Patella Tendon Rupture

Topic updated on 08/15/16 9:44pm
  • Saggital MRI showing patella tendon ruptureDisruption of the tendon attaching the patella to the tibial tubercle (the patella is a sesamoid bone making this a tendon, not a ligament)
  • Epidemiology
    • incidence
      • < 0.5% of the US population per year
    • demographic
      • most commonly in 3rd and 4th decade
      • male > female 
    • location
      • quadriceps tendon rupture > patella tendon rupture
    • risk factors
      • weakening of collagen structure
        • systemic 
          • systemic lupus erythematous
          • rheumatoid arthritis
          • chronic renal disease
          • diabetes mellitus
        • local 
          • patellar degeneration (most common)
          • previous injury
          • patellar tendinopathy
        • other
          • corticosteroid injection
  • Pathophysiology
    • mechanism
      • tensile overload of the extensor mechanism
      • most ruptures occur with knee in flexed position
        • greatest forces on tendon when knee flexion > 60 degrees
    • pathoanatomy
      • 3 patterns of injury
        • avulsion with or without bone from the inferior pole of patella (most common)
        • midsubstance
        • distal avulsion from the tibial tubercle
    • biology
      • rupture is usually the result of end stage or long-standing chronic tendon degeneration
  • Extensor mechanism of the knee
    • quadriceps femoris muscles
    • quadriceps tendon
    • patella
    • patellar tendon
    • tibial tubercle
  • Blood supply
    • infrapatellar fat pad 
    • retinacular structures (medial and lateral inferior geniculate arteries)
  • History
    • sudden quadriceps contraction with knee in a flexed position (e.g., jumping sports, missing step on stairs)
  • Symptoms
    • infrapatellar pain
    • popping sensation
    • difficulty weight-bearing
  • Physical exam
    • inspection
      • elevation of patella height
      • usually associated with a large hemarthrosis and ecchymosis
      • localized tenderness
      • palpable gap below the inferior pole of the patella
    • motion
      • unable to perform active straight leg raise or maintain passively extended knee
      • reduced ROM of knee due to pain
  • Radiographs
    • recommended views
      • AP and lateral of the knee
    • optional views
      • merchant or skyline 
    • findings
      • patella alta seen in complete rupture  
      • knee in flexion, the Insall-Salvati ratio is > 1.2 
  • Ultrasound
    • indications
      • suspected acute and chronic injuries
    • findings
      • effective at detecting and localizing disruption
      • operator and user-dependent
  • MRI
    • indications
      • differentiate partial from complete tendon rupture
      • most sensitive imaging modality
    • findings
      • site of disruption, tendon degeneration, patellar position, and associated soft tissue injuries
  • Nonoperative
    • immobilization in full extension with a progressive weight-bearing exercise program
      • indications
        • partial tears with intact extensor mechanism
      • modalities
        • application of a removable knee splint 
        • early knee range of motion
  • Operative
    • primary repair q q q 
      • indications
        • complete patellar tendon ruptures
        • ability to approximate tendon at site of disruption
      • techniques
        • end-to-end repair
        • transosseous tendon repair
        • suture anchor tendon repair
    • tendon reconstruction
      • indications
        • severely disrupted or degenerative patella tendon
      • techniques
        • semitendinosus or gracilis tendon autograft 
          • free ends of the tendons are passed through transosseous hole of the patella, and then through a transosseous hole within the tibial tubercle to make a complete circle graft.
        • other options
          • central quadriceps tendon-patellar bone autograft
          • contralateral bone-patellar tendon-bone autograft
          • allograft
    • rehabilitation q
      • may weight bear early with protected knee extension brace
      • exercises to optimize range of motion and minimizes stress on the repair include
        • passive extension and active closed chain flexion (heel slides)  
        • prone open chain knee flexion 
  • Direct primary repair
    • approach
      • longitudinal midline incision
      • expose rupture and adjacent retinacula
      • debride the ends of the rupture
    • end-to-end technique
      • approximate tendon at site of rupture
      • nonabsorbable sutures are woven with locking stitch
    • transosseous tendon repair 
      • suture the patellar tendon to the patella with a no.5 nonabsorbable transosseous suture
      • can be protected with a cerclage wire or nonabsorbable tape between patella and tibial tuberosity
    • postoperative care
      • immediate immobilization
      • weight-bearing status
      • rehabilitation


Please Rate Educational Value!
Average 4.0 of 30 Ratings

Qbank (5 Questions)

(OBQ11.28) A 35-year-old male slips on a patch of ice and falls on a hyperflexed knee. He reports hearing a "pop" during the fall and was unable to bear weight on the knee immediately after the injury. He has a large knee effusion on examination. A radiograph is shown in Figure A. He undergoes operative repair of the injury with standard technique. Which of the active range of motion exercises is MOST appropriate in the immediate postoperative period? Topic Review Topic
FIGURES: A          

1. Leg extensions
2. Heel slides
3. Standing squats
4. Rear lunges
5. Seated leg press

(OBQ08.251) A 24-year-old basketball player feels a painful "pop" in his knee when landing from a rebound. He develops immediate swelling, pain, and inability to extend his knee. A lateral radiograph is shown in Figure A. Proper management should include which of the following Topic Review Topic
FIGURES: A          

1. Physical therapy for range of motion followed by surgical reconstruction with patellar tendon autograft
2. Hinged knee brace locked at 30-degrees of flexion for 6 weeks followed by physical therapy for range of motion
3. Medializing tibial tubercle osteotomy with lateral retinacular release
4. Primary surgical repair
5. Arthroscopy for debridement versus repair

(OBQ07.152) A 40-year-old recreational basketball player injured his knee while jumping for a rebound. He felt a pop and developed immediate swelling. His radiographs are shown in Figures A and B. What is the recommended management? Topic Review Topic
FIGURES: A   B        

1. Obtain an MRI
2. Ice, rest, and observation
3. Physical therapy to regain motion
4. Knee arthroscopy and repair
5. Open surgical repair

(OBQ06.122) Which of the following rehabilitation exercises provides for restoration of range of motion while limiting stress on the repair of a ruptured patellar tendon? Topic Review Topic

1. Active open chain flexion, active closed chain extension
2. Passive flexion, active closed chain extension
3. Active closed chain flexion, active open chain extension
4. Active flexion, passive extension
5. Passive flexion, active open chain extension

This is a Never-Been-Seen Question that can only be seen in Milestone Exams
for Virtual Curriculum members.

Click HERE to learn more and purchase the Virtual Curriculum today!

HPI - Unclear history of present illness. Fell down 6 weeks ago, pt presented in the h...
poll How would you treat this patient?
566 responses patellar tendon rupture reconstruction 1.jpg patellar tendon rupture reconstruction 2.jpg patellar tendon tear 1a.jpg
HPI - Left patellar tendon tear during pickup basketball 22 years ago. s/p patellar t...
poll What would you do with this patient?
57 responses
See More Cases


tutorial on performing a heel slide
See More Videos



Topic Comments