Hip Flashcards
Remind yourself of the bony anatomy of the hip
Remind yourself of the ligaments surround the hip
Intracapsular
Ligament of head of femur (from the acetabular fossa to the fovea of the femur)
Extracapsular
There are three main extracapsular ligaments, continuous with the outer surface of the hip joint capsule:
- Iliofemoral ligament – anterior inferior iliac spine and then bifurcates before inserting into the intertrochanteric line of the femur. Y shaped. Prevents hyperextension of hip joint. Strongest.
- Pubofemoral – superior pubic rami to the intertrochanteric line of the femur. Triangular shape. Prevents excessive abduction and extension.
- Ischiofemoral– body of the ischium to the greater trochanter of the femur. Spiral orientation. Prevents hyperextension and holds the femoral head in the acetabulum.
Where does the capsule of the hip joint run from and to?
- Capsule attached to acetabulum proximally
- Distally, at the anterior it attaches to the intertrochanteric line and posteriorly it attaches ~1cm superomedial to the intertrochanteric crest
Remind yourself of the arterial supply to the hip
***Arterial supply is retrograde
- Abdominal aorta bifurcates into common iliac
- Common iliac bifurcates into internal & external iliac
- Internal goes on to supply abdominal organs
- External becomes the femoral artery (at the inguinal ligament)
- Femoral artery divides into
- Profunda femoris
- Superficial femoral
- Profunda femoris gives off:
- Medial femoral circumflex
- Lateral femoral circumflex
- Perforating arteries (supply anterolateral muscles of thigh)
- Medial & lateral circumflex form anastomoses at base of femoral neck to form a ring
- Ring gives off branches; these branches contribute to the cruciate and trochanteric anatomoses of hip
- In children, ligamentum arteriosum (branch of obturator) also acts as blood supply to femoral head
Where are the cruciate and trochanteric anastomoses of hip?
What arteries contribute to each?
Which blood vessel predominatly supplies hip?
What is the relevance of this in intracapsular #NOF?
Medial circumflex artery
Lies directly on intracapsular femoral neck therefore displaced intracapsular fractures disrupt blood supply to emoral head and femoral head will undergo AVN so pts need joint replacement rather than fixation
A #NOF is a fracture occuring between?
Subcaptial region of femoral head to 5cm distal to lesser trochanter
State some risk factors for #NOF
- Age
- Osteoporosis risk factors
- Falls risk factors
- Low BMI
- Cancer (pathological fractures)
Discuss the different types of #NOF; include any subtypes
NOF can be intracapsular or extracapsulare:
-
Intracapsular: between subcapital region of femoral head to the basocervical region
- Subcapital
- Transcervical
- Basocervical
-
Extracapsular: from intertrochanteric line to 5cm below lesser trochanter
- Intertrochanteric: between greater trochanter and lesser trochanter
- Sub-trochanteric: from lesser trochanter to 5cm distal to lesser trochanter
What classification can be used to further classify intracapsular fractures?
Describe this classification
Describe the typical presentation of #NOF
- Pain (commonlly in groin & thigh- may be referred pain to knee)
- Inability to weight bear
- Leg is shortened, externally rotated
- Pain on pin-rollling leg
Explain why the leg appears shortened, abducted and externally rotated in #NOF
Axis of rotation that usually passes obliquely through femoral head and down neck of femur now passes through greater trochanter and vertically down long axis of femur; this alters the actions the muscles have on the bone.
- Externally rotated: short lateral rotators of hip e.g. pirformis, obturator internus, sup & inf gemelli, quadratus femoris all cause external rotration of femoral shaft. Iliopsoas also now pulls lesser trochanter anteriorly contributing to external rotation
- Abducted: abductors e.g. gluteus medius & minimus abduct femur
- Shortened: muscles of thigh e.g. rectus femoris, adductor magnus and hamstrings pull distal fragment of femur upwards
What investigations should you do in a suspected #NOF
- Plain radiographs
- Affected hip (AP, lateral)
- Pelvis (AP)
- ?Full length femoral if suspect pathological fracture
- ?MRI if cannot see fracture on plain radiograph
- Bloods
- FBCs
- U&Es
- Coagulation
- Group & save
- ?CK (if long lie)
- Other investigations to complete your assessment (e.g. dipstick, CXR etc… often useful if elderly pt who has fallen & need to determine cause)
Discuss the initial management of a pt with #NOF
- A-E or ATLS (dependent of mechanism of injury/state of pt)
- Analgesia (opiod or regional anaesthesia such as iliofascial or femoral nerve blocks)
- Assess neurovascular status
Discuss the management of intracapsular #NOF
Management depends on factors such as whether fracture is displaced or non-displaced and pt factors:
Young,fit patient
- Undisplaced: internal fixation with cannulated hip screws
- Displaced: increased risk of AVN therefore total hip replacement
*NOTE: fixation may fail and may require total hip replacement later
Elderly patient
- Hip hemiarthroplasty or total hip replacement regardless of if displaced or undisplaced: do total hip in pts who are medically fit for anaesthesia, abel to walk around independently or with stick and cognitively sound.
Discuss the surgical management of extracapsular #NOF
- ORIF with dynamic hip screw or trochanteric femoral intramedullary nailing
State some immediate post-operative complications
- Pain
- Bleeding
- Leg length discrepancies
- Neurovascular damage
What internal fixation method has been used to internal fix this hip?
Dynamic hip screw
What internal fixation method has been used to internally fix this hip?
Cannulated nail screws
What internal fixation method has been used to internally fix this hip?
IM nail
Low energy injuries in young pts can result in avulsion fractures of the pelvis. State which sites are commonly affected and how these avulsion fractures usually present
What is a Morel-Lavallee lesion?
Internal degloving injury whereby skin and subcutaneous tissue are abruptly separated from underlying fascia due to trauma resulting in creation of a potential space. May spontaneously resolve or become encapsualted & persistent
What investigations are required for a suspected acetabular fracture?
- Plain film radiographs (AP, Judet, obturatro oblique and iliac oblique)
- Or CT scan (often occurs in traumatic injuries therefore CT often done anyway. ALSO GOLD STANDARD )
What is the Nottingham Hip Fracture score?
Predicts 30 day mortality after hip fracture
