Managing Minor Musculoskeletal Injuries and Conditions First Edition. David Bradley. © 2014 John Wiley & Sons, Ltd. Published 2014 by John Wiley & Sons, Ltd. Companion website:

The knee

Knee 1 This X-ray is of OA of the knee. The features shown are as follows: Loss of joint space, especially in the medial compartment. Eburnation (whitening) of the bone areas next to where the cartilage has been worn down. Osteophyte formation, especially on the medial margin. General demineralisation of the bone.

Knee 2 What do you see in this AP view of the knee? Read my comments in the notes section below.

Knee 3 An injury following a rough football tackle. What does the X-ray show? Which nearby nerve would have to be considered? What would the joint cavity contain? What do the two arrows point to? See my notes below.

Knee 4 The patient was in an RTC. The patient was the driver of the car and their knee hit the dashboard. Is there anything on the X-ray? When complete, read my notes below.

Knee 5 Is this a normal X-ray? Read my notes below after you have studied the film.

Knee 6 This is a ‘skyline’ or ‘valley’ view of the patello-femoral joint. Here the patient has a normal deep ‘valley’ for the patella to sit into. With a patient who gets frequent lateral dislocations of the patella, the high lateral condyle of the femur (yellow arrow) is usually found to be far more shallow, allowing the patella to glide off more easily; this is an over- simplification of the mechanism, however. This view may also clearly demonstrate damage to the cartilage of the patello-femoral joint in conditions such as OA and chondromalacia.

Knee 7 This X-ray of a teenage boy was taken through an aluminium splint plus bandage with safety pin. There was no history of trauma: the knee just kept ‘locking’. Do you see anything, or is it normal? See next slide for comments.

Knee 7 – my comments This blow-up view of the previous X-ray has a loose body arrowed. If this moves around the joint, some call it a ‘joint mouse’. From just this one view, I think it is from the medial border of the medial condyle, common in osteochondritis dissecans.

Knee 8 Report on this AP view of the knee. Then look at the next slide.

Knee 8 – my comments At first glance this seems to be a normal X-ray. However, it is hoped that, as well as tracking around all the corticies, you will have progressed to the inside trabeculae of the femur and tibia. Then, just as you were about to give up on finding a fracture, an oblique fracture of the neck of the fibula will have become obvious. These are sometimes associated with ankle injuries, which have been caused by a twisting MOI. The common peroneal nerve (lateral popliteal) winds around the neck of the fibula, so be sure that your patient doesn’t also have a dropped foot or weakness of the anterior muscles.