Updated: 9/18/2018

TKA Heterotopic Ossification

Topic
Review Topic
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0
Questions
1
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Techniques
3
Introduction
  • Definition
    • any bone formation in the soft tissues (other than periosteum) that develops after surgery with or without a precipitating event
    • distinct from myositis ossificans, which evelops after traumatic muscle injury and inflammation
  • Incidence
    • rates range from 1% to 42%, but less than 1% have any impact on clinical outcome
    • much less frequent than after total hip arthroplasty (THA)
  • Risk factors  
    • hypertrophic arthrosis
    • male gender
    • obesity
    • notching of anterior femur
    • periosteal injury/stripping off anterior femur
    • post-op knee effusion or hematoma
    • post-op forced manipulation for restricted motion
Classification
  • Furia and Pellegrini classification system
    • 2 Classes and 2 Grades
    • Class I: island of bone localized to suprapatellar soft tissues
    • Class II: bone organized into areas of ossification contiguous with the anterior distal femur    
    • Grade A: less than or equal to 5 cm
    • Grade B: greater than 5 cm
Presentation
  • Symptoms (rare)
    • loss of motion
    • pain
    • quadriceps muscle snapping
    • patellofemoral instability
Imaging
  • Radiographic evaluation
    • recommended views
      • AP
      • lateral
    • findings
      • ossification along anterior distal aspect of femur and within quadriceps mechanism
        • typically visible 3-4 weeks post-operatively and matures within 1-2 years
Prevention
  • High-risk patients, generally those undergoing THA and not TKA
    • external beam radiation therapy
    • pharmaceutical prophylaxis with NSAIDs
  • no literature regarding these therapies in TKA patients
Treatment
  • Nonoperative
    • observation 
      • indications
        • in majority cases as HO rarely impacts clinical outcome
  • Operative
    • surgical excision
      • indications
        • quadriceps muscle snapping
        • patellofemoral tracking difficulties
        • patellofemoral instability
 

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Technique Guides (3)
Questions (1)

(OBQ10.270) A 55-year-old patient is scheduled for total knee arthroplasty. A radiograph is provided in Figure A. Each of the following are risk factors for heterotopic ossification EXCEPT? Review Topic

QID: 3253
FIGURES:
1

Incorrect sizing of femoral and/or tibial components

60%

(1077/1791)

2

Male gender

9%

(170/1791)

3

Obesity

18%

(316/1791)

4

History of trauma

2%

(37/1791)

5

Presence of preoperative osteophytes (hypertrophic arthrosis)

10%

(185/1791)

ML 3

Select Answer to see Preferred Response

PREFERRED RESPONSE 1
Topic COMMENTS (1)
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