MOD 1 - Avascular Necrosis

Epiphyseal Pathologies Covered

• Ischemic Necrosis

• Leg-Calve-Perthes Disease

• Osteochondritis

• Freiberg Kohler’s Disease

• Kohler’s Disease

• Osgood Schlatter’s Disease

• Kienbock’s Disease 

Ischemic necrosis (adults) - Classification

depends on the cause

• idiopathic 25%

• secondary disease (trauma)

Ischemic necrosis (adults) - Description

• following trauma, particularly with joint dislocation and joint capsule tear

• common in hip, shoulder, scaphoid, knee, ankle

• 30-60 y/o

Ischemic Necrosis (adults) - Pathogenesis

micro fractures in early stages → fragmentation, compression and resorption in later stages → left untreated can lead to collapse of bone and/or arthritis

Ischemic Necrosis (adults) - Signs and Symptoms

• pain

• limp

• loss of function

Ischemic Necrosis (adults) - Radiographic Appearance

• MRI, CT and Nuclear scans are better at detecting early stages

• Crescent sign = radiolucent subcortical band representing a fracture line

• Later Stages = flat femoral head, combo of sclerotic (dense) and lytic (translucent) regions

Ischemic Necrosis (adults) - Treatment

• analgesics and NSAID

• exercise, physiotherapy

• immobilization, rest

• surgery

Legg-Calvé-Perthes Disease - Definition

• Temporary loss of blood supply at the femoral head ossification center

• Affects the epiphyseal plate before closure of the growth plate, thus affects peds

Legg-Calvé-Perthes Disease - Classification

hereditary, traumatic, inflammatory, metabolic

Legg-Calvé-Perthes Disease - Etiology

• cause is obscure

• avascular necrosis

Legg-Calvé-Perthes Disease - Common Age Group

• children 3-12 (peak 5-7)

• predominately males 4:1

Legg-Calvé-Perthes Disease - Pathogenesis

1. Early/Avascular

   • loss of blood supply to the FH leading to decrease in size

   • increased joint space, lateral femoral displacement

2. Fragmentation (of epiphyses)

   • crescent sign

   • blurred FH outlines

3. Repair

   • return of blood supply

   • new bone deposits

   • wide short femoral neck

4. Healed/Deformity

   • enlarged and flattened FH

   • enlarged GT

Legg-Calvé-Perthes Disease - Signs and Symptoms

• include vague groin pain extending down towards knee

• limping

• decreased ROM

Legg-Calvé-Perthes Disease - Radiographic Appearance

• FH = flat, small

• Epiphyseal Plate = increased density, widening

• FN = widened and decreased length

• GT = enlarged

Legg-Calvé-Perthes Disease - Treatment

• no cure, have to let it run thru all stages

• casting, traction, bedrest

• osteotomy, internal fixation

Osteochondritis Dissecans - Description

name should be Osteochondroses as there is no primary inflammation

Osteochondritis Dissecans - Classfication

Traumatic, causing avascular necrosis of the end of a bone

Osteochondritis Dissecans - Pathogenesis

• Idiopathic, traumatic

• Small fragments of subchondral bone necrotize if displaced, undisplaced frags may reattach and revascularize

• frags are known as “joint mice”

• high incidence in medial condyle 75%

Osteochondritis Dissecans - Common Group

• age 11- 20 yrs

• active in sports

Osteochondritis Dissecans - Signs and Symptoms

• joint effusion

• clicking

• locking

• tenderness

Osteochondritis Dissecans - Radiographic Appearance

• cartilage fragments are only seen on CT, MRI, NM

• aim is to assess location of frag within joint space and origin

• requires tunnel/notch view for best assessment

Osteochondritis Dissecans - Treatment

• joint arthroscope to remove joint mice and/or secure loose cartilage

• drilling to stimulate healing of subchondral bone

• Non surgical: protected WB or immobilization

Freiberg Kohler’s Disease - Classfication

Traumatic, causing avascular necrosis of the end of a bone

Freiberg Kohler’s Disease - Etiology

• avascular necrosis of 2nd MT head (smt 3rd)

• disruption of growth plate due to trauma or increased stress

Freiberg Kohler’s Disease - Common Group

• teen athletes who land with impact on the balls of their feet and young teen females who regularly wear high heeled shoes

• adolescence females 5:1 (age 13-18 yrs)

Freiberg Kohler’s Disease - Pathogenesis

Growing epiphyseal site experiences avascular necrosis due to repeated micro fractures where the middle of the metatarsal meets the growth plate

Freiberg Kohler’s Disease - Signs and Symptoms

• tenderness and pain

• localized

• aggravated with activity

Freiberg Kohler’s Disease - Radiographic Appearance

• Bone scan and MRI are better for early stages

• Initial Stage

  • articular cortex irregularity

  • sclerosis/lucency

  • altered joint space

• Later Stage

  • enlarged, flattened and fragmented head

  • altered joint space

Freiberg Kohler’s Disease - Treatment

• no known treatment

• conservative:

  • reduced activity

  • non WB

• invasive:

  • surgery for excision

  • osteochondral transplant
    

Kohler’s Disease - Classification

traumatic

Kohler’s Disease - Etiology

• trauma - usually compression type injury

• avascular necrosis of navicular bone

Kohler’s Disease - Pathogenesis

compression and/or injury during development phase, thus predom affects children 3-7 yrs (males)

Kohler’s Disease - Signs and Symptoms

• midfoot pain and swelling

• pt walks with increased weight on lat. side of foot

Kohler’s Disease - Radiographic Appearance

• patchy and/or homogenic sclerosis (increased density)

• severe cases bone collapses and fragments

• abnormal architecture evident into adulthood

Kohler’s Disease - Treatment

• resolves with time

• pain killers

• cast for 6-8 weeks

• arch supports

Classification - Osgood Schlatter’s

• inflammatory

• can be traumatic

Etiology - Osgood Schlatter’s

• repetitive strain

• commonly seen in active teens  

Pathogenesis - Osgood Schlatter’s

traction force of the patellar tendon causes inflammation and fragmentation of the immature tibia

S&S - Osgood Schlatter’s

• swollen tibial tuberosity area

• painful on resisted knee extension

• limping

• pain

Rad - Osgood Schlatter’s

• ST swelling

• loss of sharp patellar tendon margins

• tibial tub fragmentation

Treatment - Osgood Schlatter’s

• rest

• ice

• physical therapy

• NSAID

• surgery (rare)

Classification - Kienbock’s disease

• traumatic

• degenerative

• idiopathic

Etiology - Kienbock’s disease

• exact cause is unknown

• however, association seen between negative ulnar variance (rly short ulna compared to radius)

• repetitive trauma/load to the lunate

• lack of blood supply 

Pathogenesis - Kienbock’s disease

• stage 1 = x-ray appears normal, osteonecrosis only seen on MRI or bone scane

• 2 = sclerosis of lunate

• 3a = lunate collapse (no carpal instability → radioscahpoid angle <60)

• 3b= lunate collapse (carpal instability → radioscahpoid angle >60)

• 4 = lunate collapse with degenerative arthritis

Rad - Kienbock’s disease

• best seen on MRI

• dense/brighter lunate (sclerosis)

S&S - Kienbock’s disease

• center wrist pain

• swelling

• stiffness

• crepitation (creaking/crackling sound with movement)

• irreg. lunate shape

• changes in carpal alignment

Treatment - Kienbock’s disease

• no definitive cure

• NSAIDS, immoblization

• occupational therapy 

• surgery (proximal row carpectomy, fusion/arthodesis)