Flashcards in The Hip Joint & Pathology Deck (24):
What is the articulation of the hip joint?
What type of joint is the hip joint?
Head of the femur and acetabulum of the pelvis
The acetabulum is incomplete inferiorly - bridged by transverse acetabuluar ligament
Deepened by fibrocartilage acetabular labrum
Ball and socket synovial
What are the capsule attachments of the hip joint?
Anterior: intertrochanteric line
Posterior: 2/3 towards the intertrochanteric crest
How are the three bones of the hip separated?
Begins to fuse at 15-17 years
Fusion complete at 20-25 years
Which ligaments are involved in stabilising the hip joint?
Iliofemoral, pubofemoral, ischiofemoral - they have spinal orientation. They become tighter when the joint is extended
Accessory ligaments (ligament of the head of the femur - from the acetabular fossa to the fovea of the femur, and transverse acetabular ligament)
What is the blood supply to the hip joint?
Major source - the deep femoral artery gives off the medial and lateral circumflex femoral arteries. They wrap around the head of the femur.
The medial circumflex femoral artery gives rise to the retinacular arteries to supply the head and neck
Minor source - obturator artery (via the ligament of the head of the femur). This is often not adequate if it is the only supply
There is also some contribution from the inferior gluteal artery
What happens in acquired hip dislocations?
Uncommon because of stable articulation
Posterior dislocation in RTA (knee hits dashboard)
Capsule and acetabulum disrupted
Limb shortened and medially rotate
Possible sciatic nerve damage (lies posterior to joint line)
What is meant by the Garden classification of hip fractures?
Type 1: incomplete fracture
Type 2: complete fracture, non-displaced
Type 3: complete fracture, partially displaced
Type 4: complete fracture, completely displaced
What x-rays are required in hip fractures?
AP and lateral pelvis
Distal femur - always be on the look out for lyric lesions further down from the fracture
If the x-rays are inconclusive, MRI within 24 hours
Outline the initial management of a hip fracture?
ABCDE with neurovasculature examination
Pain control - reassess at 30 minutes. Paracetamol, opioids, nerve block
Assessment by orthopaedics. Geriatrician, anaesthetist
Surgery within 36 hours
What are the surgical options for hip fractures?
Intracapsular - if non-displaced/Garden1&2 - screw fixation
If displaced/Garden3&4 hemi or total hip replacement
Inter-trochanteric - dynamic hip screw
Subtrochanteric - intramedullary nail
Which ligaments convert the greater and lesser sciatic notches into foramina?
What is there importance in correct posture?
They limit rotation of the inferior part of the sacrum during transmission of weight of the body down the vertebral column in erect posture
Why is serum lactate of relevance in hip fractures?
Associated with prognosis
Admission venous lactate was associated with early death
A 1mmol/L increase in venous lactate resulted in a 1.9x fold increase in 30 day mortality
What are the displacements in an intracapsular neck of femur fracture?
The corresponding limb is shortened and externally rotated due to the pull of iliopsoas (which attaches to the lesser trochanter)
What is meant by the Nottingham hip score?
Tool used to assess 30 day and 1 year mortality following NOF# using pre-admission criteria: age, sex, Hb, co-morbidities, MMTS, living in an institution, malignancy
What is meant by trochanteric bursitis?
How does it present?
Inflammation of the greater trochanteric bursa secondary to repetitive trauma caused by iliotibial band tracking
Lateral sided hip pain although the hip joint is not involved
Pain with palpation
What are the management options in trochanteric bursitis?
Conservative: NSAIDs, stretching, physio, corticosteroid injections
If conservative measures fail - operative: open vs arthroscopic trochanteric bursectomy
What is meant by iliotibial band syndrome? (ITBS)
How does it present?
Excessive friction between the iliotibial band and the lateral femoral condyle
Common in runners, cyclists
Pain localised over the lateral femoral condyle
Recreated with deep squatting
Ober test positive
What are the management options in iliotibial band syndrome?
Conservative: rest, ice, NSAIDs, corticosteroid injection, physio
If conservative failure - surgical excision options
What is the mechanism of dislocation in total hip replacement?
Can dislocate if hip is in 'at risk' position
Excessive flexion, addiction, or rotation
Climbing out of a low seat chair is a classic cause
Crossing of ankles when lying down
Sleeping on the side of the replacement hip
Patients are given seat raises before going home
What risks are explained to the patient during consent for hip arthroplasty?
1 in 300 sciatic nerve injury
DVT in ~10% even with prophylaxis
600 people need to be treated with Heparin to prevent one person having a fatal PE
Deep infection - two stage revision
in an intra-capsular neck of femur fracture, when should a total arthroplasty be considered over a hemi-arthroplasty?
Consider a total for active patients aged younger than 75 years old who are able to walk with no more than a frame, and no cognitive impairment/dementia (more likely to dislocate)
How may a patient with OA at the hip appear whilst standing?
They have reduced internal rotation, so stand in external rotation
They stand adducted, so can appear to have a valgus deformity
They can develop a fixed flexion deformity at the hip, so are propped up on their toes, and may walk on their toes
What is meant by a Trendelenberg gait?
Due to weakness of gluteus medius and minimus, when walking the hip on the unaffected side drops (the weak musc,Es can't abduct to keep the hip level)
This then means that the patient leans to the other side (which is the affected side) to counteract the weight of the body
This means they should use a walking stick on the unaffected side to support the pelvis which drops