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 175,000 BHR implantations worldwide.

Features of the BHR include:

1. Less bone resection than conventional total hip arthroplasty
2. Availability of global, long-term clinical outcomes data
3. Functionally optimized metallurgy and design

This successful, bone conserving hip resurfacing system is well documented through independent clinical and laboratory studies. Additional clinical evidence supporting the BHR is published by national and regional arthroplasty registries. This bone conserving procedure, combined with an implant design intended to decrease the risk of dislocation and excellent survivorship, makes the BHR ideal for the younger, active male patient. For additional information, contact your local sales representative or e-mail BHR.Inquiries@smith-nephew.com.

Surgical Techniques

BHR Surgical Technique 

BHR Surgical Technique 60+62mm Heads

The BHR^◊ has over 19 years of clinical performance, and is the only hip resurfacing system with 14 years of published registry data behind it. 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.

Clinical Studies

A list of the peer-reviewed publications reporting mid to long-term survivorship data for the BHR is provided in the table below. In summary, a total of 16,560 BHR implants are reported.  Weighted average follow-up among these study populations is 7.1 years, with a weighted average survivorship estimate of 95.0 %.

Six of these studies report a total of 2,332 implants in 2,073 patients with a minimum of 10 years and a mean of 12.1 years of follow-up.  In these long-term follow-up studies the weighted average survivorship is 94.4%.

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 2015 Annual Report²⁷, tracking a total of 11,038 BHR devices, reported BHR survivorship of (95% confidence interval: 88.5 – 91.7) at 14 years follow-up, the longest of any resurfacing device.

The NJREW 2015 Annual Report²⁸, tracking a total of 19,629 BHR devices, reported BHR survivorship of 91.15% (95% confidence interval: 90.58 – 91.69) at 10 years follow-up across all patients/head sizes.^*

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.

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, which complies with ISO 5832: 2007 and is left in the ‘As-Cast’ condition.  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. 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.

BIRMINGHAM HIP^◊ INDICATIONS FOR USE

The BHR^◊ System is a single use device intended for hybrid fixation: cemented femoral head component and cementless acetabular component. 

The BHR System is intended for use in patients requiring primary hip resurfacing arthroplasty due to:

• Non-inflammatory arthritis (degenerative joint disease) such as osteoarthritis, traumatic arthritis, avascular necrosis, or dysplasia/DDH, or
• Inflammatory arthritis such as rheumatoid arthritis.

The BHR System is intended for patients who, due to their relatively younger age or increased activity level, may not be suitable for traditional total hip arthroplasty due to an increased possibility of requiring future ipsilateral hip joint revision.

CONTRAINDICATIONS

• Patients who are female
• Patients with infection or sepsis
• Patients who are skeletally immature
• Patients with any vascular insufficiency, muscular atrophy, or neuromuscular disease severe enough to compromise implant stability or postoperative recovery
• Patients with bone stock inadequate to support the device including:
  • Patients with severe osteopenia or patients with a family history of severe osteoporosis or severe osteopenia.
  • Patients with osteonecrosis or avascular necrosis (AVN) with >50% involvement of the femoral head (regardless of FICAT Grade).
  • Patients with multiple cysts of the femoral head (>1cm).
  • Note: In cases of questionable bone stock, a DEXA scan may be necessary to assess bone stock status.
• Patients with known moderate to severe renal insufficiency
• Patients who are immunosuppressed with diseases such as AIDS or persons receiving high doses of corticosteroids
• Patients who are severely overweight
• Patients with known or suspected metal sensitivity (e.g., jewelry)

WARNINGS AND PRECAUTIONS

• Patients who, from plain radiograph pre-operative templating, appear to require 48mm femoral heads should not be considered as candidates for BHR implantation.  Patients requiring a 48mm femoral head size are at a moderately elevated risk of requiring revision surgery earlier than expected.  While Smith & Nephew concluded that the increased risk associated with this head size does not outweigh the potential benefit to the patient in the specific circumstance of intra-operative downsizing from a pre-operatively templated 50mm to a measurement of 48mm at the time of surgery, surgeons should use their best medical judgment to consider this information relative to the patient’s overall medical history and prognosis in determining its appropriateness as a surgical treatment.

Patients on medications (such as high-dose or chronic aminoglycoside treatment) or with co-morbidities (such as diabetes) that increase the risk of future, significant renal impairment should be advised of the possibility of increase in systemic metal ion concentration.  Preoperative and postoperative monitoring of renal function (such creatinine, GFR, BUN) will be necessary for these patients.

• Only physicians who have received appropriate training and are familiar with the implant components, instruments, procedure, clinical applications, adverse events, and risks associated with the BHR System should use this device. Contact Smith & Nephew Orthopaedics Ltd. for the surgical technique manual and procedural training protocol. 

• Based on literature reports together with the manufacturer’s post-market data, the following were identified as risk factors for early revision:
  • Patients who receive a 48mm femoral head;
  • Patients who receive a device which is incorrectly positioned;
  • Patients who have a diagnosis of avascular necrosis;
  • Patients who have congenital dysplasia; and
  • Patients who are obese

The more risk factors a patient has, the greater the risk of procedure failure requiring a revision of the hip.

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

1.  Daniel J, Pradhan C, Ziaee H, Pynsent PB, McMinn DJW.  Results of Birmingham Hip Resurfacing at 12 to 15 years. Bone Joint J 2014; 96-B:1298–1306.

2.  Van Der Straeten C, Van Quickenborne D, De Roest B, Calistri A, Victor J, De Smet K. Metal ion levels from well-functioning Birmingham Hip Resurfacings decline significantly at ten years.  Bone Joint  2013; 95-B:1332–8.

3.  Treacy RBM, C. W.; Shears, E.; Pynsent, P. B. Birmingham hip resurfacing: a minimum follow-up of ten years. J Bone Joint Surg Br. Jan 2011; 93(1):27-33.

4.  Reito A, Puolakka T, Elo P, Pajamaki J, Eskelinen A. Outcome of Birmingham hip resurfacing at ten years: role of routine whole blood metal ion measurements in screening for pseudotumours. Int Orthop. Nov 2014; 38(11):2251-2257.

5.  Coulter GY, D. A.; Dalziel, R. E.; Shimmin, A. J. Birmingham hip resurfacing at a mean of ten years: results from an independent centre. J Bone Joint Surg Br. Mar 2012; 94(3):315-321.

6.  Matharu GS, McBryde CW, Pynsent WB, Pynsent PB, Treacy RB. The outcome of the Birmingham Hip Resurfacing in patients aged < 50 years up to 14 years post-operatively. The Bone & Joint Journal. Sep 2013; 95-B(9):1172-1177.

7.  Holland JP, Langton DJ, Hashmi M. Ten-year clinical, radiological and metal ion analysis of the Birmingham Hip Resurfacing: from a single, non-designer surgeon. J Bone Joint Surg Br. Apr 2012; 94(4):471-476.

8.  McMinn DJD, J.; Ziaee, H.; Pradhan, C. Indications and results of hip resurfacing. Int Orthop. Feb 2011; 35(2):231-237.

9.   McMinn DJD, J.; Ziaee, H.; Pradhan, C. Results of the Birmingham Hip Resurfacing dysplasia component in severe acetabular insufficiency: a six- to 9.6-year follow-up. J Bone Joint Surg Br. Jun 2008; 90(6):715-723.

10.  Aulakh TSR, C.; Kuiper, J. H.; Richardson, J. B. Hip resurfacing and osteonecrosis: results from an independent hip resurfacing register. Archives of Orthopaedic and Trauma Surgery. Jul 2010; 130(7):841-845.

11.  Carrothers ADG, R. E.; Jaiswal, A.; Richardson, J. B. Birmingham hip resurfacing: the prevalence of failure. J Bone Joint Surg Br. Oct 2010; 92(10):1344-1350.

12.  Madhu TSA, M. R.; Raman, R. N.; Sharma, H. K.; Johnson, V. G. The Birmingham hip resurfacing prosthesis: an independent single surgeon's experience at 7-year follow-up. The Journal of Arthroplasty. Jan 2011; 26(1):1-8.

13.  Pollard TCB, R. P.; Eastaugh-Waring, S. J.; Bannister, G. C. Treatment of the young active patient with osteoarthritis of the hip. A five- to seven-year comparison of hybrid total hip arthroplasty and metal-on-metal resurfacing. J Bone Joint Surg Br. May 2006; 88(5):592-600.

14.  Revell MPM, C. W.; Bhatnagar, S.; Pynsent, P. B.; Treacy, R. B. Metal-on-metal hip resurfacing in osteonecrosis of the femoral head. The Journal of Bone and Joint Surgery. American volume. Nov 2006; 88 Suppl 3:98-103.

15.  Pailhe R, Reina N, Cavaignac E, et al. Prospective study comparing functional outcomes and revision rates between hip resurfacing and total hip arthroplasty: preliminary results for 2 years. Orthop Rev (Pavia). 2013; 5(3):e20.

16.  Khan MK, J. H.; Edwards, D.; Robinson, E.; Richardson, J. B. Birmingham hip arthroplasty: five to eight years of prospective multicenter results. The Journal of Arthroplasty. Oct 2009; 24(7):1044-1050.

17.  Heilpern GNS, N. N.; Fordyce, M. J. Birmingham hip resurfacing arthroplasty: a series of 110 consecutive hips with a minimum five-year clinical and radiological follow-up. J Bone Joint Surg Br. Sep 2008; 90(9):1137-1142.

18.  Nishii TS, N.; Miki, H.; Takao, M.; Koyama, T.; Yoshikawa, H. Five-year results of metal-on-metal resurfacing arthroplasty in Asian patients. The Journal of Arthroplasty. Feb 2007; 22(2):176-183.

19.  Patel NK, Wright J, Sabharwal S, Afsharpad A, Bajekal R. Hip resurfacing arthroplasty at a non-specialist centre. Annals of the Royal College of Surgeons of England. Jan 2014; 96(1):67-72.

20.  Hing CBB, D. L.; Bailey, M.; Young, D. A.; Dalziel, R. E.; Shimmin, A. J. The results of primary Birmingham Hip resurfacings at a mean of five years. An independent prospective review of the first 230 hips. J Bone Joint Surg Br. Nov 2007;89(11):1431-1438.

21.  McBryde CWS, E.; O'Hara, J. N.; Pynsent, P. B. Metal-on-metal hip resurfacing in developmental dysplasia: a case-control study. J Bone Joint Surg Br. Jun 2008; 90(6):708-714.

22.  Steffen RTP, H. P.; Palan, J.; Beard, D. J.; Gundle, R.; McLardy-Smith, P.; Murray, D. W.; Gill, H. S. The five-year results of the Birmingham Hip Resurfacing arthroplasty: an independent series. J Bone Joint Surg Br. Apr 2008;90(4):436-441.

23.  Su EP, Housman LR, Masonis JL, Noble JW, Jr., Engh CA. Five Year Results of the First US FDA-Approved Hip Resurfacing Device. The Journal of arthroplasty. Mar 28 2014.

24.  McBryde CWT, K.; Thomas, A. M.; Treacy, R. B.; Pynsent, P. B. The influence of head size and sex on the outcome of Birmingham hip resurfacing. The Journal of bone and joint surgery. American volume. Jan 2010;92(1):105-112.

25.  Bisschop R, Boomsma MF, Van Raay JJ, Tiebosch AT, Maas M, Gerritsma CL. High prevalence of pseudotumors in patients with a Birmingham Hip Resurfacing prosthesis: a prospective cohort study of one hundred and twenty-nine patients. The Journal of bone and joint surgery. American volume. Sep 4 2013;95(17):1554-1560.

26.  Witzleb WCA, M.; Krummenauer, F.; Knecht, A.; Ranisch, H.; Gunther, K. P. Birmingham Hip Resurfacing arthroplasty: short-term clinical and radiographic outcome. European Journal of Medical Research. Jan 23 2008;13(1):39-46.

27.  Australian Orthopaedic Association National Joint Replacement Registry. Annual Report. Adelaide:AOA; 2015.

28.  National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. 12th Annual Report, 2015; Accessed from: http://www.njrreports.org.uk/.