Lower limb Flashcards
What is the blood supply to the head of femur?
In adults it is a retrograde blood supply along the neck of femur from retinacular vessels which orginate from the medial/lateral circumflex femoral artery which come from the the profunda femoris
Nutrient vessels
In children there is also blood supply along the ligamentum teres but this is obliterated later childhood. acetbular branch of obturator artery
Where are the origins of the joint capsule?
Anterior aspect runs along intertrochanteric line
Posterior aspect 1.5cm proximal to intertrochanteric line
When do you consider offering a THR for a NOF?
NICE guidelines state:
If able to walk outdoors with no more than 1 stick
No bad medical comorbidities that makes procedure unsuitable
Expected to carry out ADLs for 2 further years minimum (HEALTH Trial- THR better functional outcomes if used for longer than 2 years compared to hemis)
In my practice I also consider if they drive, how far they walk, if they are able to follow hip precautions post op and patient preference
Cemented or uncemented hemis?
Cemented
Less loosening and periprosthetic fractures
Easier revision surgery
Increased risk of bone cement implantation syndrome- cardiopulmonary compromise from embolic shower during cementing
How do you reduce the risk of bone cement implantation syndrome?
Identify those at high risk:
Male, older, diuretics, cardiopulmonary disease
Inform anaesthetist of risk and pre cementing
Wash and dry femoral canal
Use cement restrictor and suction catheter
Do not use excessive manual pressurisation for those at high risk
Anaesthetic team to be aware the cardiopulmonary support may be required- vasopressors etc.
What are some of the BPT required for NOFs?
AMTS pre op
Theatre within 36 hours
FIB in ED and pre op
Orthogeris R/V
Bone health
PT day 1- FWB D1
Dietician review
What is the WHITE 11/FRUTI trial?
Fix or replace undisplaced IC NOF #- pragmatic trial
What are the approaches to the hip you know?
Anterior approach- internervous between sartorius + TFL and the rec femoris and gleut medius
Anterolateral- TFL and gleuteus medius
Direct lateral- Hardinge- muscle splitting approach, gleutues medius and minimus cuff, releasing vastus lateralis fibres proximally to expose LT. SGN runs 3-5cm proximal to GT in beneath gleutus minimus and medius
Posterior approach- gleuteus maximus splitting, detach short external (piriformis and Obturator internus) rotators, watch out for sciatic nerve and IGA
What type of hip dislocation is commonest?
How do they present on examination?
Posterior hip dislocation- 90%
Flex, Adducted, internal rotation
Anterior- extended, abducted, external rotated
When do posterior hip dislocations happen and what are the associated injuries?
Dashboard injuries classical
Look for:
Posterior wall acetabular injuries
Femoral head #s- Pipkin
NOF#s- do not reduce if present
Sciatic nerve injury- 10-20%
Ipsilateral knee injuries
Aortic injuries- deceleration tear
ATLS approach needed
Trauma CT?
CT pelvis at least pre/post reduction
How do you reduce a closed hip dislocation?
And when should you do so?
Check there is not a NOF #!!
Explain and consent the patient for the procedure
Ensure you have a suitably trained ED/anaesthetic doctor to perform sedation- propofol ideally
Brief
Supine
Counter traction on ASIS
Flex + in line traction of hip + adduction + internal rotation- Allis vs CM technique
Check xray and then CT pelvis to assess for acetabular/head/neck fractures
Placing in traction afterwards if associated acetabular #
Reduced within 6 hours
How do you classify femoral head fractures?
Pipkin classification
1- fracture below fovea- non weight bearing surface affected
2- above fovea- weight bearing surface affected
3- involving femoral neck
4- involving acetabulum
What is the subtalar joint?
Synovial joint
Calcaneus and talus
Eversion and inversion
What is the Hawkins classification of talar fractures?
1- non displaced talar neck fracture
2- subtalar dislocation
3- subtalar and tibiotalar dislocation
4- subtalar, tibiotalar and talo-navicular dislocation
AVN risk increases and type increases
What are the complications of a hip dislocation?
AVN
Sciatic nerve injury- most neuropraxia
Recurrent dislocators- place in cricket pad splint to prevent hip flexion
Post traumatic arthritis
#s
What displacement of the parts of femur do you get in a sub troch fracture?
Proximal part flexed and ER by attachments from Iliopsoas and SERs
Distal fragment is ADDucted and shortened
Adductors causes this
What are the ligaments of hip capsule?
Iliofemoral- strongest prevents hyperextension
Pubo femoral
Ischiofemoral
What is the iliotibial band?
Longitudinal band of fibres formed from gleut max + Tensor fascial lata
Inserts into femoral condyle
Stabilises knee during extension
What are the short external rotators?
Pirformis
Gemellus sup
Obturator internus
Gem inf
Obturator ext
Quadratus femoris
Describe the course of the sciatic nerve?
L4-S3 origin
Exits via the greater sciatic foramen
90% time below piriformis
10% through piriformis
1%< above
Lies beneath gleut max
Post surface of QF
1/3 way between IT and GT
Runs in post compartment behind adductor magnus
to Popliteral fossa
Divides into tibial and common peroneal nerve at superior point of fossa
Describe the contents of the greater sciatic foramen?
Greater- 10 structures, 7ns, 3 vessels
Above Piriformis
SGN + vessels
Below piriformis
Sciatic nerve
IGN + vessels
Internal pudenal vessels
Pudendal nerve
Post femoral cutaneous nerve
N to quadratus femoris
N to obt internus
Lesser sciatic N (PINT)
Pudendal N
Internal pudendal vessels
N to obt internus
Tendon to obturator internus
What is the aim with a young NOF #
ATLS- high energy injuries- exclude other injuries
Aim to reduce and fix rather than replace
Avoid AVN- achieve bony union
How can you classify young NOFs
Pauwel’s
Degree of angulation of fracture
<30o- stable
30-50- ?stability
>50o- unstable
Determines risk of non union and AVN
How do you manage a young NOF?
Next trauma list as a priority
Closed reduction if possible-Leadbetter’s technique- The affected leg is flexed to 45° with slight abduction and then extended with internal rotation while longitudinal traction is applied.
?Capsulotomy- remove tamponading effect of joint haematoma
Open reduction if unsuccessful- ant approach to the hip + bone hooks/k wires/traction
Garden1/2- Cannulated screws
Garden 3/4- DHS
Pauwels 3- add in derotational screw
Cannulated scews- 6.5mm
Analgesia post op
Protected weight bearing + follow up
Describe the anatomy of the PCL and ACL?
LAMP
What is the blood supply to the knee joint?
Popliteal A gives off the genicular arteries
Superficial femoral a gives off descending genicular as
Anterior tibial branch gives off recurrent branch
Boundaries and contents of popliteal fossa?
Boundaries
Superomedially- semimembranosus/semitendionsus
Superolaterally- biceps femoris
Inferomedially- gastroc medial
Inferolaterally- gastroc lateral
Contents (superficial to deep)
Common peroneal + tibial N
Popliteral vein + short saphenous
POpliteal A
LNs
Differential diagnosis of swelling in popliteal fossa
Trauma
DVT
cellulitis/abscess
Baker’s cyst
Aneurysm
Varicose Vein
Bony cancer/lesion
Describe the lower leg compartments
Anterior- DPN + anterior tibial A
Anterior tibialis
EHL
EDL
Peroneus tertius
Lateral- SPN + peroneal A
Peroneus brevis + longus
Posterior- Tibial N + posterior tibial a
Superficial
Plantaris
Gastroc
Soleus
Deep
Post tib
FHL
FDL
Popliteus
What are the major concerns with acute knee dislocations?
These are high energy injuries with high rates of neurovascular injuries
Vascular injuries- 7-14%
Nerve- CPN -25%
#s- 60%
Patella tendon rupture
Ligamentous injury
How can you classify acute knee dislocations?
High energy vs ultra low energy (obese)
Direction of dislocation
Ligamentous injury
What are you looking for on examination of acute knee dislocation?
Thorough examination of neurovascular status pre relocation
Dimple sign- medial aspect- buttonhole throughing of medial femoral condyle through the medial capsule- unreducible closed
What to do if pulses/absent pulses in acute knee dislocations?
Follow BOAST guidelines for arterial injury
Relocate
Re-examine
CTA + involve vascular
If still absent post reduction then for immediate surgical exploration- do not wait for imaging
If present pulses
ABPI and <0.9 for CTA
Need serial ABPI to monitor
Genicular arteries can mask popliteal injury
How to reduce/maintain reduction in acute knee dislocations?
Traction + reverse deforming forces +/- extension
Splint in 20-30o of flexion
What are the associated injuries in tibial plateau fractures?
Can be high energy injuries
Compartment syndrome
Meniscal tears- schatzler 2/4
ACL rupture- 4/5
Neurovascular injury- 4
Classify tibial plateau fractures?
Schatzker
1- lateral spit
2- split + depression
3- depression
4- medial plateau
5- bicondylar
6- dissociated shaft and plateau
Which nerves are at risk during ankle fracture surgery?
SPN-10cm proximal to lateral malleolus
Medial approach- great saphenous nerve runs anteriorly, with tibial nerve running posteriorly in tarsal tunnel
Posterolateral- sural nerve
Important points in history for ankle fractures?
Type 2 DM, decreased mobility, peripheral neuropathy, PVD, renal disease, smoking, alcohol abuse
What to think if a isolated medial malleolus #?
Think maisonneuve!!
Knee xray
Why do you need a mortise view?
15-20o of internal rotation
Assesses the articulation of the talus, fibula and tibia- ie. the mortise
Assess lateral joint and lateral talus
What are the general management rules for ankle fractures?
If stable for treatment in a cast/boot and WBAT as tolerated
If uncertain stability for weight bearing xray at 1/2 weeks
If <60 years old and for operative intervention aim for a D0/1 fixation
Which ankle fractures are considered unstable?
Weber B #s + talar shift
Weber C fractures
Bimalleolar/triamalleolar
How do you manage unstable ankle fractures?
If <60 years old for ORIF
If >60 years old/medically comorbid:
If can get reduction and is maintained at 2 weeks for close contact casting for 6 weeks
If reduction lost for ORIF vs hindfoot nail
What is the aim of surgery for ankle fractures?
To achieve reduction and stability of the ankle mortise
How do you manage Pilon fractures?
With difficulty:
Span, scan and plan
Intra-articular fracture
So aim is to provide absolute stability and anatomical reduction of articular surface whilst maintaining soft tissues
What are the classical Pilon fragments found on CT?
Medial malleolus fragment
Volkmann fragment- posterolateral from PITFL
Chaput fragment- anterolateral from AITFL
Do you know any research that may guide your decision making about ankle fractures?
AIM study- >60 year olds, unstable ankle fractures- CCC vs ORIF- equivalent ankle fnx at 6 months- loss of reductio with CCC, more infections with ORIF. Awaiting long term follow up to see if long term complications/operations needed in either group
FAME has finished recruitment- same as AIM but for 18-60 year olds
What do you need to assess in patients with a calcaneal fracture?
Think ATLS + CT scan
A lot of associated injuries
10% have contralateral calc and spinal injuries
60% of calc #s extend into joint
Hip and lower limb examination is necessary
What are the different types of calcaneal #s?
Extra-articular
Sustenaculum tali #, calcaneal tuberosity #
vs Intra-articular
Tongue type and depression type #s
How do you manage a calcaneal fracture?
ATLS
CT scan
Cast + NWB + discuss with F&A specialist
Operative management depends on patient vs injury factors
Patient: Smoker, T2DM, alcohol, compliance
Injury: Intra-articularm Bohler’s and Gissane’s angle, open, skin necrosis- tongue type
Also note the UK HEEL trial from 2014
RCT Multicentre, looking at displaced intra-articular calc #s
No differences in outcomes between op and non op at 2 years
What is a lis franc injury?A
Tarsometarsal # dislocation characterised by traumatic disruption between the medial cuneiform and 2nd metatarsal articulation
How does lis franc injury occur?
Axial and rotational loading through plantar flexed foot
What forms the lis franc joint?
Osseous components- transverse arch with 2nd metatarsal base as key stone
Ligamentous- lis franc lig runs from medial cuneiform to 2nd metatarsal
Strongest ligament- with plantar side stronger- so dorsal subluxation is common
What to do when examining for a ?lis franc injury?
Plantar bruising is pathognomic for lis franc injury
Tender mid foot
Dorsal subluxation of 2nd metatarsal of stressing
What would you see on imaging of a lis franc injury?
Fleck sign
Widening between 1st and 2nd ray of >2mm
Disruption of line from medial aspect of 2nd metatarsal to medial aspect of medial cuneiform
Dorsal displacement of metatarsals
Weight bearing xray if unsure- can guide non operative management if no displacement
CT scan for diagnosis/pre op management
Management of lis franc injury?
Non op- if no displacement on weight bearing xray
Operative- ORIF vs percutaneous fixation vs tight ropes
What are the ligaments around the ankle?
Laterally- lateral collateral ligament-
Anterior/post talofibular ligament
calcneofibular ligament
Medially- Deltoid ligament- superfiscial:
Ant tibiotalar, tibionavicular, tibiocalcanea;
Deep
Post tibiotalar
What are the goals of a TKR?
Alleviate pain, enable ADLs, personal independence
Restore mechanical alignment, restore joint line, balance soft tissues
What are the alternatives to a TKR?
Conservative- NSAIDs, activity mods, weight loss, PT, orthotics, injections
Osteotomies
Unicompartmental
Fusion
What are the different types of knee replacements?
Unconstrained- PCL retaining or subsituting
Constrained- hinged- global ligamentous instability/trauma
When is a patient suitable for a TKR/THR?
Trialled all conservative treatment options
Impacting ADLs
Night pain
What to examine in a normal joint?
Gait
Skin
Range of movement
Stability
Leg lengths
Post op PNI assessment?
CCRISP
A2E- + gather info
Sciatic nerve identified?
Patient fall post op?
Regional nerve blocks?
Expanding haematoma
Post op dislocation- leg length discrepancies
Excessive lengthening
Compression vs direct trauma
Release compressive bandages
Flex knee
Classes of nerve injury?
Seddon’s
1- neuropraxia full recovery
2- axonotmesis-spontaneous recovery is possible
3- neurotmesis no spontaneous recovery
Bedside diagnostic aids for NEc fasc diagnosis?
LRINEC and Finger sweep test
Types of Nec Fasc?
1- polymicrobial
2- monomicrobial (GAS)
3- marine
4- fungal
Management of Nec Fasc?
Extensive immediate aggressive debridement
Microbiologist
ITU
Plastics for recon
2 consultant decision if for primary amputation
Pathophysiology of Charcot’s arthropathy?
Sensory neuropathy
Leads to to loss of protective sensation
Destruction of foot and ankle joint
Classical signs of charcot?
Warm and erythematous foot that improves with elevation
Collapse of medial arch
On xray- fragmentation, subluxing and swelling
How to manage charcot arthropathy?
Obs
Bloods
XRays
MRI- abscess vs soft tissue swelling
Bone scan- charcot vs abscess vs osteomyseltitis
Brace, osteotomies and fusion, or ampuation
