Orthopaedics Flashcards
What is baker’s cysts?
Baker’s cysts are also called popliteal cysts. A Baker’s cyst is a fluid-filled sac in the popliteal fossa, causing a lump.
The popliteal fossa is the diamond-shaped hollow area formed by the:
Semimembranosus and semitendinosus tendons (superior and medial)
Biceps femoris tendon (superior and lateral)
Medial head of the gastrocnemius (inferior and medial)
Lateral head of the gastrocnemius (inferior and lateral)
Baker’s cysts are usually secondary to __________ _______ in the knee joint.
Baker’s cysts are usually secondary to degenerative changes in the knee joint.
What is bakers cysts associated with?
- Meniscal tears (an important underlying cause)
- Osteoarthritis
- Knee injuries
- Inflammatory arthritis (e.g., rheumatoid arthritis)
________ ______ is squeezed out of the knee joint and collects in the popliteal fossa. A connection between the synovial fluid in the joint and ____ ________ ____ can remain, allowing the cyst to continue enlarging as more fluid collects there.
Baker’s cysts are contained within the ____ tissues. They do not have their own epithelial lining.
Synovial fluid is squeezed out of the knee joint and collects in the popliteal fossa. A connection between the synovial fluid in the joint and the Baker’s cyst can remain, allowing the cyst to continue enlarging as more fluid collects there.
Baker’s cysts are contained within the soft tissues. They do not have their own epithelial lining.
Presentation of baker’s Cysts
Patients may present with symptoms localised to the popliteal fossa:
- Pain or discomfort
- Fullness
- Pressure
- A palpable lump or swelling
- Restricted range of motion in the knee (with larger cysts)
What is Foucher’s sign?
On examination, the lump will be most apparent when the patient stands with their knees fully extended. The lump will get smaller or disappear when the knee is flexed to 45 degrees (Foucher’s sign).
Differential of baker’s cyst?
- DVT- most important
- Abscess
- Popliteal artery aneurysm
- Ganglion cyst
- Lipoma
- Varicose veins
- Tumour
Ix for baker’s cyst?
Ultrasound is usually the first-line investigation to confirm the diagnosis. It is also used to rule out a DVT.
MRI can evaluate the cyst further if required, for example, before surgery. They can also demonstrate underlying knee pathology, such as meniscal tears.
Mx for baker’s cyst?
No treatment is required for asymptomatic Baker’s cysts.
Non-surgical management for symptomatic Baker’s cysts include:
- Modified activity to avoid exacerbating symptoms
- Analgesia (e.g., NSAIDs)
- Physiotherapy
- Ultrasound-guided aspiration
- Steroid injections
Surgical management typically involves arthroscopic procedures to treat underlying knee pathology contributing to the cyst, such as degenerative changes or meniscal tears. Resection of the cyst is difficult, and the cyst is likely to recur, particularly when another knee pathology is present.
What is another word for back pain?
Lumbago
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
The causes of neck pain include:
- 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
- Pneumonia
- Ruptured aortic aneurysms
- Kidney stones
- Pyelonephritis
- Pancreatitis
- Prostatitis
- Pelvic inflammatory disease
- Endometriosis
The spinal nerves ___ _____ come together to form the sciatic nerve.
The spinal nerves L4 – S3 come together to form the sciatic nerve.
The sciatic nerve exits the _______ part of the pelvis through the _____ ________ _________, in the buttock area on either side. It travels down the back of the leg. At the knee, it divides into the _____ ____ and the_______ ______ _____
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.
is sciatica pain radiating from the bum to the leg unilateral or bilateral
unilateral
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 ______ ________ _______
Bilateral sciatica is a red flag for cauda equina syndrome
Sciatica symptoms suggesting spinal fracture or anklyosing spondylitis
- 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)
Sciatica examination findings
- 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)
What is sciatic stretch test?
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.
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 –
R –
Ta –
B –
Le –
Po – Prostate
R – Renal
Ta – Thyroid
B – Breast
Le – Lung
Ix for sciatica
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)
What is STarT Back Screening Tool
Managing Acute Lower Back Pain?
exclude serious underlying causes like cauda equina, ankylosing spondyltis, spinal injury
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 tolerate
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)
Management of 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
What is the difference between compound, stable and pathological fracture?
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).
What are the 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)
*
What factures occur in children
Greenstick and buckle fractures typically occur in children rather than adults. Salter-Harris fractures only occur in children (adults do not have growth plates)
What is colle’s fracture?
What deformity does it cause?
What does it usually result from?
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).
WHat is scaphoid fracture
caused by?
A scaphoid fracture is often caused by a fall onto an outstretched hand FOOSH. 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.
Which bones fractures can lead to avascular necrosis?
These are the scaphoid bone,
the femoral head, the humeral head
the talus, navicular and fifth metatarsal in the foot.
Which classification can be used to describe lateral malleolus fracture?
Weber classification
What is lateral malleolus fracture?
he 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.
Explain the weber classification?
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
WHat can pelvic ring fractures lead to?
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.
What are pathological fractures?
common sites?
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 –
R –
Ta –
B –
Le –
Po – Prostate
R – Renal
Ta – Thyroid
B – Breast
Le – Lung
WHat are 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 fal
Bone mineral density can be measured using a
DEXA scan
The WHO criteria for osteopenia and osteoporosis are:
T score of the Hip
What are 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 _________ and reducing their activity, preventing the reabsorption of bone
Bisphosphonates work by interfering with osteoclasts and reducing their activity, preventing the reabsorption of bone
S/E for Bisphosphonates
- 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
What is the alternative for bisphosphonate
What is its mechanism
Denosumab
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.
What is important for X- rays in fractures?
What do you do if x rays are inconclusive
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.
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
Management for fractures
what is closed and open reduction?
- Closed reduction via manipulation of the limb
- Open reduction via surgery
Example of closed reduction?
a Colle’s fracture in a young adult)
Complications of fractures?
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 can occur following the fracture of ____ bones (e.g., ______)
Fat embolism can occur following the fracture of long bones (e.g., femur)
Fat emoblism criteria related to fractures?
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
Fat embolisation can cause a systemic inflammatory response, resulting in ____ ________ ________
Fat embolisation can cause a systemic inflammatory response, resulting in fat embolism syndrome
What are major risk factors for hip fractures?
Who are more affected?
Increasing age and osteoporosis are major risk factors for hip fractures.
Females are affected more often than males.
Hip fractures can be categorised into:
- Intra-capsular fractures
- Extra-capsular fractures
There are some basic structures of the top of the femur:
- Head
- Neck
- Greater trochanter (lateral)
- Lesser trochanter (medial)
- Intertrochanteric line
- Shaft (body)
treatment for cauda equina?
Bilateral or severe motor weakness in the legs
Reduced anal tone on PR examination
