Ankle Arthritis - Foot & Ankle

summary
- Ankle Arthritis is degenerative joint disease of the tibiotalar joint that can be broken into three main types: osteoarthritis, post-traumatic arthritis, and inflammatory arthritis.
- Diagnosis is primarily made with plain radiographs of the ankle.
- Treatment can be nonoperative or operative depending on patient age, patient activity demands, severity of arthritis, and presence of tibiotalar deformity.

Epidemiology
- Incidence
  - less common than OA of knee and hip

Etiology
- Pathophysiology
  - causes include
    
    post-traumatic arthritis
    
    most common etiology, accounting for greater than 2/3 of all ankle arthritis
    
    primary osteoarthritis
    
    accounts for less than 10% of all ankle arthritis
    
    other etiologies include rheumatoid arthritis, osteonecrosis, neuropathic, septic, gout, and hemophiliac
  - pathoanatomy
    
    nonanatomic fracture healing alters the joint contact forces of the ankle and changes the load bearing mechanics of the ankle joint
    
    loss of cartilage on the talar body and tibial plafond results in joint space narrowing, subchondral sclerosis and eburnation

Anatomy

Osteology
- a ginglymus joint that includes the tibia, talus, and fibula
- talar dome is biconcave with a central sulcus

Range of motion
- ankle dorsiflexion: 20 degrees
- ankle plantar flexion: 50 degrees

Takakura Classification
Stage I	Early sclerosis and osteophyte formation, no joint space narrowing
Stage II	Narrowing of medial joint space (no subchondral bone contact)
Stage IIIA	Obliteration of joint space at the medial malleolus, with subchondral bone contact
Stage IIIB	Obliteration of joint space over roof of talar dome, with subchondral bone contact
Stage IV	Obliteration of joint space with complete tibiotalar contact

Presentation
- Symptoms
  - pain with weight bearing
  - loss of motion
- Physical exam
  - joint effusion
  - pain with ROM testing, loss of ROM compared to the contralateral side
  - angular deformity may be present depending on the history of trauma

Imaging
- Radiographs
  - recommended views
    
    weight bearing AP, lateral, and obliques
  - radiographic findings include
    
    loss of joint space
    
    subchondral sclerosis and cysts
    
    eburnation
    
    possible angular deformity

Treatment
- Nonoperative
  - activity modification, bracing to immobilize the ankle, and NSAIDS
    
    indications
    
    indicated as first line of treatment in mild disease
    
    single rocker sole shoe modification can improve gait and pain symptoms
    
    Arizona brace (gauntlet ankle brace)
- Operative
  - surgical management
    
    indications
    
    indicated upon failure of conservative treatment in a patient with radiographic evidence of ankle arthritis

Techniques
- Ankle debridement with anterior tibial/dorsal talar exostectomy
  - indications
    
    mild disease with pain during push off
- Distraction arthroplasty
  - controversial
  - ideal candidate younger than 45 yrs with post-traumatic arthritis
  - indications
    
    well-preserved ankle ROM
    
    moderate to severe arthritis
    
    congruent tibiotalar surface
    
    also for partial AVN talus
- Supramalleolar osteotomy
  - indications
    
    near-normal ROM
    
    minimal talar-tilt or varus heel alignment
    
    medially focused ankle arthritis
    
    stage 2 or 3a according to the Takakura-Tanaka classification for varus-type osteoarthritis
- Arthrodesis
  - indications
    
    posttraumatic or inflammatory arthritis, malalignment (with osteotomy)
    
    young, high demand laborers
  - outcomes
    
    reliable relief of pain and return to activities of daily living
  - complications
    
    long term studies demonstrate subtalar arthrosis
    
    50% of patients demonstrated subtalar arthrosis 10 years following ankle arthrodesis in one study
    
    risk factors for nonunion include smoking, adjacent joint fusion, history of failed previous arthrodesis, and avascular necrosis
    
    revision arthrodesis union rates are 85% or greater
- Arthroplasty
  - indications
    
    patient selection is crucial
    
    indications
    
    posttraumatic or inflammatory arthritis, elderly patient
    
    contraindications
    
    uncorrectable deformity, severe osteoporosis, talus osteonecrosis, charcot joint, ankle instability, obesity, and young laborers increase the risk of failure and revision
  - techniques
    
    new generation arthroplasty minimizes bony resection, retains soft tissue stabilizers, and relies on anatomic balancing
  - outcomes
    
    recent 5-10 year outcome studies demonstrate up to 90% good to excellent clinical results, long-term studies are still pending on the newest generation of ankle arthroplasty
    
    increased gait speed and stride length
  - complications
    
    syndesmosis nonunion
    
    include wound infection, deep infection, and osteolysis

Action	Numeric Key	Letter Key	Function Key
Show Bullets		S	Enter (frontside only)
20%	1	N
40%	2	H
60%	3	F	Enter (backside only)
80%	4	E
100%	5	M
Toss	0	T