The BIRMINGHAM HIP^◊ Resurfacing (BHR^◊) has demonstrated exceptional clinical results worldwide. High survival rates of 98% or better were achieved in clinical centres around the world. ^1,2,3,4,5

In addition, the recently published Australian Orthopaedic Association National Joint Replacement Registry reports BHR^◊ as having the lowest revisions per 100 observed 'component' years when comparing all resurfacing implants used in the country. ⁶

Other clinical studies have focused on predictive measurements to project long-term survivorship of the resurfaced femoral head. Researchers at the University of Oxford, England used roentgen stereophotogrammetric analysis (RSA) to measure the stability of the femoral head. At 24 months, the total three-dimensional migration of the head was not statistically significant at 0.2mm.

Previous studies have shown that implants that loosen quickly have rapid early migration. According to the authors, these results suggest the BHR^◊ femoral component is an inherently stable device predicting a good long-term performance. ^7,8

It is widely accepted that the Bone Mineral Density (BMD) of the proximal femur generally decreases after cementless THA using standard designs of femoral components. However, BMD studies conducted at Osaka University, Japan reported the post-operative BMD in the proximal femur was significantly greater in patients treated with the BHR^◊ system compared to the conventional system. The patients treated with the BHR^◊ system demonstrated preservation of the BMD in Gruen zone 1 and an increase in zone ⁷.

These results suggest that transfer of load to the proximal femur was more normal after surface replacement with the BHR^◊ system. These findings also show the BHR^◊system preserves the bone stock of the proximal femur after surgery. ⁹

Author	Site	n	Survival	Follow Up(months)
Shimmin et al 1	Melbourne	231	99.14 %	33 (25-52)
Ebied et al 2	Liverpool	100	99.00 %	17 (mean)
De Smet et al 3	Ghent	200	99.50 %	6 - 42
Treacey et al 4	Birmingham	144	98.00 %	60 (minimum)
McMinn et al 5	Birmingham	1626	98.4 %	60 (minimum)

Resurfacing Head	Number Revised	Total Number	% Revised	Observed Component Years	Revisions per 100 Observed Component Years
ASR	18	503	3.6	446	4.0
Adept	0	19	0	3	0.0
BHR	126	5799	2.2	13487	0.9
Conserve Plus	2	48	4.2	82	2.4
Cormet 2000	14	333	4.2	649	2.2
Durom	12	423	2.8	451	2.7
Recap	2	41	4.9	41	4.9
Total	177	7205	2.5	15179	1.2

Autor	Type	n	Findings
Glyn-Jones et al 7	RSA	22	Femoral migration < 0.2mm at 2 Years
Itayem et al 8	RSA	20	Vertical migration femoral component < 0.01mm at 5 Years Vertical migration acetabular component < 0.03mm at 5 Years
Kishida et al 9	BMD	26	BMD preserved / improved in proximal femur at 2 years