Knee
Patellar Tendinopathy (Jumper's Knee)
슬개건병증 (점퍼 무릎)
Overuse degeneration of the patellar tendon from repetitive jumping
- How common
- Very common in jumping athletes (14–45%)
- Typical age
- Adolescent and young adult athletes
What is it?
Repetitive eccentric loading causes microtears and disorganized collagen in the patellar tendon — a degenerative tendinopathy.
Commonly affected: Inferior pole of patella most commonly affected
How it develops
- Repetitive Jump LoadEccentric loading on landing
- MicrotearsAccumulating micro-injuries within tendon
- Incomplete RepairRepeated load before recovery
- TendinosisDisorganized collagen and neovascularization
Symptoms
- Inferior Patellar PainSharp pain at inferior pole of patella
- Jump/Land PainWorse with jumping and landing
- Sit-to-Stand PainPain when rising or descending stairs
- Morning StiffnessStiffness that improves with activity
How it is examined
- Inferior Patellar TendernessFocal tenderness at inferior patellar pole
- Single-Leg Decline SquatSingle-leg decline squat reproduces pain
- Tendon ThickeningThickened tendon on palpation
Imaging
X-ray often normal; may show inferior pole spurs or calcifications.
- Usually normal; possible inferior pole spurs
MRI/US are standard. Increased intratendinous signal.
- Proximal patellar tendon thickening
- Intratendinous T2 hyperintensity
- Neovascularity on US Doppler
Non-surgical care
- Activity ModificationCease jumping/running for 2–6 weeks
- Eccentric Training (key)Eccentric decline squats — single most effective therapy
- PT / ESWTExtracorporeal shock wave therapy, ultrasound
- PRP InjectionPlatelet-rich plasma for chronic cases
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Failed 6-month conservative, severe chronic tendinosis
Procedures that may be discussed
- Arthroscopic debridement of tendon
- Open excision of degenerative tissue + repair
Outlook
Eccentric training yields 70–80% improvement at 12 weeks.