Dr Christopher Vertullo MBBS FRACS Orth
A 62-year-old tennis player presents to you complaining of an atraumatic onset of knee pain over the last few weeks. The pain is associated with a clicking sensation at the front of the knee and is worse after playing. She has never had this type of problem before and is concerned about a meniscal tear.
When you examine her knee, you note that she has a BMI of 31, a full range of active knee motion, no effusion, some wasting of her quads and some patellofemoral crepitus. The medial side of her knee is not tender.
Your next management step should be:
A To arrange an MRI and urgent review
B To reassure that no investigations are needed at this stage as the most likely diagnosis is Patellofemoral Osteoarthritis, and that quadriceps strengthening with her physiotherapist is all that is required.
C To suggest to stop playing tennis and start some NSAID.
D To arrange an MRI and urgent orthopaedic surgical review
The correct answer is obviously B. An atraumatic onset of knee pain in a middle-aged patient will be degenerative change, in this case of the Patellofemoral joint. The initial management should be to avoid investigations at this stage, lose some weight, strengthen the quadriceps with her physio and consider NSAID prior to playing if no contraindication.
The patient then returns 6 weeks later, the pain is much better, but she wants to get an MRI to "see what is happening".
Should you order an MRI ?
The answer is "not really", as a plain radiograph, particularly looking at the Patellofemoral joint is much more helpful as the initial test. If you initial diagnosis is incorrect, and she has a meniscal tear, arthroscopy will not be indicated, unless her knee is locked or she has a repairable meniscal root tear. The place for MRI in these situations is rather limited, and only when non-operative management has failed or the diagnosis is uncertain from the history and examination. Finally, reassurance that it is safe to continue exercising is vital as it helps the patient lose weight. Patellofeomoral pain really responds to weight loss dramatically.