Quadriceps tendinosis is characterized by pain and degeneration of the quadriceps tendon at its insertion into the patella (kneecap). This structure is the tendon attachment of the quadriceps (thigh) muscles to the patella (knee cap). This structure is important in straightening the knee or slowing the knee during bending or squatting. Tendinosis represents degeneration and ultrastructural breaking down of the tendon which results in pain and functional limitations.
Initial treatment consists of medication and ice to relieve the pain, stretching and strengthening exercises of the quadriceps muscles, and modification of the activity that initially caused the problem. These all can be carried out at home, although referral to a physical therapist or athletic trainer for further evaluation and treatment may be helpful. This condition is usually much improved and manageable within six to twelve weeks if treated appropriately with conservative treatment and resting of the affected area.
Uncommonly, crutches may be needed for the first few days to weeks until there is good control of the quadriceps muscles and no limp exists. Surgery to remove the degenerated tendon tissue is rarely necessary and is only considered after at least six months of adequate rehabilitation and rest.
Frequent Signs and Symptoms
- Pain, tenderness, swelling, and sometimes warmth over the patellar tendon, most often at the superior pole of the patella (kneecap).
- Pain and loss of strength (occasionally) with straightening the knee (especially when jumping or when rising from a seated or squatting position) or bending the knee completely (squatting or kneeling)
- Crepitation (a crackling sound) when the tendon is moved or touched
Etiology (Causes)
- Strain from a sudden increase in amount or intensity of activity or overuse of the quadriceps muscles and patellar tendon
- Direct blow or injury to the knee or quadriceps
Risk Factors
- Sports that require sudden, explosive quadriceps contraction (jumping, quick starts, or kicking)
- Running sports, especially running down hills
- Poor physical conditioning (strength and flexibility, such as with weak quadriceps or tight inflexible muscles)