Table 1.

Criteria for assessing effectiveness of core decompressions

Measure	Inclusion/exclusion criteria	Examples
Additional surgery	1. Include additional surgeries associated with progression of osteonecrosis.	Total hip arthroplasty, vascularized bone grafting, osteotomy
	2. Exclude surgeries not directly related to long-term failure of core decompression.	Evacuation of a hematoma
Radiographic failure	1. Include progression to collapse.	Progression from Ficat II to III.
	2. Include progression from collapse to further stage of degeneration.	Progression from Steinberg IV to V.
	3. Exclude progression without collapse.†	Progression from ARCO I to II.

^†Studies that only indicated “progression” in stage without indicating whether the progression was to collapse were excluded from our analysis.