Quadriceps Tendon Tear-MRI

Case Details: 66 yrs male  clinically suspected to be of quadriceps tendon rupture  shows on MRI  lateral   aspect of the tendon displaying incomplete rupture with post elements more involved with soft tissue hematoma in the vicinity /  MR ridge sign of patella  with patellar bruises with no significant retraction  of tendon 

Teaching points  by Dr MGK Murthy

MRI Tech- AS Roy

• Quadriceps Tendon (QT) is  multi layered , formed by rectus femoris ( most  superficial component) (becomes tendinous 3-5cm from superior pole patella) / Vastus  medialis (becomes tendinous few mm above patella) &Vastus lateralis(3-4cm above patella tendinous) compromising middle layer with deep layer of QT formed by vastus intermedius. Blood supply is by descending branches of lateral circumflex artery/ descending/ medial & lateral geniculate arteries . Superficial layer gets good blood supply with an oval 30 by 15mm region in deep part, relatively avascular and hence susceptible 
• Average thickness 8mm with width of approximately 35mm.  Unilateral rupture beyond 40 yrs age is convention (bilateral commonly in degenerated tendons of systemic diseases) (Cf- patellar tendons rupture in young athletes less than 40 yrs , particularly jumpers) (25% jumpers knee will have QT rupture as well) 
• Xray (lateral view ) shows loss of tendon shadow /supra patellar mass / calcific density (chronic) / Patellar spurring / patella baja  etc , with axial view suggesting  Tooth sign (vertical ridging). USG could suggest focal abnormality. MRI is most definitive with identifying the incomplete variety from complete rupture variety  with  associated retraction/  hematoma / tendon edges gap  etc , apart from associated findings