Corrosion or FATIGUE??? two completely different problems, either of which are not easy or possible to identify on a visual inspection.
A FlightWest F100 lost a MAIN gear wheel assembly on landing in Norfolk Island many years ago, similar problem. I understand the flight crew were quite alarmed to see the wheel overtake them on the landing roll out!
What bothers me is the rock apes that feel that they have to inscribe their name or "tag" on the main gear strut/link because it is dirty. Reported more than once, in one case down to the metal underneath, to which the LAME said it would have to be removed and inspected.................
Half of you probably dont even operate 737's. Those who do would note that a good visual inspection of the wheel assembly's is possible, but you are looking for the obvious. Hopefully some pictures may surface soon to show the extent of the corrosion/fatigue and where abouts (inside of the axle or rim which is harder to see)