Purpose

Beginning of degenerative cartilage damage heralds the onset of primary osteoarthritis of the knee joint. When the cartilage damage exceeds a certain level, pain and other symptoms start and patient seeks active treatment. Later, a stage is reached when patient is not able to tolerate the pain and agrees for a total knee arthroplasty (TKA). There are presently no research studies highlighting the extent of histological damage of cartilage at this stage. The purpose of this study was to find out the histological stage, when surgeon and patient reaches a clinical end point and both agree for a total knee replacement surgery.

Methods and Materials

A total of consecutive 50 patients undergoing TKA in the orthopedic operation theatre with the diagnosis of primary osteoarthritis were enrolled from June 2013 to June 2015 in the present study. Samples were obtained during the total knee replacement surgery from various compartments of the knee. After the routine processing of the samples, the biopsies samples were stained with H & E stain and Alcian blue stain for light & polarised microscopy. The histologic grading of these lesions was done using the OARSI system and the worst grading from all the samples was taken into consideration

Results

The most common age group undergoing TKR was above the age of 60 and comprised of 39 cases, while 11 patients were below the age of 60. BMI of all the patients was above 25, with 27 patients having BMI < 30. Eight patients were excluded from the study as they were found to be suffering from other pathologies like inflammatory pathologies on histopathology. Of the final 42 patients undergoing TKA for primary osteoarthritis, 18 patients had OARSI grade 3 (42.85%), 23 patients had OARSI grade 4 (54.76%) and only one patient (2.38%) had OARSI grade 5 score.

Conclusion

it was concluded that 42.85% patient reach to a pain threshold of accepting TKR, even when there OARSI grade is 3, while 54.76% reach that threshold at OARSI grade 4. Only an insignificant number of patients had a high tolerance to accept TKR when there OARSI grade was 5. It raises a question if either surgeon or patients are biased towards total knee arthroplasty even when the cartilage degeneration OARSI grade is only 3. This also might put a question on the clinical need for OARSI grade 5 stage.