Brief outline of chondromalacia patellae (runner’s knee)

The underside of the patella is protected by cartilage. Chondromalacia patellae occurs when this cartilage becomes damaged and softens. Softening and degeneration of the cartilage on the underside of the kneecap in athletes is usually a result of overuse, trauma, or abnormal forces on the knee. In older adults it can be a result of degenerative arthritis. Pain under the kneecap and a grating sensation when the knee is extended are possible signs of this condition.

Cause of chondromalacia patellae (runner’s knee)

Repetitive micro-trauma to the cartilage through overuse conditions. Misalignment of the kneecap. Previous fracture or dislocation of the kneecap.

Signs and symptoms of chondromalacia patellae (runner’s knee)

Pain that worsens after sitting for prolonged periods or when using stairs or rising from a seated position. Tenderness over the kneecap. Grating or grinding sensation when the knee is extended.

Complications if left chondromalacia patellae (runner’s knee) unattended

Cartilage that degenerates and becomes rough can cause scarring in the bone surface that it rubs against. This in turn causes more inflammation. Cartilage can also be torn when it is rough, leading to loose bodies in the joint.

Brief Outline of Osgood-Schlatter Syndrome

Osgood-Schlatter syndrome is a traction-type injury of the tibial apophysis, where the patellar (tendon) ligament pulls on the tibial tuberosity just below the knee. It is a condition that affects active young teens, and is more prevalent in males (particularly boys aged 10-15) than females, and has a slightly higher prevalence in the left knee than the right. When the quadriceps are tight, or there is repetitive flexion and extension, this stress may cause inflammation and pain. A similar condition, Larsen-Johansson syndrome, results in pain and tenderness over the inferior pole (extremity) of the patella, but is treated in a similar way to Osgood-Schlatter syndrome.

Anatomy and Physiology of Osgood-Schlatter Syndrome

The patellar (tendon) ligament attaches to the patella and then continues down to attach below the knee joint at the tibial tuberosity. The bones of a developing skeleton are not as hard as mature bones. So the force of the ligament pulling up on the tibia may cause small avulsion fractures, leading to inflammation and pain. The body may try to repair and protect this area by building more bone, resulting in a bony prominence just under the knee, which gives the characteristic tibial bump. This is exacerbated in adolescents by a growth spurt, since the lengthening of bones often exceeds the growth of the muscles attached, causing tight muscles. This puts additional force on the attached tendons. During running, jumping and kicking activities, the quadriceps must contract and relax continuously, which also stresses the attachment at the tibia.

Cause of Osgood-Schlatter Syndrome

Tight quadriceps due to growth spurt. Prior knee injury. Repetitive contractions of the quadriceps muscle.

Signs and Symptoms of Osgood-Schlatter Syndrome

Pain, worse at full extension and during squatting, subsides with rest. Swelling over the the tibial tuberosity, just under the knee. Redness and inflammation of the skin just below the knee.

Complications If Left Osgood-Schlatter Syndrome Unattended

If left unattended the condition will continue to cause pain and inflammation and could lead to muscle loss int he quadriceps. In rare cases, untreated Osgood-Schlatter syndrome could lead to a complete avulsion fracture of the tibia.

Immediate Treatment of Osgood-Schlatter Syndrome

R.I.C.E. Anti-inflammatory medication. Anti-inflammatory injection. Shockwave therapy.

Rehabilitation and Prevention of Osgood-Schlatter Syndrome

Most cases of Osgood-Schlatter syndrome responds well to rest and then a regimen of stretching and strengthening the quadriceps muscles. Limiting activities that cause pain and tend to aggravate the issue is important during the recovery. Gradual increases in intensity and proper warm-up techniques will help prevent this condition.

Long-term Prognosis for Osgood-Schlatter Syndrome

This condition tends to correct itself as the bone becomes stronger and mature. The pain and inflammation go away and there rare seldom any long-term effects. Rare cases may require corticosteroid injections or shockwave therapy to aid recovery.