Orthopaedics Flashcards
What are the two main types of postoperative infection?
Superficial:
- skin
- subcutaneous tissue
- occurs within 30 days
Deep:
- to fascia and muscle
- occurs within 30 days or 90 days if prosthetic
What are the most common organisms to cause postoperative infection in a hip arthroplasty?
Coagulase negative Staph
Staph Aureus
Strep - 9%
What are some risk factors for post opp infection in ortho?
Patient factors:
- immunosuppressed
- diabetic
- malnourished
- elderly
Trauma factors:
- Trauma related injury
- Open wounds
- open fracture
Surgical factors:
- long operating time
- complicated surgery
How should post operative wound infections be managed?
Contact orthopaedic on call
Bloods: - FBC - CRP - U&ES - G&S \+/- - blood cultures
- Wound swaps
- only commence antibiotics after wound swab and with senior ortho guidance.
Why is it so important to get swabs of wound or isolation cultures of in the infection prior to antibiotics starting?
The infections can be very difficult to treat. Especially in prosthetic joints, and require large amounts of antibiotics. As such getting the right antibiotics first time is helpful.
What is the predominant blood supply to scaphoid bone?
Dorsal Carpal Branch of the radial artery
What advice should be given to someone who has had a hip replacement, to avoid dislocation?
Don’t flex hips beyond 90 degrees
Avoid deep seats
Don’t sit crossed legged
Sleep on back for 1st 6 weeks
Name some x-ray signs seen with Pagets disease:
Skull:
- Osteoporosis Circumscripta - areas of radiolucency in a circle
- Cotton wool appearance
- Tam O’Shanter sign - looks like person is wearing a hat
Pelvis:
- Cortical thickening
- Acetabular thickening
Long bones:
- Blades of grass
- Candle flame sign
Spine:
- squaring of the vertebrae
What signs on x-ray may be seen in osteomalacia?
Looser zones
- pseudofractures
Trefoil Pelvis
- Lateral indentation of acetabulum
- causes issues with cephalo-pelvis disproportion
Protrusio acetabuli
- medial indentation of the acetabulum
List some clinical findings seen in Ricket’s:
Skull:
- Delayed fontanelle closure
- Frontal bossing
- Craniotabes
Chest:
- Rachitic rosary/ Beading of the ribs (beads at costochondral joints)
- Harrison’s grooves
Limbs:
- Widening of wrists
- Genu varum/ Valgus
- Wind Swept look
Spine:
- Kyphosis
In osteoporosis what do you expect the blood results to show:
Calcium
- normal
Vitamin D
- normal
PTH
- normal
**this contrasts with osteomalacia in which you expect the opposite and PTH to be high
What is a urinary investigation that can be done into Paget’s disease?
Hydroxyproline
- break down of collagen
What is ulnar’s paradox?
The more proximal the lesion (i.e on the elbow) he lesser the deformity. Where as the more distal the lesions the worse the deformity
What are some common complications of a hip dislocation?
AVN - set in within 4 hours
Sciatic nerve pain
Recurrent dislocations
OA
List some core features of adhesive capsulitis:
Typically seen in diabetics.
- reduction in all planes especially external rotation
- active and passive movements are painful
- worse in morning
- varies between freezing phases and recovery phases
What is the management of cubital tunnel syndrome?
Soft Elbow Splints
Decompression surgery
- cubital tunnel release, ligamental tunnel is removed and scar tissue is removed
- anterior transposition of ulnar nerve
- medial epicondylectomy
*steroid injections are not used to due risk of injury to the nerve
List some differentials for a stuck finger:
Dupuytren’s contraction
Posterior interosseous nerve palsy (radial nerve)
Locked trigger finger
Subluxed MCPs
List some differentials for radial side wrist pain:
De Quervain’s Tenovaginits
Radial fracture
Scaphoid fracture
Thumb CMC joint OA
Which population of people are affected more severely from RA?
Black Caribbean
In a joint aspiration in suspected septic arthritis/ swollen joint, what investigations are done on the sample?
Visual examination
- cloudy/ colour
Gram staining
Microscopy
Culture
Crystal examination
What drug is used in septic arthritis if allergic to penicillin?
Clindamycin
What are some of the co-moralities seen in Psoratic arthritis?
Cardiovascular disease - 30% Ischemia - 10% Lymphoma 3% Obesity - 30% Uveitis - 20% Osteoporosis
What is another name for the straight leg test and when is it positive?
Lasegue sign
At 30 degrees if painful = positive sign
What x-rays should you order for a Lisfranc injury and what findings would you see on the x-ray?
Weight baring foot x-ray
and
Stress foot- graph
Miss-alignment of 1st and 2nd rays.
medial border of the base of the 2nd won’t align with the medial cuneiform
Is a infected prosthetic joint drained to dryness like a native?
No.
This can be detrimental
What is the most important aspect to consider in management of a fracture:
Soft tissue injury
- this should be done first to assess for bleeding or nerve damage.
Following this:
- reduction
What is the best investigation for assessing a intra-articular fracture?
CT Scan
What structures pass through the Carpal tunnel?
Median Nerve
4 x Flexor Digitorum Superficialis
4 x Flexor Digitorum profundus
Flexor Pollicis Longus
What muscles does the median nerve supply and which is the most sensitive for assessing the degree of muscle weakness causes by the damaged to the median nerve?
Lateral (2) Lumbricals
Opponens Pollicis
Abductor Pollicis Brevis
Flexor Pollicis Brevis
- testing Abduction of the thumb is most sensitive
- abduction is pointing the thumb away from the palmer plane *towards the sky if palms are facing up.
What is the management for Carpal tunnel syndrome?
NIght splints Steroid Injections (especially during pregnancy)
Carpal tunnel decompression surgery
- divided longitudinally not transversely - prevent damage to structures
In cubital tunnel syndrome, what structures does the ulnar nerve pass between?
Two heads of the Flexor Carpi Ulnaris
and
Cubital Tunnel Retinaculum
What are the symptoms of cubital tunnel syndrome? and what is the management?
Reduced power in the nerve distrupution and sensation
*Little finger abduction severely reduced
Clawing of digits
Hypothenar wasting
Interosseous muscle wasting
Treatment:
- Night splints
- Decompression surgery
**steroid injections are not warranted due to risk of damaging the nerve
Trigger finger is caused by constriction and thickening of what structure? and how is it treated?
Thickening of the flexor tendon
or
A1 pulley
- prevents extension of the finger
treated:
- night splints
- Steroid injection - single injection
- surgery on the A1 pulley
What disease is also known as Viking’s disease and how does it inherit?
and what is the pathology?
Dupuytren’s contracture
- Autosomal Dominant
Proliferation of myofibroblasts on the palmar fascia producing nodules and cords.
What are the therapies available for Dupeytrens contracture?
Medical:
- hand therapy
- injectable collagenases to dissolve the fibrosis plaques
Surgical:
- Needle aponeurotomy
- Fasciectomy
- Dermofasciectomy
- finger amputation
List some differentials for stuck fingers:
Dupeytrens contraction Palsy of the posterior interrouses nerve Subluxed MCPJs (often seen with RA)
List some differentials for radial sided wrist pain:
De Quervain’s stenosing tenovaginitis
Scaphoid fracture
Radial styloid fracture
Thumb OA
Scaphotrapeziotrapezoid arthritis
What is the pathology of DE Quervain’s stenosing tenovaginitis? and what is the diagnostic test.
What is the treatment?
Stenosis of the 1st dorsal extensor compartment
- Extensor pollicis brevis
- Abductor Pollicis longus
Test:
- Finkelstein test - moving hand in an ulnar position to elecit pain
Treatment:
- Splinting
- Steroid injection
Surgical:
- decompression of the 1st dorsal extensor compartment
What are the treatment options for a ganglion cysts?
leave alone
Aspirate
Surgically remove
List some differentials for lumps and bumps on the hands:
Ganglion cysts
Giant cell tumour
Heberden’s nodes, Bouchard’s nodes
Enchondroma
- often presents with pathological fracture
- benign
Skin lesions
Gouty Tophi
What are some of the causes of Subacromial impingement syndrome?
Intrinsic:
- muscle weakness
- overuse of joint
- degenerative disease
External:
- Hook shaped acromion (type III)
- Glenohumoral instability
What tests can be done to examine for subacromial impingement syndrome?
Painful Arc
- pain 60-120 degrees
Neer’s test
Hawkin’s test
What test can be done to assess for damage to the rotator cuff muscle, naming the specific muscles being exmained:
Empty cans test
- supraspinatus
External rotation
- infraspinatus
Hornblower sign
- Tere’s minor
- affected side will raise significantly higher
Belly press/ lift off
- Subscapularis
Name the bones that are typically affected by avascular necrosis:
Head and neck of femur
Scaphoid
Talus
If an elderly patient has had flu like symptoms for the past month and weight loss, and currently has a painful lower back then what are your differentials?
Metastasis
Osteomyelitis/ discitis
Osteoporosis
Mechanical back pain
What are some of the long term consequences of a hip replacement?
Chronic pain and stiffness
Leg shortening
Joist loosening requiring further surgery
What is the diagnostic test of choice for carpel tunnel syndrome?
Electromyography
- nerve conduction tests
Which clinical test can be done to establish weakness in the ulnar nerve, helping to differentiate between median nerve and ulnar nerve?
Froment’s test
- testing strength of pincer grip
What are the two x-ray signs seen of osteosarcomas?
Codman’s Triangle
- as it pulls up over the periosteum
Sun burst appearance
What features on an x-ray generally make a mass suggestive of malignancy?
Poor irregular borders
Cortical destruction
Soft tissue involvement
What staging criteria is used for bone tumours?
Enneking Stage System
What are some of the red flag symptoms of bone sarcoma?
Non- mechanical bone / joint pain
Bone pain at night
Pathological fracture
Bone swellings
Which muscle contracts the DIPJ and which the IPJ of the hand?
DIPJ: Flexor Digitorum Profundus
IPJ: Flexor Digitorum Superficialis
