Table 2.

Relationship between cause of failure^a and primary diagnosis

Diagnosis	Number of hips requiring revision	Causes of failure
		Aseptic loosening (%)	Infection (%)	Instability (%)	Component failure (%)	Peri-prosthetic fracture (%)	Pain (%)
Osteoarthritis	111	56 (50.5)	24 (21.6)	17 (15.3)	2 (1.8)	9 (8.1)	4 (3.6)
Inflammatory arthritis	20	15 (70)	2 (10)	1 (5)	0 (0.0)	2 (10)	0 (0.0)
Osteonecrosis	62	26 (41.9)	6 (9.7)	13 (21)	2 (3.2)	1 (1.6)	14 (22.6)
Dysplasia	25	15 (60)	1 (4)	6 (24)	1 (4)	1 (4)	1 (4)
Post-traumatic arthritis	14	6 (42.9)	6 (42)	4 (28.6)	0 (0.0)	0 (0.0)	0 (0.0)
Other	5	5 (100)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)

^aCause of failure is given in the table as the number of hips, with the percentage given in parentheses