Week 4 - F - Hip - Hip replacement, Avascular necrosis, Trochanteric bursitis / gluteal cuff syndrome Flashcards
Where does hip pathology typically produce pain and where does it radiate to?
Hip pathology typically produces pain in the groin which may radiate to the knee (due to obturator nerve supplying both joints)
Hip pathology may also result in buttock pain however lumbar spine and SI joints problems can give rise to pain here
Hip pathology can also purely present with knee pain. What condition is this particulaly seen in? - what demographic is affected by this condition?
Hip pathology only presenting as knee pain is particularly seen in SUFE (slipped upper femoral epiphyses)
SUFE tends to affect overweight pre-pubescent adolescent boys
Treatment is to pin the femoral head to prevent further damage
Examination of hip pathology may reveal a reduced range of motion What is usually the first movement lost i hip pathology?
Usually the first movement lost in hip pathology is loss of internal rotation
What are the two abductors that are weak causing Trendelenburg’s gait or a positive Trendelenburg sign? Which nerve supplies them?
Gluteus medius and minimus are the two abductors that when weak can cause Trendelenburg’s
They are supplied by the superior gluteal nerve (L4,5, S1)
What are the two terms synonymous for hip replacement?
Total hip arthroplasty and total hip replacement are two terms synonymous for hip replacement
THA also includes procedures like hip resurfacing however
What are the 4 components of the total hip replacement joint? Remember 2parts make up the acetabulum (socket) and two make up the femoral head (ball)
Acetabulum parts - shell and liner
Femoral parts - head and stem
THR is widely considered one of the most successful operations in modern surgery Any THA will ultimately fail as a result of loosening of one or both of the prosthetic components (acetabulum (shell and liner) or femoral (head and stem) parts) What is the expected period that a total hip replacement will last?
A total hip replacement can be expected to last 15/20 years before failure from wear or loosening
Less than 5% of implants loosen before ten years
What are the gold standard materials used in a total hip replacement?
Gold standard materials for a hip replacement are the cemented metal/polyethylene materials
(metal can be stainless steel, cobalt chrome, titanium alloy)
What is the loosening of components in a hip replacement usually due to?
Loosening of components is predominantly due to wear particles from the bearing surface causing an inflammatory response at the implant to bone interface
The inflammatory mediators result in osteoclastic bone resorption
The decision to undergo THA is dependent on the level of pain and disability which the patient experiences. What are the conservative measures for hip arthritis before a THA may be considered?
Conservative measures include
* Simple analgesics
* Physiotherapy
* Use of a stick - reduces joint force by 15%
* Weight reduction
* Modification of activities
How can the patients level of pain in hip arthritis be gauged? How can the patients disability be gauged?
Level of pain in hip arthritis can be gauged by asking about
* analgesic use,
* rest pain and
* sleep disturbance
Level of disability in hip arthritis can be gauged by asking about
* walking distance,
* activities of daily living and
* impact of the arthritic hip on hobbies
What are some of the early complications of THR?
Early local complications include
* Infection
* Dislocation
* Nerve injury
* Leg length discrepancy
* Thrombosis / PE
What are some of the late complications of THR?
Late complications include
* Loosening
* Late infection (haematogenous spread from a distance site)
* Thromboembolic disease
* Late dislocation ( due to component wear)
If infection is diagnosed within the first couple of weeks (fulminant infection) what is carried out?
Carry out a surgical washing and debridement of the joint and prolonged parenteral antibiotics (around 6 weeks) - this can be attempted to salvage the artificial joint (around 50% successful)
When a hip replacement has failed, it can be re‐done (known as a revision hip replacement) however this involves bigger and more complex surgery than a first time (primary) procedure with often substantial blood loss, around twice the complication rates and often poorer functional outcome For the reasons above, which age group are doctors more likely to carry out THR for arthritis in?
As hip replacements only last around 15/20 years, joint replacements are usually considered more in the elderly as revision hip replacements are far more complicated (in terms of intracapsular hip fracture,
* hemiarthroplasty is usually preferred for treatment if elderly and cognitively impaired,
* THR preferred in more active patients)
What is the presenting features of avascular necrosis? How is it diagnosed? What is the sign seen on which scan?
Presenting features is groin pain
Diagnosed early cases on MRI
On Xray - the lytic region of bone due to the necrosis gives rise to the classic ‘hanging rope sign’
The broad tendinous insertion of the abductor muscles is under considerable strain and is subject to tendonitis and degeneration leading to tendon tears What are the abductor muscles? What other movement do they cause? What is their nerve supply? What overlying their insertion can also become inflamed?
The abductor muscles of the hip are the gluteus medius and minimus which are involved in abduction and medial rotation of the hip
They are innervated by the superior gluteal nerve (L4,5,S1) and insert into the greater trochanter of the femur
The trochanteric bursa over which they lie can also become inflamed resulting in trochanteric bursitis
