Orthopaedics Flashcards
Bone purpose and make up
ORGAN
Functions - stability for locomotion, haematopoeisis, calcium homeostasis
Organic - cells and type I collagen (to resist tension like fibrocartilage - type II is hyaline cartilage)
Inorganic - hydroxyapatite and calcium phosphate to resist compression
Structure of bone
Metaphysis - proximal to growth plate (good blood supply, heals well)
Epiphysis - distal to growth plate
Diaphysis - rest of the shaft
Types of bone
Lamellar - mature, regular arrangement of collagen, strong, few cells - cortical and cancellous bone
Woven - immature, disorganised, in children or adults pathologically/fracture repair
Describing a fracture
- mechanism of injury (trauma, stress, pathological)
- which bone, what part
- closed/compound
- simple/comminuted
- displaced (angulated/shortened - according to distal fragment, no. of cortical widths by if lateral) or not displaced
- intra/extra-articular
- fracture pattern (transverse/spiral/oblique/segmental/greenstick/avulsion)
4 needs in bone healing
CASS Contiguity Alignment Stability Stimulation
Primary bone healing
Abnormal in real life, needs intervention for absolute stability
Cutting cones formed by osteoclasts for intramembranous ossification
Without callus - haematoma, inflammation and proliferation, cutting cones, consolidation
Secondary bone healing
With callus - haematoma, inflammation and proliferation, soft callus, hard callus, remodelling
Endochrondral ossification
Needs micromotion
Fracture time to heal
Perkin’s principles
Upper limb
- if under 12yo, 3-4 weeks
- in adult, 6-8 weeks
Lower limb (double)
- in child, 6-8 weeks
- in adult, 12-16 weeks
Axial skeleton
- 8-12 weeks (rare in children)
Factors affecting bone healing
Biological
- energy transfer
- neurovascular status
- infection
- the patient - age, smoking, diabetes, alcohol
Mechanical
- degree of displacement/reduction
- degree of movement
- mode of infection
Non-union of fracture
If not healed in double the time expected, will never heal naturally
- host factors
- injury factors
- treatment factors
Hypertrophic - excessive strain/movement at site, callus forms but fracture line persists
Atrophic - host + injury factors, absence of callus
Wolff’s law
Form follows function
Bent bone will reform straight according to where the pressure is
Secondary signs of fracture
Lipohaemarthosis
- if intra-articular, commonly in knee
- fat and blood from bone marrow into joint
- leg must be elevated to show fluid level on imaging
Haemarthrosis
- less serious
- haemorrhage into joint space
Principles of treatment of fractures
Aim to restore normal function
REDUCE
IMMOBILISE
REHABILITATE
Reduction of fractures
Only necessary if
- pressure on surrounding tissues
- intra-articular (synovial fluid washes away haematoma so can’t heal)
- multiple fractures (to get patient mobilising sooner)
To restore length, alignment, rotation in extra-articular fracture
Immobilisation of fractures
Non-operative
- plaster of paris cast
- splint
- traction
Operative
- K-wires (still callus formation, just to stabilise slightly, secondary healing)
- screws/plates (holds in absolute stability, primary healing)
- intramedullary nail (callus so secondary healing - need weight bearing 24h after surgery to get micromotion necessary)
- external fixator (secondary healing, for compound fractures, bridging plate so allows micromotion)
Rehabilitation of fractures
The earlier to move the better
MDT - physio, OT, GP, district nurse Analgesia Social worker (adapting housing) Work assessment Repeat risk management - falls, malignancy, epilepsy, osteoporosis
Fractures in children
Commonest in the areas of rapid growth – distal humerus, radius and around the growth plate
Greenstick - break on tension side, buckling on compression side (single cortical #, eg FOOSH)
Torus - 360degree buckling, bulge ‘donut’ around
Growth plate - Salter-Harris
Salter-Harris classification
For fractures of the growth plate in children, or commonly in adolescents (lots of growth, lots of cartilage)
- 90% type II
I - Straight across II - Above III - Lower IV - Two V - ERasure (crush)
Blood supply to NOF
Abdominal aorta -> common iliac
-> internal iliac
- obturator artery to head
- superior gluteal artery to greater trochanteric head
- inferior gluteal artery to lesser trochanter
All not enough to keep head of femur alive
-> external iliac -> femoral -> profunda femoris
-> LCFA + MCFA -> extracapsular anastomotic ring
Blood supply to femoral head
So if in fracture, cut the retinacular/ascending arteries, all blood supply cut off and avascular necrosis
Intracapsular NOF fractures
Shortened, internally rotates (ileopsoas to lesser trochanter pulls up)
Rare than extracapsular
Displaced or undisplaced
Garden’s classification - 1/2 give it a screw, 3/4 hip no more
NEED SURGERY within 36h (avascular necrosis will not heal alone)
- if under 55/undisplaced - cannulated screws
- if 55-75 - THR
- if 75+ - hemiarthroplasty
Extracapsular NOF fractures
More common than intracapsular, and better prognosis and blood supply not compromised
NEED SURGERY (for secondary healing, micromotion)
- intertrochanteric - DHS
- subtrochanteric (needs more support, closer to moment) - long intermedullary nail
Hip problems in children by age
Newborn - developmental dysplasia, dislocatable hips
First year - Tom-Smiths arthritis (septic)
Toddler - irritable hip, spontaneous improvement
Age 5-9 - Legg-Calve-Perthes
Age 10-14 - SUFE (limp, external fixation deformity)
Age 15-30 - early arthritis secondary to childhood problems
Age 50+ - impingement (CAM if cup too shallow, pincer if cup too big)
Old age - osteoarthritis
Contraindications to hip arthroplasty
ABSOLUTE
- active infection
- Charcot (proprioception loss)
- flail/neuromuscular impairment
- hypovascular
- inadequate soft tissue cover
RELATIVE
- young patient
- heavy demand
- obese
- poor compliance
- poor mental state
Carpal tunnel anatomy
- floor - scaphoid, lunate, triquetrum
- roof - flexor retinaculum (transverse carpal ligamentum)
Contains
- median nerve
- 9 tendons (4x flexor digitorum superficialis, 4x profundus, flexor pollucis longus)
- NO artery
Carpal tunnel syndrome
Compression of median nerve
Thumb + 2.5 fingers
Symptoms
- thenar eminence wasting
- pain, paraesthesiae, reduced sensation
- reduced dexterity
- comes and goes according to wrist position and activity
- Tinel’s and Phalen’s tests exacerbate
Treatment of carpal tunnel syndrome
Conservative
- leave alone if symptoms manageable
- wrist splint for 20 degrees extension, overnight
- pain relief - amitriptyline, gabapentin
- steroid injection into carpal tunnel, lasts 3-6 months
Surgical
- carpal tunnel release (ligament reheals longer) - the only reliable long-term cure
Cubital tunnel syndrome
Compression of ulnar nerve around medial epicondyle of humerus
Affects little and ring finger palmar and dorsally
Sensation change, pain, affected grip strength
Claw hand - hyperextension of MCP (lumbricles), fixed flexion at DIP and PIP (median nerve)
Ulnar paradox - if nerve cut above elbow, 18 months to get hand sensation back. As improves beyond elbow, claw hand, but once improvement to hand then clawhand subsides. (higher lesion = less obvious injury)
Ganglia
Cystic swelling (synovial joint fluid) in the neighbourhood of joint or tendon Can occur anywhere in the body where there is joint or tendon, but most common in wrist or hands Out-pouchings of joint capsule, fluid forced in via trapdoor
Conservative treatment (resolve on their own but may take years)
Surgical
- Aspiration -> 90% recurrence
- Excision - find root in capsule, remove and then reseal -> still 20% recurrence
Interventions not normally funded (can be painful but is mainly cosmetic)
Trigger fingers
Stenosing tenovaginitis of the flexor tendon sheath (any digit)
Inflammation of tendon, that gets stuck on sheath - very painful!
Can be congenital or acquired (idiopathic, traumatic, diabetes, rheumatoid)
Conservative - Rest (avoid making a fist) - NSAIDs - Steroid injection (majority) Operative - Release of A1 pulley – at the base of the digit
De Quervain’s
Same as trigger finger, but in extensor compartment
In anatomical snuffbox, nerves - abductor pollicis longus, extensor pollicis brevis - run in sheath
Don’t get stuck because power of wrist movement too much, but is incredibly painful
Conservative - Rest (avoid making a fist) - NSAIDs - Steroid injection (majority) Operative - Release tendon sheath
Finklestein’s test to diagnose (but essentially is just causing lots of pain)
Dupuytren’s contracture
Nodular hypertrophy and contracture of palmar fascia = tissue shortened and thickened, brings finger in and over
Familial cause - born predisposed and then something environmental triggers
- Liver disease/cirrhosis (so alcohol)
- Smoking
- Epilepsy (if take carbamazepine)
Male 10x more than female
Middle age onset
Leads to contracture of ring and little finger, MCP and/or IPJ, not DIP
Conservative
- Leave (Bill Nighy)
(Stretching splinting etc not effective)
Surgical (if progressive contracture (can’t know if will) and functional loss) - zigzag incisions
- Fasciotomy - cut the cord in half
- Fasciectomy/dermofasciectomy - cut the cord out, with or without skin
- Amputation (rare)
Always risk of recurrence
Wrist fractures
Colles’
Smith’s - reverse Colles’, distal radius fracture with volar angulation
Galleazzi - distal radius fracture with dislocation of distal radioulnar joint and intact ulnar
Scaphoid fracture - FOOSH in young adults (palpatable in anatomical snuffbox with thumb hyperextended. High rate non-union)
Colles’ fracture
- extra-articular distal radius fracture
- FOOSH in elderly
- dorsal angulation and displacement, radial angulation and displacement, shortening, distal fragment supinated
= dinner fork deformity
Humeral fractures
Supracondylar fractures
Monteggia fracture - #ulnar shaft with dislocation of radial head, mainly in children
Midshaft humerus - brace and leave if no neurovascular involvement, no problem up to 30 degrees displacement
Supracondylar fractures
- FOOSH in children
- concern re medial nerve damage (anterior interosseous branch, test with OK sign) and brachial artery damage (-> compartment syndrome) - if long term can be Volkmann’s ischaemic contracture, where permanent fixed flexion of hand and wrist
- malunion common, usually need reduction and wiring
Ankle fractures
Rarely tibia and not fibula
Fibula classified using Weber, level of syndesmosis
Calcaneum fractures most common tarsal, fall from height, commonly with associated injury eg spine compression
Vertebral fractures
Osteoporosis as diagnosis of exclusion - primary/secondary tumours/multiple myeloma/infection/trauma
Osteomyelitis
Bone infection
Common in children - vascular stasis up to growth plate
Common bugs - staphylococcus - or non-specific if can’t attribute to one bug
Presents - continuous throbbing pain, worse at night, fever/swelling/discharge
Acute/subacute/chronic
Spread - haematogenous/penetrating injury/contiguous
Conservative treatment - IV Abx 90% success
Operative - debridement, excision to healthy bone, irrigation, dead space management (+ abx)
Septic arthritis
Joint infection
Acute presentation - hot, painful, swollen, red, loss of function
Usually s. aureus, or gram -ves in elderly/immunosupressed
Risk - prosthesis, pre-existing joint disease, intra-articular steroid injections, diabetes
MEDICAL EMERGENCY - need aspiration to tailor abx and joint drainage
Treat with flucloxacillin initially (s. aureus)
Bone tumours (four things to consider)
What tumour does to bone - osteolysis, sclerosis
What bone does to tumour - indicates how fast growing if sclerosis/boxed in
Edges (demarcation)
Soft tissue swelling
Benign bone tumours
Osteochondroma
- Most common
- Aberrant cortical cartilage lesion
- Children and adults
- Usually no treatment required (1% may become malignant)
- Comes from growth plate, so becomes more proximal as you grow, then stops growing after you have finished your growth
Enchondroma
- Cartilaginous lesion
- Usually incidental finding
- Often left untreated
- Adults only
Osteoid osteoma
- Rare
- Age 5-30
- Painful (needs treatment)
- Self-limiting
- Caused by osteoblasts
Malignant primary bone tumours
RARE
Osteosarcoma
- Mostly sporadic
- Ill-defined lesion
- Needs chemotherapy and limb salvage or amputation
Ewing’s sarcoma
- Very rare
- Age 5-25
- In flat or long bones
- Very malignant, can get very large
- Needs chemotherapy and limb salvage or amputation
- 60% survival at 5 years
Chondrosarcoma
- Peak at age 80
- M>F
- Usually from a benign tumour, slow growing
- Common in pelvis and hip
- Chemo and radiotherapy less effective, needs wide excision and amputation
- Low grade 90% survival at 5 years, High grade 5% survival
Malignant secondary bone tumours
Much more likely than primary
MOSTLY FROM MULTIPLE MYELOMA (CRABI) or Mets from BLT with KP sauce - breast - lung - thyroid - kidney - prostate
Mets rarely below the knee - to spine, pelvis, ribs, proximal long bones
Often only palliative care
Cauda equina syndrome
Compression of lumbar spine nerve roots causing loss of sensation and function in bladder and bowel
- Lower back pain
- Alternating or bilateral root pain in legs
- Saddle anaesthesia
- Loss of anal tone on DRE
- Bladder (and bowel) incontinence
Due to herniated disc, tumour, fracture, narrowing of spinal canal
Need MRI
Spinal cord compression
Bilateral leg weakness
Preceding back pain
Bladder/anal sphincter involvement is late, manifests as hesitancy, frequency, painless retention
NEUROSURGICAL EMERGENCY
Signs on a motor, reflex and sensory level
- Normal signs above the level of the lesion
- LMN signs at the level of the lesion
- UMN signs below the level of the lesion (reflexes increased)
Causes
- Secondary malignancy (breast, lung, prostate, thyroid, kidney) in the spine
- Infection
- Cervical disc prolapse
- Trauma
- Haematoma (warfarin)
- Intrinsic cord tumour
- Atlanto-axial subluxation
- Myeloma
FOOSH
Fall on outstretched hand
Elderly -> Colles’
Young child -> greenstick
Young/middle age -> scaphoid fracture
Paget’s disease of bone
Metabolic bone disease - osteoclasts and osteoblasts out of balance/control
Starts with lytic bone (clasts) then becomes sclerotic (blasts)
Presentation
- Pain
- Bony deformities - skull enlargement
On radiograph
- Irregular borders
- Cortical thickening
- Trabecular coarsening (mottled)
- Bowed bone
- Expanded bone size (is what causes bowing, because fixed at eg knee and ankle so has nowhere to go)
Complications
- Fractures
- Osteoarthritis
- Osteosarcoma
Osteoarthritis on radiology
LOSS Loss of joint space Osteophytes Subchondral cysts Subchondral sclerosis
Bilateral, symmetrical ish (dominant side worse), DIPs and PIPs of hand mostly
Elbow ossification centres by age
CRITOL Capitellum - 2 Radial head - 4 Internal (medial) epicondyle - 6 Trochlea - 8 Olecranon - 10 Lateral (external) epicondyle - 12
Fuse at 14-16
Bones in wrist
Scaphoid lunate triquetrum pisiform hamate capitate trapezoid trapezium
Back pain red flags
B ladder/bowel disfunction A naesthesia (Saddle) D rop in weight unexpectedly
T rauma
U nrelenting non-mechanical pain
N eurological abnormalities
A ge of onset <20 or >55
F ever
I VDU
S teroid use
H istory of cancer (prostate, renal, breast, lung, bowel)
Intervertebral disc prolapse
Part of nucleus pulposus herniates through the annulus fibrosis
Presents with sciatica, numbness/tingling/weakness of the foot, uncomfortable to sit and either stand/lie down
BILATERAL LEG SYMPTOMS = impending cauda equina
Common in manual workers after heavy lifting
Need MRI
Conservative management unless cauda equina syndrome (surgical emergency)
Discitis/Vertebral Osteomyelitis
Discitis – Infection of the disc space
Vertebral osteomyelitis – infection of the vertebral body
- sinister back pain
- in immunocompromised or IVDU
- unwell, pyrexic, severe unrelenting back pain
- staphylococcus or streptococcus
- need to exclude spinal TB (unwell with TB symptoms + spondylitic, deformity, neurological deficit)
- need 6 weeks IV Abx + surgical drainage of abscess if present
Degenerative disc disease
Age-related condition in which one or more of the vertebral discs deteriorate or break
- pain, especially on movement + maybe numbness/tingling in extremities
- not OA, but can develop into OA if bone comes into contact and rubs
- clinical diagnosis + MRI
Unplanned care in shoulder pathology
Subluxation and Dislocation of the Acromioclavicular (AC) Joint - fall laterally onto shoulder (rugby) and tear capsule, coronoid and trapezoid ligaments as acromion is forced down. Anterior Dislocation of the Shoulder - common as shallow glenohumoral joint space and wide range of motion. From FOOSH or forced abduction and external rotation. Must rule out fracture before manipulating! Rotator cuff pathology - continuum of tendinitis, bursitis, partial tearing or complete tearing of the tendons. In age, repetitive motions. Conservative management, maybe steroid injections, only operate if sudden acute tear, impingement or calcific tendonitis. Adhesive capsulitis (frozen shoulder) - loss of passive and active shoulder movement, no clear underlying cause. Insidious onset, lose external rotation first. Should improve in 3 months.
- axillary nerve - posteriorly around surgical neck of humerus (with posterior circumflex artery). Motor to deltoid and teres minor, sensory to superior lateral cutaneous nerve (skin over shoulder)
- axillary artery
Humoral fractures and associated structures
Axillary nerve - surgical neck fracture of the humerus
Radial nerve - mid shaft fracture of the humerus, as it travels down the radial groove
Brachial Artery - supracondylar fracture of the humerus, increases the risk of volkmaan’s ischemic contractures
Axillary artery - surgical neck fracture of the humerus, but is relatively uncommon
(musculocutaneous nerve uncommonly injured)
