Patellar Tendinitis

Topic updated on 09/26/13 7:44am
  • Definition
    • activity-related anterior knee pain associated with focal patellar-tendon tenderness
    • also known as "jumper's knee"
  • Epidemiology
    • incidence
      • up to 20% of jumping athletes
    • demographics
      • more common in adolescents/young adults
        • quadriceps tendinopathy is more common in older adults
    • risk factors
      • poor quadriceps and hamstring flexibility
  • Pathophysiology
    • mechanism
      • repetitive, forceful, eccentric contraction of the extensor mechanism
    • histology
      • degenerative, rather than inflammatory
      • micro-tears of the tendinous tissue are commonly seen
  • Blazina classification system
    • phase I
      • pain after activity only
    • phase II
      • pain during and after activity
    • phase III
      • persistent pain with or without activities
      • deterioration of performance
  • Symptoms
    • insidious onset of anterior knee pain at inferior border of patella
      • initial phase
        • pain following activity
      • late phase
        • pain during activity
        • pain with prolonged flexion ("movie theater sign")
  • Physical exam
    • inspection
      • may have swelling over tendon
    • palpation
      • tenderness at inferior border of patella
    • provocative tests
      • Basset's sign
        • tenderness to palpation at distal pole of patella in full extension
        • no tenderness to palpation at distal pole of patella in full flexion
  • Radiographs
    • recommended views
      • AP, lateral, skyline views of knee
    • findings
      • usually normal
      • may show inferior traction spur (enthesophyte) in chronic cases
  • Ultrasound
    • findings
      • thickening of tendon
      • hypoechoic areas
  • MRI
    • indications
      • chronic cases
      • surgical planning
    • findings
      • tendon thickening
        • more diagnostic than presence of edema
      • increased signal intensity on both T1 and T2 images
      • loss of the posterior border of fat pad in chronic cases
  • Nonoperative
    • ice, rest, activity modification, followed by physical therapy 
      • indications
        •  most cases
      • technique
        • physical therapy
          • stretching of quadriceps and hamstrings
          • eccentric exercise program
        • ultrasound treatment may be helpful
        • taping or Chopat's strap can be used to reduce tension across patellar tendon 
    • cortisone injections
      • are contraindicated due to risk of patellar tendon rupture
  • Operative
    • surgical excision and suture repair as needed
      • indications
        • Blazina Stage III disease 
        • chronic pain and dysfunction not amendable to conservative treatment
        • partial tears
      • technique
        • can be done open or arthroscopic 
        • resect angiofibroblastic and mucoid degenerative area 
        • follow with bone abrasion at tendon insertion and suture repair/anchors as needed
      • postoperative rehab
        • initial immobilization in extension
        • progressive range-of-motion and mobilization exercises as tolerated
        • weight bearing as tolerated
      • outcomes
        • return to activities is achieved by 80% to 90% of athletes
        • there may be activity-related aching for 4 to 6 months after surgery


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Qbank (3 Questions)

(SBQ07.39) A 20-year-old football player with a two year history of anterior knee pain presents for re-evaluation. Over the last two years he has been treated conservatively with quadriceps stretching, eccentric strengthening, and activity modification with no improvement. An MRI is obtained, and a representative image is shown in Figure A. He undergoes surgical debridement, which allows him to return to his pre-injury condition. Which of the following predisposing factors are believed to lead to the development of this patient's condition? Topic Review Topic
FIGURES: A          

1. Gender
2. Increased quadriceps strength
3. Playing on soft surfaces
4. Hamstring inflexibility
5. Training with low frequency

(SBQ04.53) A 22-year-old college pole vaulter has chronic anterior pain on her jumping knee. The patient has had over 6 months of physical therapy without improvement. It initially only bothered her during training, but she is now no longer able to compete and has pain with daily activities. Her MRI is shown. What is the recommended treatment? Topic Review Topic
FIGURES: A          

1. Use of a Chopat strap
2. Intra-tendinous injection of corticosteroid
3. Intra-articular corticosteroid injection
4. Arthroscopic patellar chondroplasty
5. Surgical excision of the affected tissue



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