Table 2.

Radiological changes of the 1st metatarsal head at follow-up pre-collapse-phase/stage 1 of osteonecrosis according to the Meier and Kenzora classification: mottling, collapse phase/stage 2 partial necrosis (osteonecrotic area less than 50% of the articulating surface) and total necrosis of the 1st metatarsal head

Change	Group 1	Group 2
	Interposition arthroplasty n1 = 22 feet	Resection arthroplasty n2 = 30 feet
Normal X-ray findings	13	21
Mottling	0	2
Partial necrosis	6	5
Total necrosis	3	2