About Cartilage Repair

Histogenics is developing products for regenerating articular cartilage. Articular cartilage is the slick, dense white material located where two bony surfaces move past each other (articulate). Although thin, it can withstand high pressures, and it allows the bones of the upper and lower leg to glide past each other while the knee is bending.

Despite its strength, cartilage is vulnerable to damage by athletic activity, traumatic injury, and even daily wear and tear. This damage can cause chronic knee pain, one of the most common joint-related ailments. Injuries take the form of lesions, or worn pits, holes, or divots in the surface of the cartilage. Symptoms of an injury can include locking or catching of the knee as well as localized pain and swelling.

Damaged cartilage cannot repair or restore itself. If untreated, the damage can progressively worsen and can lead to chronic conditions such as osteoarthritis.

There are over 15 million physician office visits in the US each year for knee pain, and over 1.6 million knee arthroscopies performed. Based on numerous studies of thousands of knee arthroscopies, it is estimated that there are over 500,000 severe (Grade 3 and 4) cartilage lesions treated each year in the US, and many more that go untreated, due in part to the lack of medical options.

The incidence of cartilage injuries is growing significantly due to several factors:

• Aging population
• Increasing participation in sports among all age groups
• Increasing expectation of life-long activity
• Rising prevalence of obesity
• Growing awareness of impact of cartilage injury on later osteoarthritis (OA)
• Continued aversion to joint replacement in patients under 60
  Improvements in diagnostic cartilage imaging

Current treatment options are very limited for patients not ready for total knee replacement, and vary depending on lesion size, patient lifestyle, age, and surgeon preference.

• Debridement & Lavage does not form repair tissue.
• Microfracture produces fibrocartilage with limited functionality and durability; improvements start at 6-12 months, but begin to deteriorate after year 1.
• Carticel type ACI has shown limited and inconsistent results, and takes 2-3 hours to perform even for simple cases.
• Osteochondral autograft transplant produces harvest site co-morbidity, is limited to small defects, and is very technically demanding.
• Osteochondral allograft transplant has severe supply limitations, risk of infection, and is very technically demanding.
• Total knee replacement currently uses implants with a limited life, and therefore is reserved for severe degeneration in patients over 60 years old.

©2007 Histogenics Corporation

New ways to repair articular cartilage
Histogenics is developing products to regenerage articular cartilage in order to relieve pain, restore joint function and prevent debilitating deterioration.