Orthopaedics, gen surg Flashcards
Give four key XR changes in OA
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)
Give two renal side effects of ibuprofen use
AKI (e.g. acute tubular necrosis) or progressive kidney disease
Give two CVS SEs of ibuprofen use
HTN, HF, MI, stroke
How long do we give VTE prophylaxis for with TKRs and THRs?
28 days post elective hip replacement
14 days post elective knee replacement
What do we use to avoid prosthetic joint infections?
Prophylactic abx
What is a compound 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.
What is a pathological 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:
What is a Colle’s fracture?
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”.
What is the usual cause of a Colle’s fracture?
This is usually the result of a fall onto an outstretched hand (FOOSH).
Give the key sign with a scaphoid fracture.
Tenderness in the anatomical snuffbox
What is the usual cause of a scaphoid fracture?
FOOSH
Give a complication of a scaphoid fracture.
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.
What is the Weber classification used for?
The Weber classification can be used to describe fractures of the lateral malleolus (distal fibula).
Why is a pelvic fracture so concerning?
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.
What causes 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.
Name three main cancers that metastasise to the bones
PoRTaBLe
Po – Prostate
R – Renal
Ta – Thyroid
B – Breast
Le – Lung
How do we medically treat osteoporosis first line?
Calcium and vitamin D
Bisphosphonates (e.g., alendronic acid)
How do bisphosphonates work?
Interfering with osteoclasts and reducing their activity, preventing the reabsorption of bone
Give two key SEs of 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 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 relative stability in regards to bone fractures?
In fractures where closed and open reduction aren’t suitable, treatment involves providing 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
When does fat embolism present after fracture?
24-72 hours afterwards
What are Gurd’s criteria used for?
Diagnosis of fat embolism:
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
Describe the blood supply to the 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 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.
What is the Garden classification used for?
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)
What is a hemiarthroplasty?
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.
What would you see on examination of a hip fracture?
Shortened, abducted and externally rotated leg
Give a key sign of a fractured neck of femur (NOF)
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).
How does acute compartment syndrome differ from acute limb ischaemia?
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.
What is 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.
How do we confirm the diagnosis of chronic compartment syndrome?
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.
What shows on XR in osteomyelitis?
Periosteal reaction (changes to the surface of the bone)
Localised osteopenia (thinning of the bone)
Destruction of areas of the bone
Nothing in early disease
What is the best modality of imaging for osteomyelitis?
MRI scans
How do we treat osteomyelitis?
Surgical debridement of the infected bone and tissues
Antibiotic therapy
What is the most common cause of osteomyelitis?
Staph auerus
What is haematogenous osteomyelitis?
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.
What is the most common form of bone cancer?
Osteosarcoma
What makes up the sciatic nerve?
The spinal nerves L4 – S3 come together to form the sciatic nerve.
Where is the pain in sciatica?
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.
What might bilateral sciatica indicate?
Cauda equina syndrome
What is the 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.
How do we diagnose CES?
Emergency MRI scan within four hours
How do we investigate ankylosing spondylitis?
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 the STarT screening tool used for?
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.
What medication can we give for muscle spasm?
Benzodiazepines (e.g., diazepam) for muscle spasm (short-term only – up to 5 days)
How do we treat sciatica medically?
Mostly the same as acute low back pain.
No opioids
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
What is the cauda equina?
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).
What are the red flag symptoms of CES?
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
How does metastatic spinal cord compression present?
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.
What is 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.
How does CES differ from spinal stenosis?
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.
What is meralgia paraesthetica?
Meralgia paraesthetica refers to localised sensory symptoms of the outer thigh caused by compression of the lateral femoral cutaneous nerve. It is a mononeuropathy, meaning it only affects a single nerve.
How does meralgia paraesthetica present?
Patients present with abnormal sensations (dysaesthesia) and loss of sensation (anaesthesia) in the lateral femoral cutaneous nerve distribution. The skin of the upper-outer thigh is affected. Patients may describe symptoms of:
Burning
Numbness
Pins and needles
Cold sensation
Often aggravated by walking or standing for a long duration and improve on sitting down
How does meralgia paresthetica present on examination?
Symptoms are often worse with extension of the hip on the affected side. This can be used to reproduce symptoms on examination.
What is trochanteric bursitis? What does it cause?
Trochanteric bursitis refers to inflammation of a bursa over the greater trochanter on the outer hip.
It produces pain localised at the outer hip, referred to as greater trochanteric pain syndrome.
What are bursae?
Bursae are sacs created by synovial membrane filled with a small amount of synovial fluid. They are found at bony prominences (e.g., at the greater trochanter, knee, shoulder and elbow). They act to reduce friction between the bones and soft tissues during movement.
How does trochanteric bursitis present?
The typical presentation is a middle-aged patient with gradual-onset lateral hip pain (over the greater trochanter) that may radiate down the outer thigh. The pain is described as aching or burning. It is worse with activity, standing after sitting for a prolonged period and trying to sit cross-legged. It may disrupt sleep and be difficult to find a comfortable lying position.
How does trochanteric bursitis present OE?
Tenderness over the greater trochanter
What is the Trendelenburg test?
The Trendelenburg test involves asking the patient to stand one-legged on the affected leg. Normally, the other side of the pelvis should remain level or tilt upwards slightly. A positive Trendelenburg test is when the other side of the pelvis drops down, suggesting weakness in the affected hip.
How do we test for trochanteric bursitis?
Trendelenburg test
Resisted abduction of the hip
Resisted internal rotation of the hip
Resisted external rotation of the hip
What is the RICE mneumonic?
R – Rest
I – Ice
C – Compression
E – Elevation
What is first-line for analgesia with MSK injuries?
NSAIDs
What is Osgood-Schlatter disease?
Osgood-Schlatter disease is caused by inflammation at the tibial tuberosity where the patella ligament inserts. It is a common cause of anterior knee pain in adolescents.
It typically occurs in patients aged 10 – 15 years and is more common in males. Osgood-Schlatter disease is usually unilateral, but it can be bilateral.
What is the pathophysiology behind Osgood-Schlatter disease?
The patella tendon inserts into the tibial tuberosity. In patients with Osgood-Schlatter disease, multiple minor avulsion fractures occur where the patella ligament pulls away tiny pieces of the bone. This leads to growth of the tibial tuberosity, causing a visible lump below the knee. Initially, this lump is tender due to inflammation. As the bone heals and inflammation settles, the lump becomes hard and non-tender.
A hard, non-tender lump is then permanently present at the tibial tuberosity.
What is a Baker’s cyst?
Baker’s cysts are also called popliteal cysts. A Baker’s cyst is a fluid-filled sac in the popliteal fossa, causing a lump.
How do Baker’s cysts form?
Degenerative changes in the knee joint.
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.
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
How do we investigate Baker’s cysts?
Ultrasound is usually the first-line investigation to confirm the diagnosis. It is also used to rule out a DVT.
Where do you find the Achilles’ tendon?
The Achilles tendon connects the calf muscles (gastrocnemius and soleus) to the heel (the calcaneus bone). Flexion of the calf muscles pulls on the Achilles and causes plantar flexion of the ankle.
Which antibiotics are known to causes Achilles tendon rupture?
Fluoroquinolone antibiotics (e.g., ciprofloxacin and levofloxacin)
What is Simmonds’ calf squeeze test?
The patient is positioned prone or kneeling with the feet hanging freely off the end of the bench or couch. When squeezing the calf muscle in a leg with an intact Achilles, there will be plantar flexion of the ankle. Squeezing the calf pulls on the Achilles. When the Achilles is ruptured, the connection between the calf and the ankle is lost. Squeezing the calf will not cause plantar flexion of the ankle in a leg with a ruptured Achilles. A lack of plantar flexion is a positive result.
How do we diagnose Achilles tendon rupture?
US
