Fig. 2.

The flow-state diagram demonstrates the discrete health states considered after hip arthroscopy. Patients begin with either good hip function or a complication, which can be major or minor. After a specified duration, they progress to fair hip function. The dashed line denotes the two scenarios considered in which hip arthroscopy alters the progression of arthritis or provides symptomatic relief only. In the latter scenario, patients progress from good hip function after arthroscopy to poor hip function at the same rate as patients with fair hip function. In contrast, if hip arthroscopy alters the progression of arthritis, patients only progress to poor hip function after the progression from good to fair hip function. In the observation model, all patients begin in the “fair hip function” state.