Hip Disorders

Question 1

Avascular Necrosis

Answer 1

• Definition:
  
  • death of bone tissue due to lack of blood supply
• Mechanism:
  
  • traumatic disruption of vascular supply to femoral head, deficient circulation from other causes (ex. Sickle cell anemia)
• risks:
  
  • sickle cell anemia, Gaucher’s, SLE, steroid use, EtOH abuse, decompression injury (scuba diving), cervical neck fracture, prior injury (very common in femoral neck fractures), advanced osteoarthritis
• S/sxs:
  
  • *Insidious onset
  • *Severe pain with initial phases
  • -Dull throbbing groin pain radiating to thigh or buttock
  • -pain with activity → pain at rest (with progression)
  • -Progressive limp
  • -Limited ROM
• PE:
  
  • Pain with straight leg raise
  • -Pain with ROM of hip
  • -Antalgic gait
• Dx:
  
  • XR: normal at first → patchy areas of sclerosis, crescent sign
  • MRI may be needed
• Tx:
  
  • -Mild: rest, PT, NSAIDs
  • -Surgical decompression
  • -Hip replacement: if femoral head collapses
  • **Just know to refer to ortho
• Complications:
  
  • -femoral head collapse
  • -development of arthritis

Question 2

Femoral Acetabular Impingement

Answer 2

• Definition:
  
  • osseous deformities (extra bone) along the femoral head &/or acetabular rim rub against each other during hip motion → injury to the acetabular labrum & cartilage. Usually prominence on acetabulum bumps the femoral head → more bony growth on the femoral head (bad)
• Types:
  
  • -Cam: prominence of the femoral head
  • -Pincer: prominence of acetabular rim
  • -Mixed: both
• Most common in young adults
• S/sxs:
  
  • *Insidious onset
  • Groin pain worse with sitting, crouching (weight bearing)
  • Limp with activity
  • Decreased ROM (especially IR, ER)
• PE:
  
  • Stinchfield test: pt lying on back, have them raise leg while you put pressure against it
  • FADDIR: flexion, adduction, internal rotation (pain with)
  • negative back & hip exam
• Dx:
  
  • XR with an AP view will be negative so you need special views (Dunn view) will show crossover sign (Pincer) or loss of femoral head-neck offset (Cam)
  • MRI
• Tx:
  
  • referral to ortho for surgery
  • -NSAIDs & activity mod
• Complications:
  
  • osteoarthritis

Question 3

Pelvic Fractures

Answer 3

• Definition:
  
  • fracture of the pelvic ring & the acetabulum
• Mechanism:
  
  • high-impact injuries (MVA) or low-energy fractures (older patients)
• Types:
  
  • -Stable: involve only one side of the pelvic ring
  • -Unstable: disrupt the ring at two sites
• S/sxs:
  
  • *Variable
  • Groin pain, lateral hip pain, or buttock pain with ambulation
  • inability to ambulate or perineal ecchymosis
• PE:
  
  • evaluate for arterial injury, bladder, injury, & other fractures
  • -Stability: 1 break is stable, 2+ is unstable
  • Inspect pelvic area for swelling, ecchymosis & deformity
• Dx:
  
  • XR: AP pelvis, AP chest, lateral cervical spine (trauma)
• Tx:
  
  • Refer to ortho
  • -Low-energy: analgesics, rest, gait training
  • -High-energy: ORIF
  • Bleeding: pelvic binder & IV fluid resuscitation
• Complications:
  
  • Thrombotic complications (DVT)
  • -Sciatic nerve damage
  • -Vascular injury (bleeding)
  • -GU injuries: pain, sexual dysfunction

Question 4

Proximal Femur Hip Fracture

Answer 4

• Definition:
  
  • fracture of the proximal femur
• Mechanism:
  
  • minor or indirect trauma in the elderly, high-impact injuries in younger patients. Big question: did they fall down & they broke their hip or did the hip break & then they fell?
• Types:
  
  • -Femoral head: most serious, involves joint surface, requires surgery, may cause long-term disability, seen with dislocations.
  • -Femoral neck: most common (90%) b/c neck is anatomic weak point
  • -Intertrochanteric: b/w greater & lesser trochanters
• S/sxs:
  
  • Groin, hip, or buttock pain with the affected leg abducted & externally rotated, shortened (if displaced)
  • inability to bear weight or ability
• PE:
  
  • Need thorough baseline neurovascular exam
  • -Unable to perform straight leg raise
  • -Pain with gentle rotation of the leg
• Garden Classification:
  
  • -Stage I: incomplete fracture, undisplaced
  • -Stage II: complete fracture, undisplaced
  • -Stage III: complete fracture, incompletely displaced
  • -Stage IV: complete fracture, completely displaced
• Dx:
  
  • XR AP pelvis & lateral views
    
    • *Avoid frog-leg → causes pain
• Tx:
  
  • **Prompt referral to ortho
  • Surgery: open reduction & internal fixation (ORIF) or hip replacement are options, high post-op mortality rates
    
    • percutaneous pinning: garden stage 1-2, less complex rehab & shorter surgery
    • hip arthroplasty: garden stage 3-4, can do hemiarthroplasty or total (pre-existing OA, young pt)
  • Non-operative management: high-risk of complications, garden stage 1-2, total non weight-bearing for 5-7 weeks, tough with dementia

Question 5

Stress Fracture of the Femoral Neck

Answer 5

• Definition:
  
  • dynamic, continuing process (vs. acute) → fracture of the femoral neck
• Types:
  
  • Compression side: fractures on the inferior medial side of the femur, young athletes
  • Tension: transverse, occur on the superior aspect of the proximal femoral neck
• Epidemiology:
  
  • young/healthy military recruits, athletes, runners
• S/sxs:
  
  • Vague groin, thigh, or knee pain associated with activity or weight bearing, subsides after cessation of activity
• PE:
  
  • Tenderness at proximal thigh or groin, Pain with ROM, antalgic gait, Resisted straight leg raise maneuver
• Dx:
  
  • XR: radiolucent lines, sclerosis, periosteal new bone formation
  • -MRI: very sensitive
• Tx:
  
  • Often misdiagnosed or missed
  • Displaced fracture: surgical emergency
  • Compression-side: cessation of activity, no weight bearing x 6-8 weeks
  • Tenson-side: surgery
• Complications:
  
  • osteonecrosis

Question 6

Femoral Shaft Hip Fracture

Answer 6

• Definition:
  
  • fracture of the shaft of the femur (subtrochanteric region to supracondylar area)
• Mechanism:
  
  • high-energy trauma (MVA), can be pathologic from osteopenia or tumors but much less common
• S/sxs:
  
  • Severe pain in the high along an obvious deformity
  • Unable to move lower extremity
  • Unable to bear weight
• PE:
  
  • inspect for deformity, swelling, & open injuries
  • Neurovascular exam
• Dx:
  
  • XR: AP & Lateral views
  • XR of hip, knee, & pelvis needed (d/t high energy injury)
• Tx:
  
  • Immediate, temporary splinting
  • Surgery
  • Open injury: tetanus prophylaxis, IV abx, surgical debridement, fracture fixation

Question 7

Hip Dislocations

Answer 7

• Definition:
  
  • head of the femur is forced out of its socket in the pelvis (acetabulum). Requires significant trauma. Rare b/c the hip is a stable joint with a strong capsule & deep acetabulum
• Mechanism:
  
  • Trauma = Most common cause: MVA (#1), fall (#2)
• Types:
  
  • Posterior (90%): femoral head located posteriorly, present with hip adducted & internally rotated, occurs d/t axial load on an adducted femur
  • Anterior (10%): femoral head located anteriorly & either superior or inferior, present with hip abducted & externally rotated
• Associated Conditions:
  
  • Fracture of the femur or acetabular column, ipsilateral knee ligament injuries, neurovascular injuries
• S/sxs:
  
  • *Severe injury
  • Unable to move lower extremity
  • Posterior:
    
    • hip pain with the leg shortened, internally rotated & adducted
  • Anterior:
    
    • Hip pain with the leg externally rotated & abducted
• PE:
  
  • Must do a very thorough assessment of the patient to r/o other injuries
  • Document neurovascular exam: distal pulses, sciatic & femoral nerves
• Dx:
  
  • Beware of related injuries. Survey the entire patient!
  • XR:
    
    • -Posterior: femoral head appears smaller and femur appears adducted
    • -Anterior: femoral head appears larger and femur appears abducted
• Tx:
  
  • Medical Emergency!
  • Refer emergently
  • Closed reduction under conscious sedation ASAP to reduce risk of avascular necrosis → repeat xrays or CT to confirm reduction
• complications:
  
  • Avascular necrosis (10% of patients, increased risk with delay in reduction or incomplete reduction)
  • Sciatic neuropathy
  • Femoral neuropathy
  • Chronic pain

Question 8

Hip Strains

Answer 8

• Definition:
  
  • injuries of the muscle tedon units around the hip
• Mechanism:
  
  • vigorous muscle contraction while the muscle is on stretch, overuse injury
• S/sxs:
  
  • pain over the injured muscle exacerbated when that area continues to be used during activity
• PE:
  
  • *Difficult to exam due to deep hip muscles
  • -Hip adductors: groin tenderness & increased pain with abduction
  • Pain with resistive strength testing
• Dx:
  
  • XR to r/o other fracture or other bony lesions
• Tx:
  
  • Activity modification & NSAIDs ~6 weeks
  • RICE, passive ROM exercises, isometric exercises

Question 9

Trochanteric Bursitis

Answer 9

• Definition:
  
  • inflammation & hypertrophy at the proximal IT band at the bursa at the lateral point of the hip (greater trochanter)
• Risks:
  
  • change in running routine (affected leg is the one that is curb-side)
• Causes:
  
  • unknown etiology, lumbar spine disease, intra-articular hip pathology, limb-length inequalities, inflammatory arthritis, prior surgery in the area
• S/sxs:
  
  • Focal tenderness at the greater trochanter worse when rising from a seated position, lessens after a few steps & recurs after walking > 30 minutes
  • May radiate to knee or ankle
  • Pain with weight bearing or running
  • Sleep disturbance (side lying)
• PE:
  
  • Pain with resisted hip abduction
  • Ober Sign
  • Evaluate foot posture
• infected Trochanteric Bursitis:
  
  • -Check for inguinal lymphadenopathy (indicates infection)
  • -Redness & swelling in the area
  • -Constitutional sxs
• Dx:
  
  • *r/o spine issues first & infection
  • XR: to r/o bony abnormalities & intra-articular pathologies
  • MRI: if suspect spine or infection
• Tx:
  
  • Identify causes → activity modification
  • Supportive: ice (acute) vs heat (chronic), rest, acetaminophen or topical NSAIDs, PT, orthotics
  • -Corticosteroid injections
    *