Conditions Of The Hip And Surgery Flashcards
X ray changes in osteoarthritis
LOSS
- Loss of joint space
- Osteophytes
- Subarticular sclerosis
- Subchondral cysts (fluid filled holes in the bone) darker circles on x ray
Presentation of OA in the hip
- joint pain
- stiffness
- morning stiffness <30 mins
- worsen with activity and towards the end of the day
- restricted ROM
- crepitus on movement
- effusions around the joint
- enlargement of joints
Management of OA of the hip
- weight loss
- analgesia
- physio therapy
- intra-articular steroid injections
- joint replacement: hemiarthroplasty or THR
Pathophysiology of osteoarthritis
- imbalance between degradation of cartilage and remodelling of bone
- due to active response of chondrocytes in the articular cartilage + inflammatory cells in surrounding tissues
- remodelling causes osteophytes + subchondral cysts
Indications of elective hip replacement
- Osteoarthritis (most common)
- fractures
- septic arthritis
- osteonecrosis
- bone tumours
- rheumatoid arthritis
What are the options for elective hip replacement?
- total hip replacement: replacing both articular surfaces of the joint
- hemiarthroplasty: replacing half of the joint
- partial joint resurfacing: replacing part of the joint surfaces
Outline a total hip replacement
- lateral incision over the outer aspect of the hip made
- hip joint is dislocated
- head of the femur is removed + replaced by metal or ceramic
- stem is inserted into the femur
- this is either cemented or uncemented
- the acetabulum is hollowed out + replaced by a metal socket
- this is screwed or cemented into place
- a space is used between the new head and socket to complete the artificial joint
Chemical VTE prophylaxis after elective hip replacement
- LMWH e.g. enoxaparin for 10 days then aspirin for 28 days
Or - LMWH for 28 days with anti-embolism stocking until discharge
- alternatives : aspirin, DOACs
Mechanical VTE prophylaxis after elective hip replacement
- anti-embolism stockings
- intermittent pneumatic compression
- venous foot pumps
Risks of elective hip replacement
- infection
- damage to nearby structures e.g. superior gluteal nerve > Trendelenburg gait
- VTE
- compartment syndrome
- haemorrhage
- haematoma
- pain
- fractures
- loosening or dislocation
What is the most common organism to infect prosthetic joints?
Staphylococcus aureus
Risk factors of prosthetic joint infection
- prolonged operative time
- obesity
- diabetes
Management of prosthetic joint infection
- repeat surgery > joint irrigation, complete replacement or debridement
- prolonged abx
Categories of hip fractures
Intracapsular fractures: NOF
Extracapsular fractures: intertrochanteric + subtrochanteric
Blood supply to the head of the femur
Retrograde blood supply from the medial circumflex femoral arteries (via the retinacular arteries)
Classification of intra-capsular hip fractures
_Garden classification_
- grade 1: incomplete fracture + non-displaced
- grade 2: complete fracture + non-displaced
- grade 3: partial displacement (trabeculae are at an angle)
- grade 4: full displacement (trabeculae are parallel)
Success rate of hip replacement surgery and how long do they last?
- 95% of patients experience pain relief after surgery
- THR last 20-30 years
- hemiarthroplasty last 10-20 years
Management of NOF fracture
- if undisplaced: screws
- if displaced (grade 3/4): hemiarthroplasty or THR
When do you do a hemiarthroplasty compared to a THR?
- hemiarthroplasty: older, less mobile, more frail patients
- THR: younger, more mobile patients
Types of extra-capsular hip/femur fractures
- intertrochanetric fractures
- subtrochanetric fractures
Intertrochanetric vs subtrochanteric location
- intertrochanteric: between greater and lesser trochanter
- subtrochanteric: distal to the lesser trochanter (but within 5cm)
Treatment of intertrochanetric fractures
Dynamic/sliding hip screw
- screw into the neck and head of femur
- plate is screwed into outside of femroal shaft
- this holds the femur in position + provides controlled compression
Surgical management of subtrochanteric fractures
Intramedullary nail
- a metal pole inserted through greater trochanter into central cavity of the femoral shaft
Presentation of hip fractures
Typically older pt who has fallen
- shortened, ABducted , externally rotated
- pain in groin or hip
- pain can radiate to knee
- unable to bear weight
Imaging of suspected hip fractures
- X-ray in two views (AP and lateral)
- MRI or CT if x-ray negative but still suspect fracture
What is a key sign of fractured NOF on an AP X-ray of the hip?
Disruption of Shenton’s line
What is Shenton’s line?
One continuous line formed by the medial border of the femoral neck + continues to inferior border of the superior pubic ramus
Management of hip fracture
- analgesia
- VTE prophylaxis
- pre-op assessment (incl. bloods + ECG to ensure they are fit for surgery)
- hemiarthroplasty or THR within 48 hours
- Physiotherapy + post-op analgesia after surgery
Types of femoral shaft fractures
Proximal
Mid shaft
Supracondylar
What is the major risk after a femoral shaft fracture
Hypovolaemic shock
Mechanism of femoral shaft fracture
high energy truama e.g. fall from height, RTC
Treatment of femoral shaft fracture
- analgesia
- open or closed reduction
- Intramedullary nailing
- plaster cast
Mechanism of distal femoral fracture
Younger person - high energy sport
Older - fall from standing
What is the most common type of hip dislocation?
Why?
Posterior
Only ischiofemoral ligament on posterior surface (weakest)
Where is the femoral head palpable in central hip dislocation?
Per rectum
Leg position in posterior hip dislocation
Shortened
ADducted
Internally rotated
Leg position in anterior hip dislocation
Externally rotated
ABducted
Leg position in NOF fracture
Shortened
Externally rotated
ABducted
Mechanism of action of hip dislocations
- posterior: high energy trauma, RTC, dashboard injury
- anterior: due to forced ABduction and external rotation
- central: side impact car accidents, fall onto the sides > fracture dislocation
Complications of hip dislocation
- a vascular necrosis
- sciatic nerve injury
- superior gluteal nerve injury
- recurrent dislocation
- post traumatic OA
- infection
Management of hip dislocation
- urgent reduction
- analgesia
- address associated injuries such as fractures
Why do intracapsular NOF fractures have a high risk of avascular necrosis?
Damage to medial femoral circumflex artery
Causes of avascular necrosis
- mechanical disruption in blood supply e.g. fracture
- thrombosis
- post trauma
- excess alcohol
- hypertension
- excessive steroid use
Causes of superior gluteal nerve injury
- complication of hip surgery
- buttock injection
- greater trochanter fracture
- hip dislocation
What muscles are impacted by superior gluteal nerve injury?
What does this cause?
Gluteus medius + minimus
.
Trendelenburg’s sign due to the muscles not contracting to prevent tilting
Mechanism of pulled hamstring
Sudden muscular exertion - stretching of posterior thigh muscles
Causes of hamstring injuries
Muscle sprain
Partial or complete tear of hamstring from ischial tuberosity
What can a complete tear of hamstring muscles from the ischial tuberosity cause?
An avulsion fracture
What is an avulsion fracture?
A small piece of bone breaks off due to excessive pulling from a tendon or ligament
What is trochanteric bursitis?
Inflammation of the bursa over the greater trochanter of the outer hip
Presentation of trochanteric bursitis
- Gradual onset of lateral aching/burning hip pain that radiates down the outer thigh
- worsens with activity, standing after sitting for a prolonged period and trying to sit cross legged
What worsens trochanteric bursitis?
Activity
Standing after sitting for a prolonged period and
Trying to sit cross legged
Examination findings of trochanteric bursitis
ask patient to resist the movements of Abduction, internal rotation + external rotation > pain will be felt in bursa region
Management of trochanteric bursitis
- rest
- ICE
- analgesia
- Physiotherapy
- steroid injection
What is pseudoarthrosis?
- ‘false joint’
- occurs when a fracture fails to he normally
what is meralgia paraesthetica?
- localised sensory symptoms of the outer thigh caused by compression of the lateral femoral cutaneous nerve
- mononeuropathy
why are there no motor symptoms with meralgia paraesthetica?
the lateral femoral cutaneous nerve only carries sensory signals
presentation of meralgia paraesthetica
- abnormal sensation (dysaesthesia) + anaesthesia to upper outer thigh
- burning
- numbness
- pins + needles
- cold sensation
- localised hair loss
- worsened on prolonged walking or standing + extension of hip
- eases on sitting down
management of meralgia paraesthetica
- rest
- loose clothing
- physiotherapy
- basic analgesia, neuropathic analgesia
- local steroid injections
- surgical decompression, transection or resection
