Joint replacement is the clearest example here, because the demographic and the hospital make it common. But orthopedic physical therapy covers a good deal more: a shoulder that has stopped reaching overhead, a rotator cuff repair, an ankle that never quite recovered from a fracture, arthritis that has been managed and is no longer managing, back and neck problems with a structural cause.
Not all of it involves surgery. A fair amount of orthopedic work is done specifically to postpone or avoid it.
A good deal of it never involved an injury at all. Where the working day is spent mostly at a desk and then in the car, the pattern is a familiar one: hip flexors short after nine hours folded, glutes that have stopped contributing, a mid-back that has forgotten it rotates. It usually announces itself as low back pain that is worst on the drive home — the same journey this page is otherwise about, taken in the other direction.