According to research from the University of Bern presented at the 2009 European Congress of Radiology, athletes participating in intense sports possess a higher rate of hip osteoarthritis and an earlier onset of this disease compared to the general population. It has also been found that a correlation exists between the early onset of osteoarthritis and femoroacetabular impingement, an excess of friction in the hip joint.
Researchers from the University of Bern in Switzerland set out to examine whether these results held constant with a group of 50 karate fighters. Using a Siemens MAGNETOM Trio 3T (3 Tesla) Magnetic Resonance Imaging (MRI) scanner, the researchers examined the structural changes taking place in the joints of 97 hips belonging to the karate fighters. They also investigated the influence that karate training has on the development of osteoarthritis. In accordance with the MRI scan, a clinical examination including impingement and range of motion tests was also undertaken on the karate fighters.
Using the images from the 3T MRI scan, the shape of the femoral head of the acetabulum, the structure of the labrum, and the integrity of the cartilage was evaluated. The results showed that the age of the fighter did not show a relationship with the results yielding the amount of hip damage. “But the more years of karate training, the more labral lesions and the more cartilage damage was found. And the earlier the athlete started the training, the higher was the prevalence of an increased alpha angle, labral lesions, and cartilage damage,” states Inge Kress, a student from the University of Bern, Switzerland. Some of the results: 15 per cent of the hips examined showed normal cartilage, 78 per cent had degenerated cartilage, and seven per cent had full-thickness defects. The mean alpha angle of 64.3 degrees was found in the hips of the karate fighters. Any angle greater than 55 degrees is considered abnormal. Forty-eight out of the 97 hips had a degenerated labrum, 33 had a torn labrum and only 16 were normal. The MRIs found herniation pits, cysts, and mycoid degeneration, thus indicating much stress in the hip joint.