BIRMINGHAM HIP^◊

The BIRMINGHAM HIP^◊ Resurfacing (BHR^◊) System is a conservative approach to hip arthroplasty in which an all-metal bearing couple is used to preserve, rather than replace, a patient’s femoral head and neck. It was first implanted in July 1997, and was approved for use in the United States by the Food and Drug Administration in 2006. Since its introduction, there have been over 190,000 BHR implantations worldwide.

Features of the BHR include:

1. Less bone resection than conventional total hip arthroplasty
2. Excellent, long-term clinical outcomes ^6-8
3. Functionally optimized metallurgy and design ^5,9-10

The BHR has over 22 years of clinical performance, and is the only hip resurfacing system with 18 years of published registry data. ^7-8

When implanted in an appropriate patient, and in accordance with the surgical technique, the BHR offers a bone-conserving and clinically proven alternative to conventional total hip arthroplasty (THA) in male patients requiring a high level of post-operative function. ^1,3-4,13

BHR bone conserving system is well documented through independent clinical studies. ^11-12

Arthroplasty Registries

Revision data for the BHR is reported by various national joint registries. The largest data sets are the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJREW).

The AOANJRR 2019 Annual Report, tracking a total of 11,639 BHR devices, reported BHR revision rate of 10.8 (95% confidence interval: 10.0-11.7) at 18 years follow-up, the longest of any resurfacing device. ⁷

The NJREW 2019 Annual Report, tracking a total of 22,572 BHR devices, reported BHR revision rate of 7.8% (95% confidence interval: 7.43-8.20) at 10 years follow-up across all patients/head sizes. ⁶

For additional information, e-mail BHR.Inquiries@smith-nephew.com.

*Detailed statistical analysis of the registry data for the BHR System from the NJREW, the AOANJRR and the Swedish Hip Register suggests that female patients, male patients aged 65 and older and patients requiring femoral head components 48mm in diameter and smaller are at greater risk of early revision than other patients. It was for this reason that Smith+Nephew undertook a field safety corrective action in June 2015, which (among other things) contraindicated the use of BHR in female patients and announced the withdrawal of femoral head components sized 46mm in diameter and smaller, and their corresponding acetabular cup sizes, from the market.

The BHR^◊ is intended for use in primary hip resurfacing arthroplasty and is comprised of a cemented As Cast CoCr femoral component and an uncemented As Cast CoCr HA coated acetabular component.   The device is designed to be an alternative (more bone-conserving) option to conventional THA implants. The BHR is particularly suited to the younger, more active male patient requiring hip arthroplasty. BHR is a solution particularly suited for the younger more active male patient requiring hip arthroplasty. ^2-3,7

The BHR is intended for use only by surgeons who have received appropriate training and are familiar with the implant components, instruments, surgical technique (including with the importance of correct positioning), clinical applications, adverse events and associated risks.

The femoral and acetabular components (Figure 1 & Figure 2) are both composed of cast high-carbon-content cobalt chrome molybdenum (CoCrMo) alloy. The external surface of the femoral head is predominantly spherical in form and is highly polished. The head is hollowed internally for seating onto the prepared native femoral head, to which it is fixed using acrylic bone cement.  A distally protruding stem helps to achieve correct positioning of the head centrally along the axis of the femoral neck.

Figure 1.  BHR Femoral Head	Figure 2.  BHR Acetabular Cup

The As Cast cementless acetabular component is hemispherical in shape with a plasma-sprayed hydroxyapatite coating over a ‘cast-in’ CoCrMo beaded exterior surface, for bone ingrowth and osteointegration.¹⁴  Like the femoral component, the bearing surface of the acetabular cup component is predominantly spherical in form and is highly polished.  Initial fixation of the acetabular cup (during the 12-week period required for osteointegration) is designed to be achieved using an interference-fit approach (with the native acetabulum under-reamed by 2mm).  

For additional information e-mail BHR.Inquiries@smith-nephew.com.

1) Nam D, Barrack RL, Clohisy JC, Nunley RM. Proximal Femur Bone Density Decreases up to 5 Years After Total Hip Arthroplasty in Young, Active Patients. The Journal of arthroplasty. 2016;31(12):2825-2830.

2) Oxblom A, Hedlund H, Nemes S, et al. Patient-reported outcomes in hip resurfacing versus conventional total hip arthroplasty: a register-based matched cohort study of 726 patients. Acta orthopaedica. 2019:1-10.

3) Jonas SC, Whitehouse MR, Bick S, Bannister GC, Baker RP. An 18-year comparison of hybrid total hip replacement and Birmingham hip resurfacing in active young patients. Hip international: the journal of clinical and experimental research on hip pathology and therapy. 2019:1-8.

4) Daniel J, Pradhan C, Ziaee H, Pynsent PB, McMinn DJ. Results of Birmingham hip resurfacing at 12 to 15 years: a single-surgeon series. The bone & joint journal. 2014;96-b(10):1298-130

5) Haughom BD, Plummer DR, Moric M, Della Valle CJ. Is there a benefit to head size greater than 36 mm in total hip arthroplasty? The Journal of arthroplasty. 2016;31(1):152-155.

6)  National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJREW) 2019.16th Annual Report. Hertfordshire, UK.

7) Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) Hip, Knee & Shoulder Arthroplasty: 2019 Annual Report. Adelaide; AOA, 2019.

8) ODEP. Birmingham Hip Resurfacing Device. 2019; http://www.odep.org.uk/products.aspx. Accessed 11 March, 2019.

9) McMinn D.J.W. Development of Metal/Metal Hip Resurfacing. Hip International. 2003;13(1):41-53.

10) Li CX, Hussain A, Packer K, Kamali A. Fixation surface and bony in growth of retrieved acetabular cups for three different hip resurfacing systems. HIP International. 2010;20(3):348-349.

11) Nishii T, Sugano N, Miki H, et al. Five-year results of metal-on-metal resurfacing arthroplasty in Asian patients. The Journal of arthroplasty. 2007;22(2):176-183.

12) Back DL, Dalziel R, Young D, Shimmin A. Early results of primary Birmingham hip resurfacings. An independent prospective study of the first 230 hips. The Journal of bone and joint surgery British volume. 2005;87(3):324-329.

13) Halawi MJ, Oak SR, Brigati D, et al. Birmingham hip resurfacing versus cementless total hip arthroplasty in patients 55 years or younger: A minimum five-year follow-up. Journal of clinical orthopaedics and trauma. 2018;9(4):285-288.

14) Imai H, Miyawaki J, Kamada T, et al. Radiolucency around highly porous sockets and hydroxyapatite-coated porous sockets in total hip arthroplasty for hip dysplasia. European journal of orthopaedic surgery & traumatology : orthopedie traumatologie. 2018;29(3):611-618.