Resurfacing

 

BHRBHR

Birmingham hip resurfacing

 

Concept

 

Femur - removal of femoral head cartilage and resurfacing with metal

 

Acetabulum - standard technique

 

Bearing surface - metal on metal

 

Potential advantages

 

1.  Femoral bone stock preservation

2.  Increased stability with large heads

3. ? Improved function

 

Domb et al J Arthroplasty 2021

- 50 BHR matched to 50 conventional THA

- no difference in outcome or forgotten joint score

 

Baker et al JBJS Br 2011

- 50 BHR compared to 50 hybrid THA

- improved outcome scores and more active patients with BHR at 9 years

 

Disadvantages

 

1.  Poor modularity - difficult to adjust LLD or offset

2.  Access to acetabulum more difficult

3.  Metal ions - adverse local tissue reactions / teratogenesis

 

Australian Joint Registry 2023

 

20 year revision rate 20,000 hip resurfacing

- resurfacing 11%

- conventional THA 8%

 

In 2022

- resurfacing was 80% less common than in 2005 / 0.7% of all THA

- 97.5% performed in males

Diagnosis 20 year revision %
OA 11
DDH 19
AVN 16

 

Prosthesis 15 year revision %
Adept 6.5
Birmingham 9.5

 

Head size mm 20 year revision %
< 45 31
45-49 15
50-54 8
> 55 6

 

  Male Female
5 year 2.3 6.4
10 year 4.1 14
15 year 6.2 18.7
20 year 8.1 22.1

 

BHR revision

 

Revision

Indication for revision

 

Technique

 

Indications

 

Male / OA / good bone stock / large femoral head size

 

Contra-indications (from: Birmingham hip resurfacing technical guide)

 

Absolute Relative
Female Osteoporosis
Cysts > 1 cm Age > 65
AVN > 50% BMI > 35
< 50 mm templated head  
Known metal sensitivity - jewelry  
Impaired kidney function - metal ions

 

Techniques

 

Birmingham Resurfacing

 

BHRBHRBHRBHR

 

Smith&Nephew Birmingham Resurfacing PDF

 

Vumedi Resurfacing Video

 

Avoid

- notching

- varus

- open acetabulum

 

Technical issues

 

BHR Oversized Femoral HeadBHR Loosening

Oversized head

 

BHR Valgus v Varus Femoral Component

Varus Femoral Component

 

BHR femoral neck notchingBHR Femoral Neck Notching 2

Femoral head notching

 

BHR Open v Closed Acetabular ComponentOpen BHR

Open Acetabular Component - may cause point loading and increased metal wear

 

BHR Acetabular Component Protrusio

 

Navigation

 

Vumedi custom guides Birmingham resurfacing

 

Metal on Poly Hip Resurfacing

 

Vumedi video metal on poly hip resurfacing

 

Complications

 

Femoral Neck Fracture

 

BHR fracture

 

Risk Factors

- decreased bone mass / osteoporosis / elderly / inflammatory arthritis / AVN

- females

- femoral head and neck cysts

- femoral neck notching

- varus femoral component

 

Metallosis

 

Malloy et al JBJS Open Access 2024

- systematic review of 2,100 BHR at minimum 10 years

- 95% survival

- 20% of revisions for loosening, 20% for metal reaction

 

Aseptic loosening

 

BHR looseBHR loose

 

Issue

- cannot revise to metal on metal

- need to revision acetabular component as well

 

Matharu et al CORR 2017

- revision of 53 hip resurfacing

- 10 year survival 63%

- worse outcomes with revision of metallosis

- worse outcomes with femoral revision only to MoM bearing

 

Wong et al CORR 2015

- Australian Joint Registry of 884 resurfacings undergoing revivision

- 10% re-revision rate of 26%

 

Instability

 

Dislocated Birmingham Hip ResurfacingDislocated Birmingham Resurfacing

 

Femoral head AVN

 

Due to extensive releases required to expose / surgically dislocate femoral head

 

BHR Femoral Head AVN