Hip Flashcards

Question

What is the neurovascular supply of the hip joint?

Answer 1

- Mainly medial and lateral circumflex femoris arteries (from profunda femoris) - Medial circumflex artery is the major blood supply because the lateral circumflex artery must penetrate the thick iliofemoral ligament to reach the joint - As a result, damage to the medial circumflex artery can cause avascular necrosis of the femoral head Sciatic nerve (L4-S3), femoral nerve (L2-L4) and obturator nerve (L2-L4) supply sensation to your hip and knee. This can explain why hip and knee pain can be referred in a bidirectional manner

Answer 2

- Death of femoral head due to vascular disruption - Results in pain around hip with insidious onset - Potential causes: trauma, haematological disease, sickle cell anaemia -Fractures and dislocations can disrupt or rupture the profunda femoris (medial/lateral femoral circumflex artery) - Because the 2 arteries are from the profunda femoris, it leaves the femoral head vulnerable to avascular necrosis - Foveal artery is also commonly disrupted during dislocation Traumatic AVN: - associated with damage to medial circumflex femoral artery (the main supply to femoral head) - leads to death of cells in bony matrix and the reparative process begins, weakening the subchondral bone - can lead to bony collapse and arthritic changes to joint Atraumatic AVN: - coagulation of intraosseous microcirculation causes venous thrombosis - leads to arterial occlusion due to lack of venous outflow - this increases pressure within bone, compressing capillary beds and decreasing blood flow to the femoral head - this leads to cell death and repair, as in traumatic AVN Physical examination: - inspection of hip, skin and greater trochanter - thorough neurovascular exam is required to assess sensory and motor function - leg roll test: specific test for hip. Patient is supine, gently rolling thigh internally and externally - stinchfield test: involves resisted hip flexion - a positive test elicits pain which is likely to be associated with intraarticular hip pathology - Use MRI. It’s 98% sensitive Treatment: Non-operative= -bisphosphonates (limited to small lesions) Operative= -core depression of femoral head with or without stem cell injection: Drilling holes into femoral head. Relieves increase in pressure within femoral head, allowing blood flow and healing. Creates channels for new blood vessels to nourish the affected areas of the hip - Osteochondral (bone and cartilage grafting): used with core depression to help regenerate healthy bone and support cartilage at the hip joint. A bone graft is healthy bone tissue that is transplanted to where it is need. It can be autograft or allograft. - vascularised fibula graft: segment of fibula is taken along with its blood supply. This graft is transplanted into a hole created in the femoral head and neck, and the artery and vein are reattached to help heal the area of AVN. - total hip resurfacing: requires adequate bone stock to support resurfacing component. Metal on metal articulation - total hip replacement: most reliable pain relief. Both the head of femur and acetabulum are replaced with an artificial device. Doctor also removes damaged bone and cartilage

Answer 3

- abnormal hip development. Ball is loose in socket. In all cases, acetabulum is shallow - risk factors: female sex, first born infant, family history (genes such as HOX9 and DKK1) - There are different grades of classification: always dislocated, disloctable, subluxatable (mild case)- ball is loose in socket but won’t move out - Any interference with proper contact between femur and acetabulum in utero or infancy leads to DHH - Lower limb buds develop around 4 weeks; chondroblasts aggregate to form future bones of the hip - femoral head grows faster than acetabulum which results in under coverage of femoral head leading to abnormal development - The acetabulum continues to grow up to the age of 5 hence DHH may develop at any time from embryogenesis to 5 years - Malaligned contact for prolonged periods leads to chronic changes like hypertrophy of capsule, ligamentum teres —> preventing relocation of femoral head Examinations: -Ortolani manoeuvre: infant in supine position with hip flexed at 90 degrees and neutral position. Apply anterior force on the greater trochanter and abduct hip. If the hip is dislocated, one would feel a jerk or clunk -Barlow manoeuvre: same position as ortolani manoeuvre. Apply posterior force to trochanter, adduct hip Use ultrasound for abnormal hip examination with plain radiographs Management: - adolescent/adult hip preservation surgery - periacteabular osteotomy is an option for those with pain and shallow acetabulum - abduction splints (Pavlik harness) can be tried at an early stage for new borns. Holds the hip in position whilst allowing free movement of legs. Also tightens ligaments and promotes normal hip socket formation - For infants who fail the splints, a closed reduction with a hip spica cast is preferred - Open surgery: incision is made at the baby’s hip and femur is sometimes shortened to help fit the bone into the acetabulum. Also realigns hip

Answer 4

- Occurs in proximal femur - Most hip fractures occur in elderly patients whose bones have become weakened by osteoporosis - In young patients, it’s caused by high energy event -Hip fracture can occur in femoral neck, femoral head, Intertrochanteric area, subtrochanteric area Symptoms: - pain in groin and upper part of thigh - pain will be elicited on pin-rolling the leg 1) Femoral neck fracture (intracapsular - within capsule and extracapsular) - intracapsular = subdivided into capital, subcapital and transcervical - extracapsular = occur outside capsule. encompass Intertrochanteric(between the greater and lesser trochanter), intratrochanteric and subtrochanter fractures (found anywhere between the lesser trochanter to 5cm distally) - usually require surgery - The blood supply to the neck of femur is retrograde (passing from distal to proximal along the femoral neck to the femoral head) - The predominant supply is from the medial circumflex femoral artery which lies directly on the intracapsular femoral neck - The lateral circumflex artery provides less blood as it has to pierce the thick iliofemoral ligament - So a displaced intracapsular neck of femur can disrupt the blood supply to the femoral head, causing avascular necrosis - Any patients with a displaced intracapsular fracture will require arthroplasty, as opposed to fixation Investigations: - Plain film imaging (AP and lateral views of affected views) - Full length femoral radiographs - Basic blood tests in case transfusion is needed in surgery Management: - opioid analgesia for pain - physiotherapy - total hip replacement for displaced intracapsular fracture - open reduction: make incision over hip joint, put the bone back into place and hold the bone with pins and screws - does carry the risk of avascular necrosis Intertrochanteric fractures -treated surgically with either a sliding compression hip screw and side plate or an intramedullary nail

Answer 5

- Degenerative disease of synovial joints that causes progressive loss of articular cartilage - Increase in water content in articular cartilage and alternations in proteoglycans and collagen abnormalities - mild inflammation which progresses to moderate inflammation and hypervascularity - in the late stage of osteoarthritis, the synovium becomes thickened excessively vascular, with subchondral bone attempting to remodel damage —> this results in lytic lesions and sclerotic edges - proteolytic enzymes and cytokines increase the inflammation -Mainly occurs in people 50 years of age Symptoms: - stiffness - pain in groin or thigh that radiates to buttocks or knee - mechanical instability (e.g locking) Cause: - increasing age - family history of osteoarthritis - obesity - improper formation of the hip joint at birth (developmental dysplasia of the hip) Use radiographs Non-operative management: - NSAIDs - Walking stick - Weight loss, activity modification and exercise - Corticosteroid joint injections Operative management: - arthroscopic debridement (used to clean up arthritic joints - used for degenerative labral tears) - periacetabular osteotomy with or without femoral osteotomy (indicated in young adults with reduced hip and mild to moderate arthritis - femoral head resection (for pathological hip lesions and painful head subluxation) - Hip resurfacing (damaged bone and cartilage is removed and replaced with metal shell. Head of femur isn’t removed but instead it is called with a smooth metal covering) - Total hip arthroplasty (indicated in end stage, preferred for older patients). Doctor will remove damaged acetabulum and femoral head, then position a new metal or plastic joint surfaces to restore the function of the hip

Answer 6

Aetiology: - when proximal femur epiphysis is displaced posterinferiorly to the head and neck - hypothesised that displacement occurs due to high physiological axial load transmitted across a weak physis - endocrine disorders can weaken the physis - exact mechanism is unclear - idiopathic Symptoms - pain in hip, groin, thigh or knee - limited internal rotation. Internal rotation may elicit pain - may have Drehmann sign = external rotation and passive flexion of hip at 90 degrees - thigh atrophy may or may not be present Investigations - Use radiographs - MRI can be done - Use lab testing for endocrine or renal disorders Management: -analgesia for pain - In situ fixation: for mild cases. Doctor makes small incision near the hip, then inserts a metal screw across the growth plate to maintain the position of the femoral head and prevent any further slippage - Open reduction: doctor makes an open incision in the hip, then gently manipulates/reduce the head of femur back into its normal anatomical position - Dunn’s procedure: removing greater trochanter, screwing through the physis to align it with the head of the femur, then screwing greater trochanter back on —> this process can lead to avascular necrosis if arteries are disrupted

Answer 7

- Hip flexion of at least 120 degrees, abduction of at least 20 degrees and internal and external rotation are required for daily activities - Gait involves motion in all 3 planes (sagittal, frontal and transverse) - Use of cane on the contralateral side of the affected hip or a brace can substantially alter and frequently decrease magnitude of the hip joint reaction force

Hip Flashcards

(31 cards)