Patellar Tendinopathy Diagnosis and Treatment

Pathophysiology and Clinical Presentation

The condition involves degeneration of the normally highly arranged collagen fiber structure in the tendon, resulting in collagen disorientation and fiber separation, as noted by the American Academy of Family Physicians 1
Most cases represent chronic tendinosis rather than acute inflammation, as patients typically present after prolonged symptoms when acute inflammation has subsided, according to the American Academy of Family Physicians 1
Insidious onset of load-related localized pain on the anterior aspect of the knee, coinciding with increased activity, is a common presentation, as reported by the American Academy of Family Physicians 1
Pain is typically described as "sharp" or "stabbing" and is exacerbated by navigating stairs and prolonged sitting, as described by the American Academy of Family Physicians 1, 2

Ultrasonography shows tendon thickening, decreased echogenicity, and calcification; more specific (94%) than sensitive (58%), as noted by the American Academy of Family Physicians 1
MRI shows changes consistent with chronic degenerative tendon changes with moderate sensitivity (78%) and specificity (86%), according to the American Academy of Family Physicians 1
Plain radiography is typically unable to demonstrate soft-tissue changes but may reveal bony abnormalities, as reported by the American Academy of Family Physicians 1

Eccentric strengthening exercises should be the primary treatment approach as they reduce symptoms, increase strength, and promote tendon healing, as recommended by the American Academy of Family Physicians 2
Relative rest to decrease repetitive loading of the damaged tendon is essential, but complete immobilization should be avoided, according to the American Academy of Family Physicians 1
Corticosteroid iontophoresis can be effective for treatment of patellar tendinosis pain and function, as noted by the American Academy of Family Physicians 2
Extracorporeal shock wave therapy is a safe, noninvasive option for pain relief in chronic cases, as reported by the American Academy of Family Physicians 4

Surgery is indicated for cases refractory to 3-6 months of conservative treatment, as noted by the American Academy of Family Physicians 4