Musculoskeletal Flashcards
What is amyloidosis?
A (heterogenous) group of diseases characterised by extracellular deposition of insoluble amyloid fibrils
What are the two types of amyloidosis?
- AL amyloid = primary, immunoglobulin light chain amyloidosis, associated with Myeloma
- AA amyloid = secondary, non-familial and familial
2a. Non- familial AA = Inflammatory polyarthropathies account for 60% of cases, then chronic infections, IBD
2b. Familial AA = familial periodic Mediterranean fever syndrome
What are the risk factors for amyloidosis?
PMH of inflammatory conditions (AA)
Chronic infections (AA)
Positive FH
What are the features of primary amyloidosis (AL)?
Dependent on organ involvement:
1. Kidneys: glomerular lesions—proteinuria and nephrotic syndrome
2. Heart: restrictive cardiomyopathy (looks ‘sparkling’ on echo), arrhythmias, angina
3. Nerves: peripheral and autonomic neuropathy; carpal tunnel syndrome
4. GI: macroglossia (big tongue), malabsorption/weight, perforation, haemorrhage, obstruction, and hepatomegaly
5. Vascular: purpura, especially periorbital—a characteristic feature
What are the features of secondary non-familial amyloidosis (AA)?
PMH of chronic inflammation (e.g. RA/ IBD) or chronic infection (e.g. TB)
Affects the kidneys, liver, and spleen, and may present with proteinuria, nephrotic syndrome, or hepatosplenomegaly
Macroglossia is not seen; cardiac involvement is rare
What are the appropriate investigations for amyloidosis?
Diagnosis made with biopsy of affected tissue: positive Congo Red staining with apple-green birefringence under polarized light microscopy
The rectum or subcutaneous fat are relatively non-invasive sites for biopsy and are positive in 80%
Can also use serum amyloid precursor (SAP) scan
What is the management of amyloidosis?
AL: optimize nutrition; PO melphalan + prednisolone extends survival
High-dose IV melphalan with autologous stem cell transplantation may be better
AA: manage the underlying condition optimally
What is the prognosis of patients with amyloidosis?
Median survival is 1–2 years
Patients with myeloma and amyloidosis have a shorter survival than those with myeloma alone
What are the articulating surfaces of the ankle?
Tibia + fibula + talus
What are the two ligaments involved in the ankle joint?
Medial and lateral ligament (originating from the corresponding malleolus)
What are the muscle groups and movements of the ankle joint?
Plantarflexion: muscles in posterior compartment of leg (gastrocnemius, soleus, plantaris and posterior tibialis)
Dorsiflexion: muscles in anterior compartment of leg (tibialis anterior, extensor hallucis longus and extensor digitorum longus)
What is the neurovascular supply of the ankle?
Aterial supply = Malleolar branches of anterior tibial, posterior tibial and fibular arteries
Innervation is provided by tibial, superficial fibular and deep fibular nerves
What are the most common causes of posterior heel pain?
Achilles tendon disorders
What are the common achilles tendon disorders?
- Tendinopathy (tendinitis)
- Partial tear
- Complete rupture of the Achilles tendon
What are some risk factors for Achilles tendon disorders?
Quinolone use (e.g. ciprofloxacin) is associated
Hypercholesterolaemia → predisposes to tendon xanthomata
What are the features of achilles tendinopathy (tendinitis)?
- Gradual onset of posterior heel pain that is worse following activity
- Morning pain and stiffness are common
What is the management of achilles tendinopathy (tendinitis)?
Typically supportive
1. Simple analgesia
2. Reduction in precipitating activities
3. Calf muscle eccentric exercises (self-directed or through physiotherapy)
What are the features of Achilles tendon rupture?
Suspected if the patient reports the following whilst playing a sport or running:
1. An audible ‘pop’ in the ankle
2. Sudden onset significant pain in the calf
2. Inability to walk or continue the sport
What is the examination for Achilles tendon rupture?
Simmond’s triad
1. Ask the patient to lie prone with their feet over the bed
2. Look for an abnormal angle of declination - there will be a greater dorsiflexion of the injured foot compared to the other
3. Feel for a gap in the tendon and gently squeeze the calf muscles: if there is a rupture the achilles tendon injured foot will stay in a neutral position
What is the imaging modality of choice for Achilles tendon rupture?
Ultrasound
What is the Thompson test?
Lack of plantar flexion when calf is squeezed
What is the management for Achilles tendon rupture?
Acute referral to orthopaedic specialist
1. Non-operative : functional bracing/ casting in resting equinus
2. Operative: open end-to-end achilles tendon repair (for acute ruptures < 6 weeks) or percutaneous repair
What are some complications of Achilles tendon rupture?
- Re-rupture: higher with non-operative management
- Wound healing complications
- Sural nerve injury (percutaneous repair)
What is hallux valgus/ bunions?
- When the great toe deviates laterally to the metatarsophalangeal (MTP) joint
- The pressure of the MTP joint against a tight shoe results in a bunion
What is the aetiology of bunions?
Wearing pointed shoes or high heels
What is the management of bunions?
- Conservative: bunion pads, comfortable shoes, plastic wedge between the first and second toes
- Surgical: metatarsal osteotomy
What are ankle fractures?
Very common injuries which generally occur due to a twisting mechanism
What are the locations of ankle fractures?
Breakdown by fracture type:
1. Isolated malleolus fracture = 70%
2. Bimalleolar = 20%
3. Trimalleolar = 7%
What are the risk factors for ankle fractures?
Male
Younger age (mainly 15-24 years)
Obesity
Smoking
Alcohol consumption
What is the main mechanism of injury for ankle fractures?
Twisting injuries
What are the three ligament complexes that stabilise the ankle?
- Deltoid
- Lateral ligament complex
- Syndesmosis
What are the two tendons which stabilise the ankle?
- Peroneal tendons: peroneus longus and brevis
- Posterior tibial tendon
What are the neurovascular structures surrounding the ankle?
- Anterior tibial artery and depot peroneal nerve
- Posterior tibial artery and tibial nerve
- Superficial peroneal nerve
- Sural nerve
What are the features of an ankle fracture?
Severe ankle pain
Difficulty or inability to walk
What are the findings of an ankle fracture of a physical exam?
Ecchymosis and swelling
Deformity
Limited ankle motion
What are the Ottawa ankle rules for an ankle fracture?
State that x-rays are only necessary if there is pain in the malleolar zone and:
1. Inability to weight bear for 4 steps
2. Tenderness over the distal tibia
3. Bone tenderness over the distal fibula
What is the Weber system in ankle fractures?
Describe ankle fractures related to the level of the fibular fracture:
Type A = below the syndesmosis
Type B = fractures start at the level of the tibial plafond and may extend proximally to the syndesmosis
Type C = above the syndesmosis which may itself be damaged
How is the Weber system for ankle fractures classified?
Type A: infrasyndesmotic
Type B: transsyndesmotic
Type C: Suprasyndesmotic
What are some differentials for an ankle fracture?
Ankle sprain
Syndesmotic injury
Achilles tendon rupture
What are some features of an ankle sprain?
May be able to weight bear
Positive anterior drawer or talar tilt test
Radiographs without fracture
What are the principles of management for ankle fractures?
Depends on the stability of the ankle joint and patient’s comorbidities
1. All fractures should be promptly reduced to remove pressure on the overlying skin and subsequent necrosis
2. Young patients = usually require surgical repair often using a compression plate
3. Elderly patients = usually fare better with conservative management as their thin bones do not hold metalwork well
What are some of the non-operative management options for ankle fractures?
Short-leg AO splint
Short-leg cast
CAM boot
(for stable ankle fractures and those unfit for surgery)
What are some of the operative management options for ankle fractures?
Open reduction internal fixation
External fixation
What are the Ottawa rules (ankle fractures)?
An x-ray is only required if there is any pain in the malleolar zone and one of the following:
1. Bony tenderness at the lateral malleolar zone
2. Bony tenderness at the medial malleolar zone
3. Inability to walk 4 weight bearing steps immediately after the injury
What is the management of ankle fractures according the Weber classification?
Type A: Usually stable → reduction and cast →ORIF occasionally needed
Type B: Stability variable → may require ORIF
Type C: Unstable fracture → ORIF
What is a lisfranc injury?
When bones in the midfoot are broken or ligaments that support the midfoot are torn
What is a metatarsal stress fracture?
Stress fracture = tiny cracks in the bone caused by repetitive force often from overuse
A hairline fracture in one of the long metatarsal bones in the foot from overly stressing the foot when using it in the same way repeatedly
What is Morton’s Neuroma?
- Pain from pressure on an interdigital neuroma (thickening of tissue around a nerve) between the metatarsals
- Pain radiates to the medial side of one toe and lateral side of another, can cause pain and tingling on the ball of the foot (plantar)
- Management includes:
a. activity modification
b. NSAIDs
c. Avoid narrow shoes or high heels
d. If severe: neuroma excision
What is plantar fasciitis?
- The most common cause of heel pain seen in adults
- Caused by inflammation of the plantar fascia aponeurosis at its origin on the calcaneus
- Pain is usually worse around the medial calcaneal tuberosity
What are the risk factors for plantar fasciitis?
- Obesity (high BMI)
- Weight bearing endurance activity e.g. dancing, running
What is the pathophysiology of plantar fasciitis?
- Chronic overuse leads to micro tears in the plantar fascia
- Repetitive trauma leads to recurrent inflammation and periostitis
What are the features of plantar fasciitis?
- Sharp heel pain
- Insidious onset of heel pain, often when first getting out of bed (may prefer to walk on toes initially)
- Worse at the end of the day after prolonged standing
- Relieved by ambulation (walking)?
- Common to have symptoms bilaterally
What are the signs of plantar fasciitis on examination?
- Tender to palpation at medial tuberosity of calcaneus
- Dorsiflexion of the toes and foot increases tenderness with palpation
- Limited ankle dorsiflexion due to a tight Achilles tendon
Where is the pain usually worse in plantar fasciitis?
Medical calcaneal tuberosity (heel)
What are the investigations for plantar fasciitis?
- Usually made clinically with tenderness to palpation at the medial tuberosity of the calcaneus that worsens with dorsiflexion of the toes and foot
- Can consider imaging to exclude stress fractures e.g. bone scan
- Lab tests not indicated unless concerned of other causes of heel pain e.g. infection, inflammatory arthritis
- EMG: exclude entrapment
What is the management of plantar fasciitis?
- Conservative (first line): pain control, splinting and therapy (stretching)
a. Rest feet where possible
b. Wear shoes with good arch support and cushioned heels
c. Insoles and heel pads may be helpful - Shock wave: for chronic heel pain lasting longer than 6 months when other treatments have failed
- Surgical release with plantar fasciotomy: for persistent pain after 9 months of failed conservative measures (complications common including lateral plantar nerve injury and chronic pain)
What is Ankylosing spondylitis?
A HLA-B27 associated spondyloparthlopathy (chronic progressive inflammatory arthropathy)
What is the epidemiology of ankylosing spondylitis?
Typically presents in males (3:1) aged 20-30 years old
What are the features of ankylosing spondylitis?
- Typically a young man who presents with lower back pain and stiffness of insidious onset
- Stiffness is usually worse in the morning and improves with exercise
- Patient may experience pain at night which improves on getting up
What are the clinical signs of ankylosing spondylitis on examination?
- Reduced lateral flexion
- Reduced forward flexion: Schober’s test
- Reduced chest expansion
What is Schober’s test for ankylosing spondylitis?
- A line is drawn 10cm above and 5 cm below the back dimples (dimples of Venus)
- The distance between the two lines should increase by more than 5 cm when the patient bends as far forward as normal
Reduced lumbar spine flexion (due to vertebral fusion) in AS: < 5cm
What are the other features of ankylosing spondylitis?
- Apical fibrosis
- Anterior uveitis
- Aortic regurgitation
- Achilles tendonitis
- AVN block
- Amyloidosis
- Cauda equina syndrome
- Peripheral arthritis (more common in females)
What are the investigations of ankylosing spondylitis?
- Bloods: laboratory markers, HLA-B27 (limited use)
- Plain x-ray of the sacroiliac joints = most useful investigation
- If x-ray negative but suspicion is high = MRI
- Spirometry: restrictive
Why is HLA-B27 testing of limited use in the investigation of ankylosing spondylitis?
Positive in 90% of AS patients, but also in 10% of normal patients
What is the most useful investigation in establishing the diagnosis of ankylosing spondylitis?
Plain x-ray of the sacroiliac joints
What are the features of ankylosing spondylitis on plain x-ray of the sacroiliac joints?
May be normal in early disease. Later changes include:
1. Sacroiliitis: subchondral erosions and sclerosis
2. Squaring of lumbar vertebrae
3. ‘Bamboo spine’ - late and uncommon
4. Syndesmophytes: due to ossification of outer fibres of annulus fibrosus
What might be found on a chest x-ray in a patient with ankylosing spondylitis?
Apical fibrosis
When is an MRI used in ankylosing spondylitis?
- If an x-ray is negative for sacroiliac joint involvement but the suspicion remains high
- Will see signs of early inflammation involving sacroiliac joints (bone marrow oedema
- Confirms the diagnosis and prompts further treatment
What might be seen on spirometry in a patient with ankylosing spondylitis?
Restrictive defect due to a combination of pulmonary fibrosis, kyphosis and ankylosis of costovertebral joints
What is the management of ankylosing spondylitis?
- Encourage regular exercise such as swimming
- NSAIDs are first line (with gastric protection)
- Physiotherapy
- DMARDs e.g. sulphasalazine are only really useful if there is peripheral joint involvement
- Anti-TNF therapy should be given if there is persistently high disease activity despite conventional treatments
What is the first line drug treatment for ankylosing spondylitis?
NSAIDs e.g. naproxen 500mg BD
What is arthroplasty?
Joint replacement e.g. total hip replacement, hemiarthroplasty
What is a hip fracture?
Fracture of the hip, which a common site especially in osteoporotic elderly females
What is the risk of neck of femur fractures?
Avascular necrosis: the blood supply to the femoral head runs up the neck of the femur
Risk is greater in displaced fractures
What are the features of hip fractures?
- Pain
- Shortened and externally rotated leg
- Patient with non-displaced or incomplete neck of femur fractures may be able to weight bear
How can hip fractures/ neck of femur fractures be classified?
- Location
- Garden system
What is the location classification for neck of femur fractures?
- Intracapsular: from the edge of the femoral head to the insertion of the capsule of the hip joint
Lesser trochanter is the dividing line - Extracapsular: these can either be trochanteric or subtrochanteric
What is the Garden system for hip fractures?
Type 1: Stable fracture with impaction in valgus
Type 2: Complete fracture but undisplaced
Type 3: Displaced fracture, usually rooted and angulated but still has boney contact
Type 4: Complete boney disruption
What Garden types most commonly have blood supply disruption and so greater risk of avascular necrosis?
Types 3 and 4
What is the management of an intracapsular hip fracture?
Depends if it is displaced or undisplaced:
1. Undisplaced = internal fixation or hermiarthroplasty if unfit
2. Displaced = replacement arthroplasty (either THR or hemirthroplasty), THR is favoured if:
a. Patients were able to walk independently with no more than the use of a stick
b. Not cognitively impaired
c. Medically fit for anaesthesia and procedure
What is the management for an extra capsular hip fracture?
- Stable intertrochanteric fracture = dynamic hip screw
- Reverse oblique, transverse or subtrochanteric features = intramedullary device
What advice should be given to patients who have had a hip replacement to minimise the risk of dislocation?
- Avoid flexing the hip > 90 degrees
- Avoid low chairs
- Do not cross your legs
- Sleep on their back for the first 6 weeks
What are the different surgical techniques in hip arthroplasty?
- Cemented hip replacement (most common): metal femoral component is cemented into the femoral shaft
- Uncemented hip: increasingly popular in younger and more active patients but more expensive
- Hip resurfacing: metal cap over the femoral head (advantage of preserving femoral neck in case conventional arthroplasty is needed later in life)
What is involved in post-arthroplasty recovery?
- Physiotherapy and a course of home exercises
- Walking sticks or crutches for up to 6 weeks after replacement surgery
What are some of the complications of arthroplasty?
- Wound and joint infection
- Thromboembolism: require low dose molecular weight heparin for 4 weeks after surgery
- Risk of dislocation
What does arthroplasty mean?
Joint replacement
What sign is seen in pelvic fracture?
Positive Trendelenburg sign from superior gluteal nerve dysfunction
What is arthroscopy?
- A type of keyhole surgery for checking or repairing your joints (most commonly the knees)
- Minimally invasive
What is gout?
- A form of inflammatory arthritis
- Microcrystal synovitis caused by the deposition of monosodium urate monohydrate in the synovium
- Around 70% of first presentations affect the 1st metatarsophalangeal (MTP) joint
What is the aetiology of gout?
Underlying metabolic disturbance is chronic hyperuricaemia (uric acid > 0.45 mmol/l) which may be caused by:
1. Increased urate intake or production: dietary, lymphoma, leukaemia
2. Decreased renal excretion: idiopathic, drugs, renal dysfunction
What drugs can cause decreased renal excretion?
CANT LEAP:
Ciclosporin
Alcohol
Nicotinic acid
Thiazides
Loop diuretics
Ethambutol (AB for TB)
Aspirin
Pyrizinamide (AB for TB)
What are the predisposing factors for an acute attack of gout?
- Decreased excretion of uric acid:
a. drugs*: diuretics
b. chronic kidney disease
c. lead toxicity - Increased production of uric acid:
a. myeloproliferative/lymphoproliferative disorder
b. cytotoxic drugs
c. severe psoriasis - Lesch-Nyhan syndrome
hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency: only seen in boys, other features: renal failure, neurological deficits, learning difficulties, self-mutilation