Natural Course of Asteoarthritis of the Knee Treated With or Without Intraarticular Corticosteroid Injections
This heading was the title of an article published in 1993, that compared osteoarthritic knees treated with intraarticular corticosteroid injections to those treated without them.85 The research was done by four doctors in the Department of Orthopaedic Surgery at Yokohama City University School of Medicine in Yokohama, Japan. They were able to analyze X-rays, pain levels, and functional status of the patients at the start of treatment and after a ten-year period.
 The 82 knees not receiving corticosteroid injections were compared to the 14 knees that did receive them. The average age of the patients at the beginning of the study was 60 years-old, and at the end, 70. The median number of corticosteroid injections per joint was 25. Limb alignment was evaluated at the femorotibial angle, measured via an anteroposterior radiograph taken with the patient standing on one leg. The angle is the lateral angle between the femoral axis and the tibial axis. The results of the study revealed a significant difference in the femorotibital angle before and after the corticosteroid injections in the knees of the male patients. Specifically these knees went from 0.6 degrees of valgus at the initial visit, to a varus-angulation of 3.4 degrees.
While it is easier to microscopically study the effects of intraarticular corticosteroids in animals and compare them to non-injected joints because animals can be sacrificed, the same is not so in humans. For this reason, less human data exists, but what is available is compelling. Intrarticular corticosteroids accelerate human articular cartilage deterioration just like in animals.
 The osteoarthritis of each of the knees was classified into six grades, varying from Grade 0 (normal) to Grade 5 (severe bony defects) using the standing radiograph. (See Table 2.) In the corticosteroid-treated group, degeneration of the knee joint associated with bony defects equivalent to Grade 4 or 5 was found in five of fourteen knees, but this was only seen in three of 82 knees that received no injections. (See Table 3.) Radiographic degeneration was observed to be more advanced in the group that received corticosteroid injections than in the group that did not receive such injections. In the corticosteroid-injected knees, the radiographic grade worsened by 1.1, whereas the non-injected knees changed by only 0.6 grade. Using a paired t-test ratio, these results were statistically significant. In both groups, the clinical evaluation was performed at follow-up according to the knee rating system given in the Assessment Criteria for the Evaluation on Osteoarthritis of the Knee issued by the Japanese Orthopaedic Association. The criteria is composed of four items, including pain on walking, pain on ascending or descending stairs, range of motion, and joint effusion with a maximum score of 100 for a normal knee. (See Table 4.) The average score at follow-up was 69 in the corticosteroid-injected knees and 91 in those not treated with corticosteroid injections. The researchers confirmed that not only do corticosteroids injected into human osteoarthritic knees accelerate articular cartilage degeneration as confirmed by X-ray studies, but they deteriorate joint function compared to non-injected knees.
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