Bipolar Hip Hemiarthroplasty - Dushan Atkinson 30/9/2003

Historical paper

Reprinted in Clin Orthop. 1990 251(3-6). (Orthop.Digest 1974 2:15).

Bateman JE, Toronto , Canada .Single-assembly total hip prosthesis- preliminary report.

In 1974 Bateman introduced the use of a bipolar type of implant for hip reconstruction based ona series of 70 cases. The successful outcome of this series led to a much broader application ultimately including all types of hip deformities. Over the next 20 years, some 450,000 bipolar implants were inserted around the world.The bipolar design came about as a result of several observations.

i) Charnley’s low-friction arthroplasty system seemed to be very successful, and was now expanding to include new groups of patients,not all of which had both femoral and acetabular deformity.

ii) There were often complications when trying to fixthe acetabular component in patients with poor acetabular bone stock

iii) Over time previously implanted prostheses seemed to suffer wear and tear principally related to the femoral component

He felt that it would be beneficial to apply the Charnley’s low friction principle to fractures of the femoral neck, especially if this could be achieved without distorting the acetabulum.

The implant was designed to have a completely mobile head element, and a second head surface for motion in the acetabulum,creating a compound system providing a greater distribution for the bearing surfaces, and so minimising wear and tear both on the implant and the tissues.The internal head was made of a 22mm head locked onto an UHMW polyethylene bearing insert (low friction universal joint). This polyethylene was then capped with a metallic cup, forming a second bearing surface for the acetabulum. The device was only fixed through the femoral stem. The friction differential meant that even very small acetabular irregularities favoured movement at the inner bearing, and decreasing outer shell action on the acetabulum, and hence diminishing the amount of acetabular wear, erosion and protrusion. In addition because of the compound bearing surface, the bipolar design would provide a greater overall range of motion than unipolar and total hip designs.

In his initial series he treated 70 patients over10 months. All had early ambulation, there were no post-op complications, and no dislocations or misalignment of the prosthesis in the acetabulum. The operating time was less than a THR, with less tissue destruction and less cement required for fixation. In addition he demonstrated the self-aligning mechanism of the head within the acetabulum and that primary motion of the hip took place within the internal bearing system, rather than with the acetabulum.

Today, bipolar hemiarthroplasty is predominantly used in femoral neck fractures. But its use remains controversial. Many questions on the management of femoral neck fractures remain.

Its supporters see International Bipolar News, www.e-orthopaedics.com.

1) How should we treat a displaced intracapsular neck of femur fractures?

i) Injury 2002. 33(5): 383-6. Crossman et al, Luton and Dunstable. A survey of the treatment of displaced intracapsular femoral neck fractures in the UK . Looked at223 hospitals.

Active patients: Bipolar at 41%, ORIF at 37%, Hemiat 32%, THR at 16%, cemented 74%.

Frail patients: Bipolar at 8%, ORIF at 1%, Hemi at91%; Cemented 46%.

NO CONCENSUS

ii) JBJS2003. 85A 9:1673-81. Bhandari et al. Internal fixation compared with arthroplasty for displaced fractures of the femoral neck: a meta analysis. Meta-analysis 14/140 citations. 9 trials, 1162patients. Suggests Hemi (uni and bipolar) sig. lower revision rates c/w ORIF(up to 20%), but they have significantly increased infection rates andincreased blood loss, operative time, early mortality rates. Pain relief and function rates similar. ORIF HIGH REVISION RATE

NOCURRENT CONCENSUS, but probably by Arthroplasty

2 ) Is there a role for the bipolar hemiarthroplasty in the treatment of displaced # NOFs

i) Lijec Vjesn 1998 120(5):121-4. Maricevic . Split , Croatia . Treatment of femoral neck fractures with bipolar hemiarthroplasty. 152 cases. 3% dislocation. 1% femoral loosening. 1% infection. 1% # of stem. 1% cup #. 7% revision op. 96% Goodresult. YES

ii) Acta Orthop Scand 1991 62(2):115-20. Overgard et al. Sonderburg , Denmark . The Uncemented bipolar Hemiarthroplasty for displaced femoral neck fractures. 6 yr follow up of 171cases. Consecutive cases. Uncemented. 22% mort 1yr (65% 6yr). 4% reoperated.

3% migration/subsidence. 3% dislocation. 4%periprosth #. YES

iii) JOrtho Trauma 1991 5(3):318-24. Goldhill et al. New York .Bipolar Hemiarthroplasty for fractures of the femoral neck. Retrospective f/u1-6yrs. 247 cases. 19% mort 1 yr. 3% infection. 1% reoperated. 0%migration/erosion. 1% dislocation. YES

iv) Clin Orthop 1990 251:20-5. LaBelle et al. Grand rapids , Minnesota . Bateman bipolar hip arthroplasty for femoral neck fractures. 5-10 yr follow-up study. 128 patients. Mean 7 yr f/u. 79% no pain. 0% acetabular protrusion. 10% late revision. YES

v) JBJS1990 72(5):788-93. Wetherall et al. Royal East sussex, Hastings .The Hastings bipolar Hemiarthroplasty for subcapital fractures of the femoral neck. A 10 yr prospective study.

561 #s. 27%mort 6 months. 5.6% acetabular erosion. 95% no pain. YES

vi) JBJS1989 71(3):478-82. Rae et al. Davyhulme, Manchester .Treatment of displaced subcapital fractures with the Charnley-Hastings Hemiarthroplasty. 33 months f/u. 98 #s. 24% mort 6 mths. 6% disloc (2%interprosthetic). 2% infection. 0% acetabular erosion. 65% good result. YES

vii) Orthopaedics1989 12(12):1545-50. Ejskjaer et al. Arhus , Denmark . Fractures of the femoralneck treated with cemented bipolar Hemiarthroplasty. Cemented. 3 yr f/u. 59 #s.7% loose stems. 2% revision (pain). 3% dislocation. 0% acetabular erosion. YES

viii) ClinOrthop 1987 218:63-7. Lausten et al.Fractures of the femoral neck treated with a bipolar endoprosthesis. 51 months f/u. 77 #s. 13% femoral loosening. 75% good result. YES

x) ClinOrthop 1983 175:86-92. Giliberty . Hemiarthroplasty of the hip using a low-friction bipolar endoprosthesis. 1-8 yrs f/u. 200#s. 92% good Harris. 8% poor Harris. YES

xi) JArthroplasty 1995 10(5):667-9. Barnes et al. Arkansas .Dislocation after bipolar hemiathroplasty of the hip. 1934 cases. (Only 24 pats post-op dislocation. + 5 pats dislocated by 5 yrs (1%). 20% needed open reduction. 52% re-dislocated, 28% recurrent dislocation and re-operated). YES

LOW DISLOCATION RATE. LOW FEMORAL LOOSENING. LOW ACETABULAR EROSION. LOW REVISION RATE. GOOD FUNCTIONAL SCORE. LOW PAIN

IT WOULD APPEAR YES

3) Should the Bipolar Hemiarthroplasty have a cemented stem?