distal to the lesser trochanter (although within 5cm). The fracture occurs to the proximal shaft of the femur. These may be treated with an intramedullary nail (a metal pole inserted through the greater trochanter into the central cavity of the shaft of the femur).
Hip Fracture Presentation
The typical scenario is an older patient (over 60) who has fallen, presenting with:
Pain in the groin or hip, which may radiate to the knee
Not able to weight bear
Shortened, abducted and externally rotated leg
An essential part of assessing patients with a new hip fracture is to determine any other acute illnesses. There is often a good reason for them to fall and break a hip. They may also be suffering with:
Anaemia
Electrolyte imbalances
Arrhythmias
Heart failure
Myocardial infarction
Stroke
Urinary or chest infection
These conditions need to be identified as early as possible so that the patient can be optimised and surgery can proceed with minimal delays.
TOM TIP: The term “mechanical fall” is often used to imply a simple explanation for why the patient fell, such as tripping over an object or being knocked over. It is worth exploring the fall in more detail. In many cases, there may be a correctable underlying medical cause for the fall, such as anaemia, arrhythmia or even underlying Parkinson’s disease. There may also be social contributors to the fall, such as dehydration, incorrect eyewear, poor footwear or obstacles in the home. If you identify an underlying reversible cause, you could make a big difference to that patient and impress your orthogeriatric colleagues.
Imaging hip fractures
X-rays are the initial investigation of choice. Two views are essential, as a single view can miss the fracture. Anterior-to-posterior (AP) and lateral views are standard.
Shenton’s line can be seen on an AP x-ray of the hip. It is one continuous curving line formed by the medial border of the femoral neck and continues to the inferior border of the superior pubic ramus. Disruption of Shenton’s line is a key sign of a fractured neck of femur (NOF).
MRI or CT scanning may be used where the x-ray is negative, but a fracture is still suspected.
Managing hip fractures
On admission, patients will have:
Appropriate analgesia
Investigations to establish the diagnosis (e.g., x-rays)
Venous thromboembolism risk assessment and prophylaxis (e.g., low molecular weight heparin)
Pre-operative assessment (including bloods and an ECG) to ensure they are fit and optimised for surgery
Orthogeriatrics input
The NICE guidelines (updated 2017) say that surgery should be carried out either the same day or the day after the patient is admitted (within 48 hours).
The operation should allow the patient to weight bear straight away. This allows the physiotherapists to start mobilisation and rehabilitation as soon as possible after the operation. Post-operative analgesia is important to encourage the patient to mobilise as quickly as possible.
Compartment syndrome
Compartment syndrome is where the pressure within a fascial compartment is abnormally elevated, cutting off the blood flow to the contents of that compartment.
Fascial compartments involve muscles, nerves and blood vessels surrounded by fascia. Fascia is a sheet of strong, fibrous connective tissue that encases the contents of the compartment. It is not able to stretch or expand.
Acute compartment syndrome is an orthopaedic emergency requiring surgery (fasciotomy) to relieve the pressure within the compartment and restore blood flow. Without prompt treatment, tissue necrosis (death) and permanent damage can occur.
Compartment syndrome can be classified as acute or chronic. Most of this section relates to acute compartment syndrome.
Acute compartment syndrome is usually associated with an acute injury, where bleeding or tissue swelling (oedema) associated with the injury increases the pressure within the compartment.
Presentation of compartment syndrome
Acute compartment syndrome most often affects one of the fascial compartments in the legs, but it can also affect the forearm, feet, thigh and buttocks.
It usually presents after an acute injury, particularly:
Bone fractures
Crush injuries
Acute compartment syndrome presents with the 5 P’s:
P – Pain “disproportionate” to the underlying injury, worsened by passive stretching of the muscles
P – Paresthesia
P – Pale
P – Pressure (high)
P – Paralysis (a late and worrying feature)
Note that pulseless is not a feature, differentiating it from acute limb ischaemia. The pulses may remain intact depending on which compartment is affected.
TOM TIP: Disproportionate pain is a key characteristic of compartment syndrome. The pain is so severe that pain medications are not effective. If you see a patient with disproportionate pain after an injury in your exams, the diagnosis is probably compartment syndrome.
Managing acute compartment syndrome
Acute compartment syndrome is primarily a clinical diagnosis based on clinical signs and symptoms.
Needle manometry can be used to measure the compartment pressure. A device (manometer) measures the resistance to injecting saline through a needle into the compartment.
Initial management involves:
Escalating to the orthopaedic registrar or consultant
Removing any external dressings or bandages
Elevating the leg to heart level
Maintaining good blood pressure (avoiding hypotension)
Emergency fasciotomy is the definitive management. Ideally, this should be as soon as possible after injury (e.g., within 6 hours). If it is delayed, irreversible damage may occur, and fasciotomy may not be beneficial.
Fasciotomy involves a surgical operation to cut through the fascia, down the entire length of the compartment, and release the pressure. The compartment is explored to identify and debride any necrotic muscle tissue. The wound is left open and covered with a dressing.
Patients require repeated trips to theatre (every few days) to explore the compartment for necrotic tissue, which needs to be debrided. As the swelling improves, the wound can be gradually closed, which can take several weeks. A skin graft may be required if the wound cannot be closed around the compartment.
Chronic compartment syndrome
Chronic compartment syndrome (also called chronic exertional compartment syndrome) is usually associated with exertion. During exertion, the pressure within the compartment rises, blood flow to the compartment is restricted, and symptoms start. During rest, the pressure falls, and symptoms begin to resolve. It is not an emergency.
Symptoms are usually isolated to a specific location at the affected compartment. Symptoms include pain, numbness or paresthesia (pins and needles). They are made worse by increasing activity and resolve quickly with rest.
Needle manometry can be used to measure the pressure in the compartment before, during and after exertion to confirm the diagnosis. It may be treated with a fasciotomy.
Osteomyelitis
Osteomyelitis refers to inflammation in a bone and bone marrow, usually caused by bacterial infection.
Haematogenous osteomyelitis refers to when a pathogen is carried through the blood and seeded in the bone. This is the most common mode of infection. Alternatively, osteomyelitis can occur due to direct contamination of the bone, for example, at a fracture site or during an orthopaedic operation.
Staphylococcus aureus causes most cases of osteomyelitis.
Osteomyelitis can be acute or chronic. Patients may develop recurring or chronic infections after treatment for acute osteomyelitis.
Risk factors for osteomyelitis
The key risk factors for developing osteomyelitis are:
Open fractures
Orthopaedic operations, particularly with prosthetic joints
Diabetes, particularly with diabetic foot ulcers
Peripheral arterial disease
IV drug use
Immunosuppression
Infection in a prosthetic joint is a big problem. This occurs in around 1% of joint replacements, and extensive measures are taken to prevent it, such as perioperative prophylactic antibiotics. It is more likely to occur in revision surgery rather than during the initial joint replacement.
Presentation of osteomyelitis
The typical presentation of osteomyelitis is with:
Fever
Pain and tenderness
Erythema
Swelling
The presentation of osteomyelitis can be quite non-specific, with generalised symptoms of infection such as fever, lethargy, nausea and muscle aches.
Investigating osteomyelitis
X-rays often do not show any changes, particularly in early disease. They cannot be used to exclude osteomyelitis. The potential signs of osteomyelitis on an x-ray are:
Periosteal reaction (changes to the surface of the bone)
Localised osteopenia (thinning of the bone)
Destruction of areas of the bone
MRI scans are the best imaging investigation for establishing a diagnosis.
Blood tests will show raised inflammatory markers (e.g., WBC, CRP and ESR).
Blood cultures may be positive for the causative organism.
Bone cultures can be performed to establish the causative organism and the antibiotic sensitivities.
Managing osteomyelitis
Management involves a combination of:
Surgical debridement of the infected bone and tissues
Antibiotic therapy
Prolonged courses of antibiotics are required to treat osteomyelitis. The BNF page on osteomyelitis recommends for acute osteomyelitis:
6 weeks of flucloxacillin, possibly with rifampicin or fusidic acid added for the first 2 weeks
Alternatives to flucloxacillin are:
Clindamycin in penicillin allergy
Vancomycin or teicoplanin when treating MRSA
Chronic osteomyelitis usually requires 3 months or more of antibiotics.
Osteomyelitis associated with prosthetic joints (e.g., a hip replacement) may require complete revision surgery to replace the prosthesis.
Sarcoma
Sarcomas are cancers originating in the muscles, bones or other types of connective tissue. There are many subtypes of sarcoma, which vary in their histology, location and degree of malignancy.
Types of bone sarcoma include:
Osteosarcoma – the most common form of bone cancer
Chondrosarcoma – cancer originating from the cartilage
Ewing sarcoma – a form of bone and soft tissue cancer most often affecting children and young adults
Types of soft tissue sarcoma include:
Rhabdomyosarcoma – originating from skeletal muscle
Leiomyosarcoma – originating from smooth muscle cancer
Liposarcoma – originating from adipose (fat) tissue
Synovial sarcoma – originating from soft tissues around the joints
Angiosarcoma – originating from the blood and lymph vessels
Kaposi’s sarcoma – cancer caused by human herpesvirus 8, most often seen in patients with end-stage HIV, causing typical red/purple raised skin lesions but also affecting other parts of the body
The prognosis depends greatly on the type, location, size and stage of the sarcoma. It can range from a greater than 90% 5-year survival for well-differentiated and resectable liposarcoma, to less than 10% for angiosarcoma affecting the liver.
Presentation of sarcoma
The presenting symptoms of sarcoma will vary dependent on the location and size of the lesion. The key features that should raise suspicions are:
A soft tissue lump, particularly if growing, painful or large
Bone swelling
Persistent bone pain
Investigating sarcoma
X-ray is the initial investigation for bony lumps or persistent pain.
Ultrasound is the initial investigation for soft tissue lumps.
CT or MRI scans may be used to visualise the lesion in more detail and look for metastatic spread (particularly a CT thorax, as sarcoma most often spreads to the lungs).
Biopsy is required to look at the histology of the cancer.
Staging sarcoma
Staging is either with the TNM staging system or a number system that grades the cancer from stage 1 (earliest) to stage 4 (most advanced).
The most common location for sarcoma to metastasise to is the lungs.
Managing sarcoma
Management will be guided by the sarcoma multidisciplinary team (MDT). There are specialist sarcoma centres in various locations in the UK that specialise in managing sarcoma. This concentrates the expertise about these relatively rare and often challenging cancers to ensure patients get the best care.
Sarcoma treatment will depend on the type, location, size and stage of the sarcoma. This may involve:
Surgery (surgical resection is the preferred treatment)
Radiotherapy
Chemotherapy
Palliative care
Back pain and sciatica
Low back pain is very common and has many causes. Lumbago is another term for low back pain. Non-specific or mechanical lower back pain refers to the majority of patients who do not have a specific disease causing their lower back pain.
Sciatica refers to the symptoms associated with irritation of the sciatic nerve.
Acute low back pain should improve within 1-2 weeks. Recovery can take longer (4-6 weeks) for sciatica.
Chronic lower back pain can have a massive impact on the patient’s quality of life and be difficult to manage.
There are several challenges with managing patients with lower back pain:
Identifying serious underlying pathology
Speeding up recovery
Reducing the risk of chronic lower back pain
Managing symptoms in chronic lower back pain
Causes of mechanical back pain
Muscle or ligament sprain
Facet joint dysfunction
Sacroiliac joint dysfunction
Herniated disc
Spondylolisthesis (anterior displacement of a vertebra out of line with the one below)
Scoliosis (curved spine)
Degenerative changes (arthritis) affecting the discs and facet joints
Causes of neck pain
Muscle or ligament strain (e.g., poor posture or repetitive activities)
Torticollis (waking up with a unilaterally stiff and painful neck due to muscle spasm)
Whiplash (typically after a road traffic accident)
Cervical spondylosis (degenerative changes to the vertebrae)
Red-Flag Causes of Back Pain
It is essential to look out for features that may indicate underlying:
Spinal fracture (e.g., major trauma)
Cauda equina (e.g., saddle anaesthesia, urinary retention, incontinence or bilateral neurological signs)
Spinal stenosis (e.g., intermittent neurogenic claudication)
Ankylosing spondylitis (e.g., age under 40, gradual onset, morning stiffness or night-time pain)
Spinal infection (e.g., fever or a history of IV drug use)
Other causes of back pain
Keep in mind that back pain may not always be related to the spine. There is a long list of abdominal or thoracic conditions that can cause back pain, including:
Pneumonia
Ruptured aortic aneurysms
Kidney stones
Pyelonephritis
Pancreatitis
Prostatitis
Pelvic inflammatory disease
Endometriosis
Sciatica
The spinal nerves L4 – S3 come together to form the sciatic nerve. The sciatic nerve exits the posterior part of the pelvis through the greater sciatic foramen, in the buttock area on either side. It travels down the back of the leg. At the knee, it divides into the tibial nerve and the common peroneal nerve.
The sciatic nerve supplies sensation to the lateral lower leg and the foot. It supplies motor function to the posterior thigh, lower leg and foot.
Sciatica causes unilateral pain from the buttock radiating down the back of the thigh to below the knee or feet. It might be described as an “electric” or “shooting” pain. Other symptoms are paraesthesia (pins and needles), numbness and motor weakness. Reflexes may be affected depending on the affected nerve root.
The main causes of sciatica are lumbosacral nerve root compression by:
Herniated disc
Spondylolisthesis (anterior displacement of a vertebra out of line with the one below)
Spinal stenosis
Bilateral sciatica is a red flag for cauda equina syndrome.
Assessing back pain
Key symptoms in the history are:
Major trauma (spinal fracture)
Stiffness in the morning or with rest (ankylosing spondylitis)
Age under 40 (ankylosing spondylitis)
Gradual onset of progressive pain (ankylosing spondylitis or cancer)
Night pain (ankylosing spondylitis or cancer)
Age over 50 (cancer)
Weight loss (cancer)
Bilateral neurological motor or sensory symptoms (cauda equina)
Saddle anaesthesia (cauda equina)
Urinary retention or incontinence (cauda equina)
Faecal incontinence (cauda equina)
History of cancer with potential metastasis (cauda equina or spinal metastases)
Fever (spinal infection)
IV drug use (spinal infection)
Key findings on examination are:
Localised tenderness to the spine (spinal fracture or cancer)
Bilateral neurological motor or sensory signs (cauda equina)
Bladder distention implying urinary retention (cauda equina)
Reduced anal tone on PR examination (cauda equina)
The sciatic stretch test can be used to help diagnose sciatica. The patient lies on their back with their leg straight. The examiner lifts one leg from the ankle with the knee extended until the limit of hip flexion is reached (usually around 80-90 degrees). Then the examiner dorsiflexes the patient’s ankle. Sciatica-type pain in the buttock/posterior thigh indicates sciatic nerve root irritation. Symptoms improve with flexing the knee.
TOM TIP: It is worth remembering the main cancers that metastasise to the bones. A history of these in an exam patient presenting with back pain should make you think of possible cauda equina or spinal metastases. You can remember them with the PoRTaBLe mnemonic:
Po – Prostate
R – Renal
Ta – Thyroid
B – Breast
Le – Lung
Investigating back pain
Generally, patients with mechanical/non-specific lower back pain can be diagnosed clinically and do not require further investigations.
X-rays or CT scans can be used to diagnose spinal fractures.
An emergency MRI scan is required in patients with suspected cauda equina (within hours of the presentation).
Investigations for suspected ankylosing spondylitis are:
Inflammatory markers (CRP and ESR)
X-ray of the spinal and sacrum (may show a fused “bamboo spine” in later-stage disease)
MRI of the spine (may show bone marrow oedema early in the disease)
STarT Back Screening Tool
The STarT Back tool was developed by Keele University to stratify the risk of a patient presenting with acute back pain developing chronic back pain. This helps guide the intensity of the initial interventions (e.g., referral for group exercises, physiotherapy and cognitive behavioural therapy).
It involves 9 questions that assess the patient’s function and psychological response to the back pain. It gives a:
Total score (out of 9)
Subscore on the 4 psychosocial questions (out of 4)
The interpretation gives a risk of developing chronic back pain:
Low Risk
Medium Risk
High Risk
Total Score
3 or less
More than 3
More than 3
Subscore
3 or less
3 or less
More than 3
Managing acute lower back pain
First, exclude serious underlying causes. If concerned about symptoms or signs of an underlying condition, arrange further investigations and refer appropriately. For example:
Same-day referral to the on-call orthopaedic team for an urgent MRI scan if cauda equina is suspected
Inflammatory markers and an urgent rheumatology review if ankylosing spondylitis is suspected
Full in-line spinal immobilisation, admission to a trauma unit and x-rays/CT scans for spinal injury after major trauma
Patients with neurological symptoms or signs on examination, particularly if progressive or severe, may require referral to orthopaedics or neurosurgery (potentially urgently).
The StarT Back tool can be used to stratify the risk of developing chronic back pain.
The NICE clinical knowledge summaries (updated 2020) give the options for managing non-specific low back pain based on the outcome of risk stratification, as briefly summarised below (always check the latest guidelines when treating patients).
Patients at low risk of chronic back pain can generally be managed with:
Self-management
Education
Reassurance
Analgesia
Staying active and continuing to mobilise as tolerated
Additional options for patients at medium or high risk of developing chronic back pain include:
Physiotherapy
Group exercise
Cognitive behavioural therapy
The NICE clinical knowledge summaries advise for analgesia:
NSAIDs (e.g., ibuprofen or naproxen) first-line
Codeine as an alternative
Benzodiazepines (e.g., diazepam) for muscle spasm (short-term only – up to 5 days)
They specifically state not to use opioids, antidepressants, amitriptyline, gabapentin or pregabalin for low back pain.
Patients need safety-net advice to report red flag symptoms, such as saddle anaesthesia or incontinence.
Radiofrequency denervation may be an option in patients with chronic low back pain originating in the facet joints. Radiofrequency is used to target and damage the medial branch nerves that supply sensation to the facet joints associated with the back pain. This is done under a local anaesthetic.
Managing sciatica
The initial management of sciatica is mostly the same as acute low back pain.
The NICE clinical knowledge summaries (updated 2020) state not to use medications such as gabapentin, pregabalin, diazepam or oral corticosteroids for sciatica. They state not to use opioids for chronic sciatica.
They suggest considering a neuropathic medication if symptoms are persisting or worsening at follow up, but not gabapentin or pregabalin, leaving at the main choices of:
Amitriptyline
Duloxetine
Specialist management options for chronic sciatica include:
Epidural corticosteroid injections
Local anaesthetic injections
Radiofrequency denervation
Spinal decompression
Pathophysiology of cauda equina syndrome
Cauda equina syndrome is a surgical emergency where the nerve roots of the cauda equina at the bottom of the spine are compressed. It requires emergency decompression surgery to prevent permanent neurological dysfunction. However, even with immediate decompression, patients may still not regain full function.
Pathophysiology
The cauda equina (translated as “horse’s tail”) is a collection of nerve roots that travel through the spinal canal after the spinal cord terminates around L2/L3. The spinal cord tapers down at the end in a section called the conus medullaris. The nerve roots exit either side of the spinal column at their vertebral level (L3, L4, L5, S1, S2, S3, S4, S5 and Co).
The nerves of the cauda equina supply:
Sensation to the lower limbs, perineum, bladder and rectum
Motor innervation to the lower limbs and the anal and urethral sphincters
Parasympathetic innervation of the bladder and rectum
In cauda equina syndrome, the nerves of the cauda equina are compressed. There are several possible causes of compression, including:
Herniated disc (the most common cause)
Tumours, particularly metastasis
Spondylolisthesis (anterior displacement of a vertebra out of line with the one below)
Abscess (infection)
Trauma
Red flags of cauda equina syndrome
Saddle anaesthesia (loss of sensation in the perineum – around the genitals and anus)
Loss of sensation in the bladder and rectum (not knowing when they are full)
Urinary retention or incontinence
Faecal incontinence
Bilateral sciatica
Bilateral or severe motor weakness in the legs
Reduced anal tone on PR examination
TOM TIP: A common way people ask about saddle anaesthesia when taking a history is to ask, “does it feel normal when you wipe after opening your bowels?”
Managing cauda equina syndrome
Cauda equina is a neurosurgical emergency. It requires:
Immediate hospital admission
Emergency MRI scan to confirm or exclude cauda equina syndrome
Neurosurgical input to consider lumbar decompression surgery
Surgery should be performed as soon as possible to increase the chances of regaining function. Even with early surgery, patients can be left with bladder, bowel or sexual dysfunction. Leg weakness and sensory impairment can also persist.
Metastatic spinal cord compression
When a metastatic lesion compresses the spinal cord (before the end of the spinal cord and the start of the cauda equina), this is called metastatic spinal cord compression (MSCC). This is different to cauda equina, which specifically refers to compression of the cauda equina.
MSCC presents similarly to cauda equina, with back pain and motor and sensory signs and symptoms. A key feature is back pain that is worse on coughing or straining.
MSCC is an oncological emergency and requires rapid imaging and management. There are specialist MSCC coordinators who should be involved early to coordinate the imaging and treatment of patients with MSCC.
Treatments will depend on individual factors. They may include:
High dose dexamethasone (to reduce swelling in the tumour and relieve compression)
Analgesia
Surgery
Radiotherapy
Chemotherapy
TOM TIP: Cauda equina presents with lower motor neuron signs (reduced tone and reduced reflexes). The nerves being compressed are lower motor neurons that have already exited the spinal cord. When the spinal cord is being compressed higher up by metastatic spinal cord compression, upper motor neuron signs (increased tone, brisk reflexes and upping plantar responses) will be seen.
Spinal stenosis
Spinal stenosis refers to the narrowing of part of the spinal canal, resulting in compression of the spinal cord or nerve roots. This usually affects the cervical or lumbar spine. This section focuses on lumbar spinal stenosis, which is the most common type.
Spinal stenosis is more likely to occur in patients older than 60 years, relating to degenerative changes in the spine.
Types of spinal stenosis
Central stenosis – narrowing of the central spinal canal
Lateral stenosis – narrowing of the nerve root canals
Foramina stenosis – narrowing of the intervertebral foramina
Causes of spinal stenosis
Several conditions can cause the spinal canal to narrow, including:
Congenital spinal stenosis
Degenerative changes, including facet joint changes, disc disease and bone spurs
Herniated discs
Thickening of the ligamenta flava or posterior longitudinal ligament
Spinal fractures
Spondylolisthesis (anterior displacement of a vertebra out of line with the one below)
Tumours
